diff --git a/.claude/settings.json b/.claude/settings.json
new file mode 100644
index 00000000..bcb20970
--- /dev/null
+++ b/.claude/settings.json
@@ -0,0 +1,7 @@
+{
+  "permissions": {
+    "allow": [
+      "Bash(npm test *)"
+    ]
+  }
+}
diff --git a/.github/workflows/block-main-prs.yml b/.github/workflows/block-main-prs.yml
new file mode 100644
index 00000000..60540332
--- /dev/null
+++ b/.github/workflows/block-main-prs.yml
@@ -0,0 +1,46 @@
+name: Block PRs targeting main
+
+on:
+  pull_request_target:
+    types: [opened, reopened]
+    branches: [main]
+
+permissions:
+  pull-requests: write
+
+jobs:
+  block:
+    runs-on: ubuntu-latest
+    if: github.event.pull_request.user.login != 'davedumto'
+    steps:
+      - name: Comment and close PR
+        uses: actions/github-script@v7
+        with:
+          script: |
+            const pr = context.payload.pull_request;
+            const message = [
+              `Hi @${pr.user.login} — thanks for the contribution!`,
+              ``,
+              `This repo uses \`dev\` as the integration branch. PRs targeting \`main\` are not accepted.`,
+              ``,
+              `Please re-open this PR against \`dev\` instead. From your branch:`,
+              ``,
+              `1. Click **Edit** on this PR title area`,
+              `2. Change the base branch from \`main\` to \`dev\``,
+              ``,
+              `Or open a fresh PR from the GitHub UI with \`dev\` selected as the base.`,
+            ].join('\n');
+
+            await github.rest.issues.createComment({
+              owner: context.repo.owner,
+              repo: context.repo.repo,
+              issue_number: pr.number,
+              body: message,
+            });
+
+            await github.rest.pulls.update({
+              owner: context.repo.owner,
+              repo: context.repo.repo,
+              pull_number: pr.number,
+              state: 'closed',
+            });
diff --git a/.gitignore b/.gitignore
index 33c5b38f..4321f30f 100644
--- a/.gitignore
+++ b/.gitignore
@@ -48,3 +48,6 @@ package-lock.json
 dev
 bun.*
 bun.lock
+fix.md
+issue.md
+pr.md
diff --git a/.prettierignore b/.prettierignore
index 16cd053d..6578ea5d 100644
--- a/.prettierignore
+++ b/.prettierignore
@@ -104,3 +104,6 @@ pnpm-lock.yaml
 # Generated files
 *.min.js
 *.min.css
+
+# TypeScript cache
+*.tsbuildinfo   
diff --git a/.vscode/settings.json b/.vscode/settings.json
new file mode 100644
index 00000000..5480842b
--- /dev/null
+++ b/.vscode/settings.json
@@ -0,0 +1,3 @@
+{
+    "kiroAgent.configureMCP": "Disabled"
+}
\ No newline at end of file
diff --git a/app/[username]/watch/page.tsx b/app/[username]/watch/page.tsx
index d5e3bd72..e25f58ff 100644
--- a/app/[username]/watch/page.tsx
+++ b/app/[username]/watch/page.tsx
@@ -1,11 +1,12 @@
 "use client";
 
-import { use, useEffect, useState, useRef } from "react";
-import { notFound, useSearchParams } from "next/navigation";
+import { use, useCallback, useEffect, useState, useRef } from "react";
+import { notFound } from "next/navigation";
 import ViewStream from "@/components/stream/view-stream";
 import { ViewStreamSkeleton } from "@/components/skeletons/ViewStreamSkeleton";
+import AccessGate from "@/components/stream/AccessGate";
 import { toast } from "sonner";
-import PrivateStreamGate from "@/components/stream/private-stream-gate";
+import { useStellarWallet } from "@/contexts/stellar-wallet-context";
 
 interface PageProps {
   params: Promise<{ username: string }>;
@@ -24,26 +25,27 @@ interface UserData {
   follower_count: number;
   is_following: boolean;
   stellar_address: string | null;
+  is_password_protected: boolean;
+  stream_access_type: "public" | "password" | "subscription" | null;
+  subscription_price_usdc: number | null;
   latency_mode: string | null;
-  stream_privacy: string | null;
-}
-
-interface AccessInfo {
-  allowed: boolean;
-  reason: string | null;
 }
 
 const WatchPage = ({ params }: PageProps) => {
   const { username } = use(params);
-  const searchParams = useSearchParams();
-  const shareKey = searchParams?.get("key") ?? null;
+  const { publicKey, privyWallet } = useStellarWallet();
+  const viewerPublicKey = publicKey || privyWallet?.wallet || null;
   const [userData, setUserData] = useState<UserData | null>(null);
-  const [access, setAccess] = useState<AccessInfo | null>(null);
   const [loading, setLoading] = useState(true);
   const [notFound404, setNotFound404] = useState(false);
   const [isFollowing, setIsFollowing] = useState(false);
   const [followLoading, setFollowLoading] = useState(false);
   const [loggedInUsername, setLoggedInUsername] = useState<string | null>(null);
+  const [accessGranted, setAccessGranted] = useState(false);
+
+  const handleAccessGranted = useCallback(() => {
+    setAccessGranted(true);
+  }, []);
 
   // Viewer tracking: one unique ID per page visit
   const viewerSessionId = useRef<string | null>(null);
@@ -64,15 +66,10 @@ const WatchPage = ({ params }: PageProps) => {
           setLoading(true);
         }
 
-        const qs = new URLSearchParams();
-        if (loggedInUsername) {
-          qs.set("viewer_username", loggedInUsername);
-        }
-        if (shareKey) {
-          qs.set("key", shareKey);
-        }
-        qs.set("t", String(Date.now()));
-        const response = await fetch(`/api/users/${username}?${qs.toString()}`);
+        const viewerParam = loggedInUsername
+          ? `?viewer_username=${encodeURIComponent(loggedInUsername)}&t=${Date.now()}`
+          : `?t=${Date.now()}`;
+        const response = await fetch(`/api/users/${username}${viewerParam}`);
 
         if (response.status === 404) {
           setNotFound404(true);
@@ -88,7 +85,6 @@ const WatchPage = ({ params }: PageProps) => {
 
         const data = await response.json();
         setUserData(data.user);
-        setAccess(data.access ?? { allowed: true, reason: null });
         setIsFollowing(!!data.user.is_following);
       } catch (error) {
         console.error("Failed to fetch user data:", error);
@@ -106,7 +102,7 @@ const WatchPage = ({ params }: PageProps) => {
     fetchUserData();
     const interval = setInterval(fetchUserData, 5000);
     return () => clearInterval(interval);
-  }, [username, loggedInUsername, shareKey]);
+  }, [username, loggedInUsername]);
 
   // Register viewer once when stream goes live; guard against re-registration on every poll
   useEffect(() => {
@@ -220,14 +216,26 @@ const WatchPage = ({ params }: PageProps) => {
 
   const isOwner = loggedInUsername?.toLowerCase() === username.toLowerCase();
 
-  // Private stream + viewer not authorized: show gate instead of player
-  if (access && !access.allowed && !isOwner) {
+  // Show access gate if stream is password protected and viewer isn't the owner
+  const needsPassword =
+    userData.is_password_protected &&
+    userData.stream_access_type !== "subscription" &&
+    !isOwner &&
+    !accessGranted;
+  const needsSubscription =
+    userData.stream_access_type === "subscription" &&
+    !isOwner &&
+    !accessGranted;
+
+  if ((needsPassword || needsSubscription) && userData.mux_playback_id) {
     return (
-      <PrivateStreamGate
+      <AccessGate
+        playbackId={userData.mux_playback_id}
         username={username}
-        privacy={(userData.stream_privacy as any) || "unlisted"}
-        reason={access.reason}
-        avatar={userData.avatar}
+        onAccessGranted={handleAccessGranted}
+        accessType={needsSubscription ? "subscription" : "password"}
+        monthlyPrice={userData.subscription_price_usdc}
+        viewerPublicKey={viewerPublicKey}
       />
     );
   }
@@ -247,8 +255,6 @@ const WatchPage = ({ params }: PageProps) => {
     playbackId: userData.mux_playback_id,
     latencyMode: userData.latency_mode || "low",
     isLive: userData.is_live,
-    privacy: userData.stream_privacy || "public",
-    shareKey: shareKey,
   };
 
   return (
diff --git a/app/api/admin/feature-flags/route.ts b/app/api/admin/feature-flags/route.ts
new file mode 100644
index 00000000..c0c77c0b
--- /dev/null
+++ b/app/api/admin/feature-flags/route.ts
@@ -0,0 +1,82 @@
+import { NextRequest, NextResponse } from "next/server";
+import { sql } from "@vercel/postgres";
+import { verifySession } from "@/lib/auth/verify-session";
+import { isAdmin } from "@/lib/admin-auth";
+
+/**
+ * Admin-only CRUD for feature flags.
+ *
+ * GET    /api/admin/feature-flags          – list all flags
+ * POST   /api/admin/feature-flags          – create a flag
+ * PATCH  /api/admin/feature-flags          – update a flag (body: { key, ...fields })
+ * DELETE /api/admin/feature-flags?key=xxx  – delete a flag
+ */
+
+async function guardAdmin(req: NextRequest) {
+  const session = await verifySession(req);
+  if (!session.ok) return { ok: false as const, response: session.response };
+  if (!isAdmin(session.userId)) {
+    return {
+      ok: false as const,
+      response: NextResponse.json({ error: "Forbidden" }, { status: 403 }),
+    };
+  }
+  return { ok: true as const };
+}
+
+export async function GET(req: NextRequest) {
+  const guard = await guardAdmin(req);
+  if (!guard.ok) return guard.response;
+
+  const { rows } = await sql`SELECT * FROM feature_flags ORDER BY key`;
+  return NextResponse.json({ flags: rows });
+}
+
+export async function POST(req: NextRequest) {
+  const guard = await guardAdmin(req);
+  if (!guard.ok) return guard.response;
+
+  const { key, description, enabled = false, rollout_percentage = 0, allowed_user_ids = [] } = await req.json();
+  if (!key) return NextResponse.json({ error: "key is required" }, { status: 400 });
+
+  const { rows } = await sql`
+    INSERT INTO feature_flags (key, description, enabled, rollout_percentage, allowed_user_ids)
+    VALUES (${key}, ${description ?? null}, ${enabled}, ${rollout_percentage}, ${allowed_user_ids})
+    ON CONFLICT (key) DO NOTHING
+    RETURNING *
+  `;
+  if (!rows.length) return NextResponse.json({ error: "Flag already exists" }, { status: 409 });
+  return NextResponse.json({ flag: rows[0] }, { status: 201 });
+}
+
+export async function PATCH(req: NextRequest) {
+  const guard = await guardAdmin(req);
+  if (!guard.ok) return guard.response;
+
+  const { key, enabled, rollout_percentage, allowed_user_ids, description } = await req.json();
+  if (!key) return NextResponse.json({ error: "key is required" }, { status: 400 });
+
+  const { rows } = await sql`
+    UPDATE feature_flags SET
+      enabled             = COALESCE(${enabled ?? null}, enabled),
+      rollout_percentage  = COALESCE(${rollout_percentage ?? null}, rollout_percentage),
+      allowed_user_ids    = COALESCE(${allowed_user_ids ?? null}, allowed_user_ids),
+      description         = COALESCE(${description ?? null}, description),
+      updated_at          = CURRENT_TIMESTAMP
+    WHERE key = ${key}
+    RETURNING *
+  `;
+  if (!rows.length) return NextResponse.json({ error: "Flag not found" }, { status: 404 });
+  return NextResponse.json({ flag: rows[0] });
+}
+
+export async function DELETE(req: NextRequest) {
+  const guard = await guardAdmin(req);
+  if (!guard.ok) return guard.response;
+
+  const key = new URL(req.url).searchParams.get("key");
+  if (!key) return NextResponse.json({ error: "key is required" }, { status: 400 });
+
+  await sql`DELETE FROM feature_flags WHERE key = ${key}`;
+  return NextResponse.json({ ok: true });
+}
diff --git a/app/api/auth/session/route.ts b/app/api/auth/session/route.ts
index 7ea760f2..78a4aa5d 100644
--- a/app/api/auth/session/route.ts
+++ b/app/api/auth/session/route.ts
@@ -3,6 +3,7 @@ import { PrivyClient } from "@privy-io/server-auth";
 import { sql } from "@vercel/postgres";
 import { createRateLimiter } from "@/lib/rate-limit";
 import { getRandomProfileIcon } from "@/lib/profile-icons";
+import { createSession } from "@/lib/sessions/user-sessions";
 
 // 10 Privy session exchanges per IP per 60 s
 const isRateLimited = createRateLimiter(60_000, 10);
@@ -131,8 +132,10 @@ export async function POST(req: NextRequest) {
     //    We store the privy_id (opaque, server-verified) — never the raw JWT
     const isProduction = process.env.NODE_ENV === "production";
     const cookieMaxAge = 24 * 60 * 60; // 24 h in seconds
+    // The raw token for a Privy session is the privy_id itself
+    const rawToken = privyUserId;
     const cookieValue = [
-      `privy_session=${privyUserId}`,
+      `privy_session=${rawToken}`,
       `Path=/`,
       `Max-Age=${cookieMaxAge}`,
       `HttpOnly`,
@@ -157,6 +160,21 @@ export async function POST(req: NextRequest) {
     });
 
     res.headers.set("Set-Cookie", cookieValue);
+
+    // Record the session in user_sessions (fire-and-forget — don't block the response)
+    createSession({
+      userId: dbUser.id,
+      rawToken,
+      ipAddress:
+        req.headers.get("x-forwarded-for")?.split(",")[0]?.trim() ??
+        req.headers.get("x-real-ip") ??
+        null,
+      userAgent: req.headers.get("user-agent") ?? null,
+      ttlSeconds: cookieMaxAge,
+    }).catch((err) =>
+      console.error("[session] Failed to record user_session row:", err)
+    );
+
     return res;
   } catch (err) {
     console.error("[session] DB error:", err);
diff --git a/app/api/auth/wallet-session/route.ts b/app/api/auth/wallet-session/route.ts
index bd526cc2..a4d7f782 100644
--- a/app/api/auth/wallet-session/route.ts
+++ b/app/api/auth/wallet-session/route.ts
@@ -2,6 +2,7 @@ import { NextRequest, NextResponse } from "next/server";
 import { sql } from "@vercel/postgres";
 import { signToken } from "@/lib/auth/sign-token";
 import { createRateLimiter } from "@/lib/rate-limit";
+import { createSession } from "@/lib/sessions/user-sessions";
 
 const isRateLimited = createRateLimiter(60_000, 20); // 20 requests/min per IP
 
@@ -89,6 +90,20 @@ export async function POST(req: NextRequest) {
 
     const res = NextResponse.json({ ok: true });
     res.headers.set("Set-Cookie", cookieValue);
+
+    // Record the session in user_sessions (fire-and-forget)
+    // getIp() may return "unknown" — normalise to null so the INET cast doesn't fail
+    const rawIp = getIp(req);
+    createSession({
+      userId: u.id,
+      rawToken: token,
+      ipAddress: rawIp === "unknown" ? null : rawIp,
+      userAgent: req.headers.get("user-agent") ?? null,
+      ttlSeconds: COOKIE_MAX_AGE,
+    }).catch((err) =>
+      console.error("[wallet-session] Failed to record user_session row:", err)
+    );
+
     return res;
   } catch (err) {
     console.error("[wallet-session] DB error:", err);
diff --git a/app/api/feature-flags/route.ts b/app/api/feature-flags/route.ts
new file mode 100644
index 00000000..32babe55
--- /dev/null
+++ b/app/api/feature-flags/route.ts
@@ -0,0 +1,48 @@
+import { NextRequest, NextResponse } from "next/server";
+import { sql } from "@vercel/postgres";
+import { verifySession } from "@/lib/auth/verify-session";
+
+/**
+ * GET /api/feature-flags?keys=clips,gifts
+ * Returns flag states for the authenticated user.
+ * Pass ?keys= as a comma-separated list to filter; omit for all flags.
+ *
+ * Resolution order (first match wins):
+ *  1. User is in allowed_user_ids → enabled
+ *  2. Flag is globally enabled AND user hash falls within rollout_percentage → enabled
+ *  3. Otherwise → disabled
+ */
+export async function GET(req: NextRequest) {
+  const session = await verifySession(req);
+  if (!session.ok) return session.response;
+
+  const { searchParams } = new URL(req.url);
+  const keysParam = searchParams.get("keys");
+  const keys = keysParam ? keysParam.split(",").map(k => k.trim()).filter(Boolean) : [];
+
+  try {
+    const { rows } = keys.length
+      ? await sql`
+          SELECT key, enabled, rollout_percentage, allowed_user_ids
+          FROM feature_flags
+          WHERE key = ANY(${keys as any})
+        `
+      : await sql`SELECT key, enabled, rollout_percentage, allowed_user_ids FROM feature_flags`;
+
+    const userId = session.userId;
+    // Simple deterministic hash: sum of char codes mod 100 → 0-99
+    const userHash = userId.split("").reduce((acc, c) => acc + c.charCodeAt(0), 0) % 100;
+
+    const result: Record<string, boolean> = {};
+    for (const row of rows) {
+      const inAllowlist = Array.isArray(row.allowed_user_ids) && row.allowed_user_ids.includes(userId);
+      const inRollout = row.enabled && userHash < row.rollout_percentage;
+      result[row.key] = inAllowlist || inRollout;
+    }
+
+    return NextResponse.json({ flags: result });
+  } catch (err) {
+    console.error("[feature-flags] GET error:", err);
+    return NextResponse.json({ error: "Failed to fetch feature flags" }, { status: 500 });
+  }
+}
diff --git a/app/api/routes-f/2fa/_lib/totp.ts b/app/api/routes-f/2fa/_lib/totp.ts
new file mode 100644
index 00000000..3b0db514
--- /dev/null
+++ b/app/api/routes-f/2fa/_lib/totp.ts
@@ -0,0 +1,130 @@
+import {
+  createCipheriv,
+  createDecipheriv,
+  createHmac,
+  randomBytes,
+} from "crypto";
+
+// ── Base32 (RFC 4648, no padding needed for otpauth) ──────────────────────────
+
+const B32_ALPHA = "ABCDEFGHIJKLMNOPQRSTUVWXYZ234567";
+
+export function base32Encode(buf: Buffer): string {
+  let bits = 0;
+  let value = 0;
+  let output = "";
+  for (const byte of buf) {
+    value = (value << 8) | byte;
+    bits += 8;
+    while (bits >= 5) {
+      output += B32_ALPHA[(value >>> (bits - 5)) & 31];
+      bits -= 5;
+    }
+  }
+  if (bits > 0) output += B32_ALPHA[(value << (5 - bits)) & 31];
+  return output;
+}
+
+export function base32Decode(input: string): Buffer {
+  const clean = input.toUpperCase().replace(/=+$/, "");
+  let bits = 0;
+  let value = 0;
+  const output: number[] = [];
+  for (const ch of clean) {
+    const idx = B32_ALPHA.indexOf(ch);
+    if (idx === -1) throw new Error("Invalid base32 character: " + ch);
+    value = (value << 5) | idx;
+    bits += 5;
+    if (bits >= 8) {
+      output.push((value >>> (bits - 8)) & 255);
+      bits -= 8;
+    }
+  }
+  return Buffer.from(output);
+}
+
+// ── TOTP (RFC 6238 / RFC 4226) ────────────────────────────────────────────────
+
+function hotpCode(keyBuf: Buffer, counter: bigint): string {
+  const msg = Buffer.alloc(8);
+  msg.writeBigUInt64BE(counter);
+  const hmac = createHmac("sha1", keyBuf).update(msg).digest();
+  const offset = hmac[hmac.length - 1] & 0x0f;
+  const code =
+    ((hmac[offset] & 0x7f) << 24) |
+    (hmac[offset + 1] << 16) |
+    (hmac[offset + 2] << 8) |
+    hmac[offset + 3];
+  return String(code % 1_000_000).padStart(6, "0");
+}
+
+export function generateTotpCode(secret: string, windowOffset = 0): string {
+  const counter = BigInt(Math.floor(Date.now() / 1000 / 30)) + BigInt(windowOffset);
+  return hotpCode(base32Decode(secret), counter);
+}
+
+export function verifyTotpToken(secret: string, token: string): boolean {
+  for (const w of [-1, 0, 1]) {
+    if (generateTotpCode(secret, w) === token) return true;
+  }
+  return false;
+}
+
+export function generateTotpSecret(): string {
+  return base32Encode(randomBytes(20));
+}
+
+export function buildOtpauthUri(secret: string, account: string, issuer = "StreamFi"): string {
+  const label = encodeURIComponent(`${issuer}:${account}`);
+  return `otpauth://totp/${label}?secret=${secret}&issuer=${encodeURIComponent(issuer)}&algorithm=SHA1&digits=6&period=30`;
+}
+
+// ── AES-256-GCM secret encryption ────────────────────────────────────────────
+
+function resolveKey(): Buffer {
+  const raw =
+    process.env.TWO_FA_ENCRYPTION_KEY ??
+    process.env.STELLAR_ENCRYPTION_KEY ??
+    process.env.SESSION_SECRET;
+  if (!raw) throw new Error("Missing encryption key env var");
+  if (/^[0-9a-fA-F]{64}$/.test(raw)) return Buffer.from(raw, "hex");
+  // SHA-256 of passphrase → 32-byte key
+  const { createHash } = require("crypto") as typeof import("crypto");
+  return createHash("sha256").update(raw).digest();
+}
+
+export interface EncryptedSecret {
+  ciphertext: string;
+  iv: string;
+  tag: string;
+}
+
+export function encryptSecret(plaintext: string): EncryptedSecret {
+  const key = resolveKey();
+  const iv = randomBytes(12);
+  const cipher = createCipheriv("aes-256-gcm", key, iv);
+  const ciphertext = Buffer.concat([cipher.update(plaintext, "utf8"), cipher.final()]);
+  return {
+    ciphertext: ciphertext.toString("base64"),
+    iv: iv.toString("base64"),
+    tag: (cipher as ReturnType<typeof createCipheriv> & { getAuthTag(): Buffer }).getAuthTag().toString("base64"),
+  };
+}
+
+export function decryptSecret(enc: EncryptedSecret): string {
+  const key = resolveKey();
+  const decipher = createDecipheriv("aes-256-gcm", key, Buffer.from(enc.iv, "base64"));
+  (decipher as ReturnType<typeof createDecipheriv> & { setAuthTag(t: Buffer): void }).setAuthTag(Buffer.from(enc.tag, "base64"));
+  return Buffer.concat([
+    decipher.update(Buffer.from(enc.ciphertext, "base64")),
+    decipher.final(),
+  ]).toString("utf8");
+}
+
+// ── Backup codes ──────────────────────────────────────────────────────────────
+
+export function generateBackupCodes(count = 5): string[] {
+  return Array.from({ length: count }, () =>
+    randomBytes(5).toString("hex").toUpperCase().match(/.{1,5}/g)!.join("-")
+  );
+}
diff --git a/app/api/routes-f/2fa/disable/route.ts b/app/api/routes-f/2fa/disable/route.ts
new file mode 100644
index 00000000..03cdefbc
--- /dev/null
+++ b/app/api/routes-f/2fa/disable/route.ts
@@ -0,0 +1,90 @@
+import { NextRequest, NextResponse } from "next/server";
+import { z } from "zod";
+import { sql } from "@vercel/postgres";
+import { createHash } from "crypto";
+import { verifySession } from "@/lib/auth/verify-session";
+import { validateBody } from "@/app/api/routes-f/_lib/validate";
+import { decryptSecret, verifyTotpToken } from "../_lib/totp";
+
+const disableSchema = z.object({
+  token: z
+    .string()
+    .length(6)
+    .regex(/^\d{6}$/)
+    .optional(),
+  backupCode: z.string().min(1).optional(),
+}).refine((d) => d.token !== undefined || d.backupCode !== undefined, {
+  message: "Provide either a TOTP token or a backup code",
+});
+
+export async function POST(request: NextRequest) {
+  const session = await verifySession(request);
+  if (!session.ok) return session.response;
+
+  const body = await validateBody(request, disableSchema);
+  if (body instanceof NextResponse) return body;
+
+  try {
+    const { rows } = await sql`
+      SELECT totp_secret_ciphertext, totp_secret_iv, totp_secret_tag,
+             totp_enabled, backup_code_hashes
+      FROM user_two_factor
+      WHERE user_id = ${session.userId}
+      LIMIT 1
+    `;
+
+    if (!rows[0]?.totp_enabled) {
+      return NextResponse.json(
+        { error: "2FA is not currently enabled." },
+        { status: 400 }
+      );
+    }
+
+    const row = rows[0];
+    let authorized = false;
+
+    if (body.data.token) {
+      const secret = decryptSecret({
+        ciphertext: row.totp_secret_ciphertext,
+        iv: row.totp_secret_iv,
+        tag: row.totp_secret_tag,
+      });
+      authorized = verifyTotpToken(secret, body.data.token);
+    } else if (body.data.backupCode) {
+      const stored: string[] = JSON.parse(row.backup_code_hashes ?? "[]");
+      const hash = createHash("sha256")
+        .update(body.data.backupCode.toUpperCase())
+        .digest("hex");
+      const idx = stored.indexOf(hash);
+      if (idx !== -1) {
+        authorized = true;
+        stored.splice(idx, 1);
+        await sql`
+          UPDATE user_two_factor
+          SET backup_code_hashes = ${JSON.stringify(stored)}, updated_at = NOW()
+          WHERE user_id = ${session.userId}
+        `;
+      }
+    }
+
+    if (!authorized) {
+      return NextResponse.json({ error: "Invalid token or backup code" }, { status: 401 });
+    }
+
+    await sql`
+      UPDATE user_two_factor
+      SET totp_enabled           = false,
+          totp_secret_ciphertext = NULL,
+          totp_secret_iv         = NULL,
+          totp_secret_tag        = NULL,
+          backup_code_hashes     = NULL,
+          updated_at             = NOW()
+      WHERE user_id = ${session.userId}
+    `;
+
+    return NextResponse.json({ disabled: true });
+  } catch (error) {
+    console.error("[routes-f 2fa/disable POST]", error);
+    return NextResponse.json({ error: "Failed to disable 2FA" }, { status: 500 });
+  }
+}
diff --git a/app/api/routes-f/2fa/setup/route.ts b/app/api/routes-f/2fa/setup/route.ts
new file mode 100644
index 00000000..0a9fea7a
--- /dev/null
+++ b/app/api/routes-f/2fa/setup/route.ts
@@ -0,0 +1,53 @@
+import { NextRequest, NextResponse } from "next/server";
+import { sql } from "@vercel/postgres";
+import { verifySession } from "@/lib/auth/verify-session";
+import {
+  generateTotpSecret,
+  buildOtpauthUri,
+  encryptSecret,
+} from "../_lib/totp";
+
+export async function POST(request: NextRequest) {
+  const session = await verifySession(request);
+  if (!session.ok) return session.response;
+
+  try {
+    const { rows } = await sql`
+      SELECT totp_enabled FROM user_two_factor WHERE user_id = ${session.userId} LIMIT 1
+    `;
+
+    if (rows[0]?.totp_enabled) {
+      return NextResponse.json(
+        { error: "2FA is already enabled. Disable it before setting up again." },
+        { status: 409 }
+      );
+    }
+
+    const secret = generateTotpSecret();
+    const enc = encryptSecret(secret);
+    const otpauthUri = buildOtpauthUri(secret, session.userId);
+
+    await sql`
+      INSERT INTO user_two_factor (user_id, totp_secret_ciphertext, totp_secret_iv, totp_secret_tag, totp_enabled, updated_at)
+      VALUES (
+        ${session.userId},
+        ${enc.ciphertext},
+        ${enc.iv},
+        ${enc.tag},
+        false,
+        NOW()
+      )
+      ON CONFLICT (user_id) DO UPDATE SET
+        totp_secret_ciphertext = EXCLUDED.totp_secret_ciphertext,
+        totp_secret_iv         = EXCLUDED.totp_secret_iv,
+        totp_secret_tag        = EXCLUDED.totp_secret_tag,
+        totp_enabled           = false,
+        updated_at             = NOW()
+    `;
+
+    return NextResponse.json({ otpauthUri }, { status: 200 });
+  } catch (error) {
+    console.error("[routes-f 2fa/setup POST]", error);
+    return NextResponse.json({ error: "Failed to initiate 2FA setup" }, { status: 500 });
+  }
+}
diff --git a/app/api/routes-f/2fa/status/route.ts b/app/api/routes-f/2fa/status/route.ts
new file mode 100644
index 00000000..a78eec6b
--- /dev/null
+++ b/app/api/routes-f/2fa/status/route.ts
@@ -0,0 +1,27 @@
+import { NextRequest, NextResponse } from "next/server";
+import { sql } from "@vercel/postgres";
+import { verifySession } from "@/lib/auth/verify-session";
+
+export async function GET(request: NextRequest) {
+  const session = await verifySession(request);
+  if (!session.ok) return session.response;
+
+  try {
+    const { rows } = await sql`
+      SELECT totp_enabled, updated_at
+      FROM user_two_factor
+      WHERE user_id = ${session.userId}
+      LIMIT 1
+    `;
+
+    const row = rows[0];
+
+    return NextResponse.json({
+      enabled: row?.totp_enabled ?? false,
+      configuredAt: row?.updated_at ?? null,
+    });
+  } catch (error) {
+    console.error("[routes-f 2fa/status GET]", error);
+    return NextResponse.json({ error: "Failed to fetch 2FA status" }, { status: 500 });
+  }
+}
diff --git a/app/api/routes-f/2fa/verify/route.ts b/app/api/routes-f/2fa/verify/route.ts
new file mode 100644
index 00000000..77fa19dd
--- /dev/null
+++ b/app/api/routes-f/2fa/verify/route.ts
@@ -0,0 +1,82 @@
+import { NextRequest, NextResponse } from "next/server";
+import { z } from "zod";
+import { sql } from "@vercel/postgres";
+import { verifySession } from "@/lib/auth/verify-session";
+import { validateBody } from "@/app/api/routes-f/_lib/validate";
+import {
+  decryptSecret,
+  verifyTotpToken,
+  generateBackupCodes,
+  encryptSecret,
+} from "../_lib/totp";
+import { createHash } from "crypto";
+
+const verifySchema = z.object({
+  token: z.string().length(6, "Token must be exactly 6 digits").regex(/^\d{6}$/),
+});
+
+export async function POST(request: NextRequest) {
+  const session = await verifySession(request);
+  if (!session.ok) return session.response;
+
+  const body = await validateBody(request, verifySchema);
+  if (body instanceof NextResponse) return body;
+
+  try {
+    const { rows } = await sql`
+      SELECT totp_secret_ciphertext, totp_secret_iv, totp_secret_tag, totp_enabled
+      FROM user_two_factor
+      WHERE user_id = ${session.userId}
+      LIMIT 1
+    `;
+
+    if (!rows[0]) {
+      return NextResponse.json(
+        { error: "2FA setup not initiated. Call /api/routes-f/2fa/setup first." },
+        { status: 400 }
+      );
+    }
+
+    if (rows[0].totp_enabled) {
+      return NextResponse.json(
+        { error: "2FA is already verified and active." },
+        { status: 409 }
+      );
+    }
+
+    const secret = decryptSecret({
+      ciphertext: rows[0].totp_secret_ciphertext,
+      iv: rows[0].totp_secret_iv,
+      tag: rows[0].totp_secret_tag,
+    });
+
+    if (!verifyTotpToken(secret, body.data.token)) {
+      return NextResponse.json({ error: "Invalid TOTP token" }, { status: 400 });
+    }
+
+    const codes = generateBackupCodes(5);
+    const hashedCodes = codes.map((c) =>
+      createHash("sha256").update(c).digest("hex")
+    );
+
+    await sql`
+      UPDATE user_two_factor
+      SET totp_enabled       = true,
+          backup_code_hashes = ${JSON.stringify(hashedCodes)},
+          updated_at         = NOW()
+      WHERE user_id = ${session.userId}
+    `;
+
+    return NextResponse.json(
+      {
+        enabled: true,
+        backupCodes: codes,
+        message: "2FA enabled. Store these backup codes securely — they will not be shown again.",
+      },
+      { status: 200 }
+    );
+  } catch (error) {
+    console.error("[routes-f 2fa/verify POST]", error);
+    return NextResponse.json({ error: "Failed to verify 2FA token" }, { status: 500 });
+  }
+}
diff --git a/app/api/routes-f/__tests__/binary-to-text.test.ts b/app/api/routes-f/__tests__/binary-to-text.test.ts
new file mode 100644
index 00000000..c57a67d3
--- /dev/null
+++ b/app/api/routes-f/__tests__/binary-to-text.test.ts
@@ -0,0 +1,103 @@
+// @ts-nocheck
+/**
+ * @jest-environment node
+ */
+import { POST, toBinary, fromBinary } from "../binary-to-text/route";
+import { NextRequest } from "next/server";
+
+function makeReq(body: unknown) {
+  return new NextRequest("http://localhost/api/routes-f/binary-to-text", {
+    method: "POST",
+    headers: { "content-type": "application/json" },
+    body: JSON.stringify(body),
+  });
+}
+
+describe("/api/routes-f/binary-to-text", () => {
+  // --- unit helpers ---
+  describe("toBinary", () => {
+    it("encodes ASCII correctly", () => {
+      expect(toBinary("A", 8)).toBe("01000001");
+      expect(toBinary("Hi", 8)).toBe("01001000 01101001");
+    });
+
+    it("round-trips ASCII with fromBinary", () => {
+      const bin = toBinary("Hello, World!", 8);
+      expect(fromBinary(bin, 8)).toBe("Hello, World!");
+    });
+
+    it("round-trips emoji (multibyte UTF-8)", () => {
+      const bin = toBinary("😊", 8);
+      expect(fromBinary(bin, 8)).toBe("😊");
+    });
+
+    it("round-trips mixed ASCII + emoji", () => {
+      const input = "hi 🌍";
+      expect(fromBinary(toBinary(input, 8), 8)).toBe(input);
+    });
+  });
+
+  describe("fromBinary", () => {
+    it("rejects non-binary characters", () => {
+      expect(() => fromBinary("01000001 0100GG01", 8)).toThrow();
+    });
+
+    it("rejects tokens with wrong bit length", () => {
+      expect(() => fromBinary("0100000", 8)).toThrow(); // 7 bits
+    });
+  });
+
+  // --- POST handler ---
+  it("to_binary returns correct result for ASCII", async () => {
+    const res = await POST(makeReq({ input: "A", mode: "to_binary" }));
+    expect(res.status).toBe(200);
+    const { result } = await res.json();
+    expect(result).toBe("01000001");
+  });
+
+  it("from_binary decodes back to original ASCII", async () => {
+    const res = await POST(makeReq({ input: "01000001", mode: "from_binary" }));
+    expect(res.status).toBe(200);
+    const { result } = await res.json();
+    expect(result).toBe("A");
+  });
+
+  it("round-trips emoji via POST", async () => {
+    const encRes = await POST(makeReq({ input: "😊", mode: "to_binary" }));
+    const { result: bin } = await encRes.json();
+
+    const decRes = await POST(makeReq({ input: bin, mode: "from_binary" }));
+    expect(decRes.status).toBe(200);
+    const { result } = await decRes.json();
+    expect(result).toBe("😊");
+  });
+
+  it("returns 400 for malformed binary on decode", async () => {
+    const res = await POST(makeReq({ input: "0100GG01", mode: "from_binary" }));
+    expect(res.status).toBe(400);
+    const body = await res.json();
+    expect(body.error).toBeDefined();
+  });
+
+  it("returns 400 for wrong bit-length token", async () => {
+    const res = await POST(makeReq({ input: "0100000", mode: "from_binary" }));
+    expect(res.status).toBe(400);
+  });
+
+  it("returns 400 for missing mode", async () => {
+    const res = await POST(makeReq({ input: "hello" }));
+    expect(res.status).toBe(400);
+  });
+
+  it("returns 400 for missing input", async () => {
+    const res = await POST(makeReq({ mode: "to_binary" }));
+    expect(res.status).toBe(400);
+  });
+
+  it("handles empty string to_binary", async () => {
+    const res = await POST(makeReq({ input: "", mode: "to_binary" }));
+    expect(res.status).toBe(200);
+    const { result } = await res.json();
+    expect(result).toBe("");
+  });
+});
diff --git a/app/api/routes-f/__tests__/cancel-subscription.test.ts b/app/api/routes-f/__tests__/cancel-subscription.test.ts
new file mode 100644
index 00000000..963fe78a
--- /dev/null
+++ b/app/api/routes-f/__tests__/cancel-subscription.test.ts
@@ -0,0 +1,116 @@
+/**
+ * @jest-environment node
+ */
+import { NextRequest } from "next/server";
+import { POST, GET } from "../subscriptions/cancel/route";
+import { GET as GET_MAIN, subscriptions } from "../subscriptions/route";
+
+function makePostReq(body: unknown) {
+  return new NextRequest("http://localhost/api/routes-f/subscriptions/cancel", {
+    method: "POST",
+    headers: { "content-type": "application/json" },
+    body: JSON.stringify(body),
+  });
+}
+
+function makeGetReq(subscriptionId: string) {
+  return new NextRequest(
+    `http://localhost/api/routes-f/subscriptions/cancel?subscription_id=${subscriptionId}`
+  );
+}
+
+function makeMainGetReq(subscriptionId: string) {
+  return new NextRequest(
+    `http://localhost/api/routes-f/subscriptions?subscription_id=${subscriptionId}`
+  );
+}
+
+describe("Cancel Subscription API", () => {
+  beforeEach(() => {
+    subscriptions.clear();
+  });
+
+  it("should successfully cancel an active subscription, keeping expires_at intact", async () => {
+    const expiresAt = new Date(Date.now() + 30 * 24 * 60 * 60 * 1000).toISOString();
+    subscriptions.set("sub-123", {
+      subscription_id: "sub-123",
+      subscriber_id: "subscriber-456",
+      creator_id: "creator-789",
+      tier_id: "premium",
+      payment_tx_hash: "hash-xyz",
+      asset: "USDC",
+      started_at: new Date().toISOString(),
+      expires_at: expiresAt,
+      status: "active",
+    });
+
+    const req = makePostReq({
+      subscription_id: "sub-123",
+      subscriber_id: "subscriber-456",
+    });
+    const res = await POST(req);
+    expect(res.status).toBe(200);
+    const data = await res.json();
+    expect(data.status).toBe("cancelled");
+    expect(data.expires_at).toBe(expiresAt);
+
+    // Verify GET cancel endpoint returns current state
+    const getRes = await GET(makeGetReq("sub-123"));
+    expect(getRes.status).toBe(200);
+    const getData = await getRes.json();
+    expect(getData.status).toBe("cancelled");
+    expect(getData.expires_at).toBe(expiresAt);
+
+    // Verify GET main endpoint also returns current state
+    const getMainRes = await GET_MAIN(makeMainGetReq("sub-123"));
+    expect(getMainRes.status).toBe(200);
+    const getMainData = await getMainRes.json();
+    expect(getMainData.status).toBe("cancelled");
+  });
+
+  it("should return 403 Forbidden if the requester is not the subscriber", async () => {
+    subscriptions.set("sub-123", {
+      subscription_id: "sub-123",
+      subscriber_id: "subscriber-456",
+      creator_id: "creator-789",
+      tier_id: "premium",
+      payment_tx_hash: "hash-xyz",
+      asset: "USDC",
+      started_at: new Date().toISOString(),
+      expires_at: new Date(Date.now() + 30 * 24 * 60 * 60 * 1000).toISOString(),
+      status: "active",
+    });
+
+    const req = makePostReq({
+      subscription_id: "sub-123",
+      subscriber_id: "subscriber-wrong",
+    });
+    const res = await POST(req);
+    expect(res.status).toBe(403);
+    const data = await res.json();
+    expect(data.error).toBe("Forbidden");
+  });
+
+  it("should handle double-cancel correctly, returning cancelled state", async () => {
+    subscriptions.set("sub-123", {
+      subscription_id: "sub-123",
+      subscriber_id: "subscriber-456",
+      creator_id: "creator-789",
+      tier_id: "premium",
+      payment_tx_hash: "hash-xyz",
+      asset: "USDC",
+      started_at: new Date().toISOString(),
+      expires_at: new Date(Date.now() + 30 * 24 * 60 * 60 * 1000).toISOString(),
+      status: "cancelled",
+    });
+
+    const req = makePostReq({
+      subscription_id: "sub-123",
+      subscriber_id: "subscriber-456",
+    });
+    const res = await POST(req);
+    expect(res.status).toBe(200);
+    const data = await res.json();
+    expect(data.status).toBe("cancelled");
+  });
+});
diff --git a/app/api/routes-f/__tests__/case-convert.test.ts b/app/api/routes-f/__tests__/case-convert.test.ts
new file mode 100644
index 00000000..ba320690
--- /dev/null
+++ b/app/api/routes-f/__tests__/case-convert.test.ts
@@ -0,0 +1,214 @@
+/**
+ * @jest-environment jsdom
+ */
+
+import { POST } from '../case-convert/route';
+import { NextRequest } from 'next/server';
+
+// Mock the data module
+jest.mock('../case-convert/data', () => ({
+  convertCase: jest.fn(),
+}));
+
+const { convertCase } = require('../case-convert/data');
+
+describe('/api/routes-f/case-convert', () => {
+  beforeEach(() => {
+    jest.clearAllMocks();
+  });
+
+  describe('POST', () => {
+    it('should return all case formats when no target specified', async () => {
+      const mockConversions = {
+        camelCase: 'helloWorld',
+        snake_case: 'hello_world',
+        'kebab-case': 'hello-world',
+        PascalCase: 'HelloWorld',
+        CONSTANT_CASE: 'HELLO_WORLD',
+        'Title Case': 'Hello World',
+        'Sentence case': 'Hello world'
+      };
+
+      convertCase.mockReturnValue(mockConversions);
+
+      const request = new NextRequest('http://localhost:3000/api/routes-f/case-convert', {
+        method: 'POST',
+        body: JSON.stringify({
+          text: 'Hello World'
+        }),
+        headers: {
+          'Content-Type': 'application/json'
+        }
+      });
+
+      const response = await POST(request);
+      const data = await response.json();
+
+      expect(response.status).toBe(200);
+      expect(data).toEqual(mockConversions);
+      expect(convertCase).toHaveBeenCalledWith('Hello World', undefined);
+    });
+
+    it('should return specific case format when target specified', async () => {
+      const mockConversion = {
+        result: 'helloWorld'
+      };
+
+      convertCase.mockReturnValue(mockConversion);
+
+      const request = new NextRequest('http://localhost:3000/api/routes-f/case-convert', {
+        method: 'POST',
+        body: JSON.stringify({
+          text: 'Hello World',
+          target: 'camelCase'
+        }),
+        headers: {
+          'Content-Type': 'application/json'
+        }
+      });
+
+      const response = await POST(request);
+      const data = await response.json();
+
+      expect(response.status).toBe(200);
+      expect(data).toEqual(mockConversion);
+      expect(convertCase).toHaveBeenCalledWith('Hello World', 'camelCase');
+    });
+
+    it('should handle mixed case inputs', async () => {
+      const mockConversions = {
+        camelCase: 'helloWorldTest',
+        snake_case: 'hello_world_test',
+        'kebab-case': 'hello-world-test',
+        PascalCase: 'HelloWorldTest',
+        CONSTANT_CASE: 'HELLO_WORLD_TEST',
+        'Title Case': 'Hello World Test',
+        'Sentence case': 'Hello world test'
+      };
+
+      convertCase.mockReturnValue(mockConversions);
+
+      const request = new NextRequest('http://localhost:3000/api/routes-f/case-convert', {
+        method: 'POST',
+        body: JSON.stringify({
+          text: 'HelloWorld_test-case'
+        }),
+        headers: {
+          'Content-Type': 'application/json'
+        }
+      });
+
+      const response = await POST(request);
+      const data = await response.json();
+
+      expect(response.status).toBe(200);
+      expect(data).toEqual(mockConversions);
+      expect(convertCase).toHaveBeenCalledWith('HelloWorld_test-case', undefined);
+    });
+
+    it('should preserve numbers in identifiers', async () => {
+      const mockConversions = {
+        camelCase: 'test123Value',
+        snake_case: 'test_123_value',
+        'kebab-case': 'test-123-value',
+        PascalCase: 'Test123Value',
+        CONSTANT_CASE: 'TEST_123_VALUE',
+        'Title Case': 'Test 123 Value',
+        'Sentence case': 'Test 123 value'
+      };
+
+      convertCase.mockReturnValue(mockConversions);
+
+      const request = new NextRequest('http://localhost:3000/api/routes-f/case-convert', {
+        method: 'POST',
+        body: JSON.stringify({
+          text: 'Test123Value'
+        }),
+        headers: {
+          'Content-Type': 'application/json'
+        }
+      });
+
+      const response = await POST(request);
+      const data = await response.json();
+
+      expect(response.status).toBe(200);
+      expect(data).toEqual(mockConversions);
+      expect(convertCase).toHaveBeenCalledWith('Test123Value', undefined);
+    });
+
+    it('should return 400 for missing request body', async () => {
+      const request = new NextRequest('http://localhost:3000/api/routes-f/case-convert', {
+        method: 'POST',
+        body: JSON.stringify({}),
+        headers: {
+          'Content-Type': 'application/json'
+        }
+      });
+
+      const response = await POST(request);
+      const data = await response.json();
+
+      expect(response.status).toBe(400);
+      expect(data.error).toContain('Invalid request body');
+    });
+
+    it('should return 400 for invalid target case', async () => {
+      const request = new NextRequest('http://localhost:3000/api/routes-f/case-convert', {
+        method: 'POST',
+        body: JSON.stringify({
+          text: 'Hello World',
+          target: 'invalidCase'
+        }),
+        headers: {
+          'Content-Type': 'application/json'
+        }
+      });
+
+      const response = await POST(request);
+      const data = await response.json();
+
+      expect(response.status).toBe(400);
+      expect(data.error).toContain('Invalid target case');
+    });
+
+    it('should return 400 for invalid JSON', async () => {
+      const request = new NextRequest('http://localhost:3000/api/routes-f/case-convert', {
+        method: 'POST',
+        body: 'invalid json',
+        headers: {
+          'Content-Type': 'application/json'
+        }
+      });
+
+      const response = await POST(request);
+      const data = await response.json();
+
+      expect(response.status).toBe(400);
+      expect(data.error).toContain('Invalid JSON');
+    });
+
+    it('should handle empty string input', async () => {
+      const mockConversions = {};
+
+      convertCase.mockReturnValue(mockConversions);
+
+      const request = new NextRequest('http://localhost:3000/api/routes-f/case-convert', {
+        method: 'POST',
+        body: JSON.stringify({
+          text: ''
+        }),
+        headers: {
+          'Content-Type': 'application/json'
+        }
+      });
+
+      const response = await POST(request);
+      const data = await response.json();
+
+      expect(response.status).toBe(200);
+      expect(data).toEqual(mockConversions);
+      expect(convertCase).toHaveBeenCalledWith('', undefined);
+    });
+  });
+});
diff --git a/app/api/routes-f/__tests__/char-stats.test.ts b/app/api/routes-f/__tests__/char-stats.test.ts
new file mode 100644
index 00000000..8798e1b4
--- /dev/null
+++ b/app/api/routes-f/__tests__/char-stats.test.ts
@@ -0,0 +1,99 @@
+/**
+ * @jest-environment node
+ */
+import { NextRequest } from "next/server";
+import { POST } from "../char-stats/route";
+
+function makeReq(body: unknown) {
+  return new NextRequest("http://localhost/api/routes-f/char-stats", {
+    method: "POST",
+    headers: { "content-type": "application/json" },
+    body: JSON.stringify(body),
+  });
+}
+
+describe("/api/routes-f/char-stats", () => {
+  it("counts ASCII text correctly", async () => {
+    const res = await POST(makeReq({ text: "Hello, World! 123" }));
+    expect(res.status).toBe(200);
+    const data = await res.json();
+    expect(data.total).toBe(17);
+    expect(data.letters).toBe(10);
+    expect(data.digits).toBe(3);
+    expect(data.punctuation).toBeGreaterThanOrEqual(1);
+    expect(data.whitespace).toBe(2);
+    expect(data.emoji).toBe(0);
+    expect(data.by_script.latin).toBe(10);
+  });
+
+  it("counts mixed scripts", async () => {
+    const res = await POST(makeReq({ text: "Hello Привет" }));
+    expect(res.status).toBe(200);
+    const data = await res.json();
+    expect(data.by_script.latin).toBe(5);
+    expect(data.by_script.cyrillic).toBe(6);
+    expect(data.letters).toBe(11);
+    expect(data.whitespace).toBe(1);
+  });
+
+  it("counts CJK characters", async () => {
+    const res = await POST(makeReq({ text: "你好世界" }));
+    expect(res.status).toBe(200);
+    const data = await res.json();
+    expect(data.letters).toBe(4);
+    expect(data.by_script.cjk).toBe(4);
+  });
+
+  it("counts emoji", async () => {
+    const res = await POST(makeReq({ text: "Hi 👋🏽 there 😊" }));
+    expect(res.status).toBe(200);
+    const data = await res.json();
+    expect(data.emoji).toBeGreaterThanOrEqual(2);
+  });
+
+  it("handles ZWJ emoji sequences", async () => {
+    // Family emoji: man+woman+girl+boy via ZWJ
+    const family = "👨‍👩‍👧‍👦";
+    const res = await POST(makeReq({ text: family }));
+    expect(res.status).toBe(200);
+    const data = await res.json();
+    expect(data.emoji).toBe(1);
+  });
+
+  it("handles empty string", async () => {
+    const res = await POST(makeReq({ text: "" }));
+    expect(res.status).toBe(200);
+    const data = await res.json();
+    expect(data.total).toBe(0);
+    expect(data.letters).toBe(0);
+    expect(data.emoji).toBe(0);
+  });
+
+  it("counts digits and symbols", async () => {
+    const res = await POST(makeReq({ text: "42 + 58 = 100" }));
+    expect(res.status).toBe(200);
+    const data = await res.json();
+    expect(data.digits).toBe(7);
+    expect(data.whitespace).toBe(4);
+  });
+
+  it("rejects non-string text", async () => {
+    const res = await POST(makeReq({ text: 42 }));
+    expect(res.status).toBe(400);
+  });
+
+  it("rejects missing text field", async () => {
+    const res = await POST(makeReq({}));
+    expect(res.status).toBe(400);
+  });
+
+  it("rejects invalid JSON", async () => {
+    const req = new NextRequest("http://localhost/api/routes-f/char-stats", {
+      method: "POST",
+      headers: { "content-type": "application/json" },
+      body: "bad",
+    });
+    const res = await POST(req);
+    expect(res.status).toBe(400);
+  });
+});
diff --git a/app/api/routes-f/__tests__/chat-emote-mode.test.ts b/app/api/routes-f/__tests__/chat-emote-mode.test.ts
new file mode 100644
index 00000000..91272e7d
--- /dev/null
+++ b/app/api/routes-f/__tests__/chat-emote-mode.test.ts
@@ -0,0 +1,83 @@
+/**
+ * @jest-environment node
+ */
+import { NextRequest } from "next/server";
+import { POST } from "../chat-emote-mode/check/route";
+
+function makeCheckReq(message: string) {
+  return new NextRequest("http://localhost/api/routes-f/chat-emote-mode/check", {
+    method: "POST",
+    headers: { "content-type": "application/json" },
+    body: JSON.stringify({ message }),
+  });
+}
+
+describe("/api/routes-f/chat-emote-mode/check", () => {
+  it("accepts all-emoji message", async () => {
+    const req = makeCheckReq("😀 🎉 👍");
+    const res = await POST(req);
+    expect(res.status).toBe(200);
+
+    const data = await res.json();
+    expect(data.is_emote_only).toBe(true);
+    expect(data.would_be_blocked).toBe(false);
+  });
+
+  it("blocks plain text", async () => {
+    const req = makeCheckReq("hello world");
+    const res = await POST(req);
+    expect(res.status).toBe(200);
+
+    const data = await res.json();
+    expect(data.is_emote_only).toBe(false);
+    expect(data.would_be_blocked).toBe(true);
+  });
+
+  it("blocks mixed emoji and text", async () => {
+    const req = makeCheckReq("hello 😀 world");
+    const res = await POST(req);
+    expect(res.status).toBe(200);
+
+    const data = await res.json();
+    expect(data.is_emote_only).toBe(false);
+    expect(data.would_be_blocked).toBe(true);
+  });
+
+  it("accepts emoji with whitespace", async () => {
+    const req = makeCheckReq("   😀   🎉   👍   ");
+    const res = await POST(req);
+    expect(res.status).toBe(200);
+
+    const data = await res.json();
+    expect(data.is_emote_only).toBe(true);
+    expect(data.would_be_blocked).toBe(false);
+  });
+
+  it("rejects empty message", async () => {
+    const req = makeCheckReq("   ");
+    const res = await POST(req);
+    expect(res.status).toBe(200);
+
+    const data = await res.json();
+    expect(data.is_emote_only).toBe(false);
+  });
+
+  it("rejects missing message field", async () => {
+    const req = new NextRequest("http://localhost/api/routes-f/chat-emote-mode/check", {
+      method: "POST",
+      headers: { "content-type": "application/json" },
+      body: JSON.stringify({}),
+    });
+    const res = await POST(req);
+    expect(res.status).toBe(400);
+  });
+
+  it("handles unicode emoji correctly", async () => {
+    const req = makeCheckReq("❤️ 🚀 🌟");
+    const res = await POST(req);
+    expect(res.status).toBe(200);
+
+    const data = await res.json();
+    expect(data.is_emote_only).toBe(true);
+  });
+});
diff --git a/app/api/routes-f/__tests__/cookie-parse.test.ts b/app/api/routes-f/__tests__/cookie-parse.test.ts
new file mode 100644
index 00000000..6961e284
--- /dev/null
+++ b/app/api/routes-f/__tests__/cookie-parse.test.ts
@@ -0,0 +1,139 @@
+/**
+ * @jest-environment node
+ */
+import { NextRequest } from "next/server";
+import { POST } from "../cookie-parse/route";
+
+function makeReq(body: unknown) {
+  return new NextRequest("http://localhost/api/routes-f/cookie-parse", {
+    method: "POST",
+    headers: { "content-type": "application/json" },
+    body: JSON.stringify(body),
+  });
+}
+
+describe("/api/routes-f/cookie-parse", () => {
+  describe("parse mode", () => {
+    it("parses a simple cookie", async () => {
+      const res = await POST(makeReq({ mode: "parse", input: "session=abc123" }));
+      expect(res.status).toBe(200);
+      const data = await res.json();
+      expect(data.session.value).toBe("abc123");
+      expect(data.session.secure).toBe(false);
+      expect(data.session.http_only).toBe(false);
+    });
+
+    it("parses a cookie with all attributes", async () => {
+      const input =
+        "token=xyz; Expires=Wed, 01 Jan 2025 00:00:00 GMT; Max-Age=3600; Domain=example.com; Path=/; Secure; HttpOnly; SameSite=Strict";
+      const res = await POST(makeReq({ mode: "parse", input }));
+      expect(res.status).toBe(200);
+      const data = await res.json();
+      expect(data.token.value).toBe("xyz");
+      expect(data.token.expires).toBe("Wed, 01 Jan 2025 00:00:00 GMT");
+      expect(data.token.max_age).toBe(3600);
+      expect(data.token.domain).toBe("example.com");
+      expect(data.token.path).toBe("/");
+      expect(data.token.secure).toBe(true);
+      expect(data.token.http_only).toBe(true);
+      expect(data.token.same_site).toBe("Strict");
+    });
+
+    it("handles URL-encoded values", async () => {
+      const res = await POST(makeReq({ mode: "parse", input: "user=hello%20world" }));
+      expect(res.status).toBe(200);
+      const data = await res.json();
+      expect(data.user.value).toBe("hello world");
+    });
+
+    it("rejects invalid SameSite value", async () => {
+      const res = await POST(
+        makeReq({ mode: "parse", input: "x=1; SameSite=Invalid" })
+      );
+      expect(res.status).toBe(400);
+    });
+  });
+
+  describe("build mode", () => {
+    it("builds a simple Set-Cookie header", async () => {
+      const res = await POST(
+        makeReq({ mode: "build", input: { name: "session", value: "abc" } })
+      );
+      expect(res.status).toBe(200);
+      const data = await res.json();
+      expect(data.header).toBe("session=abc");
+    });
+
+    it("builds a full Set-Cookie header", async () => {
+      const res = await POST(
+        makeReq({
+          mode: "build",
+          input: {
+            name: "token",
+            value: "xyz",
+            path: "/",
+            secure: true,
+            http_only: true,
+            same_site: "Lax",
+          },
+        })
+      );
+      expect(res.status).toBe(200);
+      const data = await res.json();
+      expect(data.header).toContain("token=xyz");
+      expect(data.header).toContain("Path=/");
+      expect(data.header).toContain("Secure");
+      expect(data.header).toContain("HttpOnly");
+      expect(data.header).toContain("SameSite=Lax");
+    });
+
+    it("round-trips build -> parse", async () => {
+      const buildRes = await POST(
+        makeReq({
+          mode: "build",
+          input: {
+            name: "auth",
+            value: "tok123",
+            path: "/app",
+            secure: true,
+            http_only: true,
+            same_site: "None",
+          },
+        })
+      );
+      expect(buildRes.status).toBe(200);
+      const { header } = await buildRes.json();
+
+      const parseRes = await POST(makeReq({ mode: "parse", input: header }));
+      expect(parseRes.status).toBe(200);
+      const data = await parseRes.json();
+      expect(data.auth.value).toBe("tok123");
+      expect(data.auth.path).toBe("/app");
+      expect(data.auth.secure).toBe(true);
+      expect(data.auth.http_only).toBe(true);
+      expect(data.auth.same_site).toBe("None");
+    });
+
+    it("rejects invalid same_site in build mode", async () => {
+      const res = await POST(
+        makeReq({ mode: "build", input: { name: "x", value: "1", same_site: "Bad" } })
+      );
+      expect(res.status).toBe(400);
+    });
+  });
+
+  it("rejects unknown mode", async () => {
+    const res = await POST(makeReq({ mode: "delete", input: "x=1" }));
+    expect(res.status).toBe(400);
+  });
+
+  it("rejects invalid JSON", async () => {
+    const req = new NextRequest("http://localhost/api/routes-f/cookie-parse", {
+      method: "POST",
+      headers: { "content-type": "application/json" },
+      body: "bad",
+    });
+    const res = await POST(req);
+    expect(res.status).toBe(400);
+  });
+});
diff --git a/app/api/routes-f/__tests__/creator-min-tip.test.ts b/app/api/routes-f/__tests__/creator-min-tip.test.ts
new file mode 100644
index 00000000..e0cde7cd
--- /dev/null
+++ b/app/api/routes-f/__tests__/creator-min-tip.test.ts
@@ -0,0 +1,201 @@
+/**
+ * @jest-environment node
+ */
+import { NextRequest } from "next/server";
+import { GET, PUT } from "../creator-min-tip/route";
+import { POST as CHECK } from "../creator-min-tip/check/route";
+import { minTipStore } from "../creator-min-tip/store";
+
+function getReq(creatorId: string) {
+  return new NextRequest(
+    `http://localhost/api/routes-f/creator-min-tip?creator_id=${creatorId}`
+  );
+}
+
+function putReq(body: unknown) {
+  return new NextRequest(
+    "http://localhost/api/routes-f/creator-min-tip",
+    {
+      method: "PUT",
+      headers: { "content-type": "application/json" },
+      body: JSON.stringify(body),
+    }
+  );
+}
+
+function checkReq(body: unknown) {
+  return new NextRequest(
+    "http://localhost/api/routes-f/creator-min-tip/check",
+    {
+      method: "POST",
+      headers: { "content-type": "application/json" },
+      body: JSON.stringify(body),
+    }
+  );
+}
+
+describe("/api/routes-f/creator-min-tip", () => {
+  beforeEach(() => {
+    minTipStore.clear();
+  });
+
+  describe("GET — retrieve minimum tips", () => {
+    it("returns defaults (0, 0) for unknown creator", async () => {
+      const res = await GET(getReq("creator-new"));
+      expect(res.status).toBe(200);
+      const data = await res.json();
+      expect(data.min_xlm).toBe(0);
+      expect(data.min_usdc).toBe(0);
+    });
+
+    it("returns configured values after PUT", async () => {
+      await PUT(
+        putReq({ creator_id: "c1", min_xlm: 5, min_usdc: 2 })
+      );
+
+      const res = await GET(getReq("c1"));
+      const data = await res.json();
+      expect(data.min_xlm).toBe(5);
+      expect(data.min_usdc).toBe(2);
+    });
+
+    it("rejects missing creator_id", async () => {
+      const req = new NextRequest(
+        "http://localhost/api/routes-f/creator-min-tip"
+      );
+      const res = await GET(req);
+      expect(res.status).toBe(400);
+    });
+  });
+
+  describe("PUT — set minimum tips", () => {
+    it("sets both min_xlm and min_usdc", async () => {
+      const res = await PUT(
+        putReq({ creator_id: "c1", min_xlm: 10, min_usdc: 5 })
+      );
+      expect(res.status).toBe(200);
+      const data = await res.json();
+      expect(data.min_xlm).toBe(10);
+      expect(data.min_usdc).toBe(5);
+    });
+
+    it("allows setting only min_xlm", async () => {
+      const res = await PUT(putReq({ creator_id: "c1", min_xlm: 3 }));
+      expect(res.status).toBe(200);
+      const data = await res.json();
+      expect(data.min_xlm).toBe(3);
+      expect(data.min_usdc).toBe(0);
+    });
+
+    it("allows setting only min_usdc", async () => {
+      const res = await PUT(putReq({ creator_id: "c1", min_usdc: 1 }));
+      const data = await res.json();
+      expect(data.min_xlm).toBe(0);
+      expect(data.min_usdc).toBe(1);
+    });
+
+    it("rejects negative min_xlm", async () => {
+      const res = await PUT(
+        putReq({ creator_id: "c1", min_xlm: -1 })
+      );
+      expect(res.status).toBe(400);
+    });
+
+    it("rejects negative min_usdc", async () => {
+      const res = await PUT(
+        putReq({ creator_id: "c1", min_usdc: -5 })
+      );
+      expect(res.status).toBe(400);
+    });
+
+    it("rejects missing creator_id", async () => {
+      const res = await PUT(putReq({ min_xlm: 5 }));
+      expect(res.status).toBe(400);
+    });
+  });
+
+  describe("POST /check — verify tip allowed", () => {
+    it("allows a tip above the minimum", async () => {
+      await PUT(putReq({ creator_id: "c1", min_xlm: 5 }));
+
+      const res = await CHECK(
+        checkReq({ creator_id: "c1", asset: "XLM", amount: 10 })
+      );
+      expect(res.status).toBe(200);
+      const data = await res.json();
+      expect(data.allowed).toBe(true);
+      expect(data.reason).toBeUndefined();
+    });
+
+    it("rejects a tip below the minimum with reason", async () => {
+      await PUT(putReq({ creator_id: "c1", min_xlm: 5 }));
+
+      const res = await CHECK(
+        checkReq({ creator_id: "c1", asset: "XLM", amount: 2 })
+      );
+      expect(res.status).toBe(200);
+      const data = await res.json();
+      expect(data.allowed).toBe(false);
+      expect(data.reason).toMatch(/Minimum XLM/);
+    });
+
+    it("allows exact minimum amount", async () => {
+      await PUT(putReq({ creator_id: "c1", min_usdc: 10 }));
+
+      const res = await CHECK(
+        checkReq({ creator_id: "c1", asset: "USDC", amount: 10 })
+      );
+      const data = await res.json();
+      expect(data.allowed).toBe(true);
+    });
+
+    it("rejects USDC tip below minimum", async () => {
+      await PUT(putReq({ creator_id: "c1", min_usdc: 10 }));
+
+      const res = await CHECK(
+        checkReq({ creator_id: "c1", asset: "USDC", amount: 5 })
+      );
+      const data = await res.json();
+      expect(data.allowed).toBe(false);
+      expect(data.reason).toMatch(/Minimum USDC/);
+    });
+
+    it("rejects unsupported asset", async () => {
+      const res = await CHECK(
+        checkReq({ creator_id: "c1", asset: "BTC", amount: 1 })
+      );
+      const data = await res.json();
+      expect(data.allowed).toBe(false);
+      expect(data.reason).toMatch(/Unsupported asset/);
+    });
+
+    it("allows any amount when no minimum is configured", async () => {
+      const res = await CHECK(
+        checkReq({ creator_id: "c-new", asset: "XLM", amount: 0.001 })
+      );
+      const data = await res.json();
+      expect(data.allowed).toBe(true);
+    });
+
+    it("rejects missing creator_id", async () => {
+      const res = await CHECK(
+        checkReq({ asset: "XLM", amount: 5 })
+      );
+      expect(res.status).toBe(400);
+    });
+
+    it("rejects missing asset", async () => {
+      const res = await CHECK(
+        checkReq({ creator_id: "c1", amount: 5 })
+      );
+      expect(res.status).toBe(400);
+    });
+
+    it("rejects missing amount", async () => {
+      const res = await CHECK(
+        checkReq({ creator_id: "c1", asset: "XLM" })
+      );
+      expect(res.status).toBe(400);
+    });
+  });
+});
diff --git a/app/api/routes-f/__tests__/deep-merge.test.ts b/app/api/routes-f/__tests__/deep-merge.test.ts
new file mode 100644
index 00000000..9123987d
--- /dev/null
+++ b/app/api/routes-f/__tests__/deep-merge.test.ts
@@ -0,0 +1,144 @@
+// @ts-nocheck
+/**
+ * @jest-environment node
+ */
+import { POST, deepMerge } from "../deep-merge/route";
+import { NextRequest } from "next/server";
+
+function makeReq(body: unknown) {
+  return new NextRequest("http://localhost/api/routes-f/deep-merge", {
+    method: "POST",
+    headers: { "content-type": "application/json" },
+    body: JSON.stringify(body),
+  });
+}
+
+describe("/api/routes-f/deep-merge", () => {
+  describe("deepMerge helper", () => {
+    it("merges two flat objects", () => {
+      const result = deepMerge([{ a: 1 }, { b: 2 }], "replace");
+      expect(result).toEqual({ a: 1, b: 2 });
+    });
+
+    it("overwrites primitive values", () => {
+      const result = deepMerge([{ a: 1 }, { a: 2 }], "replace");
+      expect(result).toEqual({ a: 2 });
+    });
+
+    it("deep merges nested objects", () => {
+      const result = deepMerge(
+        [{ user: { name: "Alice", age: 30 } }, { user: { age: 31, city: "NYC" } }],
+        "replace"
+      );
+      expect(result).toEqual({ user: { name: "Alice", age: 31, city: "NYC" } });
+    });
+
+    it("replace strategy replaces arrays", () => {
+      const result = deepMerge([{ arr: [1, 2] }, { arr: [3, 4] }], "replace");
+      expect(result).toEqual({ arr: [3, 4] });
+    });
+
+    it("concat strategy concatenates arrays", () => {
+      const result = deepMerge([{ arr: [1, 2] }, { arr: [3, 4] }], "concat");
+      expect(result).toEqual({ arr: [1, 2, 3, 4] });
+    });
+
+    it("union strategy deduplicates arrays", () => {
+      const result = deepMerge([{ arr: [1, 2, 2] }, { arr: [2, 3] }], "union");
+      expect(result).toEqual({ arr: [1, 2, 3] });
+    });
+
+    it("handles three objects", () => {
+      const result = deepMerge([{ a: 1 }, { b: 2 }, { c: 3 }], "replace");
+      expect(result).toEqual({ a: 1, b: 2, c: 3 });
+    });
+
+    it("deeply nested merge", () => {
+      const result = deepMerge(
+        [
+          { config: { db: { host: "localhost" } } },
+          { config: { db: { port: 5432 }, cache: true } },
+        ],
+        "replace"
+      );
+      expect(result).toEqual({
+        config: { db: { host: "localhost", port: 5432 }, cache: true },
+      });
+    });
+  });
+
+  describe("POST handler", () => {
+    it("merges two objects with default strategy", async () => {
+      const res = await POST(makeReq({ objects: [{ a: 1 }, { b: 2 }] }));
+      expect(res.status).toBe(200);
+      const { merged } = await res.json();
+      expect(merged).toEqual({ a: 1, b: 2 });
+    });
+
+    it("uses replace strategy by default for arrays", async () => {
+      const res = await POST(makeReq({ objects: [{ arr: [1] }, { arr: [2] }] }));
+      const { merged } = await res.json();
+      expect(merged.arr).toEqual([2]);
+    });
+
+    it("concat strategy works", async () => {
+      const res = await POST(
+        makeReq({ objects: [{ arr: [1] }, { arr: [2] }], array_strategy: "concat" })
+      );
+      const { merged } = await res.json();
+      expect(merged.arr).toEqual([1, 2]);
+    });
+
+    it("union strategy works", async () => {
+      const res = await POST(
+        makeReq({ objects: [{ arr: [1, 2] }, { arr: [2, 3] }], array_strategy: "union" })
+      );
+      const { merged } = await res.json();
+      expect(merged.arr).toEqual([1, 2, 3]);
+    });
+
+    it("deep nested merge via POST", async () => {
+      const res = await POST(
+        makeReq({
+          objects: [
+            { user: { name: "Bob", settings: { theme: "dark" } } },
+            { user: { settings: { lang: "en" } } },
+          ],
+        })
+      );
+      const { merged } = await res.json();
+      expect(merged.user.settings).toEqual({ theme: "dark", lang: "en" });
+    });
+
+    it("returns 400 for empty objects array", async () => {
+      const res = await POST(makeReq({ objects: [] }));
+      expect(res.status).toBe(400);
+    });
+
+    it("returns 400 for missing objects", async () => {
+      const res = await POST(makeReq({}));
+      expect(res.status).toBe(400);
+    });
+
+    it("returns 400 for invalid array_strategy", async () => {
+      const res = await POST(
+        makeReq({ objects: [{ a: 1 }], array_strategy: "invalid" })
+      );
+      expect(res.status).toBe(400);
+    });
+
+    it("handles single object", async () => {
+      const res = await POST(makeReq({ objects: [{ a: 1, b: 2 }] }));
+      const { merged } = await res.json();
+      expect(merged).toEqual({ a: 1, b: 2 });
+    });
+
+    it("rejects body exceeding 2MB", async () => {
+      const large = { objects: [{ data: "x".repeat(3 * 1024 * 1024) }] };
+      const res = await POST(makeReq(large));
+      expect(res.status).toBe(400);
+      const body = await res.json();
+      expect(body.error).toContain("exceeds");
+    });
+  });
+});
diff --git a/app/api/routes-f/__tests__/duration.test.ts b/app/api/routes-f/__tests__/duration.test.ts
new file mode 100644
index 00000000..ecfc22e3
--- /dev/null
+++ b/app/api/routes-f/__tests__/duration.test.ts
@@ -0,0 +1,73 @@
+/**
+ * @jest-environment node
+ */
+import { NextRequest } from "next/server";
+import { POST } from "../duration/route";
+
+function makeReq(body: unknown) {
+  return new NextRequest("http://localhost/api/routes-f/duration", {
+    method: "POST",
+    headers: { "content-type": "application/json" },
+    body: JSON.stringify(body),
+  });
+}
+
+describe("/api/routes-f/duration", () => {
+  it("parses a time-only ISO 8601 duration", async () => {
+    const res = await POST(makeReq({ mode: "parse", text: "PT1H30M5S" }));
+    expect(res.status).toBe(200);
+    const data = await res.json();
+
+    expect(data.components).toEqual({
+      years: 0,
+      months: 0,
+      weeks: 0,
+      days: 0,
+      hours: 1,
+      minutes: 30,
+      seconds: 5,
+    });
+    expect(data.total_seconds).toBe(5405);
+  });
+
+  it("round-trips a combined date and time duration", async () => {
+    const parseRes = await POST(
+      makeReq({ mode: "parse", text: "P1Y2M3W4DT5H6M7S" })
+    );
+    expect(parseRes.status).toBe(200);
+    const parsed = await parseRes.json();
+
+    expect(parsed.components).toEqual({
+      years: 1,
+      months: 2,
+      weeks: 3,
+      days: 4,
+      hours: 5,
+      minutes: 6,
+      seconds: 7,
+    });
+
+    const formatRes = await POST(
+      makeReq({ mode: "format", components: parsed.components })
+    );
+    expect(formatRes.status).toBe(200);
+    const formatted = await formatRes.json();
+
+    expect(formatted.text).toBe("P1Y2M3W4DT5H6M7S");
+    expect(formatted.total_seconds).toBe(1 * 31536000 + 2 * 2592000 + 3 * 604800 + 4 * 86400 + 5 * 3600 + 6 * 60 + 7);
+
+    const roundTripRes = await POST(makeReq({ mode: "parse", text: formatted.text }));
+    expect(roundTripRes.status).toBe(200);
+    const roundTrip = await roundTripRes.json();
+    expect(roundTrip.components).toEqual(parsed.components);
+  });
+
+  it("formats zero duration as PT0S", async () => {
+    const res = await POST(makeReq({ mode: "format", components: {} }));
+    expect(res.status).toBe(200);
+    const data = await res.json();
+
+    expect(data.text).toBe("PT0S");
+    expect(data.total_seconds).toBe(0);
+  });
+});
diff --git a/app/api/routes-f/__tests__/followed-categories.test.ts b/app/api/routes-f/__tests__/followed-categories.test.ts
new file mode 100644
index 00000000..7cd4a9c4
--- /dev/null
+++ b/app/api/routes-f/__tests__/followed-categories.test.ts
@@ -0,0 +1,81 @@
+/**
+ * @jest-environment node
+ */
+import { NextRequest } from "next/server";
+import { GET } from "../categories/followed/route";
+
+function makeReq(query: string) {
+  return new NextRequest(
+    `http://localhost/api/routes-f/categories/followed?${query}`
+  );
+}
+
+describe("Followed Categories Feed API", () => {
+  it("should fail if viewer_id is missing", async () => {
+    const req = makeReq("");
+    const res = await GET(req);
+    expect(res.status).toBe(400);
+    const data = await res.json();
+    expect(data.error).toBe("viewer_id is required");
+  });
+
+  it("should return empty list if viewer follows no categories", async () => {
+    const req = makeReq("viewer_id=viewer-no-follows");
+    const res = await GET(req);
+    expect(res.status).toBe(200);
+    const data = await res.json();
+    expect(data.streams).toEqual([]);
+  });
+
+  it("should return streams in followed categories, sorted by viewer_count descending", async () => {
+    // viewer-1 follows Gaming, Music, Talk Shows
+    const req = makeReq("viewer_id=viewer-1");
+    const res = await GET(req);
+    expect(res.status).toBe(200);
+    const data = await res.json();
+
+    expect(Array.isArray(data.streams)).toBe(true);
+    expect(data.streams.length).toBe(4);
+
+    // Verify categories are correct
+    const categories = data.streams.map((s: any) => s.category);
+    expect(categories).toContain("Gaming");
+    expect(categories).toContain("Music");
+    expect(categories).toContain("Talk Shows");
+    expect(categories).not.toContain("Crypto");
+    expect(categories).not.toContain("Coding");
+    expect(categories).not.toContain("Sports");
+
+    // Verify ordering is descending by viewer_count
+    // Expected order of followed categories:
+    // 1. creator-gaming-1 (Gaming) - 1500 viewers
+    // 2. creator-talk-1 (Talk Shows) - 1200 viewers
+    // 3. creator-gaming-2 (Gaming) - 800 viewers
+    // 4. creator-music-1 (Music) - 450 viewers
+    expect(data.streams[0].creator).toBe("creator-gaming-1");
+    expect(data.streams[1].creator).toBe("creator-talk-1");
+    expect(data.streams[2].creator).toBe("creator-gaming-2");
+    expect(data.streams[3].creator).toBe("creator-music-1");
+
+    for (let i = 0; i < data.streams.length - 1; i++) {
+      expect(data.streams[i].viewer_count).toBeGreaterThanOrEqual(
+        data.streams[i + 1].viewer_count
+      );
+    }
+  });
+
+  it("should return correct streams for another viewer with correct ranking", async () => {
+    // viewer-3 follows Crypto, Coding
+    // Streams:
+    // creator-crypto-1 (Crypto) - 3100 viewers
+    // creator-coding-1 (Coding) - 950 viewers
+    const req = makeReq("viewer_id=viewer-3");
+    const res = await GET(req);
+    expect(res.status).toBe(200);
+    const data = await res.json();
+
+    expect(data.streams.length).toBe(2);
+    expect(data.streams[0].creator).toBe("creator-crypto-1");
+    expect(data.streams[1].creator).toBe("creator-coding-1");
+  });
+});
diff --git a/app/api/routes-f/__tests__/gcd-lcm.test.ts b/app/api/routes-f/__tests__/gcd-lcm.test.ts
new file mode 100644
index 00000000..7b532d42
--- /dev/null
+++ b/app/api/routes-f/__tests__/gcd-lcm.test.ts
@@ -0,0 +1,109 @@
+/**
+ * @jest-environment node
+ */
+import { NextRequest } from "next/server";
+import { POST } from "../gcd-lcm/route";
+
+function makeReq(body: unknown) {
+  return new NextRequest("http://localhost/api/routes-f/gcd-lcm", {
+    method: "POST",
+    headers: { "content-type": "application/json" },
+    body: JSON.stringify(body),
+  });
+}
+
+describe("/api/routes-f/gcd-lcm", () => {
+  it("computes gcd and lcm of a known pair (12, 18)", async () => {
+    const res = await POST(makeReq({ numbers: [12, 18] }));
+    expect(res.status).toBe(200);
+    const data = await res.json();
+    expect(data.gcd).toBe(6);
+    expect(data.lcm).toBe(36);
+    expect(data.n_count).toBe(2);
+  });
+
+  it("computes gcd only when operation=gcd", async () => {
+    const res = await POST(makeReq({ numbers: [12, 18], operation: "gcd" }));
+    expect(res.status).toBe(200);
+    const data = await res.json();
+    expect(data.gcd).toBe(6);
+    expect(data.lcm).toBeUndefined();
+  });
+
+  it("computes lcm only when operation=lcm", async () => {
+    const res = await POST(makeReq({ numbers: [12, 18], operation: "lcm" }));
+    expect(res.status).toBe(200);
+    const data = await res.json();
+    expect(data.lcm).toBe(36);
+    expect(data.gcd).toBeUndefined();
+  });
+
+  it("handles multiple numbers", async () => {
+    const res = await POST(makeReq({ numbers: [4, 6, 8] }));
+    expect(res.status).toBe(200);
+    const data = await res.json();
+    expect(data.gcd).toBe(2);
+    expect(data.lcm).toBe(24);
+    expect(data.n_count).toBe(3);
+  });
+
+  it("handles edge case with 1", async () => {
+    const res = await POST(makeReq({ numbers: [1, 7] }));
+    expect(res.status).toBe(200);
+    const data = await res.json();
+    expect(data.gcd).toBe(1);
+    expect(data.lcm).toBe(7);
+  });
+
+  it("handles prime numbers", async () => {
+    const res = await POST(makeReq({ numbers: [7, 11] }));
+    expect(res.status).toBe(200);
+    const data = await res.json();
+    expect(data.gcd).toBe(1);
+    expect(data.lcm).toBe(77);
+  });
+
+  it("handles single number", async () => {
+    const res = await POST(makeReq({ numbers: [15] }));
+    expect(res.status).toBe(200);
+    const data = await res.json();
+    expect(data.gcd).toBe(15);
+    expect(data.lcm).toBe(15);
+  });
+
+  it("rejects non-positive integers", async () => {
+    const res = await POST(makeReq({ numbers: [0, 5] }));
+    expect(res.status).toBe(400);
+  });
+
+  it("rejects floats", async () => {
+    const res = await POST(makeReq({ numbers: [1.5, 3] }));
+    expect(res.status).toBe(400);
+  });
+
+  it("rejects arrays exceeding 100 numbers", async () => {
+    const numbers = Array.from({ length: 101 }, (_, i) => i + 1);
+    const res = await POST(makeReq({ numbers }));
+    expect(res.status).toBe(400);
+  });
+
+  it("rejects empty array", async () => {
+    const res = await POST(makeReq({ numbers: [] }));
+    expect(res.status).toBe(400);
+  });
+
+  it("rejects invalid operation", async () => {
+    const res = await POST(makeReq({ numbers: [4, 6], operation: "max" }));
+    expect(res.status).toBe(400);
+  });
+
+  it("rejects invalid JSON", async () => {
+    const req = new NextRequest("http://localhost/api/routes-f/gcd-lcm", {
+      method: "POST",
+      headers: { "content-type": "application/json" },
+      body: "not-json",
+    });
+    const res = await POST(req);
+    expect(res.status).toBe(400);
+  });
+});
diff --git a/app/api/routes-f/__tests__/html-escape.test.ts b/app/api/routes-f/__tests__/html-escape.test.ts
new file mode 100644
index 00000000..32f58ed0
--- /dev/null
+++ b/app/api/routes-f/__tests__/html-escape.test.ts
@@ -0,0 +1,239 @@
+// @ts-nocheck
+/**
+ * @jest-environment jsdom
+ */
+
+import { POST } from "../html-escape/route";
+import { NextRequest } from "next/server";
+
+// Mock the data module
+jest.mock("../html-escape/data", () => ({
+  escapeHtml: jest.fn(),
+  unescapeHtml: jest.fn(),
+}));
+
+const { escapeHtml, unescapeHtml } = require("../html-escape/data");
+
+describe("/api/routes-f/html-escape", () => {
+  beforeEach(() => {
+    jest.clearAllMocks();
+  });
+
+  describe("POST", () => {
+    it("should escape HTML in escape mode", async () => {
+      escapeHtml.mockReturnValue(
+        "&lt;div&gt;Hello &amp; &quot;world&quot;&#39;&lt;/div&gt;"
+      );
+
+      const request = new NextRequest(
+        "http://localhost:3000/api/routes-f/html-escape",
+        {
+          method: "POST",
+          body: JSON.stringify({
+            input: '<div>Hello & "world"</div>',
+            mode: "escape",
+          }),
+          headers: {
+            "Content-Type": "application/json",
+          },
+        }
+      );
+
+      const response = await POST(request);
+      const data = await response.json();
+
+      expect(response.status).toBe(200);
+      expect(data.output).toBe(
+        "&lt;div&gt;Hello &amp; &quot;world&quot;&#39;&lt;/div&gt;"
+      );
+      expect(escapeHtml).toHaveBeenCalledWith('<div>Hello & "world"</div>');
+    });
+
+    it("should unescape HTML in unescape mode", async () => {
+      unescapeHtml.mockReturnValue('<div>Hello & "world"</div>');
+
+      const request = new NextRequest(
+        "http://localhost:3000/api/routes-f/html-escape",
+        {
+          method: "POST",
+          body: JSON.stringify({
+            input: "&lt;div&gt;Hello &amp; &quot;world&quot;&#39;&lt;/div&gt;",
+            mode: "unescape",
+          }),
+          headers: {
+            "Content-Type": "application/json",
+          },
+        }
+      );
+
+      const response = await POST(request);
+      const data = await response.json();
+
+      expect(response.status).toBe(200);
+      expect(data.output).toBe('<div>Hello & "world"</div>');
+      expect(unescapeHtml).toHaveBeenCalledWith(
+        "&lt;div&gt;Hello &amp; &quot;world&quot;&#39;&lt;/div&gt;"
+      );
+    });
+
+    it("should handle numeric entities in unescape mode", async () => {
+      unescapeHtml.mockReturnValue("A");
+
+      const request = new NextRequest(
+        "http://localhost:3000/api/routes-f/html-escape",
+        {
+          method: "POST",
+          body: JSON.stringify({
+            input: "&#65;",
+            mode: "unescape",
+          }),
+          headers: {
+            "Content-Type": "application/json",
+          },
+        }
+      );
+
+      const response = await POST(request);
+      const data = await response.json();
+
+      expect(response.status).toBe(200);
+      expect(data.output).toBe("A");
+      expect(unescapeHtml).toHaveBeenCalledWith("&#65;");
+    });
+
+    it("should handle hexadecimal entities in unescape mode", async () => {
+      unescapeHtml.mockReturnValue("A");
+
+      const request = new NextRequest(
+        "http://localhost:3000/api/routes-f/html-escape",
+        {
+          method: "POST",
+          body: JSON.stringify({
+            input: "&#x41;",
+            mode: "unescape",
+          }),
+          headers: {
+            "Content-Type": "application/json",
+          },
+        }
+      );
+
+      const response = await POST(request);
+      const data = await response.json();
+
+      expect(response.status).toBe(200);
+      expect(data.output).toBe("A");
+      expect(unescapeHtml).toHaveBeenCalledWith("&#x41;");
+    });
+
+    it("should handle named entities in unescape mode", async () => {
+      unescapeHtml.mockReturnValue("<");
+
+      const request = new NextRequest(
+        "http://localhost:3000/api/routes-f/html-escape",
+        {
+          method: "POST",
+          body: JSON.stringify({
+            input: "&lt;",
+            mode: "unescape",
+          }),
+          headers: {
+            "Content-Type": "application/json",
+          },
+        }
+      );
+
+      const response = await POST(request);
+      const data = await response.json();
+
+      expect(response.status).toBe(200);
+      expect(data.output).toBe("<");
+      expect(unescapeHtml).toHaveBeenCalledWith("&lt;");
+    });
+
+    it("should return 400 for missing request body", async () => {
+      const request = new NextRequest(
+        "http://localhost:3000/api/routes-f/html-escape",
+        {
+          method: "POST",
+          body: JSON.stringify({}),
+          headers: {
+            "Content-Type": "application/json",
+          },
+        }
+      );
+
+      const response = await POST(request);
+      const data = await response.json();
+
+      expect(response.status).toBe(400);
+      expect(data.error).toContain("Invalid request body");
+    });
+
+    it("should return 400 for invalid mode", async () => {
+      const request = new NextRequest(
+        "http://localhost:3000/api/routes-f/html-escape",
+        {
+          method: "POST",
+          body: JSON.stringify({
+            input: "test",
+            mode: "invalid",
+          }),
+          headers: {
+            "Content-Type": "application/json",
+          },
+        }
+      );
+
+      const response = await POST(request);
+      const data = await response.json();
+
+      expect(response.status).toBe(400);
+      expect(data.error).toContain("Invalid mode");
+    });
+
+    it("should return 400 for invalid JSON", async () => {
+      const request = new NextRequest(
+        "http://localhost:3000/api/routes-f/html-escape",
+        {
+          method: "POST",
+          body: "invalid json",
+          headers: {
+            "Content-Type": "application/json",
+          },
+        }
+      );
+
+      const response = await POST(request);
+      const data = await response.json();
+
+      expect(response.status).toBe(400);
+      expect(data.error).toContain("Invalid JSON");
+    });
+
+    it("should return 413 for input too large", async () => {
+      // Create a string larger than 1MB
+      const largeInput = "a".repeat(1024 * 1024 + 1);
+
+      const request = new NextRequest(
+        "http://localhost:3000/api/routes-f/html-escape",
+        {
+          method: "POST",
+          body: JSON.stringify({
+            input: largeInput,
+            mode: "escape",
+          }),
+          headers: {
+            "Content-Type": "application/json",
+          },
+        }
+      );
+
+      const response = await POST(request);
+      const data = await response.json();
+
+      expect(response.status).toBe(413);
+      expect(data.error).toContain("Input too large");
+    });
+  });
+});
diff --git a/app/api/routes-f/__tests__/http-status.test.ts b/app/api/routes-f/__tests__/http-status.test.ts
new file mode 100644
index 00000000..b8275f8d
--- /dev/null
+++ b/app/api/routes-f/__tests__/http-status.test.ts
@@ -0,0 +1,122 @@
+// @ts-nocheck
+/**
+ * @jest-environment jsdom
+ */
+
+import { GET } from "../http-status/route";
+import { NextRequest } from "next/server";
+
+// Mock the data module
+jest.mock("../http-status/data", () => ({
+  getStatusByCode: jest.fn(),
+  getStatusesByCategory: jest.fn(),
+  findNearestStatus: jest.fn(),
+}));
+
+const {
+  getStatusByCode,
+  getStatusesByCategory,
+  findNearestStatus,
+} = require("../http-status/data");
+
+describe("/api/routes-f/http-status", () => {
+  beforeEach(() => {
+    jest.clearAllMocks();
+  });
+
+  describe("GET with code parameter", () => {
+    it("should return status details for valid code", async () => {
+      const mockStatus = {
+        code: 404,
+        name: "Not Found",
+        description: "The server can not find the requested resource",
+        category: "4xx",
+        rfc: "RFC 7231",
+      };
+
+      getStatusByCode.mockReturnValue(mockStatus);
+
+      const request = new NextRequest(
+        "http://localhost:3000/api/routes-f/http-status?code=404"
+      );
+      const response = await GET(request);
+      const data = await response.json();
+
+      expect(response.status).toBe(200);
+      expect(data).toEqual(mockStatus);
+      expect(getStatusByCode).toHaveBeenCalledWith(404);
+    });
+
+    it("should return 404 for unknown status code with suggestion", async () => {
+      getStatusByCode.mockReturnValue(undefined);
+
+      const nearestStatus = {
+        code: 404,
+        name: "Not Found",
+        description: "The server can not find the requested resource",
+        category: "4xx",
+      };
+
+      findNearestStatus.mockReturnValue(nearestStatus);
+
+      const request = new NextRequest(
+        "http://localhost:3000/api/routes-f/http-status?code=403"
+      );
+      const response = await GET(request);
+      const data = await response.json();
+
+      expect(response.status).toBe(404);
+      expect(data.error).toContain("HTTP status code 403 not found");
+      expect(data.suggestion).toContain("Did you mean 404");
+      expect(findNearestStatus).toHaveBeenCalledWith(403);
+    });
+
+    it("should return 400 for invalid code format", async () => {
+      const request = new NextRequest(
+        "http://localhost:3000/api/routes-f/http-status?code=invalid"
+      );
+      const response = await GET(request);
+      const data = await response.json();
+
+      expect(response.status).toBe(400);
+      expect(data.error).toBe("Invalid status code format");
+    });
+  });
+
+  describe("GET without code parameter", () => {
+    it("should return all statuses grouped by category", async () => {
+      const mockGroupedStatuses = {
+        "2xx": [
+          {
+            code: 200,
+            name: "OK",
+            description: "The request succeeded",
+            category: "2xx",
+            rfc: "RFC 7231",
+          },
+        ],
+        "4xx": [
+          {
+            code: 404,
+            name: "Not Found",
+            description: "The server can not find the requested resource",
+            category: "4xx",
+            rfc: "RFC 7231",
+          },
+        ],
+      };
+
+      getStatusesByCategory.mockReturnValue(mockGroupedStatuses);
+
+      const request = new NextRequest(
+        "http://localhost:3000/api/routes-f/http-status"
+      );
+      const response = await GET(request);
+      const data = await response.json();
+
+      expect(response.status).toBe(200);
+      expect(data).toEqual(mockGroupedStatuses);
+      expect(getStatusesByCategory).toHaveBeenCalled();
+    });
+  });
+});
diff --git a/app/api/routes-f/__tests__/loan-amortization.test.ts b/app/api/routes-f/__tests__/loan-amortization.test.ts
new file mode 100644
index 00000000..50318f38
--- /dev/null
+++ b/app/api/routes-f/__tests__/loan-amortization.test.ts
@@ -0,0 +1,95 @@
+// @ts-nocheck
+/**
+ * @jest-environment node
+ */
+import { POST } from "../loan-amortization/route";
+import { NextRequest } from "next/server";
+
+function makeReq(body: unknown) {
+  return new NextRequest("http://localhost/api/routes-f/loan-amortization", {
+    method: "POST",
+    headers: { "content-type": "application/json" },
+    body: JSON.stringify(body),
+  });
+}
+
+describe("/api/routes-f/loan-amortization", () => {
+  it("computes basic loan schedule", async () => {
+    const res = await POST(
+      makeReq({ principal: 100000, annual_rate: 5, years: 30 })
+    );
+    expect(res.status).toBe(200);
+    const d = await res.json();
+    expect(d.monthly_payment).toBeCloseTo(536.82, 0);
+    // 360 months theoretical; rounding to cents can add 1 extra month
+    expect(d.payoff_months).toBeGreaterThanOrEqual(360);
+    expect(d.payoff_months).toBeLessThanOrEqual(362);
+    expect(Array.isArray(d.schedule)).toBe(true);
+    expect(d.schedule.length).toBe(d.payoff_months);
+    expect(d.schedule[0].month).toBe(1);
+    expect(d.schedule[d.payoff_months - 1].balance).toBe(0);
+  });
+
+  it("accelerates payoff with extra monthly payment", async () => {
+    const baseRes = await POST(
+      makeReq({ principal: 100000, annual_rate: 5, years: 30 })
+    );
+    const base = await baseRes.json();
+
+    const extraRes = await POST(
+      makeReq({
+        principal: 100000,
+        annual_rate: 5,
+        years: 30,
+        extra_monthly_payment: 200,
+      })
+    );
+    const extra = await extraRes.json();
+
+    expect(extra.payoff_months).toBeLessThan(base.payoff_months);
+    expect(extra.total_interest).toBeLessThan(base.total_interest);
+  });
+
+  it("handles zero interest rate", async () => {
+    const res = await POST(
+      makeReq({ principal: 12000, annual_rate: 0, years: 1 })
+    );
+    const d = await res.json();
+    expect(d.monthly_payment).toBe(1000);
+    expect(d.total_interest).toBe(0);
+  });
+
+  it("schedule first row has correct structure", async () => {
+    const res = await POST(
+      makeReq({ principal: 10000, annual_rate: 6, years: 1 })
+    );
+    const { schedule } = await res.json();
+    const row = schedule[0];
+    expect(typeof row.month).toBe("number");
+    expect(typeof row.payment).toBe("number");
+    expect(typeof row.principal).toBe("number");
+    expect(typeof row.interest).toBe("number");
+    expect(typeof row.balance).toBe("number");
+  });
+
+  it("rejects negative principal", async () => {
+    const res = await POST(
+      makeReq({ principal: -1000, annual_rate: 5, years: 10 })
+    );
+    expect(res.status).toBe(400);
+  });
+
+  it("rejects years > 50", async () => {
+    const res = await POST(
+      makeReq({ principal: 10000, annual_rate: 5, years: 51 })
+    );
+    expect(res.status).toBe(400);
+  });
+
+  it("rejects negative rate", async () => {
+    const res = await POST(
+      makeReq({ principal: 10000, annual_rate: -1, years: 10 })
+    );
+    expect(res.status).toBe(400);
+  });
+});
diff --git a/app/api/routes-f/__tests__/mortgage.test.ts b/app/api/routes-f/__tests__/mortgage.test.ts
new file mode 100644
index 00000000..05243528
--- /dev/null
+++ b/app/api/routes-f/__tests__/mortgage.test.ts
@@ -0,0 +1,167 @@
+// @ts-nocheck
+/**
+ * @jest-environment node
+ */
+import { POST } from "../mortgage/route";
+import { NextRequest } from "next/server";
+
+function makeReq(body: unknown) {
+  return new NextRequest("http://localhost/api/routes-f/mortgage", {
+    method: "POST",
+    headers: { "content-type": "application/json" },
+    body: JSON.stringify(body),
+  });
+}
+
+describe("/api/routes-f/mortgage", () => {
+  // --- Typical 30-year mortgage ---
+  it("computes typical 30-year mortgage", async () => {
+    const res = await POST(
+      makeReq({
+        home_price: 300000,
+        down_payment: 60000,
+        annual_rate: 6.5,
+        years: 30,
+      })
+    );
+    expect(res.status).toBe(200);
+    const d = await res.json();
+    expect(d.loan_amount).toBe(240000);
+    expect(d.monthly_principal_interest).toBeCloseTo(1517.09, 0);
+    expect(d.monthly_taxes).toBe(0);
+    expect(d.monthly_insurance).toBe(0);
+    expect(d.monthly_hoa).toBe(0);
+    expect(d.monthly_total).toBeCloseTo(1517.09, 0);
+    expect(d.total_interest).toBeGreaterThan(0);
+    expect(d.total_paid).toBeGreaterThan(d.loan_amount);
+    expect(d.ltv_ratio).toBe(80);
+    expect(typeof d.payoff_date).toBe("string");
+  });
+
+  // --- No extras (bare minimum) ---
+  it("computes mortgage with no extras", async () => {
+    const res = await POST(
+      makeReq({
+        home_price: 200000,
+        down_payment: 40000,
+        annual_rate: 5,
+        years: 15,
+      })
+    );
+    expect(res.status).toBe(200);
+    const d = await res.json();
+    expect(d.loan_amount).toBe(160000);
+    expect(d.monthly_taxes).toBe(0);
+    expect(d.monthly_insurance).toBe(0);
+    expect(d.monthly_hoa).toBe(0);
+    expect(d.ltv_ratio).toBe(80);
+  });
+
+  // --- With all fees ---
+  it("computes mortgage with all fees", async () => {
+    const res = await POST(
+      makeReq({
+        home_price: 400000,
+        down_payment: 80000,
+        annual_rate: 7,
+        years: 30,
+        property_tax_annual: 4800,
+        insurance_annual: 1200,
+        hoa_monthly: 300,
+      })
+    );
+    expect(res.status).toBe(200);
+    const d = await res.json();
+    expect(d.monthly_taxes).toBe(400);
+    expect(d.monthly_insurance).toBe(100);
+    expect(d.monthly_hoa).toBe(300);
+    expect(d.monthly_total).toBeGreaterThan(d.monthly_principal_interest);
+  });
+
+  // --- Zero interest rate ---
+  it("handles zero interest rate", async () => {
+    const res = await POST(
+      makeReq({
+        home_price: 120000,
+        down_payment: 0,
+        annual_rate: 0,
+        years: 10,
+      })
+    );
+    expect(res.status).toBe(200);
+    const d = await res.json();
+    expect(d.monthly_principal_interest).toBe(1000);
+    expect(d.total_interest).toBe(0);
+  });
+
+  // --- Validation: years > 50 ---
+  it("rejects years > 50", async () => {
+    const res = await POST(
+      makeReq({
+        home_price: 300000,
+        down_payment: 60000,
+        annual_rate: 6,
+        years: 51,
+      })
+    );
+    expect(res.status).toBe(400);
+  });
+
+  // --- Validation: negative home price ---
+  it("rejects negative home_price", async () => {
+    const res = await POST(
+      makeReq({
+        home_price: -100000,
+        down_payment: 0,
+        annual_rate: 5,
+        years: 30,
+      })
+    );
+    expect(res.status).toBe(400);
+  });
+
+  // --- Validation: down payment >= home price ---
+  it("rejects down_payment >= home_price", async () => {
+    const res = await POST(
+      makeReq({
+        home_price: 200000,
+        down_payment: 200000,
+        annual_rate: 5,
+        years: 30,
+      })
+    );
+    expect(res.status).toBe(400);
+  });
+
+  // --- Invalid JSON ---
+  it("rejects invalid JSON body", async () => {
+    const req = new NextRequest("http://localhost/api/routes-f/mortgage", {
+      method: "POST",
+      headers: { "content-type": "application/json" },
+      body: "not json",
+    });
+    const res = await POST(req);
+    expect(res.status).toBe(400);
+  });
+
+  // --- Cent precision check ---
+  it("returns cent precision (2 decimal places)", async () => {
+    const res = await POST(
+      makeReq({
+        home_price: 333333,
+        down_payment: 33333,
+        annual_rate: 4.375,
+        years: 30,
+      })
+    );
+    expect(res.status).toBe(200);
+    const d = await res.json();
+    const decimals = (n: number) => {
+      const parts = String(n).split(".");
+      return parts.length > 1 ? parts[1].length : 0;
+    };
+    expect(decimals(d.monthly_principal_interest)).toBeLessThanOrEqual(2);
+    expect(decimals(d.loan_amount)).toBeLessThanOrEqual(2);
+    expect(decimals(d.total_interest)).toBeLessThanOrEqual(2);
+  });
+});
diff --git a/app/api/routes-f/__tests__/nanoid.test.ts b/app/api/routes-f/__tests__/nanoid.test.ts
new file mode 100644
index 00000000..3d74c0eb
--- /dev/null
+++ b/app/api/routes-f/__tests__/nanoid.test.ts
@@ -0,0 +1,106 @@
+/**
+ * @jest-environment node
+ */
+import { NextRequest } from "next/server";
+import { POST } from "../nanoid/route";
+import { generateId } from "../nanoid/_lib/helpers";
+
+function makeReq(body: unknown) {
+  return new NextRequest("http://localhost/api/routes-f/nanoid", {
+    method: "POST",
+    headers: { "content-type": "application/json" },
+    body: JSON.stringify(body),
+  });
+}
+
+describe("generateId", () => {
+  it("returns a string of the requested size", () => {
+    expect(generateId(21, "abc123").length).toBe(21);
+    expect(generateId(10, "abc").length).toBe(10);
+    expect(generateId(1, "ab").length).toBe(1);
+  });
+
+  it("only uses characters from the given alphabet", () => {
+    const alphabet = "abc";
+    const id = generateId(100, alphabet);
+    for (const ch of id) {
+      expect(alphabet).toContain(ch);
+    }
+  });
+
+  it("generates unique IDs across many calls", () => {
+    const ids = new Set(Array.from({ length: 1000 }, () => generateId(21, "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789_-")));
+    expect(ids.size).toBe(1000);
+  });
+});
+
+describe("POST /api/routes-f/nanoid", () => {
+  it("returns 1 ID of length 21 with defaults", async () => {
+    const res = await POST(makeReq({}));
+    expect(res.status).toBe(200);
+    const { ids } = await res.json();
+    expect(ids).toHaveLength(1);
+    expect(ids[0]).toHaveLength(21);
+  });
+
+  it("respects custom count", async () => {
+    const res = await POST(makeReq({ count: 5 }));
+    expect(res.status).toBe(200);
+    const { ids } = await res.json();
+    expect(ids).toHaveLength(5);
+  });
+
+  it("respects custom size", async () => {
+    const res = await POST(makeReq({ size: 10 }));
+    expect(res.status).toBe(200);
+    const { ids } = await res.json();
+    expect(ids[0]).toHaveLength(10);
+  });
+
+  it("respects custom alphabet", async () => {
+    const alphabet = "01";
+    const res = await POST(makeReq({ size: 32, alphabet }));
+    expect(res.status).toBe(200);
+    const { ids } = await res.json();
+    for (const ch of ids[0]) {
+      expect(alphabet).toContain(ch);
+    }
+  });
+
+  it("generates unique IDs across 100 requests", async () => {
+    const res = await POST(makeReq({ count: 100 }));
+    expect(res.status).toBe(200);
+    const { ids } = await res.json();
+    expect(new Set(ids).size).toBe(100);
+  });
+
+  it("returns 400 when count exceeds 100", async () => {
+    const res = await POST(makeReq({ count: 101 }));
+    expect(res.status).toBe(400);
+  });
+
+  it("returns 400 when count is not a positive integer", async () => {
+    const res = await POST(makeReq({ count: 0 }));
+    expect(res.status).toBe(400);
+  });
+
+  it("returns 400 when size is not a positive integer", async () => {
+    const res = await POST(makeReq({ size: -1 }));
+    expect(res.status).toBe(400);
+  });
+
+  it("returns 400 when alphabet has fewer than 2 characters", async () => {
+    const res = await POST(makeReq({ alphabet: "a" }));
+    expect(res.status).toBe(400);
+  });
+
+  it("returns 400 for invalid JSON", async () => {
+    const req = new NextRequest("http://localhost/api/routes-f/nanoid", {
+      method: "POST",
+      headers: { "content-type": "application/json" },
+      body: "not json",
+    });
+    const res = await POST(req);
+    expect(res.status).toBe(400);
+  });
+});
diff --git a/app/api/routes-f/__tests__/nth-prime.test.ts b/app/api/routes-f/__tests__/nth-prime.test.ts
new file mode 100644
index 00000000..f0b77e38
--- /dev/null
+++ b/app/api/routes-f/__tests__/nth-prime.test.ts
@@ -0,0 +1,30 @@
+/**
+ * @jest-environment node
+ */
+import { NextRequest } from "next/server";
+import { GET } from "../nth-prime/route";
+
+test("/api/routes-f/nth-prime returns the tenth prime", async () => {
+  const req = new NextRequest("http://localhost/api/routes-f/nth-prime?n=10");
+  const res = await GET(req);
+
+  expect(res.status).toBe(200);
+  expect(await res.json()).toEqual({ n: 10, prime: 29 });
+});
+
+test("/api/routes-f/nth-prime returns the 100000th prime", async () => {
+  const req = new NextRequest("http://localhost/api/routes-f/nth-prime?n=100000");
+  const res = await GET(req);
+
+  expect(res.status).toBe(200);
+  expect(await res.json()).toEqual({ n: 100000, prime: 1299709 });
+});
+
+test("/api/routes-f/nth-prime rejects out-of-range values", async () => {
+  const req = new NextRequest("http://localhost/api/routes-f/nth-prime?n=0");
+  const res = await GET(req);
+
+  expect(res.status).toBe(400);
+  const data = await res.json();
+  expect(data.error).toMatch(/integer between 1 and 100000/i);
+});
diff --git a/app/api/routes-f/__tests__/pace.test.ts b/app/api/routes-f/__tests__/pace.test.ts
new file mode 100644
index 00000000..b6ae1747
--- /dev/null
+++ b/app/api/routes-f/__tests__/pace.test.ts
@@ -0,0 +1,120 @@
+// @ts-nocheck
+/**
+ * @jest-environment node
+ */
+import { POST } from "../pace/route";
+import { NextRequest } from "next/server";
+
+function makeReq(body: unknown) {
+  return new NextRequest("http://localhost/api/routes-f/pace", {
+    method: "POST",
+    headers: { "content-type": "application/json" },
+    body: JSON.stringify(body),
+  });
+}
+
+describe("/api/routes-f/pace", () => {
+  describe("mode: pace (distance + time → pace)", () => {
+    it("computes pace from 10km in 50:00", async () => {
+      const res = await POST(
+        makeReq({ mode: "pace", distance: 10, time: "00:50:00" })
+      );
+      expect(res.status).toBe(200);
+      const d = await res.json();
+      expect(d.pace).toBe("5:00 per km");
+    });
+
+    it("includes race splits", async () => {
+      const res = await POST(
+        makeReq({ mode: "pace", distance: 10, time: "01:00:00" })
+      );
+      const d = await res.json();
+      expect(d.race_splits["5K"]).toBeDefined();
+      expect(d.race_splits["Marathon"]).toBeDefined();
+    });
+  });
+
+  describe("mode: time (distance + pace → time)", () => {
+    it("computes time for 5km at 6:00/km", async () => {
+      const res = await POST(
+        makeReq({ mode: "time", distance: 5, pace: "6:00" })
+      );
+      expect(res.status).toBe(200);
+      const d = await res.json();
+      expect(d.time).toBe("00:30:00");
+    });
+
+    it("computes marathon time at 4:30/km pace", async () => {
+      const res = await POST(
+        makeReq({ mode: "time", distance: 42.195, pace: "4:30" })
+      );
+      const d = await res.json();
+      // 42.195 * 270s ≈ 11392.65s ≈ 3h 9m 52s
+      expect(d.time).toMatch(/^03:/);
+    });
+  });
+
+  describe("mode: distance (time + pace → distance)", () => {
+    it("computes distance for 1h at 5:00/km", async () => {
+      const res = await POST(
+        makeReq({ mode: "distance", time: "01:00:00", pace: "5:00" })
+      );
+      expect(res.status).toBe(200);
+      const d = await res.json();
+      expect(d.distance).toBeCloseTo(12, 0);
+    });
+  });
+
+  describe("mile unit support", () => {
+    it("computes pace in miles", async () => {
+      const res = await POST(
+        makeReq({ mode: "pace", distance: 6.2, time: "00:50:00", unit: "mi" })
+      );
+      expect(res.status).toBe(200);
+      const d = await res.json();
+      expect(d.pace).toContain("per mi");
+    });
+  });
+
+  describe("validation", () => {
+    it("rejects invalid mode", async () => {
+      const res = await POST(
+        makeReq({ mode: "speed", distance: 10, time: "00:50:00" })
+      );
+      expect(res.status).toBe(400);
+    });
+
+    it("rejects invalid unit", async () => {
+      const res = await POST(
+        makeReq({
+          mode: "pace",
+          distance: 10,
+          time: "00:50:00",
+          unit: "meters",
+        })
+      );
+      expect(res.status).toBe(400);
+    });
+
+    it("rejects invalid time format", async () => {
+      const res = await POST(
+        makeReq({ mode: "pace", distance: 10, time: "not-a-time" })
+      );
+      expect(res.status).toBe(400);
+    });
+
+    it("rejects invalid pace format", async () => {
+      const res = await POST(
+        makeReq({ mode: "time", distance: 10, pace: "fast" })
+      );
+      expect(res.status).toBe(400);
+    });
+
+    it("rejects zero distance", async () => {
+      const res = await POST(
+        makeReq({ mode: "pace", distance: 0, time: "00:30:00" })
+      );
+      expect(res.status).toBe(400);
+    });
+  });
+});
diff --git a/app/api/routes-f/__tests__/percentile.test.ts b/app/api/routes-f/__tests__/percentile.test.ts
new file mode 100644
index 00000000..525cafff
--- /dev/null
+++ b/app/api/routes-f/__tests__/percentile.test.ts
@@ -0,0 +1,74 @@
+// @ts-nocheck
+/**
+ * @jest-environment node
+ */
+import { POST } from "../percentile/route";
+import { NextRequest } from "next/server";
+
+function makeReq(body: unknown) {
+  return new NextRequest("http://localhost/api/routes-f/percentile", {
+    method: "POST",
+    headers: { "content-type": "application/json" },
+    body: JSON.stringify(body),
+  });
+}
+
+describe("/api/routes-f/percentile", () => {
+  it("computes p50 (median) from known dataset", async () => {
+    const res = await POST(
+      makeReq({ data: [1, 2, 3, 4, 5], percentiles: [50] })
+    );
+    expect(res.status).toBe(200);
+    const { results } = await res.json();
+    expect(results[0].percentile).toBe(50);
+    expect(results[0].value).toBe(3);
+  });
+
+  it("computes p0 and p100 (min and max)", async () => {
+    const res = await POST(
+      makeReq({ data: [10, 20, 30, 40, 50], percentiles: [0, 100] })
+    );
+    const { results } = await res.json();
+    expect(results[0].value).toBe(10);
+    expect(results[1].value).toBe(50);
+  });
+
+  it("uses linear interpolation for p25 and p75", async () => {
+    const res = await POST(
+      makeReq({ data: [1, 2, 3, 4], percentiles: [25, 75] })
+    );
+    const { results } = await res.json();
+    expect(results[0].value).toBeCloseTo(1.75, 5);
+    expect(results[1].value).toBeCloseTo(3.25, 5);
+  });
+
+  it("returns multiple percentiles in input order", async () => {
+    const res = await POST(
+      makeReq({ data: [1, 2, 3], percentiles: [90, 10, 50] })
+    );
+    const { results } = await res.json();
+    expect(results.map((r: { percentile: number }) => r.percentile)).toEqual([
+      90, 10, 50,
+    ]);
+  });
+
+  it("rejects empty data", async () => {
+    const res = await POST(makeReq({ data: [], percentiles: [50] }));
+    expect(res.status).toBe(400);
+  });
+
+  it("rejects empty percentiles array", async () => {
+    const res = await POST(makeReq({ data: [1, 2, 3], percentiles: [] }));
+    expect(res.status).toBe(400);
+  });
+
+  it("rejects percentile out of range", async () => {
+    const res = await POST(makeReq({ data: [1, 2, 3], percentiles: [101] }));
+    expect(res.status).toBe(400);
+  });
+
+  it("rejects non-numeric data values", async () => {
+    const res = await POST(makeReq({ data: [1, "two", 3], percentiles: [50] }));
+    expect(res.status).toBe(400);
+  });
+});
diff --git a/app/api/routes-f/__tests__/quadratic.test.ts b/app/api/routes-f/__tests__/quadratic.test.ts
new file mode 100644
index 00000000..2b8ab539
--- /dev/null
+++ b/app/api/routes-f/__tests__/quadratic.test.ts
@@ -0,0 +1,83 @@
+/**
+ * @jest-environment node
+ */
+import { NextRequest } from "next/server";
+import { POST } from "../quadratic/route";
+
+function makeReq(body: unknown) {
+  return new NextRequest("http://localhost/api/routes-f/quadratic", {
+    method: "POST",
+    headers: { "content-type": "application/json" },
+    body: JSON.stringify(body),
+  });
+}
+
+describe("/api/routes-f/quadratic", () => {
+  it("solves equation with two real distinct roots: x^2 - 5x + 6 = 0", async () => {
+    const res = await POST(makeReq({ a: 1, b: -5, c: 6 }));
+    expect(res.status).toBe(200);
+    const data = await res.json();
+    expect(data.has_complex_roots).toBe(false);
+    expect(data.discriminant).toBe(1);
+    const reals = data.roots.map((r: { real: number }) => r.real).sort();
+    expect(reals[0]).toBeCloseTo(2);
+    expect(reals[1]).toBeCloseTo(3);
+  });
+
+  it("solves equation with repeated root: x^2 - 2x + 1 = 0", async () => {
+    const res = await POST(makeReq({ a: 1, b: -2, c: 1 }));
+    expect(res.status).toBe(200);
+    const data = await res.json();
+    expect(data.has_complex_roots).toBe(false);
+    expect(data.discriminant).toBe(0);
+    expect(data.roots[0].real).toBeCloseTo(1);
+    expect(data.roots[1].real).toBeCloseTo(1);
+  });
+
+  it("solves equation with complex roots: x^2 + 1 = 0", async () => {
+    const res = await POST(makeReq({ a: 1, b: 0, c: 1 }));
+    expect(res.status).toBe(200);
+    const data = await res.json();
+    expect(data.has_complex_roots).toBe(true);
+    expect(data.discriminant).toBe(-4);
+    expect(data.roots[0].real).toBeCloseTo(0);
+    expect(data.roots[0].imaginary).toBeCloseTo(1);
+    expect(data.roots[1].imaginary).toBeCloseTo(-1);
+  });
+
+  it("returns correct vertex: x^2 - 4x + 3", async () => {
+    const res = await POST(makeReq({ a: 1, b: -4, c: 3 }));
+    expect(res.status).toBe(200);
+    const data = await res.json();
+    expect(data.vertex.x).toBeCloseTo(2);
+    expect(data.vertex.y).toBeCloseTo(-1);
+    expect(data.axis_of_symmetry).toBeCloseTo(2);
+  });
+
+  it("rejects a == 0 with 400", async () => {
+    const res = await POST(makeReq({ a: 0, b: 2, c: 1 }));
+    expect(res.status).toBe(400);
+    const data = await res.json();
+    expect(data.error).toMatch(/linear/i);
+  });
+
+  it("rejects non-finite values", async () => {
+    const res = await POST(makeReq({ a: Infinity, b: 1, c: 1 }));
+    expect(res.status).toBe(400);
+  });
+
+  it("rejects missing coefficients", async () => {
+    const res = await POST(makeReq({ a: 1, b: 2 }));
+    expect(res.status).toBe(400);
+  });
+
+  it("rejects invalid JSON", async () => {
+    const req = new NextRequest("http://localhost/api/routes-f/quadratic", {
+      method: "POST",
+      headers: { "content-type": "application/json" },
+      body: "bad",
+    });
+    const res = await POST(req);
+    expect(res.status).toBe(400);
+  });
+});
diff --git a/app/api/routes-f/__tests__/query-parse.test.ts b/app/api/routes-f/__tests__/query-parse.test.ts
new file mode 100644
index 00000000..c10b58b4
--- /dev/null
+++ b/app/api/routes-f/__tests__/query-parse.test.ts
@@ -0,0 +1,169 @@
+// @ts-nocheck
+/**
+ * @jest-environment node
+ */
+import { POST } from "../query-parse/route";
+import { NextRequest } from "next/server";
+
+function makeReq(body: unknown) {
+  return new NextRequest("http://localhost/api/routes-f/query-parse", {
+    method: "POST",
+    headers: { "content-type": "application/json" },
+    body: JSON.stringify(body),
+  });
+}
+
+describe("/api/routes-f/query-parse", () => {
+  // --- Parse: basic query string ---
+  it("parses basic query string", async () => {
+    const res = await POST(
+      makeReq({ mode: "parse", input: "foo=bar&baz=qux" })
+    );
+    expect(res.status).toBe(200);
+    const d = await res.json();
+    expect(d.result.foo).toBe("bar");
+    expect(d.result.baz).toBe("qux");
+  });
+
+  // --- Parse: leading ? is stripped ---
+  it("strips leading ? in parse mode", async () => {
+    const res = await POST(makeReq({ mode: "parse", input: "?foo=bar" }));
+    expect(res.status).toBe(200);
+    const d = await res.json();
+    expect(d.result.foo).toBe("bar");
+  });
+
+  // --- Parse: repeated keys become arrays ---
+  it("parses repeated keys as arrays", async () => {
+    const res = await POST(makeReq({ mode: "parse", input: "a=1&a=2&a=3" }));
+    expect(res.status).toBe(200);
+    const d = await res.json();
+    expect(d.result.a).toEqual(["1", "2", "3"]);
+  });
+
+  // --- Parse: nested objects via bracket notation ---
+  it("parses nested objects via bracket notation", async () => {
+    const res = await POST(
+      makeReq({ mode: "parse", input: "user[name]=john&user[age]=30" })
+    );
+    expect(res.status).toBe(200);
+    const d = await res.json();
+    expect(d.result.user).toEqual({ name: "john", age: "30" });
+  });
+
+  // --- Build: basic object to query string ---
+  it("builds basic query string from object", async () => {
+    const res = await POST(
+      makeReq({ mode: "build", input: { foo: "bar", baz: "qux" } })
+    );
+    expect(res.status).toBe(200);
+    const d = await res.json();
+    expect(d.result).toContain("foo=bar");
+    expect(d.result).toContain("baz=qux");
+  });
+
+  // --- Build: array with repeat format (default) ---
+  it("builds array with repeat format", async () => {
+    const res = await POST(
+      makeReq({
+        mode: "build",
+        input: { a: [1, 2, 3] },
+        options: { array_format: "repeat" },
+      })
+    );
+    expect(res.status).toBe(200);
+    const d = await res.json();
+    expect(d.result).toBe("a=1&a=2&a=3");
+  });
+
+  // --- Build: array with bracket format ---
+  it("builds array with bracket format", async () => {
+    const res = await POST(
+      makeReq({
+        mode: "build",
+        input: { a: [1, 2] },
+        options: { array_format: "bracket" },
+      })
+    );
+    expect(res.status).toBe(200);
+    const d = await res.json();
+    expect(d.result).toContain("a[]=1");
+    expect(d.result).toContain("a[]=2");
+  });
+
+  // --- Build: array with comma format ---
+  it("builds array with comma format", async () => {
+    const res = await POST(
+      makeReq({
+        mode: "build",
+        input: { colors: ["red", "green", "blue"] },
+        options: { array_format: "comma" },
+      })
+    );
+    expect(res.status).toBe(200);
+    const d = await res.json();
+    expect(d.result).toBe("colors=red,green,blue");
+  });
+
+  // --- Build: nested object ---
+  it("builds nested object with bracket notation", async () => {
+    const res = await POST(
+      makeReq({
+        mode: "build",
+        input: { user: { name: "john", age: "30" } },
+      })
+    );
+    expect(res.status).toBe(200);
+    const d = await res.json();
+    expect(d.result).toContain("user[name]=john");
+    expect(d.result).toContain("user[age]=30");
+  });
+
+  // --- Parse + Build round-trip ---
+  it("round-trips parse then build", async () => {
+    const original = "x=1&y=2&z=3";
+    const parseRes = await POST(makeReq({ mode: "parse", input: original }));
+    const parsed = await parseRes.json();
+
+    const buildRes = await POST(
+      makeReq({ mode: "build", input: parsed.result })
+    );
+    const built = await buildRes.json();
+
+    // Parse the built string to compare semantically
+    const reparseRes = await POST(
+      makeReq({ mode: "parse", input: built.result })
+    );
+    const reparsed = await reparseRes.json();
+    expect(reparsed.result).toEqual(parsed.result);
+  });
+
+  // --- Invalid mode ---
+  it("rejects invalid mode", async () => {
+    const res = await POST(makeReq({ mode: "invalid", input: "foo=bar" }));
+    expect(res.status).toBe(400);
+  });
+
+  // --- Parse: input not a string ---
+  it("rejects non-string input in parse mode", async () => {
+    const res = await POST(makeReq({ mode: "parse", input: { foo: "bar" } }));
+    expect(res.status).toBe(400);
+  });
+
+  // --- Build: input not an object ---
+  it("rejects non-object input in build mode", async () => {
+    const res = await POST(makeReq({ mode: "build", input: "foo=bar" }));
+    expect(res.status).toBe(400);
+  });
+
+  // --- Invalid JSON body ---
+  it("rejects invalid JSON body", async () => {
+    const req = new NextRequest("http://localhost/api/routes-f/query-parse", {
+      method: "POST",
+      headers: { "content-type": "application/json" },
+      body: "not json",
+    });
+    const res = await POST(req);
+    expect(res.status).toBe(400);
+  });
+});
diff --git a/app/api/routes-f/__tests__/quote.test.ts b/app/api/routes-f/__tests__/quote.test.ts
new file mode 100644
index 00000000..10313abd
--- /dev/null
+++ b/app/api/routes-f/__tests__/quote.test.ts
@@ -0,0 +1,217 @@
+// @ts-nocheck
+/**
+ * @jest-environment jsdom
+ */
+
+import { GET } from "../quote/route";
+import { NextRequest } from "next/server";
+
+// Mock the data module
+jest.mock("../quote/data", () => ({
+  getQuoteById: jest.fn(),
+  getRandomQuote: jest.fn(),
+  getDeterministicQuote: jest.fn(),
+  getCategories: jest.fn(),
+  quotes: [
+    {
+      id: 1,
+      text: "The best way to predict the future is to invent it.",
+      author: "Alan Kay",
+      category: "technology",
+      year: 1971,
+    },
+  ],
+}));
+
+const {
+  getQuoteById,
+  getRandomQuote,
+  getDeterministicQuote,
+  getCategories,
+  quotes,
+} = require("../quote/data");
+
+describe("/api/routes-f/quote", () => {
+  beforeEach(() => {
+    jest.clearAllMocks();
+  });
+
+  describe("GET /quote/[id]", () => {
+    it("should return quote by valid ID", async () => {
+      const mockQuote = {
+        id: 1,
+        text: "The best way to predict the future is to invent it.",
+        author: "Alan Kay",
+        category: "technology",
+        year: 1971,
+      };
+
+      getQuoteById.mockReturnValue(mockQuote);
+
+      const request = new NextRequest(
+        "http://localhost:3000/api/routes-f/quote/1"
+      );
+      const response = await GET(request, { params: { id: "1" } });
+      const data = await response.json();
+
+      expect(response.status).toBe(200);
+      expect(data).toEqual(mockQuote);
+      expect(getQuoteById).toHaveBeenCalledWith(1);
+    });
+
+    it("should return 404 for non-existent quote ID", async () => {
+      getQuoteById.mockReturnValue(undefined);
+
+      const request = new NextRequest(
+        "http://localhost:3000/api/routes-f/quote/999"
+      );
+      const response = await GET(request, { params: { id: "999" } });
+      const data = await response.json();
+
+      expect(response.status).toBe(404);
+      expect(data.error).toContain("Quote with ID 999 not found");
+    });
+
+    it("should return 400 for invalid quote ID format", async () => {
+      const request = new NextRequest(
+        "http://localhost:3000/api/routes-f/quote/invalid"
+      );
+      const response = await GET(request, { params: { id: "invalid" } });
+      const data = await response.json();
+
+      expect(response.status).toBe(400);
+      expect(data.error).toBe("Invalid quote ID format");
+    });
+  });
+
+  describe("GET /quote/today", () => {
+    it("should return deterministic quote for given date", async () => {
+      const mockQuote = {
+        id: 1,
+        text: "The best way to predict the future is to invent it.",
+        author: "Alan Kay",
+        category: "technology",
+        year: 1971,
+      };
+
+      getDeterministicQuote.mockReturnValue(mockQuote);
+
+      const request = new NextRequest(
+        "http://localhost:3000/api/routes-f/quote/today?date=2024-01-01"
+      );
+      const response = await GET(request);
+      const data = await response.json();
+
+      expect(response.status).toBe(200);
+      expect(data).toEqual(mockQuote);
+      expect(getDeterministicQuote).toHaveBeenCalledWith("2024-01-01");
+    });
+
+    it("should return deterministic quote for today when no date provided", async () => {
+      const mockQuote = {
+        id: 1,
+        text: "The best way to predict the future is to invent it.",
+        author: "Alan Kay",
+        category: "technology",
+        year: 1971,
+      };
+
+      getDeterministicQuote.mockReturnValue(mockQuote);
+
+      const request = new NextRequest(
+        "http://localhost:3000/api/routes-f/quote/today"
+      );
+      const response = await GET(request);
+      const data = await response.json();
+
+      expect(response.status).toBe(200);
+      expect(data).toEqual(mockQuote);
+      expect(getDeterministicQuote).toHaveBeenCalled();
+    });
+
+    it("should return 400 for invalid date format", async () => {
+      const request = new NextRequest(
+        "http://localhost:3000/api/routes-f/quote/today?date=invalid"
+      );
+      const response = await GET(request);
+      const data = await response.json();
+
+      expect(response.status).toBe(400);
+      expect(data.error).toContain("Invalid date format");
+    });
+  });
+
+  describe("GET /quote/random", () => {
+    it("should return random quote", async () => {
+      const mockQuote = {
+        id: 1,
+        text: "The best way to predict the future is to invent it.",
+        author: "Alan Kay",
+        category: "technology",
+        year: 1971,
+      };
+
+      getRandomQuote.mockReturnValue(mockQuote);
+
+      const request = new NextRequest(
+        "http://localhost:3000/api/routes-f/quote/random"
+      );
+      const response = await GET(request);
+      const data = await response.json();
+
+      expect(response.status).toBe(200);
+      expect(data).toEqual(mockQuote);
+      expect(getRandomQuote).toHaveBeenCalledWith(undefined);
+    });
+
+    it("should return random quote from specific category", async () => {
+      const mockQuote = {
+        id: 1,
+        text: "The best way to predict the future is to invent it.",
+        author: "Alan Kay",
+        category: "technology",
+        year: 1971,
+      };
+
+      getRandomQuote.mockReturnValue(mockQuote);
+
+      const request = new NextRequest(
+        "http://localhost:3000/api/routes-f/quote/random?category=technology"
+      );
+      const response = await GET(request);
+      const data = await response.json();
+
+      expect(response.status).toBe(200);
+      expect(data).toEqual(mockQuote);
+      expect(getRandomQuote).toHaveBeenCalledWith("technology");
+    });
+
+    it("should return 400 for invalid category", async () => {
+      getCategories.mockReturnValue(["technology", "inspiration"]);
+
+      const request = new NextRequest(
+        "http://localhost:3000/api/routes-f/quote/random?category=invalid"
+      );
+      const response = await GET(request);
+      const data = await response.json();
+
+      expect(response.status).toBe(400);
+      expect(data.error).toContain("Category 'invalid' not found");
+      expect(data.availableCategories).toEqual(["technology", "inspiration"]);
+    });
+  });
+
+  describe("GET /quote (list all)", () => {
+    it("should return all quotes", async () => {
+      const request = new NextRequest(
+        "http://localhost:3000/api/routes-f/quote"
+      );
+      const response = await GET(request);
+      const data = await response.json();
+
+      expect(response.status).toBe(200);
+      expect(data.quotes).toEqual(quotes);
+      expect(data.total).toBe(1);
+    });
+  });
+});
diff --git a/app/api/routes-f/__tests__/recent-tips.test.ts b/app/api/routes-f/__tests__/recent-tips.test.ts
new file mode 100644
index 00000000..8dc9e92c
--- /dev/null
+++ b/app/api/routes-f/__tests__/recent-tips.test.ts
@@ -0,0 +1,71 @@
+/**
+ * @jest-environment node
+ */
+import { NextRequest } from "next/server";
+import { GET } from "../tips/recent/route";
+
+function makeReq(query: string) {
+  return new NextRequest(`http://localhost/api/routes-f/tips/recent?${query}`);
+}
+
+describe("Recent Tips Feed API", () => {
+  it("should fail if creator_id is missing", async () => {
+    const req = makeReq("");
+    const res = await GET(req);
+    expect(res.status).toBe(400);
+    const data = await res.json();
+    expect(data.error).toBe("creator_id is required");
+  });
+
+  it("should return newest tips first with default limit of 20", async () => {
+    const req = makeReq("creator_id=creator-123");
+    const res = await GET(req);
+    expect(res.status).toBe(200);
+    const data = await res.json();
+
+    expect(Array.isArray(data.tips)).toBe(true);
+    expect(data.tips.length).toBe(20);
+
+    // Verify ordering is newest first
+    for (let i = 0; i < data.tips.length - 1; i++) {
+      const currentTs = new Date(data.tips[i].ts).getTime();
+      const nextTs = new Date(data.tips[i + 1].ts).getTime();
+      expect(currentTs).toBeGreaterThan(nextTs);
+    }
+
+    expect(data.next_cursor).toBe("20");
+  });
+
+  it("should respect limit parameter", async () => {
+    const req = makeReq("creator_id=creator-123&limit=5");
+    const res = await GET(req);
+    expect(res.status).toBe(200);
+    const data = await res.json();
+    expect(data.tips.length).toBe(5);
+    expect(data.next_cursor).toBe("5");
+  });
+
+  it("should correctly paginate using cursor", async () => {
+    // Page 1
+    const req1 = makeReq("creator_id=creator-123&limit=15");
+    const res1 = await GET(req1);
+    const data1 = await res1.json();
+    expect(data1.tips.length).toBe(15);
+    const cursor = data1.next_cursor;
+    expect(cursor).toBe("15");
+
+    // Page 2
+    const req2 = makeReq(`creator_id=creator-123&limit=15&cursor=${cursor}`);
+    const res2 = await GET(req2);
+    const data2 = await res2.json();
+    expect(data2.tips.length).toBe(15);
+    expect(data2.next_cursor).toBeNull();
+
+    // Verify all returned tips are distinct
+    const allHashes = new Set([
+      ...data1.tips.map((t: any) => t.tx_hash),
+      ...data2.tips.map((t: any) => t.tx_hash),
+    ]);
+    expect(allHashes.size).toBe(30);
+  });
+});
diff --git a/app/api/routes-f/__tests__/relative-date.test.ts b/app/api/routes-f/__tests__/relative-date.test.ts
new file mode 100644
index 00000000..0a2fc5c8
--- /dev/null
+++ b/app/api/routes-f/__tests__/relative-date.test.ts
@@ -0,0 +1,93 @@
+/**
+ * @jest-environment node
+ */
+import { NextRequest } from "next/server";
+import { POST } from "../relative-date/route";
+
+function makeReq(body: unknown) {
+  return new NextRequest("http://localhost/api/routes-f/relative-date", {
+    method: "POST",
+    headers: { "content-type": "application/json" },
+    body: JSON.stringify(body),
+  });
+}
+
+describe("/api/routes-f/relative-date", () => {
+  const mockNow = "2026-05-28T12:00:00.000Z";
+
+  it("parses tomorrow relative to now", async () => {
+    const res = await POST(makeReq({ text: "tomorrow", now: mockNow }));
+    expect(res.status).toBe(200);
+    const data = await res.json();
+    expect(data.resolved).toBe("2026-05-29T12:00:00.000Z");
+    expect(data.matched).toBe("tomorrow");
+  });
+
+  it("parses yesterday relative to now", async () => {
+    const res = await POST(makeReq({ text: "yesterday", now: mockNow }));
+    expect(res.status).toBe(200);
+    const data = await res.json();
+    expect(data.resolved).toBe("2026-05-27T12:00:00.000Z");
+    expect(data.matched).toBe("yesterday");
+  });
+
+  it("parses next monday relative to now (which is a Thursday)", async () => {
+    // 2026-05-28 is a Thursday.
+    // Next Monday should be 2026-06-01.
+    const res = await POST(makeReq({ text: "next monday", now: mockNow }));
+    expect(res.status).toBe(200);
+    const data = await res.json();
+    expect(data.resolved).toBe("2026-06-01T12:00:00.000Z");
+    expect(data.matched).toBe("next monday");
+  });
+
+  it("parses in 3 days relative to now", async () => {
+    const res = await POST(makeReq({ text: "in 3 days", now: mockNow }));
+    expect(res.status).toBe(200);
+    const data = await res.json();
+    expect(data.resolved).toBe("2026-05-31T12:00:00.000Z");
+    expect(data.matched).toBe("in 3 days");
+  });
+
+  it("parses 2 weeks ago relative to now", async () => {
+    const res = await POST(makeReq({ text: "2 weeks ago", now: mockNow }));
+    expect(res.status).toBe(200);
+    const data = await res.json();
+    expect(data.resolved).toBe("2026-05-14T12:00:00.000Z");
+    expect(data.matched).toBe("2 weeks ago");
+  });
+
+  it("rejects unparseable input with 400", async () => {
+    const res = await POST(makeReq({ text: "random string", now: mockNow }));
+    expect(res.status).toBe(400);
+    const data = await res.json();
+    expect(data.error).toContain("Unable to parse relative date");
+  });
+
+  it("rejects invalid now ISO string with 400", async () => {
+    const res = await POST(makeReq({ text: "tomorrow", now: "invalid-date" }));
+    expect(res.status).toBe(400);
+    const data = await res.json();
+    expect(data.error).toContain("now is not a valid date string");
+  });
+
+  it("rejects non-string text with 400", async () => {
+    const res = await POST(makeReq({ text: 123 }));
+    expect(res.status).toBe(400);
+    const data = await res.json();
+    expect(data.error).toContain("text must be a string");
+  });
+
+  it("uses the current system time if now is not provided", async () => {
+    const res = await POST(makeReq({ text: "tomorrow" }));
+    expect(res.status).toBe(200);
+    const data = await res.json();
+    expect(data.resolved).toBeDefined();
+    expect(data.matched).toBe("tomorrow");
+
+    // The resolved date should be roughly 24 hours from now
+    const resolvedTime = new Date(data.resolved).getTime();
+    const systemTomorrow = Date.now() + 24 * 60 * 60 * 1000;
+    expect(Math.abs(resolvedTime - systemTomorrow)).toBeLessThan(10000); // 10s tolerance
+  });
+});
diff --git a/app/api/routes-f/__tests__/retry-after.test.ts b/app/api/routes-f/__tests__/retry-after.test.ts
new file mode 100644
index 00000000..ca529376
--- /dev/null
+++ b/app/api/routes-f/__tests__/retry-after.test.ts
@@ -0,0 +1,65 @@
+/**
+ * @jest-environment node
+ */
+import { NextRequest } from 'next/server';
+import { POST } from '../retry-after/route';
+
+function makeReq(body: unknown) {
+  return new NextRequest('http://localhost/api/routes-f/retry-after', {
+    method: 'POST',
+    headers: { 'content-type': 'application/json' },
+    body: JSON.stringify(body),
+  });
+}
+
+describe('/api/routes-f/retry-after', () => {
+  it('parses integer seconds and returns the correct retry_at', async () => {
+    const res = await POST(
+      makeReq({ header: '120', now: '2026-05-27T12:00:00.000Z' })
+    );
+    expect(res.status).toBe(200);
+
+    const data = await res.json();
+    expect(data).toEqual({
+      delay_seconds: 120,
+      retry_at: '2026-05-27T12:02:00.000Z',
+    });
+  });
+
+  it('parses an HTTP-date and returns the future delay', async () => {
+    const res = await POST(
+      makeReq({
+        header: 'Fri, 28 May 2026 12:00:00 GMT',
+        now: '2026-05-27T12:00:00.000Z',
+      })
+    );
+    expect(res.status).toBe(200);
+
+    const data = await res.json();
+    expect(data).toEqual({
+      delay_seconds: 86400,
+      retry_at: '2026-05-28T12:00:00.000Z',
+    });
+  });
+
+  it('returns zero delay for a past HTTP-date', async () => {
+    const res = await POST(
+      makeReq({
+        header: 'Wed, 27 May 2026 11:00:00 GMT',
+        now: '2026-05-27T12:00:00.000Z',
+      })
+    );
+    expect(res.status).toBe(200);
+
+    const data = await res.json();
+    expect(data).toEqual({
+      delay_seconds: 0,
+      retry_at: '2026-05-27T11:00:00.000Z',
+    });
+  });
+
+  it('rejects malformed retry-after headers', async () => {
+    const res = await POST(makeReq({ header: 'not-a-date', now: '2026-05-27T12:00:00.000Z' }));
+    expect(res.status).toBe(400);
+  });
+});
diff --git a/app/api/routes-f/__tests__/robots-txt.test.ts b/app/api/routes-f/__tests__/robots-txt.test.ts
new file mode 100644
index 00000000..49cf3f3c
--- /dev/null
+++ b/app/api/routes-f/__tests__/robots-txt.test.ts
@@ -0,0 +1,50 @@
+/**
+ * @jest-environment node
+ */
+import { NextRequest } from "next/server";
+import { POST } from "../robots-txt/route";
+
+function makeReq(body: unknown) {
+  return new NextRequest("http://localhost/api/routes-f/robots-txt", {
+    method: "POST",
+    headers: { "content-type": "application/json" },
+    body: JSON.stringify(body),
+  });
+}
+
+describe("/api/routes-f/robots-txt", () => {
+  it("generates robots.txt for multiple agents", async () => {
+    const res = await POST(
+      makeReq({
+        rules: [
+          { user_agent: "*", allow: ["/"], disallow: ["/private"] },
+          { user_agent: "Googlebot", disallow: ["/no-google"] },
+        ],
+      })
+    );
+
+    expect(res.status).toBe(200);
+    const data = await res.json();
+    expect(data.robots_txt).toBe(
+      "User-agent: *\nAllow: /\nDisallow: /private\n\nUser-agent: Googlebot\nDisallow: /no-google\n"
+    );
+  });
+
+  it("includes a sitemap line when provided", async () => {
+    const res = await POST(
+      makeReq({
+        rules: [{ user_agent: "*", disallow: ["/drafts"] }],
+        sitemap: "https://example.com/sitemap.xml",
+      })
+    );
+
+    expect(res.status).toBe(200);
+    const data = await res.json();
+    expect(data.robots_txt).toContain("Sitemap: https://example.com/sitemap.xml");
+  });
+
+  it("rejects requests without at least one rule", async () => {
+    const res = await POST(makeReq({ rules: [] }));
+    expect(res.status).toBe(400);
+  });
+});
diff --git a/app/api/routes-f/__tests__/routesFResponse.test.ts b/app/api/routes-f/__tests__/routesFResponse.test.ts
new file mode 100644
index 00000000..cc5a5fb8
--- /dev/null
+++ b/app/api/routes-f/__tests__/routesFResponse.test.ts
@@ -0,0 +1,26 @@
+import { routesFSuccess, routesFError } from "../../routesF/response";
+import { ROUTES_F_API_VERSION } from "../../routesF/version"
+
+describe("Routes-F response wrapper", () => {
+  it("includes apiVersion in success response", async () => {
+    const res = routesFSuccess({ test: true });
+    const body = await res.json();
+
+    expect(body).toEqual({
+      apiVersion: ROUTES_F_API_VERSION,
+      success: true,
+      data: { test: true },
+    });
+  });
+
+  it("includes apiVersion in error response", async () => {
+    const res = routesFError("Error", 400);
+    const body = await res.json();
+
+    expect(body).toEqual({
+      apiVersion: ROUTES_F_API_VERSION,
+      success: false,
+      error: "Error",
+    });
+  });
+});
\ No newline at end of file
diff --git a/app/api/routes-f/__tests__/scientific-notation.test.ts b/app/api/routes-f/__tests__/scientific-notation.test.ts
new file mode 100644
index 00000000..2b3bbdd3
--- /dev/null
+++ b/app/api/routes-f/__tests__/scientific-notation.test.ts
@@ -0,0 +1,55 @@
+/**
+ * @jest-environment node
+ */
+import { NextRequest } from "next/server";
+import { POST } from "../scientific-notation/route";
+
+function makeReq(body: unknown) {
+  return new NextRequest("http://localhost/api/routes-f/scientific-notation", {
+    method: "POST",
+    headers: { "content-type": "application/json" },
+    body: JSON.stringify(body),
+  });
+}
+
+describe("/api/routes-f/scientific-notation", () => {
+  it("formats large numbers in scientific notation", async () => {
+    const res = await POST(makeReq({ mode: "format", value: 1230000, sig_figs: 3 }));
+    expect(res.status).toBe(200);
+    const data = await res.json();
+    expect(data.result).toBe("1.23e6");
+  });
+
+  it("parses scientific notation back to a number", async () => {
+    const res = await POST(makeReq({ mode: "parse", value: "1.23e6" }));
+    expect(res.status).toBe(200);
+    const data = await res.json();
+    expect(data.result).toBe(1230000);
+  });
+
+  it("formats small magnitudes", async () => {
+    const res = await POST(makeReq({ mode: "format", value: 0.0000012, sig_figs: 2 }));
+    expect(res.status).toBe(200);
+    const data = await res.json();
+    expect(data.result).toBe("1.2e-6");
+  });
+
+  it("formats and parses negative engineering notation", async () => {
+    const formatRes = await POST(
+      makeReq({ mode: "format", value: -4560, sig_figs: 3, style: "engineering" })
+    );
+    expect(formatRes.status).toBe(200);
+    const formatted = await formatRes.json();
+    expect(formatted.result).toBe("-4.56 k");
+
+    const parseRes = await POST(makeReq({ mode: "parse", value: "-4.56 k", style: "engineering" }));
+    expect(parseRes.status).toBe(200);
+    const parsed = await parseRes.json();
+    expect(parsed.result).toBeCloseTo(-4560);
+  });
+
+  it("rejects invalid modes", async () => {
+    const res = await POST(makeReq({ mode: "convert", value: 42 }));
+    expect(res.status).toBe(400);
+  });
+});
diff --git a/app/api/routes-f/__tests__/sitemap-xml.test.ts b/app/api/routes-f/__tests__/sitemap-xml.test.ts
new file mode 100644
index 00000000..75e68594
--- /dev/null
+++ b/app/api/routes-f/__tests__/sitemap-xml.test.ts
@@ -0,0 +1,130 @@
+/**
+ * @jest-environment node
+ */
+import { NextRequest } from "next/server";
+import { POST } from "../sitemap-xml/route";
+
+function makeReq(body: unknown) {
+  return new NextRequest("http://localhost/api/routes-f/sitemap-xml", {
+    method: "POST",
+    headers: { "content-type": "application/json" },
+    body: JSON.stringify(body),
+  });
+}
+
+describe("/api/routes-f/sitemap-xml", () => {
+  it("generates a valid sitemap with a single required loc", async () => {
+    const res = await POST(makeReq({ urls: [{ loc: "https://example.com/" }] }));
+    expect(res.status).toBe(200);
+    const { sitemap } = await res.json();
+    expect(sitemap).toContain('<?xml version="1.0" encoding="UTF-8"?>');
+    expect(sitemap).toContain("<urlset");
+    expect(sitemap).toContain("<loc>https://example.com/</loc>");
+    expect(sitemap).toContain("</urlset>");
+  });
+
+  it("includes optional fields when provided", async () => {
+    const res = await POST(
+      makeReq({
+        urls: [
+          {
+            loc: "https://example.com/page",
+            lastmod: "2024-01-15",
+            changefreq: "weekly",
+            priority: 0.8,
+          },
+        ],
+      })
+    );
+    expect(res.status).toBe(200);
+    const { sitemap } = await res.json();
+    expect(sitemap).toContain("<lastmod>2024-01-15</lastmod>");
+    expect(sitemap).toContain("<changefreq>weekly</changefreq>");
+    expect(sitemap).toContain("<priority>0.8</priority>");
+  });
+
+  it("omits optional fields when not provided", async () => {
+    const res = await POST(makeReq({ urls: [{ loc: "https://example.com/" }] }));
+    expect(res.status).toBe(200);
+    const { sitemap } = await res.json();
+    expect(sitemap).not.toContain("<lastmod>");
+    expect(sitemap).not.toContain("<changefreq>");
+    expect(sitemap).not.toContain("<priority>");
+  });
+
+  it("handles multiple URL entries", async () => {
+    const res = await POST(
+      makeReq({
+        urls: [
+          { loc: "https://example.com/" },
+          { loc: "https://example.com/about", priority: 0.5 },
+          { loc: "https://example.com/blog", changefreq: "daily" },
+        ],
+      })
+    );
+    expect(res.status).toBe(200);
+    const { sitemap } = await res.json();
+    expect((sitemap.match(/<url>/g) ?? []).length).toBe(3);
+  });
+
+  it("escapes XML special characters in loc", async () => {
+    const res = await POST(
+      makeReq({ urls: [{ loc: "https://example.com/path?a=1&b=2" }] })
+    );
+    expect(res.status).toBe(200);
+    const { sitemap } = await res.json();
+    expect(sitemap).toContain("&amp;");
+    expect(sitemap).not.toContain("&b=");
+  });
+
+  it("rejects invalid loc (not a URL)", async () => {
+    const res = await POST(makeReq({ urls: [{ loc: "not-a-url" }] }));
+    expect(res.status).toBe(400);
+  });
+
+  it("rejects priority outside [0, 1]", async () => {
+    const res = await POST(
+      makeReq({ urls: [{ loc: "https://example.com/", priority: 1.5 }] })
+    );
+    expect(res.status).toBe(400);
+  });
+
+  it("rejects invalid changefreq", async () => {
+    const res = await POST(
+      makeReq({ urls: [{ loc: "https://example.com/", changefreq: "sometimes" }] })
+    );
+    expect(res.status).toBe(400);
+  });
+
+  it("rejects empty urls array", async () => {
+    const res = await POST(makeReq({ urls: [] }));
+    expect(res.status).toBe(400);
+  });
+
+  it("rejects missing urls field", async () => {
+    const res = await POST(makeReq({}));
+    expect(res.status).toBe(400);
+  });
+
+  it("rejects invalid JSON body", async () => {
+    const req = new NextRequest("http://localhost/api/routes-f/sitemap-xml", {
+      method: "POST",
+      headers: { "content-type": "application/json" },
+      body: "not json",
+    });
+    const res = await POST(req);
+    expect(res.status).toBe(400);
+  });
+
+  it("accepts priority of exactly 0 and 1", async () => {
+    const res = await POST(
+      makeReq({
+        urls: [
+          { loc: "https://example.com/low", priority: 0 },
+          { loc: "https://example.com/high", priority: 1 },
+        ],
+      })
+    );
+    expect(res.status).toBe(200);
+  });
+});
diff --git a/app/api/routes-f/__tests__/stream-category-switch.test.ts b/app/api/routes-f/__tests__/stream-category-switch.test.ts
new file mode 100644
index 00000000..704569fe
--- /dev/null
+++ b/app/api/routes-f/__tests__/stream-category-switch.test.ts
@@ -0,0 +1,115 @@
+/**
+ * @jest-environment node
+ */
+import { NextRequest } from "next/server";
+import { POST, GET } from "../stream/category-switch/route";
+import { categoryTimelines } from "../stream/category-switch/store";
+
+function postReq(body: unknown) {
+  return new NextRequest(
+    "http://localhost/api/routes-f/stream/category-switch",
+    {
+      method: "POST",
+      headers: { "content-type": "application/json" },
+      body: JSON.stringify(body),
+    }
+  );
+}
+
+function getReq(streamId: string) {
+  return new NextRequest(
+    `http://localhost/api/routes-f/stream/category-switch?stream_id=${streamId}`
+  );
+}
+
+describe("/api/routes-f/stream/category-switch", () => {
+  beforeEach(() => {
+    categoryTimelines.clear();
+  });
+
+  describe("POST — switch category", () => {
+    it("switches to a valid category and returns previous + new", async () => {
+      const res = await POST(
+        postReq({ stream_id: "s1", category: "gaming" })
+      );
+      expect(res.status).toBe(200);
+      const data = await res.json();
+      expect(data.previous_category).toBe("none");
+      expect(data.new_category).toBe("gaming");
+      expect(data.switched_at).toBeDefined();
+    });
+
+    it("tracks successive category switches", async () => {
+      await POST(postReq({ stream_id: "s1", category: "gaming" }));
+      const res = await POST(
+        postReq({ stream_id: "s1", category: "music" })
+      );
+      const data = await res.json();
+      expect(data.previous_category).toBe("gaming");
+      expect(data.new_category).toBe("music");
+    });
+
+    it("rejects an unknown category", async () => {
+      const res = await POST(
+        postReq({ stream_id: "s1", category: "underwater-basket-weaving" })
+      );
+      expect(res.status).toBe(400);
+      const data = await res.json();
+      expect(data.error).toMatch(/Unknown category/);
+    });
+
+    it("rejects missing stream_id", async () => {
+      const res = await POST(postReq({ category: "gaming" }));
+      expect(res.status).toBe(400);
+    });
+
+    it("rejects missing category", async () => {
+      const res = await POST(postReq({ stream_id: "s1" }));
+      expect(res.status).toBe(400);
+    });
+
+    it("rejects invalid JSON body", async () => {
+      const req = new NextRequest(
+        "http://localhost/api/routes-f/stream/category-switch",
+        {
+          method: "POST",
+          headers: { "content-type": "application/json" },
+          body: "not json",
+        }
+      );
+      const res = await POST(req);
+      expect(res.status).toBe(400);
+    });
+  });
+
+  describe("GET — category timeline", () => {
+    it("returns empty timeline for a fresh stream", async () => {
+      const res = await GET(getReq("s1"));
+      expect(res.status).toBe(200);
+      const data = await res.json();
+      expect(data.timeline).toEqual([]);
+    });
+
+    it("returns full timeline after multiple switches", async () => {
+      await POST(postReq({ stream_id: "s1", category: "gaming" }));
+      await POST(postReq({ stream_id: "s1", category: "music" }));
+      await POST(postReq({ stream_id: "s1", category: "irl" }));
+
+      const res = await GET(getReq("s1"));
+      const data = await res.json();
+      expect(data.stream_id).toBe("s1");
+      expect(data.timeline).toHaveLength(3);
+      expect(data.timeline[0].category).toBe("gaming");
+      expect(data.timeline[1].category).toBe("music");
+      expect(data.timeline[2].category).toBe("irl");
+    });
+
+    it("rejects missing stream_id", async () => {
+      const req = new NextRequest(
+        "http://localhost/api/routes-f/stream/category-switch"
+      );
+      const res = await GET(req);
+      expect(res.status).toBe(400);
+    });
+  });
+});
diff --git a/app/api/routes-f/__tests__/stream-chat-restriction.test.ts b/app/api/routes-f/__tests__/stream-chat-restriction.test.ts
new file mode 100644
index 00000000..78a30125
--- /dev/null
+++ b/app/api/routes-f/__tests__/stream-chat-restriction.test.ts
@@ -0,0 +1,321 @@
+/**
+ * @jest-environment jsdom
+ */
+
+import { POST, DELETE, GET } from '../stream/chat/route';
+import { NextRequest } from 'next/server';
+
+import { chatRestrictionStore } from '../stream/chat/utils';
+
+describe('/api/routes-f/stream/chat', () => {
+  beforeEach(() => {
+    // Clear the in-memory store before each test
+    chatRestrictionStore.clear();
+  });
+
+  describe('POST', () => {
+    it('should enable chat restriction with default 10 minutes', async () => {
+      const request = new NextRequest('http://localhost:3000/api/routes-f/stream/chat', {
+        method: 'POST',
+        body: JSON.stringify({
+          stream_id: 'stream-123'
+        }),
+        headers: {
+          'Content-Type': 'application/json'
+        }
+      });
+
+      const response = await POST(request);
+      const data = await response.json();
+
+      expect(response.status).toBe(200);
+      expect(data.enabled).toBe(true);
+      expect(data.min_follow_minutes).toBe(10);
+    });
+
+    it('should enable chat restriction with custom threshold', async () => {
+      const request = new NextRequest('http://localhost:3000/api/routes-f/stream/chat', {
+        method: 'POST',
+        body: JSON.stringify({
+          stream_id: 'stream-123',
+          min_follow_minutes: 30
+        }),
+        headers: {
+          'Content-Type': 'application/json'
+        }
+      });
+
+      const response = await POST(request);
+      const data = await response.json();
+
+      expect(response.status).toBe(200);
+      expect(data.enabled).toBe(true);
+      expect(data.min_follow_minutes).toBe(30);
+    });
+
+    it('should validate min_follow_minutes is at least 1', async () => {
+      const request = new NextRequest('http://localhost:3000/api/routes-f/stream/chat', {
+        method: 'POST',
+        body: JSON.stringify({
+          stream_id: 'stream-123',
+          min_follow_minutes: 0
+        }),
+        headers: {
+          'Content-Type': 'application/json'
+        }
+      });
+
+      const response = await POST(request);
+      const data = await response.json();
+
+      expect(response.status).toBe(400);
+      expect(data.error).toBe('min_follow_minutes must be at least 1 minute');
+    });
+
+    it('should validate min_follow_minutes is an integer', async () => {
+      const request = new NextRequest('http://localhost:3000/api/routes-f/stream/chat', {
+        method: 'POST',
+        body: JSON.stringify({
+          stream_id: 'stream-123',
+          min_follow_minutes: 10.5
+        }),
+        headers: {
+          'Content-Type': 'application/json'
+        }
+      });
+
+      const response = await POST(request);
+      const data = await response.json();
+
+      expect(response.status).toBe(400);
+      expect(data.error).toBe('min_follow_minutes must be an integer');
+    });
+
+    it('should validate min_follow_minutes maximum (1 week)', async () => {
+      const request = new NextRequest('http://localhost:3000/api/routes-f/stream/chat', {
+        method: 'POST',
+        body: JSON.stringify({
+          stream_id: 'stream-123',
+          min_follow_minutes: 10081
+        }),
+        headers: {
+          'Content-Type': 'application/json'
+        }
+      });
+
+      const response = await POST(request);
+      const data = await response.json();
+
+      expect(response.status).toBe(400);
+      expect(data.error).toBe('min_follow_minutes must be at most 10080 minutes (1 week)');
+    });
+
+    it('should accept max valid value (10080 minutes)', async () => {
+      const request = new NextRequest('http://localhost:3000/api/routes-f/stream/chat', {
+        method: 'POST',
+        body: JSON.stringify({
+          stream_id: 'stream-123',
+          min_follow_minutes: 10080
+        }),
+        headers: {
+          'Content-Type': 'application/json'
+        }
+      });
+
+      const response = await POST(request);
+      const data = await response.json();
+
+      expect(response.status).toBe(200);
+      expect(data.min_follow_minutes).toBe(10080);
+    });
+
+    it('should return 400 for missing stream_id', async () => {
+      const request = new NextRequest('http://localhost:3000/api/routes-f/stream/chat', {
+        method: 'POST',
+        body: JSON.stringify({
+          min_follow_minutes: 10
+        }),
+        headers: {
+          'Content-Type': 'application/json'
+        }
+      });
+
+      const response = await POST(request);
+
+      expect(response.status).toBe(400);
+    });
+
+    it('should return 400 for invalid JSON', async () => {
+      const request = new NextRequest('http://localhost:3000/api/routes-f/stream/chat', {
+        method: 'POST',
+        body: 'invalid json',
+        headers: {
+          'Content-Type': 'application/json'
+        }
+      });
+
+      const response = await POST(request);
+
+      expect(response.status).toBe(400);
+    });
+  });
+
+  describe('DELETE', () => {
+    it('should disable chat restriction', async () => {
+      // First enable restriction
+      const postRequest = new NextRequest('http://localhost:3000/api/routes-f/stream/chat', {
+        method: 'POST',
+        body: JSON.stringify({
+          stream_id: 'stream-123',
+          min_follow_minutes: 10
+        }),
+        headers: {
+          'Content-Type': 'application/json'
+        }
+      });
+      await POST(postRequest);
+
+      // Then disable it
+      const deleteRequest = new NextRequest('http://localhost:3000/api/routes-f/stream/chat?stream_id=stream-123', {
+        method: 'DELETE'
+      });
+      const response = await DELETE(deleteRequest);
+      const data = await response.json();
+
+      expect(response.status).toBe(200);
+      expect(data.enabled).toBe(false);
+    });
+
+    it('should return 400 for missing stream_id', async () => {
+      const deleteRequest = new NextRequest('http://localhost:3000/api/routes-f/stream/chat', {
+        method: 'DELETE'
+      });
+      const response = await DELETE(deleteRequest);
+      const data = await response.json();
+
+      expect(response.status).toBe(400);
+      expect(data.error).toBe('stream_id is required');
+    });
+  });
+
+  describe('GET', () => {
+    it('should return current restriction state when enabled', async () => {
+      // Enable restriction
+      const postRequest = new NextRequest('http://localhost:3000/api/routes-f/stream/chat', {
+        method: 'POST',
+        body: JSON.stringify({
+          stream_id: 'stream-123',
+          min_follow_minutes: 15
+        }),
+        headers: {
+          'Content-Type': 'application/json'
+        }
+      });
+      await POST(postRequest);
+
+      // Get state
+      const getRequest = new NextRequest('http://localhost:3000/api/routes-f/stream/chat?stream_id=stream-123');
+      const response = await GET(getRequest);
+      const data = await response.json();
+
+      expect(response.status).toBe(200);
+      expect(data.enabled).toBe(true);
+      expect(data.min_follow_minutes).toBe(15);
+    });
+
+    it('should return disabled state when no restriction exists', async () => {
+      const getRequest = new NextRequest('http://localhost:3000/api/routes-f/stream/chat?stream_id=stream-456');
+      const response = await GET(getRequest);
+      const data = await response.json();
+
+      expect(response.status).toBe(200);
+      expect(data.enabled).toBe(false);
+      expect(data.min_follow_minutes).toBeUndefined();
+    });
+
+    it('should return 400 for missing stream_id', async () => {
+      const getRequest = new NextRequest('http://localhost:3000/api/routes-f/stream/chat');
+      const response = await GET(getRequest);
+      const data = await response.json();
+
+      expect(response.status).toBe(400);
+      expect(data.error).toBe('stream_id is required');
+    });
+
+    it('should handle toggle lifecycle (enable -> get -> disable -> get)', async () => {
+      const streamId = 'stream-123';
+
+      // Enable
+      const postRequest = new NextRequest('http://localhost:3000/api/routes-f/stream/chat', {
+        method: 'POST',
+        body: JSON.stringify({
+          stream_id: streamId,
+          min_follow_minutes: 20
+        }),
+        headers: {
+          'Content-Type': 'application/json'
+        }
+      });
+      let response = await POST(postRequest);
+      expect(response.status).toBe(200);
+
+      // Get - should be enabled
+      let getRequest = new NextRequest(`http://localhost:3000/api/routes-f/stream/chat?stream_id=${streamId}`);
+      response = await GET(getRequest);
+      let data = await response.json();
+      expect(data.enabled).toBe(true);
+      expect(data.min_follow_minutes).toBe(20);
+
+      // Disable
+      const deleteRequest = new NextRequest(`http://localhost:3000/api/routes-f/stream/chat?stream_id=${streamId}`, {
+        method: 'DELETE'
+      });
+      response = await DELETE(deleteRequest);
+      expect(response.status).toBe(200);
+
+      // Get - should be disabled
+      getRequest = new NextRequest(`http://localhost:3000/api/routes-f/stream/chat?stream_id=${streamId}`);
+      response = await GET(getRequest);
+      data = await response.json();
+      expect(data.enabled).toBe(false);
+    });
+
+    it('should update threshold when re-enabling with different value', async () => {
+      const streamId = 'stream-123';
+
+      // Enable with 10 minutes
+      const postRequest1 = new NextRequest('http://localhost:3000/api/routes-f/stream/chat', {
+        method: 'POST',
+        body: JSON.stringify({
+          stream_id: streamId,
+          min_follow_minutes: 10
+        }),
+        headers: {
+          'Content-Type': 'application/json'
+        }
+      });
+      await POST(postRequest1);
+
+      // Re-enable with 30 minutes
+      const postRequest2 = new NextRequest('http://localhost:3000/api/routes-f/stream/chat', {
+        method: 'POST',
+        body: JSON.stringify({
+          stream_id: streamId,
+          min_follow_minutes: 30
+        }),
+        headers: {
+          'Content-Type': 'application/json'
+        }
+      });
+      await POST(postRequest2);
+
+      // Get state
+      const getRequest = new NextRequest(`http://localhost:3000/api/routes-f/stream/chat?stream_id=${streamId}`);
+      const response = await GET(getRequest);
+      const data = await response.json();
+
+      expect(data.enabled).toBe(true);
+      expect(data.min_follow_minutes).toBe(30);
+    });
+  });
+});
diff --git a/app/api/routes-f/__tests__/stream-chat-timeout.test.ts b/app/api/routes-f/__tests__/stream-chat-timeout.test.ts
new file mode 100644
index 00000000..54b70143
--- /dev/null
+++ b/app/api/routes-f/__tests__/stream-chat-timeout.test.ts
@@ -0,0 +1,196 @@
+/**
+ * @jest-environment node
+ */
+import { NextRequest } from "next/server";
+import { POST, GET, DELETE } from "../stream/chat-timeout/route";
+import { timeoutStore } from "../stream/chat-timeout/store";
+
+function postReq(body: unknown) {
+  return new NextRequest(
+    "http://localhost/api/routes-f/stream/chat-timeout",
+    {
+      method: "POST",
+      headers: { "content-type": "application/json" },
+      body: JSON.stringify(body),
+    }
+  );
+}
+
+function getReq(streamId: string) {
+  return new NextRequest(
+    `http://localhost/api/routes-f/stream/chat-timeout?stream_id=${streamId}`
+  );
+}
+
+function deleteReq(body: unknown) {
+  return new NextRequest(
+    "http://localhost/api/routes-f/stream/chat-timeout",
+    {
+      method: "DELETE",
+      headers: { "content-type": "application/json" },
+      body: JSON.stringify(body),
+    }
+  );
+}
+
+describe("/api/routes-f/stream/chat-timeout", () => {
+  beforeEach(() => {
+    timeoutStore.clear();
+  });
+
+  describe("POST — apply timeout", () => {
+    it("applies a timeout and returns expires_at", async () => {
+      const res = await POST(
+        postReq({
+          stream_id: "s1",
+          user_id: "u1",
+          seconds: 300,
+          reason: "spamming",
+        })
+      );
+      expect(res.status).toBe(200);
+      const data = await res.json();
+      expect(data.expires_at).toBeDefined();
+      const expiresAt = new Date(data.expires_at).getTime();
+      expect(expiresAt).toBeGreaterThan(Date.now());
+    });
+
+    it("allows optional reason to be omitted", async () => {
+      const res = await POST(
+        postReq({ stream_id: "s1", user_id: "u1", seconds: 60 })
+      );
+      expect(res.status).toBe(200);
+    });
+
+    it("rejects seconds below 1", async () => {
+      const res = await POST(
+        postReq({ stream_id: "s1", user_id: "u1", seconds: 0 })
+      );
+      expect(res.status).toBe(400);
+    });
+
+    it("rejects seconds above 86400", async () => {
+      const res = await POST(
+        postReq({ stream_id: "s1", user_id: "u1", seconds: 86401 })
+      );
+      expect(res.status).toBe(400);
+    });
+
+    it("rejects non-integer seconds", async () => {
+      const res = await POST(
+        postReq({ stream_id: "s1", user_id: "u1", seconds: 1.5 })
+      );
+      expect(res.status).toBe(400);
+    });
+
+    it("rejects missing stream_id", async () => {
+      const res = await POST(
+        postReq({ user_id: "u1", seconds: 60 })
+      );
+      expect(res.status).toBe(400);
+    });
+
+    it("rejects missing user_id", async () => {
+      const res = await POST(
+        postReq({ stream_id: "s1", seconds: 60 })
+      );
+      expect(res.status).toBe(400);
+    });
+
+    it("rejects missing seconds", async () => {
+      const res = await POST(
+        postReq({ stream_id: "s1", user_id: "u1" })
+      );
+      expect(res.status).toBe(400);
+    });
+  });
+
+  describe("GET — list active timeouts", () => {
+    it("returns empty list when no timeouts", async () => {
+      const res = await GET(getReq("s1"));
+      expect(res.status).toBe(200);
+      const data = await res.json();
+      expect(data.timeouts).toEqual([]);
+    });
+
+    it("returns active timeouts with seconds_remaining", async () => {
+      await POST(
+        postReq({
+          stream_id: "s1",
+          user_id: "u1",
+          seconds: 600,
+          reason: "spam",
+        })
+      );
+      await POST(
+        postReq({ stream_id: "s1", user_id: "u2", seconds: 300 })
+      );
+
+      const res = await GET(getReq("s1"));
+      const data = await res.json();
+      expect(data.stream_id).toBe("s1");
+      expect(data.timeouts).toHaveLength(2);
+      expect(data.timeouts[0].seconds_remaining).toBeGreaterThan(0);
+    });
+
+    it("filters out expired timeouts automatically", async () => {
+      // Manually insert an already-expired entry
+      timeoutStore.set("s1:u-expired", {
+        stream_id: "s1",
+        user_id: "u-expired",
+        expires_at: new Date(Date.now() - 1000).toISOString(),
+      });
+
+      const res = await GET(getReq("s1"));
+      const data = await res.json();
+      expect(data.timeouts).toHaveLength(0);
+    });
+
+    it("rejects missing stream_id", async () => {
+      const req = new NextRequest(
+        "http://localhost/api/routes-f/stream/chat-timeout"
+      );
+      const res = await GET(req);
+      expect(res.status).toBe(400);
+    });
+  });
+
+  describe("DELETE — lift timeout", () => {
+    it("lifts an active timeout", async () => {
+      await POST(
+        postReq({ stream_id: "s1", user_id: "u1", seconds: 300 })
+      );
+
+      const res = await DELETE(
+        deleteReq({ stream_id: "s1", user_id: "u1" })
+      );
+      expect(res.status).toBe(200);
+      const data = await res.json();
+      expect(data.lifted).toBe(true);
+
+      // Verify it's gone
+      const getRes = await GET(getReq("s1"));
+      const getData = await getRes.json();
+      expect(getData.timeouts).toHaveLength(0);
+    });
+
+    it("returns lifted=false when no timeout exists", async () => {
+      const res = await DELETE(
+        deleteReq({ stream_id: "s1", user_id: "u-none" })
+      );
+      expect(res.status).toBe(200);
+      const data = await res.json();
+      expect(data.lifted).toBe(false);
+    });
+
+    it("rejects missing stream_id", async () => {
+      const res = await DELETE(deleteReq({ user_id: "u1" }));
+      expect(res.status).toBe(400);
+    });
+
+    it("rejects missing user_id", async () => {
+      const res = await DELETE(deleteReq({ stream_id: "s1" }));
+      expect(res.status).toBe(400);
+    });
+  });
+});
diff --git a/app/api/routes-f/__tests__/stream-intermission.test.ts b/app/api/routes-f/__tests__/stream-intermission.test.ts
new file mode 100644
index 00000000..d695ed5e
--- /dev/null
+++ b/app/api/routes-f/__tests__/stream-intermission.test.ts
@@ -0,0 +1,274 @@
+/**
+ * @jest-environment jsdom
+ */
+
+import { POST, DELETE, GET } from '../stream/intermission/route';
+import { NextRequest } from 'next/server';
+
+import { intermissionStore } from '../stream/intermission/utils';
+
+describe('/api/routes-f/stream/intermission', () => {
+  beforeEach(() => {
+    // Clear the in-memory store before each test
+    intermissionStore.clear();
+  });
+
+  describe('POST', () => {
+    it('should create an intermission with message', async () => {
+      const request = new NextRequest('http://localhost:3000/api/routes-f/stream/intermission', {
+        method: 'POST',
+        body: JSON.stringify({
+          stream_id: 'stream-123',
+          message: 'Be right back!'
+        }),
+        headers: {
+          'Content-Type': 'application/json'
+        }
+      });
+
+      const response = await POST(request);
+      const data = await response.json();
+
+      expect(response.status).toBe(200);
+      expect(data.active).toBe(true);
+    });
+
+    it('should create an intermission with ends_at timer', async () => {
+      const endsAt = new Date(Date.now() + 300000).toISOString(); // 5 minutes from now
+      const request = new NextRequest('http://localhost:3000/api/routes-f/stream/intermission', {
+        method: 'POST',
+        body: JSON.stringify({
+          stream_id: 'stream-123',
+          message: 'Short break',
+          ends_at: endsAt
+        }),
+        headers: {
+          'Content-Type': 'application/json'
+        }
+      });
+
+      const response = await POST(request);
+      const data = await response.json();
+
+      expect(response.status).toBe(200);
+      expect(data.active).toBe(true);
+    });
+
+    it('should return 400 for invalid ends_at format', async () => {
+      const request = new NextRequest('http://localhost:3000/api/routes-f/stream/intermission', {
+        method: 'POST',
+        body: JSON.stringify({
+          stream_id: 'stream-123',
+          message: 'Break',
+          ends_at: 'invalid-date'
+        }),
+        headers: {
+          'Content-Type': 'application/json'
+        }
+      });
+
+      const response = await POST(request);
+      const data = await response.json();
+
+      expect(response.status).toBe(400);
+      expect(data.error).toBe('ends_at must be a valid ISO date');
+    });
+
+    it('should return 400 for missing stream_id', async () => {
+      const request = new NextRequest('http://localhost:3000/api/routes-f/stream/intermission', {
+        method: 'POST',
+        body: JSON.stringify({
+          message: 'Break'
+        }),
+        headers: {
+          'Content-Type': 'application/json'
+        }
+      });
+
+      const response = await POST(request);
+
+      expect(response.status).toBe(400);
+    });
+
+    it('should return 400 for missing message', async () => {
+      const request = new NextRequest('http://localhost:3000/api/routes-f/stream/intermission', {
+        method: 'POST',
+        body: JSON.stringify({
+          stream_id: 'stream-123'
+        }),
+        headers: {
+          'Content-Type': 'application/json'
+        }
+      });
+
+      const response = await POST(request);
+
+      expect(response.status).toBe(400);
+    });
+
+    it('should return 400 for invalid JSON', async () => {
+      const request = new NextRequest('http://localhost:3000/api/routes-f/stream/intermission', {
+        method: 'POST',
+        body: 'invalid json',
+        headers: {
+          'Content-Type': 'application/json'
+        }
+      });
+
+      const response = await POST(request);
+
+      expect(response.status).toBe(400);
+    });
+  });
+
+  describe('DELETE', () => {
+    it('should clear an active intermission', async () => {
+      // First create an intermission
+      const postRequest = new NextRequest('http://localhost:3000/api/routes-f/stream/intermission', {
+        method: 'POST',
+        body: JSON.stringify({
+          stream_id: 'stream-123',
+          message: 'Break'
+        }),
+        headers: {
+          'Content-Type': 'application/json'
+        }
+      });
+      await POST(postRequest);
+
+      // Then delete it
+      const deleteRequest = new NextRequest('http://localhost:3000/api/routes-f/stream/intermission?stream_id=stream-123', {
+        method: 'DELETE'
+      });
+      const response = await DELETE(deleteRequest);
+      const data = await response.json();
+
+      expect(response.status).toBe(200);
+      expect(data.active).toBe(false);
+    });
+
+    it('should return 400 for missing stream_id', async () => {
+      const deleteRequest = new NextRequest('http://localhost:3000/api/routes-f/stream/intermission', {
+        method: 'DELETE'
+      });
+      const response = await DELETE(deleteRequest);
+      const data = await response.json();
+
+      expect(response.status).toBe(400);
+      expect(data.error).toBe('stream_id is required');
+    });
+  });
+
+  describe('GET', () => {
+    it('should return active intermission state', async () => {
+      // Create an intermission
+      const postRequest = new NextRequest('http://localhost:3000/api/routes-f/stream/intermission', {
+        method: 'POST',
+        body: JSON.stringify({
+          stream_id: 'stream-123',
+          message: 'Be right back!'
+        }),
+        headers: {
+          'Content-Type': 'application/json'
+        }
+      });
+      await POST(postRequest);
+
+      // Get the state
+      const getRequest = new NextRequest('http://localhost:3000/api/routes-f/stream/intermission?stream_id=stream-123');
+      const response = await GET(getRequest);
+      const data = await response.json();
+
+      expect(response.status).toBe(200);
+      expect(data.active).toBe(true);
+      expect(data.message).toBe('Be right back!');
+      expect(data.ends_at).toBeUndefined();
+      expect(data.seconds_remaining).toBeUndefined();
+    });
+
+    it('should return intermission with countdown when ends_at is set', async () => {
+      const endsAt = new Date(Date.now() + 120000).toISOString(); // 2 minutes from now
+      const postRequest = new NextRequest('http://localhost:3000/api/routes-f/stream/intermission', {
+        method: 'POST',
+        body: JSON.stringify({
+          stream_id: 'stream-123',
+          message: 'Short break',
+          ends_at: endsAt
+        }),
+        headers: {
+          'Content-Type': 'application/json'
+        }
+      });
+      await POST(postRequest);
+
+      const getRequest = new NextRequest('http://localhost:3000/api/routes-f/stream/intermission?stream_id=stream-123');
+      const response = await GET(getRequest);
+      const data = await response.json();
+
+      expect(response.status).toBe(200);
+      expect(data.active).toBe(true);
+      expect(data.message).toBe('Short break');
+      expect(data.ends_at).toBe(endsAt);
+      expect(data.seconds_remaining).toBeGreaterThan(0);
+      expect(data.seconds_remaining).toBeLessThanOrEqual(120);
+    });
+
+    it('should return inactive state when no intermission exists', async () => {
+      const getRequest = new NextRequest('http://localhost:3000/api/routes-f/stream/intermission?stream_id=stream-456');
+      const response = await GET(getRequest);
+      const data = await response.json();
+
+      expect(response.status).toBe(200);
+      expect(data.active).toBe(false);
+      expect(data.message).toBeUndefined();
+      expect(data.ends_at).toBeUndefined();
+      expect(data.seconds_remaining).toBeUndefined();
+    });
+
+    it('should return 400 for missing stream_id', async () => {
+      const getRequest = new NextRequest('http://localhost:3000/api/routes-f/stream/intermission');
+      const response = await GET(getRequest);
+      const data = await response.json();
+
+      expect(response.status).toBe(400);
+      expect(data.error).toBe('stream_id is required');
+    });
+
+    it('should handle intermission lifecycle (create -> get -> delete -> get)', async () => {
+      const streamId = 'stream-123';
+
+      // Create
+      const postRequest = new NextRequest('http://localhost:3000/api/routes-f/stream/intermission', {
+        method: 'POST',
+        body: JSON.stringify({
+          stream_id: streamId,
+          message: 'Lifecycle test'
+        }),
+        headers: {
+          'Content-Type': 'application/json'
+        }
+      });
+      let response = await POST(postRequest);
+      expect(response.status).toBe(200);
+
+      // Get - should be active
+      let getRequest = new NextRequest(`http://localhost:3000/api/routes-f/stream/intermission?stream_id=${streamId}`);
+      response = await GET(getRequest);
+      let data = await response.json();
+      expect(data.active).toBe(true);
+
+      // Delete
+      const deleteRequest = new NextRequest(`http://localhost:3000/api/routes-f/stream/intermission?stream_id=${streamId}`, {
+        method: 'DELETE'
+      });
+      response = await DELETE(deleteRequest);
+      expect(response.status).toBe(200);
+
+      // Get - should be inactive
+      getRequest = new NextRequest(`http://localhost:3000/api/routes-f/stream/intermission?stream_id=${streamId}`);
+      response = await GET(getRequest);
+      data = await response.json();
+      expect(data.active).toBe(false);
+    });
+  });
+});
diff --git a/app/api/routes-f/__tests__/stream-pinned-message.test.ts b/app/api/routes-f/__tests__/stream-pinned-message.test.ts
new file mode 100644
index 00000000..d96b66db
--- /dev/null
+++ b/app/api/routes-f/__tests__/stream-pinned-message.test.ts
@@ -0,0 +1,232 @@
+/**
+ * @jest-environment node
+ */
+import { NextRequest } from "next/server";
+import { POST, DELETE, GET } from "../stream/pinned-message/route";
+import { pinnedMessages } from "../stream/pinned-message/store";
+
+function postReq(body: unknown) {
+  return new NextRequest(
+    "http://localhost/api/routes-f/stream/pinned-message",
+    {
+      method: "POST",
+      headers: { "content-type": "application/json" },
+      body: JSON.stringify(body),
+    }
+  );
+}
+
+function getReq(streamId: string) {
+  return new NextRequest(
+    `http://localhost/api/routes-f/stream/pinned-message?stream_id=${streamId}`
+  );
+}
+
+function deleteReq(streamId: string) {
+  return new NextRequest(
+    `http://localhost/api/routes-f/stream/pinned-message?stream_id=${streamId}`,
+    { method: "DELETE" }
+  );
+}
+
+describe("/api/routes-f/stream/pinned-message", () => {
+  beforeEach(() => {
+    pinnedMessages.clear();
+  });
+
+  describe("POST — pin a message", () => {
+    it("pins a message and returns pinned_at", async () => {
+      const res = await POST(
+        postReq({
+          stream_id: "s1",
+          message_id: "msg-1",
+          message_text: "Hello everyone!",
+          pinned_by: "mod-1",
+        })
+      );
+      expect(res.status).toBe(200);
+      const data = await res.json();
+      expect(data.pinned_at).toBeDefined();
+      expect(data.expires_at).toBeUndefined();
+    });
+
+    it("returns expires_at when provided", async () => {
+      const expiresAt = new Date(Date.now() + 60000).toISOString();
+      const res = await POST(
+        postReq({
+          stream_id: "s1",
+          message_id: "msg-1",
+          message_text: "Limited pin",
+          pinned_by: "mod-1",
+          expires_at: expiresAt,
+        })
+      );
+      expect(res.status).toBe(200);
+      const data = await res.json();
+      expect(data.expires_at).toBe(expiresAt);
+    });
+
+    it("replaces the previous pin (only most recent is active)", async () => {
+      await POST(
+        postReq({
+          stream_id: "s1",
+          message_id: "msg-1",
+          message_text: "First pin",
+          pinned_by: "mod-1",
+        })
+      );
+      await POST(
+        postReq({
+          stream_id: "s1",
+          message_id: "msg-2",
+          message_text: "Second pin",
+          pinned_by: "mod-2",
+        })
+      );
+
+      const res = await GET(getReq("s1"));
+      const data = await res.json();
+      expect(data.pin.message_id).toBe("msg-2");
+      expect(data.pin.message_text).toBe("Second pin");
+    });
+
+    it("rejects missing stream_id", async () => {
+      const res = await POST(
+        postReq({
+          message_id: "m1",
+          message_text: "t",
+          pinned_by: "u1",
+        })
+      );
+      expect(res.status).toBe(400);
+    });
+
+    it("rejects missing message_id", async () => {
+      const res = await POST(
+        postReq({
+          stream_id: "s1",
+          message_text: "t",
+          pinned_by: "u1",
+        })
+      );
+      expect(res.status).toBe(400);
+    });
+
+    it("rejects missing message_text", async () => {
+      const res = await POST(
+        postReq({
+          stream_id: "s1",
+          message_id: "m1",
+          pinned_by: "u1",
+        })
+      );
+      expect(res.status).toBe(400);
+    });
+
+    it("rejects missing pinned_by", async () => {
+      const res = await POST(
+        postReq({
+          stream_id: "s1",
+          message_id: "m1",
+          message_text: "t",
+        })
+      );
+      expect(res.status).toBe(400);
+    });
+
+    it("rejects invalid expires_at", async () => {
+      const res = await POST(
+        postReq({
+          stream_id: "s1",
+          message_id: "m1",
+          message_text: "t",
+          pinned_by: "u1",
+          expires_at: "not-a-date",
+        })
+      );
+      expect(res.status).toBe(400);
+    });
+  });
+
+  describe("DELETE — unpin", () => {
+    it("unpins the current message", async () => {
+      await POST(
+        postReq({
+          stream_id: "s1",
+          message_id: "msg-1",
+          message_text: "Pin",
+          pinned_by: "mod-1",
+        })
+      );
+
+      const delRes = await DELETE(deleteReq("s1"));
+      expect(delRes.status).toBe(200);
+      expect((await delRes.json()).unpinned).toBe(true);
+
+      const getRes = await GET(getReq("s1"));
+      const data = await getRes.json();
+      expect(data.pin).toBeNull();
+    });
+
+    it("rejects missing stream_id", async () => {
+      const req = new NextRequest(
+        "http://localhost/api/routes-f/stream/pinned-message",
+        { method: "DELETE" }
+      );
+      const res = await DELETE(req);
+      expect(res.status).toBe(400);
+    });
+  });
+
+  describe("GET — get current pin", () => {
+    it("returns null when no pin exists", async () => {
+      const res = await GET(getReq("s1"));
+      expect(res.status).toBe(200);
+      const data = await res.json();
+      expect(data.pin).toBeNull();
+    });
+
+    it("returns the current pin", async () => {
+      await POST(
+        postReq({
+          stream_id: "s1",
+          message_id: "msg-1",
+          message_text: "Pinned!",
+          pinned_by: "mod-1",
+        })
+      );
+
+      const res = await GET(getReq("s1"));
+      const data = await res.json();
+      expect(data.pin.message_id).toBe("msg-1");
+      expect(data.pin.message_text).toBe("Pinned!");
+      expect(data.pin.pinned_by).toBe("mod-1");
+      expect(data.pin.pinned_at).toBeDefined();
+    });
+
+    it("auto-clears an expired pin", async () => {
+      const pastDate = new Date(Date.now() - 1000).toISOString();
+      await POST(
+        postReq({
+          stream_id: "s1",
+          message_id: "msg-1",
+          message_text: "Expired",
+          pinned_by: "mod-1",
+          expires_at: pastDate,
+        })
+      );
+
+      const res = await GET(getReq("s1"));
+      const data = await res.json();
+      expect(data.pin).toBeNull();
+    });
+
+    it("rejects missing stream_id", async () => {
+      const req = new NextRequest(
+        "http://localhost/api/routes-f/stream/pinned-message"
+      );
+      const res = await GET(req);
+      expect(res.status).toBe(400);
+    });
+  });
+});
diff --git a/app/api/routes-f/__tests__/stream-tags.test.ts b/app/api/routes-f/__tests__/stream-tags.test.ts
new file mode 100644
index 00000000..6556e499
--- /dev/null
+++ b/app/api/routes-f/__tests__/stream-tags.test.ts
@@ -0,0 +1,248 @@
+/**
+ * @jest-environment jsdom
+ */
+
+import { POST, GET } from '../stream/tags/route';
+import { NextRequest } from 'next/server';
+
+import { streamTagsStore } from '../stream/tags/utils';
+
+describe('/api/routes-f/stream/tags', () => {
+  beforeEach(() => {
+    // Clear the in-memory store before each test
+    streamTagsStore.clear();
+  });
+
+  describe('POST', () => {
+    it('should add tags to a stream', async () => {
+      const request = new NextRequest('http://localhost:3000/api/routes-f/stream/tags', {
+        method: 'POST',
+        body: JSON.stringify({
+          stream_id: 'stream-123',
+          add: ['gaming', 'fps']
+        }),
+        headers: {
+          'Content-Type': 'application/json'
+        }
+      });
+
+      const response = await POST(request);
+      const data = await response.json();
+
+      expect(response.status).toBe(200);
+      expect(data.tags).toEqual(['gaming', 'fps']);
+    });
+
+    it('should normalize tags to lowercase and hyphenated', async () => {
+      const request = new NextRequest('http://localhost:3000/api/routes-f/stream/tags', {
+        method: 'POST',
+        body: JSON.stringify({
+          stream_id: 'stream-123',
+          add: ['GAMING', 'First Person Shooter', '  RPG  ']
+        }),
+        headers: {
+          'Content-Type': 'application/json'
+        }
+      });
+
+      const response = await POST(request);
+      const data = await response.json();
+
+      expect(response.status).toBe(200);
+      expect(data.tags).toEqual(['gaming', 'first-person-shooter', 'rpg']);
+    });
+
+    it('should remove tags from a stream', async () => {
+      // First add tags
+      const addRequest = new NextRequest('http://localhost:3000/api/routes-f/stream/tags', {
+        method: 'POST',
+        body: JSON.stringify({
+          stream_id: 'stream-123',
+          add: ['gaming', 'fps', 'rpg']
+        }),
+        headers: {
+          'Content-Type': 'application/json'
+        }
+      });
+      await POST(addRequest);
+
+      // Then remove one
+      const removeRequest = new NextRequest('http://localhost:3000/api/routes-f/stream/tags', {
+        method: 'POST',
+        body: JSON.stringify({
+          stream_id: 'stream-123',
+          remove: ['fps']
+        }),
+        headers: {
+          'Content-Type': 'application/json'
+        }
+      });
+
+      const response = await POST(removeRequest);
+      const data = await response.json();
+
+      expect(response.status).toBe(200);
+      expect(data.tags).toEqual(['gaming', 'rpg']);
+    });
+
+    it('should deduplicate tags', async () => {
+      const request = new NextRequest('http://localhost:3000/api/routes-f/stream/tags', {
+        method: 'POST',
+        body: JSON.stringify({
+          stream_id: 'stream-123',
+          add: ['gaming', 'GAMING', 'gaming']
+        }),
+        headers: {
+          'Content-Type': 'application/json'
+        }
+      });
+
+      const response = await POST(request);
+      const data = await response.json();
+
+      expect(response.status).toBe(200);
+      expect(data.tags).toEqual(['gaming']);
+    });
+
+    it('should cap tags at 10', async () => {
+      // First add 10 tags
+      const addRequest = new NextRequest('http://localhost:3000/api/routes-f/stream/tags', {
+        method: 'POST',
+        body: JSON.stringify({
+          stream_id: 'stream-123',
+          add: ['tag1', 'tag2', 'tag3', 'tag4', 'tag5', 'tag6', 'tag7', 'tag8', 'tag9', 'tag10']
+        }),
+        headers: {
+          'Content-Type': 'application/json'
+        }
+      });
+      await POST(addRequest);
+
+      // Try to add one more
+      const overflowRequest = new NextRequest('http://localhost:3000/api/routes-f/stream/tags', {
+        method: 'POST',
+        body: JSON.stringify({
+          stream_id: 'stream-123',
+          add: ['tag11']
+        }),
+        headers: {
+          'Content-Type': 'application/json'
+        }
+      });
+
+      const response = await POST(overflowRequest);
+      const data = await response.json();
+
+      expect(response.status).toBe(400);
+      expect(data.error).toBe('Maximum 10 tags allowed');
+    });
+
+    it('should handle add and remove in same request', async () => {
+      // First add tags
+      const addRequest = new NextRequest('http://localhost:3000/api/routes-f/stream/tags', {
+        method: 'POST',
+        body: JSON.stringify({
+          stream_id: 'stream-123',
+          add: ['gaming', 'fps', 'rpg']
+        }),
+        headers: {
+          'Content-Type': 'application/json'
+        }
+      });
+      await POST(addRequest);
+
+      // Add and remove in same request
+      const request = new NextRequest('http://localhost:3000/api/routes-f/stream/tags', {
+        method: 'POST',
+        body: JSON.stringify({
+          stream_id: 'stream-123',
+          add: ['action'],
+          remove: ['rpg']
+        }),
+        headers: {
+          'Content-Type': 'application/json'
+        }
+      });
+
+      const response = await POST(request);
+      const data = await response.json();
+
+      expect(response.status).toBe(200);
+      expect(data.tags).toEqual(['gaming', 'fps', 'action']);
+    });
+
+    it('should return 400 for missing stream_id', async () => {
+      const request = new NextRequest('http://localhost:3000/api/routes-f/stream/tags', {
+        method: 'POST',
+        body: JSON.stringify({
+          add: ['gaming']
+        }),
+        headers: {
+          'Content-Type': 'application/json'
+        }
+      });
+
+      const response = await POST(request);
+      const data = await response.json();
+
+      expect(response.status).toBe(400);
+    });
+
+    it('should return 400 for invalid JSON', async () => {
+      const request = new NextRequest('http://localhost:3000/api/routes-f/stream/tags', {
+        method: 'POST',
+        body: 'invalid json',
+        headers: {
+          'Content-Type': 'application/json'
+        }
+      });
+
+      const response = await POST(request);
+
+      expect(response.status).toBe(400);
+    });
+  });
+
+  describe('GET', () => {
+    it('should return current tags for a stream', async () => {
+      // First add tags
+      const addRequest = new NextRequest('http://localhost:3000/api/routes-f/stream/tags', {
+        method: 'POST',
+        body: JSON.stringify({
+          stream_id: 'stream-123',
+          add: ['gaming', 'fps']
+        }),
+        headers: {
+          'Content-Type': 'application/json'
+        }
+      });
+      await POST(addRequest);
+
+      // Then get them
+      const getRequest = new NextRequest('http://localhost:3000/api/routes-f/stream/tags?stream_id=stream-123');
+      const response = await GET(getRequest);
+      const data = await response.json();
+
+      expect(response.status).toBe(200);
+      expect(data.tags).toEqual(['gaming', 'fps']);
+    });
+
+    it('should return empty array for stream with no tags', async () => {
+      const getRequest = new NextRequest('http://localhost:3000/api/routes-f/stream/tags?stream_id=stream-456');
+      const response = await GET(getRequest);
+      const data = await response.json();
+
+      expect(response.status).toBe(200);
+      expect(data.tags).toEqual([]);
+    });
+
+    it('should return 400 for missing stream_id', async () => {
+      const getRequest = new NextRequest('http://localhost:3000/api/routes-f/stream/tags');
+      const response = await GET(getRequest);
+      const data = await response.json();
+
+      expect(response.status).toBe(400);
+      expect(data.error).toBe('stream_id is required');
+    });
+  });
+});
diff --git a/app/api/routes-f/__tests__/stream-title.test.ts b/app/api/routes-f/__tests__/stream-title.test.ts
new file mode 100644
index 00000000..9582889b
--- /dev/null
+++ b/app/api/routes-f/__tests__/stream-title.test.ts
@@ -0,0 +1,208 @@
+/**
+ * @jest-environment jsdom
+ */
+
+import { PATCH, GET } from '../stream/title/route';
+import { NextRequest } from 'next/server';
+
+import { titleHistoryStore } from '../stream/title/utils';
+
+describe('/api/routes-f/stream/title', () => {
+  beforeEach(() => {
+    // Clear the in-memory store before each test
+    titleHistoryStore.clear();
+  });
+
+  describe('PATCH', () => {
+    it('should update stream title and return timestamp', async () => {
+      const request = new NextRequest('http://localhost:3000/api/routes-f/stream/title', {
+        method: 'PATCH',
+        body: JSON.stringify({
+          stream_id: 'stream-123',
+          title: 'My Awesome Stream'
+        }),
+        headers: {
+          'Content-Type': 'application/json'
+        }
+      });
+
+      const response = await PATCH(request);
+      const data = await response.json();
+
+      expect(response.status).toBe(200);
+      expect(data.title).toBe('My Awesome Stream');
+      expect(data.updated_at).toBeDefined();
+      expect(typeof data.updated_at).toBe('string');
+    });
+
+    it('should validate title length (min 1 char)', async () => {
+      const request = new NextRequest('http://localhost:3000/api/routes-f/stream/title', {
+        method: 'PATCH',
+        body: JSON.stringify({
+          stream_id: 'stream-123',
+          title: ''
+        }),
+        headers: {
+          'Content-Type': 'application/json'
+        }
+      });
+
+      const response = await PATCH(request);
+      const data = await response.json();
+
+      expect(response.status).toBe(400);
+      expect(data.error).toBe('Title must be at least 1 character');
+    });
+
+    it('should validate title length (max 100 chars)', async () => {
+      const longTitle = 'a'.repeat(101);
+      const request = new NextRequest('http://localhost:3000/api/routes-f/stream/title', {
+        method: 'PATCH',
+        body: JSON.stringify({
+          stream_id: 'stream-123',
+          title: longTitle
+        }),
+        headers: {
+          'Content-Type': 'application/json'
+        }
+      });
+
+      const response = await PATCH(request);
+      const data = await response.json();
+
+      expect(response.status).toBe(400);
+      expect(data.error).toBe('Title must be at most 100 characters');
+    });
+
+    it('should accept title exactly at 100 characters', async () => {
+      const title = 'a'.repeat(100);
+      const request = new NextRequest('http://localhost:3000/api/routes-f/stream/title', {
+        method: 'PATCH',
+        body: JSON.stringify({
+          stream_id: 'stream-123',
+          title: title
+        }),
+        headers: {
+          'Content-Type': 'application/json'
+        }
+      });
+
+      const response = await PATCH(request);
+      const data = await response.json();
+
+      expect(response.status).toBe(200);
+      expect(data.title).toBe(title);
+    });
+
+    it('should return 400 for missing stream_id', async () => {
+      const request = new NextRequest('http://localhost:3000/api/routes-f/stream/title', {
+        method: 'PATCH',
+        body: JSON.stringify({
+          title: 'My Stream'
+        }),
+        headers: {
+          'Content-Type': 'application/json'
+        }
+      });
+
+      const response = await PATCH(request);
+
+      expect(response.status).toBe(400);
+    });
+
+    it('should return 400 for invalid JSON', async () => {
+      const request = new NextRequest('http://localhost:3000/api/routes-f/stream/title', {
+        method: 'PATCH',
+        body: 'invalid json',
+        headers: {
+          'Content-Type': 'application/json'
+        }
+      });
+
+      const response = await PATCH(request);
+
+      expect(response.status).toBe(400);
+    });
+  });
+
+  describe('GET', () => {
+    it('should return last 10 title changes for a stream', async () => {
+      // Add 12 title changes
+      for (let i = 1; i <= 12; i++) {
+        const request = new NextRequest('http://localhost:3000/api/routes-f/stream/title', {
+          method: 'PATCH',
+          body: JSON.stringify({
+            stream_id: 'stream-123',
+            title: `Title ${i}`
+          }),
+          headers: {
+            'Content-Type': 'application/json'
+          }
+        });
+        await PATCH(request);
+      }
+
+      // Get history
+      const getRequest = new NextRequest('http://localhost:3000/api/routes-f/stream/title?stream_id=stream-123');
+      const response = await GET(getRequest);
+      const data = await response.json();
+
+      expect(response.status).toBe(200);
+      expect(data.history).toHaveLength(10);
+      expect(data.history[0].title).toBe('Title 12'); // Most recent first
+      expect(data.history[9].title).toBe('Title 3'); // Oldest of the 10
+    });
+
+    it('should return empty array for stream with no history', async () => {
+      const getRequest = new NextRequest('http://localhost:3000/api/routes-f/stream/title?stream_id=stream-456');
+      const response = await GET(getRequest);
+      const data = await response.json();
+
+      expect(response.status).toBe(200);
+      expect(data.history).toEqual([]);
+    });
+
+    it('should maintain chronological order (newest first)', async () => {
+      const request1 = new NextRequest('http://localhost:3000/api/routes-f/stream/title', {
+        method: 'PATCH',
+        body: JSON.stringify({
+          stream_id: 'stream-123',
+          title: 'First Title'
+        }),
+        headers: {
+          'Content-Type': 'application/json'
+        }
+      });
+      await PATCH(request1);
+
+      const request2 = new NextRequest('http://localhost:3000/api/routes-f/stream/title', {
+        method: 'PATCH',
+        body: JSON.stringify({
+          stream_id: 'stream-123',
+          title: 'Second Title'
+        }),
+        headers: {
+          'Content-Type': 'application/json'
+        }
+      });
+      await PATCH(request2);
+
+      const getRequest = new NextRequest('http://localhost:3000/api/routes-f/stream/title?stream_id=stream-123');
+      const response = await GET(getRequest);
+      const data = await response.json();
+
+      expect(response.status).toBe(200);
+      expect(data.history[0].title).toBe('Second Title');
+      expect(data.history[1].title).toBe('First Title');
+    });
+
+    it('should return 400 for missing stream_id', async () => {
+      const getRequest = new NextRequest('http://localhost:3000/api/routes-f/stream/title');
+      const response = await GET(getRequest);
+      const data = await response.json();
+
+      expect(response.status).toBe(400);
+      expect(data.error).toBe('stream_id is required');
+    });
+  });
+});
diff --git a/app/api/routes-f/__tests__/subscriber-roster.test.ts b/app/api/routes-f/__tests__/subscriber-roster.test.ts
new file mode 100644
index 00000000..991cd3f0
--- /dev/null
+++ b/app/api/routes-f/__tests__/subscriber-roster.test.ts
@@ -0,0 +1,56 @@
+/**
+ * @jest-environment node
+ */
+import { NextRequest } from "next/server";
+import { GET } from "../subscriber-roster/route";
+
+function makeReq(creatorId: string) {
+  const req = new NextRequest("http://localhost/api/routes-f/subscriber-roster", {
+    method: "GET",
+  });
+  req.nextUrl.searchParams.set("creator_id", creatorId);
+  return req;
+}
+
+describe("/api/routes-f/subscriber-roster", () => {
+  it("returns subscriber list with tier breakdown", async () => {
+    const req = makeReq("creator123");
+    const res = await GET(req);
+    expect(res.status).toBe(200);
+
+    const data = await res.json();
+    expect(data).toHaveProperty("subscribers");
+    expect(data).toHaveProperty("by_tier");
+    expect(data).toHaveProperty("monthly_recurring_revenue_usdc");
+    expect(Array.isArray(data.subscribers)).toBe(true);
+  });
+
+  it("computes MRR correctly", async () => {
+    const req = makeReq("creator123");
+    const res = await GET(req);
+    const data = await res.json();
+
+    expect(typeof data.monthly_recurring_revenue_usdc).toBe("number");
+    expect(data.monthly_recurring_revenue_usdc).toBeGreaterThanOrEqual(0);
+  });
+
+  it("sorts subscribers by started_at descending", async () => {
+    const req = makeReq("creator123");
+    const res = await GET(req);
+    const data = await res.json();
+
+    if (data.subscribers.length > 1) {
+      for (let i = 0; i < data.subscribers.length - 1; i++) {
+        const current = new Date(data.subscribers[i].started_at);
+        const next = new Date(data.subscribers[i + 1].started_at);
+        expect(current.getTime()).toBeGreaterThanOrEqual(next.getTime());
+      }
+    }
+  });
+
+  it("rejects missing creator_id", async () => {
+    const req = new NextRequest("http://localhost/api/routes-f/subscriber-roster");
+    const res = await GET(req);
+    expect(res.status).toBe(400);
+  });
+});
diff --git a/app/api/routes-f/__tests__/subscription-badges.test.ts b/app/api/routes-f/__tests__/subscription-badges.test.ts
new file mode 100644
index 00000000..9b827355
--- /dev/null
+++ b/app/api/routes-f/__tests__/subscription-badges.test.ts
@@ -0,0 +1,144 @@
+/**
+ * @jest-environment node
+ */
+import { NextRequest } from "next/server";
+import { GET } from "../subscriptions/badges/route";
+import { subscriptions } from "../subscriptions/route";
+
+function makeReq(creatorId: string, subscriberId: string) {
+  return new NextRequest(
+    `http://localhost/api/routes-f/subscriptions/badges?creator_id=${creatorId}&subscriber_id=${subscriberId}`
+  );
+}
+
+describe("Subscription Badges by Tier API", () => {
+  beforeEach(() => {
+    subscriptions.clear();
+  });
+
+  it("should return has_sub false if no subscription exists", async () => {
+    const req = makeReq("creator-1", "user-1");
+    const res = await GET(req);
+    expect(res.status).toBe(200);
+    const data = await res.json();
+    expect(data.has_sub).toBe(false);
+    expect(data.months_subscribed).toBe(0);
+    expect(data.tier_id).toBeUndefined();
+  });
+
+  it("should return active subscription details (single tier)", async () => {
+    const creatorId = "creator-1";
+    const subscriberId = "user-1";
+
+    const now = Date.now();
+    // 30 days active sub
+    subscriptions.set("sub-1", {
+      subscription_id: "sub-1",
+      subscriber_id: subscriberId,
+      creator_id: creatorId,
+      tier_id: "premium",
+      payment_tx_hash: "hash-1",
+      asset: "USDC",
+      started_at: new Date(now - 15 * 24 * 60 * 60 * 1000).toISOString(),
+      expires_at: new Date(now + 15 * 24 * 60 * 60 * 1000).toISOString(),
+    });
+
+    const req = makeReq(creatorId, subscriberId);
+    const res = await GET(req);
+    expect(res.status).toBe(200);
+    const data = await res.json();
+
+    expect(data.has_sub).toBe(true);
+    expect(data.tier_id).toBe("premium");
+    expect(data.badge_url).toBe("/api/routes-f/subscriptions/badges/svg");
+    expect(data.months_subscribed).toBe(1); // 30 days total
+  });
+
+  it("should stack months_subscribed across non-overlapping historical subscriptions", async () => {
+    const creatorId = "creator-1";
+    const subscriberId = "user-1";
+    const now = Date.now();
+
+    // Sub 1: Active premium sub (30 days, from now-15d to now+15d)
+    subscriptions.set("sub-1", {
+      subscription_id: "sub-1",
+      subscriber_id: subscriberId,
+      creator_id: creatorId,
+      tier_id: "premium",
+      payment_tx_hash: "hash-1",
+      asset: "USDC",
+      started_at: new Date(now - 15 * 24 * 60 * 60 * 1000).toISOString(),
+      expires_at: new Date(now + 15 * 24 * 60 * 60 * 1000).toISOString(),
+    });
+
+    // Sub 2: Past basic sub (30 days, from now-75d to now-45d)
+    subscriptions.set("sub-2", {
+      subscription_id: "sub-2",
+      subscriber_id: subscriberId,
+      creator_id: creatorId,
+      tier_id: "basic",
+      payment_tx_hash: "hash-2",
+      asset: "XLM",
+      started_at: new Date(now - 75 * 24 * 60 * 60 * 1000).toISOString(),
+      expires_at: new Date(now - 45 * 24 * 60 * 60 * 1000).toISOString(),
+    });
+
+    // Sub 3: Even older basic sub (60 days, from now-150d to now-90d)
+    subscriptions.set("sub-3", {
+      subscription_id: "sub-3",
+      subscriber_id: subscriberId,
+      creator_id: creatorId,
+      tier_id: "basic",
+      payment_tx_hash: "hash-3",
+      asset: "XLM",
+      started_at: new Date(now - 150 * 24 * 60 * 60 * 1000).toISOString(),
+      expires_at: new Date(now - 90 * 24 * 60 * 60 * 1000).toISOString(),
+    });
+
+    const req = makeReq(creatorId, subscriberId);
+    const res = await GET(req);
+    expect(res.status).toBe(200);
+    const data = await res.json();
+
+    expect(data.has_sub).toBe(true);
+    expect(data.tier_id).toBe("premium"); // Returns current active tier
+    expect(data.months_subscribed).toBe(4); // 30 + 30 + 60 = 120 days -> 4 months
+  });
+
+  it("should not double count overlapping subscription days", async () => {
+    const creatorId = "creator-1";
+    const subscriberId = "user-1";
+    const now = Date.now();
+
+    // Sub 1: 30 days
+    subscriptions.set("sub-1", {
+      subscription_id: "sub-1",
+      subscriber_id: subscriberId,
+      creator_id: creatorId,
+      tier_id: "premium",
+      payment_tx_hash: "hash-1",
+      asset: "USDC",
+      started_at: new Date(now - 15 * 24 * 60 * 60 * 1000).toISOString(),
+      expires_at: new Date(now + 15 * 24 * 60 * 60 * 1000).toISOString(),
+    });
+
+    // Sub 2: Overlapping (starts 5 days into sub-1, runs for 30 days)
+    subscriptions.set("sub-2", {
+      subscription_id: "sub-2",
+      subscriber_id: subscriberId,
+      creator_id: creatorId,
+      tier_id: "premium",
+      payment_tx_hash: "hash-2",
+      asset: "USDC",
+      started_at: new Date(now - 10 * 24 * 60 * 60 * 1000).toISOString(),
+      expires_at: new Date(now + 20 * 24 * 60 * 60 * 1000).toISOString(),
+    });
+
+    const req = makeReq(creatorId, subscriberId);
+    const res = await GET(req);
+    const data = await res.json();
+
+    // Total interval: now-15 to now+20 (35 days total) -> Math.floor(35/30) = 1 month
+    expect(data.months_subscribed).toBe(1);
+  });
+});
diff --git a/app/api/routes-f/__tests__/subscription-tiers.test.ts b/app/api/routes-f/__tests__/subscription-tiers.test.ts
new file mode 100644
index 00000000..23502dd8
--- /dev/null
+++ b/app/api/routes-f/__tests__/subscription-tiers.test.ts
@@ -0,0 +1,117 @@
+/**
+ * @jest-environment node
+ */
+import { NextRequest } from "next/server";
+import { GET, POST } from "../subscription-tiers/route";
+
+function makeReq(body?: unknown) {
+  return new NextRequest("http://localhost/api/routes-f/subscription-tiers", {
+    method: body ? "POST" : "GET",
+    headers: { "content-type": "application/json" },
+    body: body ? JSON.stringify(body) : undefined,
+  });
+}
+
+function makeAuthReq(body: unknown) {
+  const req = new NextRequest("http://localhost/api/routes-f/subscription-tiers", {
+    method: "POST",
+    headers: {
+      "content-type": "application/json",
+      cookie: "session=mock-token",
+    },
+    body: JSON.stringify(body),
+  });
+  return req;
+}
+
+describe("/api/routes-f/subscription-tiers", () => {
+  describe("POST", () => {
+    it("creates a tier with valid fields", async () => {
+      const req = makeAuthReq({
+        name: "Basic",
+        price_usdc: 5,
+        duration_days: 30,
+        perks: ["badge"],
+      });
+      const res = await POST(req);
+      expect(res.status).toBe(201);
+
+      const data = await res.json();
+      expect(data).toHaveProperty("id");
+      expect(data.name).toBe("Basic");
+      expect(data.price_usdc).toBe(5);
+    });
+
+    it("rejects tier with missing name", async () => {
+      const req = makeAuthReq({
+        price_usdc: 5,
+        duration_days: 30,
+      });
+      const res = await POST(req);
+      expect(res.status).toBe(400);
+    });
+
+    it("rejects tier with zero price", async () => {
+      const req = makeAuthReq({
+        name: "Free",
+        price_usdc: 0,
+        duration_days: 30,
+      });
+      const res = await POST(req);
+      expect(res.status).toBe(400);
+    });
+
+    it("rejects tier with negative duration", async () => {
+      const req = makeAuthReq({
+        name: "Bad",
+        price_usdc: 5,
+        duration_days: -1,
+      });
+      const res = await POST(req);
+      expect(res.status).toBe(400);
+    });
+
+    it("caps at 5 tiers per creator", async () => {
+      for (let i = 0; i < 5; i++) {
+        const req = makeAuthReq({
+          name: `Tier ${i}`,
+          price_usdc: i + 1,
+          duration_days: 30,
+        });
+        const res = await POST(req);
+        expect(res.status).toBe(201);
+      }
+
+      const sixthReq = makeAuthReq({
+        name: "Tier 6",
+        price_usdc: 6,
+        duration_days: 30,
+      });
+      const sixthRes = await POST(sixthReq);
+      expect(sixthRes.status).toBe(400);
+
+      const data = await sixthRes.json();
+      expect(data.error).toContain("Cannot exceed 5");
+    });
+  });
+
+  describe("GET", () => {
+    it("lists tiers for creator", async () => {
+      const req = makeReq();
+      req.nextUrl.searchParams.set("creator_id", "user123");
+
+      const res = await GET(req);
+      expect(res.status).toBe(200);
+
+      const data = await res.json();
+      expect(data).toHaveProperty("tiers");
+      expect(Array.isArray(data.tiers)).toBe(true);
+    });
+
+    it("rejects missing creator_id", async () => {
+      const req = makeReq();
+      const res = await GET(req);
+      expect(res.status).toBe(400);
+    });
+  });
+});
diff --git a/app/api/routes-f/__tests__/template-interpolation.test.ts b/app/api/routes-f/__tests__/template-interpolation.test.ts
new file mode 100644
index 00000000..efd941dc
--- /dev/null
+++ b/app/api/routes-f/__tests__/template-interpolation.test.ts
@@ -0,0 +1,78 @@
+/**
+ * @jest-environment node
+ */
+import { NextRequest } from "next/server";
+import { POST } from "../template-interpolation/route";
+
+function makeReq(body: unknown) {
+  return new NextRequest("http://localhost/api/routes-f/template-interpolation", {
+    method: "POST",
+    headers: { "content-type": "application/json" },
+    body: JSON.stringify(body),
+  });
+}
+
+describe("/api/routes-f/template-interpolation", () => {
+  it("interpolates nested values using dot paths", async () => {
+    const res = await POST(
+      makeReq({
+        template: "Hello {{user.name}}, your city is {{user.location.city}}.",
+        values: { user: { name: "Alice", location: { city: "Seattle" } } },
+      })
+    );
+
+    expect(res.status).toBe(200);
+    expect(await res.json()).toEqual({
+      output: "Hello Alice, your city is Seattle.",
+      missing_keys: [],
+    });
+  });
+
+  it("replaces missing values with empty strings when on_missing is empty", async () => {
+    const res = await POST(
+      makeReq({
+        template: "Hi {{user.name}}, {{user.age}} years old.",
+        values: { user: { name: "Bob" } },
+        on_missing: "empty",
+      })
+    );
+
+    expect(res.status).toBe(200);
+    expect(await res.json()).toEqual({
+      output: "Hi Bob,  years old.",
+      missing_keys: ["user.age"],
+    });
+  });
+
+  it("keeps placeholders when on_missing is keep", async () => {
+    const res = await POST(
+      makeReq({
+        template: "Hello {{user.name}} and {{user.nickname}}.",
+        values: { user: { name: "Sam" } },
+        on_missing: "keep",
+      })
+    );
+
+    expect(res.status).toBe(200);
+    expect(await res.json()).toEqual({
+      output: "Hello Sam and {{user.nickname}}.",
+      missing_keys: ["user.nickname"],
+    });
+  });
+
+  it("returns error when on_missing is error and values are missing", async () => {
+    const res = await POST(
+      makeReq({
+        template: "{{a}} {{b}}",
+        values: { a: "1" },
+        on_missing: "error",
+      })
+    );
+
+    expect(res.status).toBe(400);
+    expect(await res.json()).toEqual({
+      error: "Missing values for template placeholders.",
+      missing_keys: ["b"],
+    });
+  });
+});
diff --git a/app/api/routes-f/__tests__/text-fingerprint.test.ts b/app/api/routes-f/__tests__/text-fingerprint.test.ts
new file mode 100644
index 00000000..aa87b8f7
--- /dev/null
+++ b/app/api/routes-f/__tests__/text-fingerprint.test.ts
@@ -0,0 +1,119 @@
+/**
+ * @jest-environment node
+ */
+import { NextRequest } from "next/server";
+import { POST } from "../text-fingerprint/route";
+import { fingerprint, normalizeText } from "../text-fingerprint/_lib/helpers";
+
+function makeReq(body: unknown) {
+  return new NextRequest("http://localhost/api/routes-f/text-fingerprint", {
+    method: "POST",
+    headers: { "content-type": "application/json" },
+    body: JSON.stringify(body),
+  });
+}
+
+describe("normalizeText", () => {
+  it("lowercases text", () => {
+    expect(normalizeText("Hello World")).toBe("hello world");
+  });
+
+  it("strips punctuation and collapses resulting whitespace", () => {
+    // comma and ! become spaces → collapse → "hello world"
+    expect(normalizeText("hello, world!")).toBe("hello world");
+    // apostrophe → space, period → space, collapse → "it s a test"
+    expect(normalizeText("it's a test.")).toBe("it s a test");
+  });
+
+  it("collapses whitespace and trims", () => {
+    expect(normalizeText("  foo   bar  ")).toBe("foo bar");
+  });
+});
+
+describe("fingerprint", () => {
+  it("returns a sha256 hex fingerprint and normalized text", () => {
+    const result = fingerprint("Hello World");
+    expect(result.fingerprint).toMatch(/^[0-9a-f]{64}$/);
+    expect(result.normalized).toBe("hello world");
+  });
+
+  it("same fingerprint for texts differing only in word order", () => {
+    const a = fingerprint("foo bar baz");
+    const b = fingerprint("baz foo bar");
+    expect(a.fingerprint).toBe(b.fingerprint);
+  });
+
+  it("same fingerprint for texts differing only in case", () => {
+    const a = fingerprint("Hello World");
+    const b = fingerprint("hello world");
+    expect(a.fingerprint).toBe(b.fingerprint);
+  });
+
+  it("same fingerprint for texts differing only in punctuation and order", () => {
+    const a = fingerprint("The quick, brown fox!");
+    const b = fingerprint("fox brown quick the");
+    expect(a.fingerprint).toBe(b.fingerprint);
+  });
+
+  it("different fingerprint for genuinely different content", () => {
+    const a = fingerprint("hello world");
+    const b = fingerprint("goodbye world");
+    expect(a.fingerprint).not.toBe(b.fingerprint);
+  });
+
+  it("is idempotent for same input", () => {
+    const a = fingerprint("test text");
+    const b = fingerprint("test text");
+    expect(a.fingerprint).toBe(b.fingerprint);
+  });
+
+  it("handles empty string", () => {
+    const result = fingerprint("");
+    expect(result.fingerprint).toMatch(/^[0-9a-f]{64}$/);
+    expect(result.normalized).toBe("");
+  });
+});
+
+describe("POST /api/routes-f/text-fingerprint", () => {
+  it("returns fingerprint and normalized for valid text", async () => {
+    const res = await POST(makeReq({ text: "Hello World" }));
+    expect(res.status).toBe(200);
+    const data = await res.json();
+    expect(data).toHaveProperty("fingerprint");
+    expect(data).toHaveProperty("normalized");
+    expect(data.fingerprint).toMatch(/^[0-9a-f]{64}$/);
+  });
+
+  it("returns same fingerprint for order-swapped text", async () => {
+    const res1 = await POST(makeReq({ text: "apple banana cherry" }));
+    const res2 = await POST(makeReq({ text: "cherry apple banana" }));
+    const d1 = await res1.json();
+    const d2 = await res2.json();
+    expect(d1.fingerprint).toBe(d2.fingerprint);
+  });
+
+  it("returns 400 for missing text field", async () => {
+    const res = await POST(makeReq({}));
+    expect(res.status).toBe(400);
+  });
+
+  it("returns 400 when text is not a string", async () => {
+    const res = await POST(makeReq({ text: 123 }));
+    expect(res.status).toBe(400);
+  });
+
+  it("returns 400 for non-object body", async () => {
+    const res = await POST(makeReq("just a string"));
+    expect(res.status).toBe(400);
+  });
+
+  it("returns 400 for invalid JSON", async () => {
+    const req = new NextRequest("http://localhost/api/routes-f/text-fingerprint", {
+      method: "POST",
+      headers: { "content-type": "application/json" },
+      body: "not json",
+    });
+    const res = await POST(req);
+    expect(res.status).toBe(400);
+  });
+});
diff --git a/app/api/routes-f/__tests__/text-similarity.test.ts b/app/api/routes-f/__tests__/text-similarity.test.ts
new file mode 100644
index 00000000..8dee4473
--- /dev/null
+++ b/app/api/routes-f/__tests__/text-similarity.test.ts
@@ -0,0 +1,52 @@
+/**
+ * @jest-environment node
+ */
+import { NextRequest } from "next/server";
+import { POST } from "../text-similarity/route";
+
+function makeReq(body: unknown) {
+  return new NextRequest("http://localhost/api/routes-f/text-similarity", {
+    method: "POST",
+    headers: { "content-type": "application/json" },
+    body: JSON.stringify(body),
+  });
+}
+
+describe("/api/routes-f/text-similarity", () => {
+  it("returns 1 for identical text on both Jaccard and cosine", async () => {
+    const res = await POST(makeReq({ a: "The quick brown fox", b: "The quick brown fox" }));
+    expect(res.status).toBe(200);
+    const data = await res.json();
+
+    expect(data.jaccard).toBe(1);
+    expect(data.cosine).toBe(1);
+  });
+
+  it("returns 0 for completely disjoint text", async () => {
+    const res = await POST(makeReq({ a: "apple orange", b: "cat dog" }));
+    expect(res.status).toBe(200);
+    const data = await res.json();
+
+    expect(data.jaccard).toBe(0);
+    expect(data.cosine).toBe(0);
+  });
+
+  it("computes partial overlap using both algorithms", async () => {
+    const res = await POST(
+      makeReq({ a: "quick brown fox", b: "brown fox jumps", algorithm: "both" })
+    );
+    expect(res.status).toBe(200);
+    const data = await res.json();
+
+    expect(data.jaccard).toBe(0.5);
+    expect(data.cosine).toBeCloseTo(0.6667, 3);
+  });
+
+  it("supports single-algorithm selection", async () => {
+    const res = await POST(makeReq({ a: "a b c", b: "a b", algorithm: "jaccard" }));
+    expect(res.status).toBe(200);
+    const data = await res.json();
+
+    expect(data).toEqual({ jaccard: 0.6666666666666666 });
+  });
+});
diff --git a/app/api/routes-f/__tests__/tips-anonymous.test.ts b/app/api/routes-f/__tests__/tips-anonymous.test.ts
new file mode 100644
index 00000000..4e5bd704
--- /dev/null
+++ b/app/api/routes-f/__tests__/tips-anonymous.test.ts
@@ -0,0 +1,78 @@
+/**
+ * @jest-environment node
+ */
+import { NextRequest } from "next/server";
+import { POST } from "../tips/route";
+
+function makeReq(body: unknown) {
+  return new NextRequest("http://localhost/api/routes-f/tips", {
+    method: "POST",
+    headers: { "content-type": "application/json" },
+    body: JSON.stringify(body),
+  });
+}
+
+describe("/api/routes-f/tips", () => {
+  describe("POST", () => {
+    it("toggles anonymous flag on a tip", async () => {
+      const req = makeReq({
+        tip_id: "tip123",
+        anonymous: true,
+      });
+      const res = await POST(req);
+      expect(res.status).toBe(200);
+
+      const data = await res.json();
+      expect(data).toHaveProperty("updated");
+      expect(data.updated).toBe(true);
+      expect(data.tip).toHaveProperty("anonymous");
+    });
+
+    it("accepts boolean toggle to false", async () => {
+      const req = makeReq({
+        tip_id: "tip456",
+        anonymous: false,
+      });
+      const res = await POST(req);
+      expect(res.status).toBe(200);
+
+      const data = await res.json();
+      expect(data.updated).toBe(true);
+      expect(data.tip.anonymous).toBe(false);
+    });
+
+    it("rejects missing tip_id", async () => {
+      const req = makeReq({
+        anonymous: true,
+      });
+      const res = await POST(req);
+      expect(res.status).toBe(400);
+    });
+
+    it("rejects missing anonymous field", async () => {
+      const req = makeReq({
+        tip_id: "tip789",
+      });
+      const res = await POST(req);
+      expect(res.status).toBe(400);
+    });
+
+    it("rejects non-boolean anonymous", async () => {
+      const req = makeReq({
+        tip_id: "tip789",
+        anonymous: "yes",
+      });
+      const res = await POST(req);
+      expect(res.status).toBe(400);
+    });
+
+    it("returns 404 for non-existent tip", async () => {
+      const req = makeReq({
+        tip_id: "nonexistent",
+        anonymous: true,
+      });
+      const res = await POST(req);
+      expect(res.status).toBe(404);
+    });
+  });
+});
diff --git a/app/api/routes-f/__tests__/triangle.test.ts b/app/api/routes-f/__tests__/triangle.test.ts
new file mode 100644
index 00000000..c5402f99
--- /dev/null
+++ b/app/api/routes-f/__tests__/triangle.test.ts
@@ -0,0 +1,146 @@
+// @ts-nocheck
+/**
+ * @jest-environment node
+ */
+import { POST } from "../triangle/route";
+import { NextRequest } from "next/server";
+
+function makeReq(body: unknown) {
+  return new NextRequest("http://localhost/api/routes-f/triangle", {
+    method: "POST",
+    headers: { "content-type": "application/json" },
+    body: JSON.stringify(body),
+  });
+}
+
+describe("/api/routes-f/triangle", () => {
+  // --- Equilateral triangle ---
+  it("calculates equilateral triangle from sides", async () => {
+    const res = await POST(makeReq({ mode: "sides", sides: [5, 5, 5] }));
+    expect(res.status).toBe(200);
+    const d = await res.json();
+    expect(d.is_valid_triangle).toBe(true);
+    expect(d.type).toBe("equilateral");
+    expect(d.angle_type).toBe("acute");
+    expect(d.angles_deg[0]).toBeCloseTo(60, 1);
+    expect(d.angles_deg[1]).toBeCloseTo(60, 1);
+    expect(d.angles_deg[2]).toBeCloseTo(60, 1);
+    expect(d.perimeter).toBe(15);
+    expect(d.area).toBeCloseTo(10.8253, 2);
+  });
+
+  // --- Isosceles triangle ---
+  it("calculates isosceles triangle from sides", async () => {
+    const res = await POST(makeReq({ mode: "sides", sides: [5, 5, 8] }));
+    expect(res.status).toBe(200);
+    const d = await res.json();
+    expect(d.type).toBe("isosceles");
+  });
+
+  // --- Scalene triangle ---
+  it("calculates scalene triangle from sides", async () => {
+    const res = await POST(makeReq({ mode: "sides", sides: [3, 4, 6] }));
+    expect(res.status).toBe(200);
+    const d = await res.json();
+    expect(d.type).toBe("scalene");
+  });
+
+  // --- Right triangle (3-4-5) ---
+  it("detects right triangle (3-4-5)", async () => {
+    const res = await POST(makeReq({ mode: "sides", sides: [3, 4, 5] }));
+    expect(res.status).toBe(200);
+    const d = await res.json();
+    expect(d.is_valid_triangle).toBe(true);
+    expect(d.angle_type).toBe("right");
+    expect(d.type).toBe("scalene");
+    expect(d.area).toBe(6);
+    expect(d.perimeter).toBe(12);
+  });
+
+  // --- Obtuse triangle ---
+  it("detects obtuse triangle", async () => {
+    const res = await POST(makeReq({ mode: "sides", sides: [2, 3, 4] }));
+    expect(res.status).toBe(200);
+    const d = await res.json();
+    expect(d.angle_type).toBe("obtuse");
+  });
+
+  // --- Vertices mode ---
+  it("calculates triangle from vertices", async () => {
+    const res = await POST(
+      makeReq({
+        mode: "vertices",
+        vertices: [
+          [0, 0],
+          [4, 0],
+          [0, 3],
+        ],
+      })
+    );
+    expect(res.status).toBe(200);
+    const d = await res.json();
+    expect(d.is_valid_triangle).toBe(true);
+    expect(d.area).toBe(6);
+    expect(d.angle_type).toBe("right");
+    expect(d.centroid).toBeDefined();
+    expect(d.centroid.x).toBeCloseTo(1.3333, 2);
+    expect(d.centroid.y).toBeCloseTo(1, 2);
+  });
+
+  // --- Invalid triangle (sides don't satisfy triangle inequality) ---
+  it("rejects invalid triangle inequality", async () => {
+    const res = await POST(makeReq({ mode: "sides", sides: [1, 2, 10] }));
+    expect(res.status).toBe(400);
+  });
+
+  // --- Degenerate triangle (collinear points) ---
+  it("rejects degenerate triangle (collinear)", async () => {
+    const res = await POST(
+      makeReq({
+        mode: "vertices",
+        vertices: [
+          [0, 0],
+          [1, 1],
+          [2, 2],
+        ],
+      })
+    );
+    expect(res.status).toBe(400);
+  });
+
+  // --- Invalid mode ---
+  it("rejects invalid mode", async () => {
+    const res = await POST(makeReq({ mode: "invalid", sides: [3, 4, 5] }));
+    expect(res.status).toBe(400);
+  });
+
+  // --- Missing sides ---
+  it("rejects missing sides in sides mode", async () => {
+    const res = await POST(makeReq({ mode: "sides" }));
+    expect(res.status).toBe(400);
+  });
+
+  // --- Negative side ---
+  it("rejects negative sides", async () => {
+    const res = await POST(makeReq({ mode: "sides", sides: [-1, 3, 4] }));
+    expect(res.status).toBe(400);
+  });
+
+  // --- Invalid JSON ---
+  it("rejects invalid JSON body", async () => {
+    const req = new NextRequest("http://localhost/api/routes-f/triangle", {
+      method: "POST",
+      headers: { "content-type": "application/json" },
+      body: "not json",
+    });
+    const res = await POST(req);
+    expect(res.status).toBe(400);
+  });
+
+  // --- Circumradius is returned ---
+  it("returns circumradius", async () => {
+    const res = await POST(makeReq({ mode: "sides", sides: [3, 4, 5] }));
+    const d = await res.json();
+    expect(d.circumradius).toBe(2.5);
+  });
+});
diff --git a/app/api/routes-f/__tests__/url-parse.test.ts b/app/api/routes-f/__tests__/url-parse.test.ts
new file mode 100644
index 00000000..6365e3a3
--- /dev/null
+++ b/app/api/routes-f/__tests__/url-parse.test.ts
@@ -0,0 +1,112 @@
+// @ts-nocheck
+/**
+ * @jest-environment node
+ */
+import { POST } from "../url-parse/route";
+import { NextRequest } from "next/server";
+
+function makeReq(body: unknown) {
+  return new NextRequest("http://localhost/api/routes-f/url-parse", {
+    method: "POST",
+    headers: { "content-type": "application/json" },
+    body: JSON.stringify(body),
+  });
+}
+
+describe("/api/routes-f/url-parse", () => {
+  // --- Full URL with auth and query ---
+  it("parses full URL with auth, query, and hash", async () => {
+    const res = await POST(
+      makeReq({
+        url: "https://user:pass@example.com:8080/path/to/page?foo=bar&baz=qux#section",
+      })
+    );
+    expect(res.status).toBe(200);
+    const d = await res.json();
+    expect(d.protocol).toBe("https:");
+    expect(d.host).toBe("example.com:8080");
+    expect(d.hostname).toBe("example.com");
+    expect(d.port).toBe("8080");
+    expect(d.pathname).toBe("/path/to/page");
+    expect(d.search).toBe("?foo=bar&baz=qux");
+    expect(d.hash).toBe("#section");
+    expect(d.username).toBe("user");
+    expect(d.password).toBe("pass");
+    expect(d.query.foo).toBe("bar");
+    expect(d.query.baz).toBe("qux");
+    expect(d.path_segments).toEqual(["path", "to", "page"]);
+    expect(d.origin).toBe("https://example.com:8080");
+  });
+
+  // --- Repeated query keys become arrays ---
+  it("handles repeated query keys as arrays", async () => {
+    const res = await POST(
+      makeReq({ url: "https://example.com?tag=a&tag=b&tag=c" })
+    );
+    expect(res.status).toBe(200);
+    const d = await res.json();
+    expect(d.query.tag).toEqual(["a", "b", "c"]);
+  });
+
+  // --- Varied protocols ---
+  it("parses ftp URL", async () => {
+    const res = await POST(
+      makeReq({ url: "ftp://files.example.com/pub/readme.txt" })
+    );
+    expect(res.status).toBe(200);
+    const d = await res.json();
+    expect(d.protocol).toBe("ftp:");
+    expect(d.hostname).toBe("files.example.com");
+    expect(d.path_segments).toEqual(["pub", "readme.txt"]);
+  });
+
+  // --- Simple URL with no port/auth ---
+  it("parses simple URL with default port", async () => {
+    const res = await POST(makeReq({ url: "https://example.com/about" }));
+    expect(res.status).toBe(200);
+    const d = await res.json();
+    expect(d.port).toBe("");
+    expect(d.pathname).toBe("/about");
+    expect(d.hash).toBe("");
+    expect(d.search).toBe("");
+  });
+
+  // --- Invalid URL ---
+  it("rejects invalid URL", async () => {
+    const res = await POST(makeReq({ url: "not-a-url" }));
+    expect(res.status).toBe(400);
+  });
+
+  // --- Missing url field ---
+  it("rejects missing url field", async () => {
+    const res = await POST(makeReq({}));
+    expect(res.status).toBe(400);
+  });
+
+  // --- URL too long ---
+  it("rejects URL exceeding 4KB", async () => {
+    const longUrl = "https://example.com/" + "a".repeat(5000);
+    const res = await POST(makeReq({ url: longUrl }));
+    expect(res.status).toBe(400);
+  });
+
+  // --- Invalid JSON body ---
+  it("rejects invalid JSON body", async () => {
+    const req = new NextRequest("http://localhost/api/routes-f/url-parse", {
+      method: "POST",
+      headers: { "content-type": "application/json" },
+      body: "not json",
+    });
+    const res = await POST(req);
+    expect(res.status).toBe(400);
+  });
+
+  // --- URL with empty path ---
+  it("handles URL with empty path", async () => {
+    const res = await POST(makeReq({ url: "https://example.com" }));
+    expect(res.status).toBe(200);
+    const d = await res.json();
+    expect(d.pathname).toBe("/");
+    expect(d.path_segments).toEqual([]);
+  });
+});
diff --git a/app/api/routes-f/__tests__/xml-to-json.test.ts b/app/api/routes-f/__tests__/xml-to-json.test.ts
new file mode 100644
index 00000000..c743451c
--- /dev/null
+++ b/app/api/routes-f/__tests__/xml-to-json.test.ts
@@ -0,0 +1,83 @@
+// @ts-nocheck
+/**
+ * @jest-environment node
+ */
+import { POST } from "../xml-to-json/route";
+import { NextRequest } from "next/server";
+
+function makeReq(body: unknown) {
+  return new NextRequest("http://localhost/api/routes-f/xml-to-json", {
+    method: "POST",
+    headers: { "content-type": "application/json" },
+    body: JSON.stringify(body),
+  });
+}
+
+describe("/api/routes-f/xml-to-json", () => {
+  it("converts simple XML element", async () => {
+    const res = await POST(makeReq({ xml: "<root><name>Alice</name></root>" }));
+    expect(res.status).toBe(200);
+    const { json, root_element } = await res.json();
+    expect(root_element).toBe("root");
+    expect(json.root.name["#text"]).toBe("Alice");
+  });
+
+  it("handles attributes with default @ prefix", async () => {
+    const res = await POST(makeReq({ xml: '<root id="42"><item/></root>' }));
+    const { json } = await res.json();
+    expect(json.root["@id"]).toBe("42");
+  });
+
+  it("respects custom attribute_prefix", async () => {
+    const res = await POST(
+      makeReq({ xml: '<root id="1"/>', attribute_prefix: "_" })
+    );
+    const { json } = await res.json();
+    expect(json.root["_id"]).toBe("1");
+  });
+
+  it("respects custom text_key", async () => {
+    const res = await POST(
+      makeReq({ xml: "<root>hello</root>", text_key: "$" })
+    );
+    const { json } = await res.json();
+    expect(json.root["$"]).toBe("hello");
+  });
+
+  it("handles nested elements", async () => {
+    const xml = "<book><title>Rust</title><author>Steve</author></book>";
+    const res = await POST(makeReq({ xml }));
+    const { json } = await res.json();
+    expect(json.book.title["#text"]).toBe("Rust");
+    expect(json.book.author["#text"]).toBe("Steve");
+  });
+
+  it("handles CDATA sections", async () => {
+    const xml = "<root><![CDATA[<b>raw html</b>]]></root>";
+    const res = await POST(makeReq({ xml }));
+    const { json } = await res.json();
+    expect(json.root["#text"]).toContain("<b>raw html</b>");
+  });
+
+  it("returns 400 for malformed XML", async () => {
+    const res = await POST(makeReq({ xml: "<root><unclosed>" }));
+    expect(res.status).toBe(400);
+    const body = await res.json();
+    expect(body.error).toBeDefined();
+  });
+
+  it("returns 400 for mismatched closing tag", async () => {
+    const res = await POST(makeReq({ xml: "<root></other>" }));
+    expect(res.status).toBe(400);
+  });
+
+  it("returns 400 for empty xml", async () => {
+    const res = await POST(makeReq({ xml: "" }));
+    expect(res.status).toBe(400);
+  });
+
+  it("returns 400 when xml is missing", async () => {
+    const res = await POST(makeReq({}));
+    expect(res.status).toBe(400);
+  });
+});
diff --git a/app/api/routes-f/_lib/duration.ts b/app/api/routes-f/_lib/duration.ts
new file mode 100644
index 00000000..caf847a6
--- /dev/null
+++ b/app/api/routes-f/_lib/duration.ts
@@ -0,0 +1,103 @@
+export type DurationComponents = {
+  years?: number;
+  months?: number;
+  weeks?: number;
+  days?: number;
+  hours?: number;
+  minutes?: number;
+  seconds?: number;
+};
+
+const DURATION_PATTERN = /^P(?:(\d+(?:\.\d+)?)Y)?(?:(\d+(?:\.\d+)?)M)?(?:(\d+(?:\.\d+)?)W)?(?:(\d+(?:\.\d+)?)D)?(?:T(?:(\d+(?:\.\d+)?)H)?(?:(\d+(?:\.\d+)?)M)?(?:(\d+(?:\.\d+)?)S)?)?$/;
+
+export function parseDuration(text: string): DurationComponents {
+  if (typeof text !== "string") {
+    throw new Error("Duration text must be a string.");
+  }
+
+  const match = DURATION_PATTERN.exec(text);
+  if (!match) {
+    throw new Error("Invalid ISO 8601 duration format.");
+  }
+
+  const [
+    ,
+    years = "0",
+    months = "0",
+    weeks = "0",
+    days = "0",
+    hours = "0",
+    minutes = "0",
+    seconds = "0",
+  ] = match;
+
+  return {
+    years: Number(years),
+    months: Number(months),
+    weeks: Number(weeks),
+    days: Number(days),
+    hours: Number(hours),
+    minutes: Number(minutes),
+    seconds: Number(seconds),
+  };
+}
+
+export function formatDuration(components: DurationComponents): string {
+  const normalized = normalizeComponents(components);
+  const { years, months, weeks, days, hours, minutes, seconds } = normalized;
+
+  if (!years && !months && !weeks && !days && !hours && !minutes && !seconds) {
+    return "PT0S";
+  }
+
+  let text = "P";
+
+  if (years) text += `${years}Y`;
+  if (months) text += `${months}M`;
+  if (weeks) text += `${weeks}W`;
+  if (days) text += `${days}D`;
+
+  if (hours || minutes || seconds) {
+    text += "T";
+    if (hours) text += `${hours}H`;
+    if (minutes) text += `${minutes}M`;
+    if (seconds) text += `${seconds}S`;
+  }
+
+  return text;
+}
+
+export function durationToSeconds(components: DurationComponents): number {
+  const { years, months, weeks, days, hours, minutes, seconds } = normalizeComponents(components);
+
+  return (
+    years * 31536000 +
+    months * 2592000 +
+    weeks * 604800 +
+    days * 86400 +
+    hours * 3600 +
+    minutes * 60 +
+    seconds
+  );
+}
+
+export function normalizeComponents(components: DurationComponents): Required<DurationComponents> {
+  const normalized = {
+    years: 0,
+    months: 0,
+    weeks: 0,
+    days: 0,
+    hours: 0,
+    minutes: 0,
+    seconds: 0,
+    ...components,
+  };
+
+  for (const [key, value] of Object.entries(normalized)) {
+    if (typeof value !== "number" || !Number.isFinite(value) || value < 0) {
+      throw new Error("Duration components must be non-negative finite numbers.");
+    }
+  }
+
+  return normalized;
+}
diff --git a/app/api/routes-f/_lib/prime.ts b/app/api/routes-f/_lib/prime.ts
new file mode 100644
index 00000000..3749d193
--- /dev/null
+++ b/app/api/routes-f/_lib/prime.ts
@@ -0,0 +1,52 @@
+function getSieveLimit(n: number): number {
+  if (n < 6) {
+    return 15;
+  }
+
+  return Math.ceil(n * (Math.log(n) + Math.log(Math.log(n)))) + 10;
+}
+
+function sieveNthPrime(n: number, limit: number): number | null {
+  const sieve = new Uint8Array(limit + 1);
+  sieve.fill(1);
+  sieve[0] = 0;
+  sieve[1] = 0;
+
+  let count = 0;
+
+  for (let i = 2; i <= limit; i += 1) {
+    if (!sieve[i]) {
+      continue;
+    }
+
+    count += 1;
+    if (count === n) {
+      return i;
+    }
+
+    const step = i * i;
+    if (step <= limit) {
+      for (let j = step; j <= limit; j += i) {
+        sieve[j] = 0;
+      }
+    }
+  }
+
+  return null;
+}
+
+export function findNthPrime(n: number): number {
+  if (!Number.isInteger(n) || n < 1 || n > 100000) {
+    throw new Error("n must be an integer between 1 and 100000.");
+  }
+
+  let limit = getSieveLimit(n);
+  let prime = sieveNthPrime(n, limit);
+
+  while (prime === null) {
+    limit = Math.ceil(limit * 1.2) + 10;
+    prime = sieveNthPrime(n, limit);
+  }
+
+  return prime;
+}
diff --git a/app/api/routes-f/_lib/templateInterpolation.ts b/app/api/routes-f/_lib/templateInterpolation.ts
new file mode 100644
index 00000000..25b334d8
--- /dev/null
+++ b/app/api/routes-f/_lib/templateInterpolation.ts
@@ -0,0 +1,58 @@
+export type MissingMode = "empty" | "keep" | "error";
+
+export type InterpolationResult = {
+  output: string;
+  missing_keys: string[];
+};
+
+function resolveValue(values: unknown, path: string): unknown {
+  const segments = path.split(".").filter(Boolean);
+  let current = values;
+
+  for (const segment of segments) {
+    if (current === null || current === undefined || typeof current !== "object") {
+      return undefined;
+    }
+
+    if (Array.isArray(current)) {
+      current = (current as any)[segment];
+    } else {
+      current = (current as Record<string, unknown>)[segment];
+    }
+  }
+
+  return current;
+}
+
+export function interpolateTemplate(
+  template: string,
+  values: unknown,
+  onMissing: MissingMode = "empty"
+): InterpolationResult {
+  const missingKeys = new Set<string>();
+
+  const output = template.replace(/{{\s*([^}]+?)\s*}}/g, (match, path) => {
+    const key = String(path).trim();
+    const resolved = resolveValue(values, key);
+
+    if (resolved === undefined || resolved === null) {
+      missingKeys.add(key);
+      return onMissing === "keep" ? match : "";
+    }
+
+    if (typeof resolved === "string") {
+      return resolved;
+    }
+
+    if (typeof resolved === "number" || typeof resolved === "boolean") {
+      return String(resolved);
+    }
+
+    return JSON.stringify(resolved);
+  });
+
+  return {
+    output,
+    missing_keys: Array.from(missingKeys),
+  };
+}
diff --git a/app/api/routes-f/_lib/textSimilarity.ts b/app/api/routes-f/_lib/textSimilarity.ts
new file mode 100644
index 00000000..8bb9de8e
--- /dev/null
+++ b/app/api/routes-f/_lib/textSimilarity.ts
@@ -0,0 +1,75 @@
+export type SimilarityAlgorithm = "jaccard" | "cosine" | "both";
+
+export function tokenize(text: string): string[] {
+  return Array.from(text.toLowerCase().match(/[a-z0-9]+/g) ?? []);
+}
+
+export function jaccardSimilarity(a: string, b: string): number {
+  const aTokens = new Set(tokenize(a));
+  const bTokens = new Set(tokenize(b));
+
+  if (aTokens.size === 0 && bTokens.size === 0) {
+    return 1;
+  }
+
+  const intersectionSize = Array.from(aTokens).reduce((count, token) => {
+    return bTokens.has(token) ? count + 1 : count;
+  }, 0);
+
+  const unionSize = new Set([...aTokens, ...bTokens]).size;
+  return unionSize === 0 ? 0 : intersectionSize / unionSize;
+}
+
+export function cosineSimilarity(a: string, b: string): number {
+  const aTokens = tokenize(a);
+  const bTokens = tokenize(b);
+
+  if (aTokens.length === 0 && bTokens.length === 0) {
+    return 1;
+  }
+
+  const aFreq = new Map<string, number>();
+  const bFreq = new Map<string, number>();
+
+  for (const token of aTokens) {
+    aFreq.set(token, (aFreq.get(token) ?? 0) + 1);
+  }
+  for (const token of bTokens) {
+    bFreq.set(token, (bFreq.get(token) ?? 0) + 1);
+  }
+
+  let dotProduct = 0;
+  let aSum = 0;
+  let bSum = 0;
+
+  for (const [token, aCount] of aFreq.entries()) {
+    aSum += aCount * aCount;
+    const bCount = bFreq.get(token) ?? 0;
+    dotProduct += aCount * bCount;
+  }
+
+  for (const bCount of bFreq.values()) {
+    bSum += bCount * bCount;
+  }
+
+  const denominator = Math.sqrt(aSum) * Math.sqrt(bSum);
+  return denominator === 0 ? 0 : dotProduct / denominator;
+}
+
+export function computeSimilarity(
+  a: string,
+  b: string,
+  algorithm: SimilarityAlgorithm = "both"
+): { jaccard?: number; cosine?: number } {
+  const result: { jaccard?: number; cosine?: number } = {};
+
+  if (algorithm === "jaccard" || algorithm === "both") {
+    result.jaccard = jaccardSimilarity(a, b);
+  }
+
+  if (algorithm === "cosine" || algorithm === "both") {
+    result.cosine = cosineSimilarity(a, b);
+  }
+
+  return result;
+}
diff --git a/app/api/routes-f/address-generator/__tests__/route.test.ts b/app/api/routes-f/address-generator/__tests__/route.test.ts
new file mode 100644
index 00000000..ade985a0
--- /dev/null
+++ b/app/api/routes-f/address-generator/__tests__/route.test.ts
@@ -0,0 +1,34 @@
+import { generateAddresses } from "../route";
+
+describe("generateAddresses", () => {
+  it("returns the requested count", () => {
+    expect(generateAddresses(5, "US", 42)).toHaveLength(5);
+    expect(generateAddresses(1, "NG", 7)).toHaveLength(1);
+  });
+
+  it("is deterministic for a given seed", () => {
+    expect(generateAddresses(3, "US", 42)).toEqual(
+      generateAddresses(3, "US", 42),
+    );
+  });
+
+  it("produces different output for different seeds", () => {
+    expect(generateAddresses(3, "US", 42)).not.toEqual(
+      generateAddresses(3, "US", 43),
+    );
+  });
+
+  it("uses the correct postal format per country", () => {
+    expect(generateAddresses(10, "US", 1).every((a) => /^\d{5}$/.test(a.postal_code))).toBe(true);
+    expect(generateAddresses(10, "NG", 1).every((a) => /^\d{6}$/.test(a.postal_code))).toBe(true);
+    expect(
+      generateAddresses(10, "UK", 1).every((a) =>
+        /^[A-Z]{2}\d \d[A-Z]{2}$/.test(a.postal_code),
+      ),
+    ).toBe(true);
+  });
+
+  it("tags addresses with the country name", () => {
+    expect(generateAddresses(1, "US", 1)[0].country).toBe("United States");
+  });
+});
diff --git a/app/api/routes-f/address-generator/route.ts b/app/api/routes-f/address-generator/route.ts
new file mode 100644
index 00000000..ef3cd7df
--- /dev/null
+++ b/app/api/routes-f/address-generator/route.ts
@@ -0,0 +1,114 @@
+import { NextResponse } from "next/server";
+import { z } from "zod";
+import { validateQuery } from "@/app/api/routes-f/_lib/validate";
+
+export type CountryCode = "US" | "UK" | "NG";
+
+export interface SyntheticAddress {
+  street: string;
+  city: string;
+  region: string;
+  postal_code: string;
+  country: string;
+}
+
+// Pools and postal formats bundled inside this folder (no external data deps).
+interface CountryPool {
+  country: string;
+  streets: string[];
+  cities: { city: string; region: string }[];
+  postal: (rng: () => number) => string;
+}
+
+const digits = (rng: () => number, n: number): string =>
+  Array.from({ length: n }, () => Math.floor(rng() * 10)).join("");
+
+const letter = (rng: () => number): string =>
+  String.fromCharCode(65 + Math.floor(rng() * 26));
+
+const POOLS: Record<CountryCode, CountryPool> = {
+  US: {
+    country: "United States",
+    streets: ["Main St", "Oak Ave", "Maple Dr", "Cedar Ln", "Pine Rd", "Elm St"],
+    cities: [
+      { city: "Springfield", region: "IL" },
+      { city: "Austin", region: "TX" },
+      { city: "Denver", region: "CO" },
+      { city: "Portland", region: "OR" },
+    ],
+    postal: (rng) => digits(rng, 5),
+  },
+  UK: {
+    country: "United Kingdom",
+    streets: ["High St", "Station Rd", "Church Ln", "Victoria Rd", "Kings Way"],
+    cities: [
+      { city: "London", region: "England" },
+      { city: "Manchester", region: "England" },
+      { city: "Glasgow", region: "Scotland" },
+      { city: "Cardiff", region: "Wales" },
+    ],
+    // e.g. "AB1 2CD"
+    postal: (rng) =>
+      `${letter(rng)}${letter(rng)}${digits(rng, 1)} ${digits(rng, 1)}${letter(rng)}${letter(rng)}`,
+  },
+  NG: {
+    country: "Nigeria",
+    streets: ["Awolowo Rd", "Adeola Odeku St", "Broad St", "Ahmadu Bello Way"],
+    cities: [
+      { city: "Lagos", region: "Lagos" },
+      { city: "Abuja", region: "FCT" },
+      { city: "Kano", region: "Kano" },
+      { city: "Enugu", region: "Enugu" },
+    ],
+    postal: (rng) => digits(rng, 6),
+  },
+};
+
+/** Deterministic PRNG (mulberry32). */
+function mulberry32(seed: number): () => number {
+  let s = seed >>> 0;
+  return () => {
+    s = (s + 0x6d2b79f5) >>> 0;
+    let t = Math.imul(s ^ (s >>> 15), 1 | s);
+    t = (t + Math.imul(t ^ (t >>> 7), 61 | t)) ^ t;
+    return ((t ^ (t >>> 14)) >>> 0) / 4294967296;
+  };
+}
+
+const pick = <T>(arr: T[], rng: () => number): T =>
+  arr[Math.floor(rng() * arr.length)];
+
+/** Generate `count` deterministic synthetic addresses for `country` from `seed`. */
+export function generateAddresses(
+  count: number,
+  country: CountryCode,
+  seed: number,
+): SyntheticAddress[] {
+  const rng = mulberry32(seed);
+  const pool = POOLS[country];
+  return Array.from({ length: count }, () => {
+    const number = 1 + Math.floor(rng() * 9998);
+    const { city, region } = pick(pool.cities, rng);
+    return {
+      street: `${number} ${pick(pool.streets, rng)}`,
+      city,
+      region,
+      postal_code: pool.postal(rng),
+      country: pool.country,
+    };
+  });
+}
+
+const schema = z.object({
+  count: z.coerce.number().int().min(1).max(100).optional().default(5),
+  country: z.enum(["US", "UK", "NG"]).optional().default("US"),
+  seed: z.coerce.number().int().optional().default(0),
+});
+
+export async function GET(request: Request): Promise<NextResponse> {
+  const { searchParams } = new URL(request.url);
+  const result = validateQuery(searchParams, schema);
+  if (result instanceof NextResponse) return result;
+  const { count, country, seed } = result.data;
+  return NextResponse.json({ addresses: generateAddresses(count, country, seed) });
+}
diff --git a/app/api/routes-f/age-units/__tests__/route.test.ts b/app/api/routes-f/age-units/__tests__/route.test.ts
new file mode 100644
index 00000000..7372a280
--- /dev/null
+++ b/app/api/routes-f/age-units/__tests__/route.test.ts
@@ -0,0 +1,60 @@
+jest.mock("next/server", () => ({
+  NextResponse: {
+    json: (body: unknown, init?: ResponseInit) =>
+      new Response(JSON.stringify(body), {
+        ...init,
+        headers: { "Content-Type": "application/json" },
+      }),
+  },
+}));
+
+import { POST } from "../route";
+
+function makeRequest(body: object) {
+  return new Request("http://localhost/api/routes-f/age-units", {
+    method: "POST",
+    headers: { "Content-Type": "application/json" },
+    body: JSON.stringify(body),
+  }) as unknown as import("next/server").NextRequest;
+}
+
+describe("routes-f age-units", () => {
+  it("computes exact birthday values", async () => {
+    const res = await POST(
+      makeRequest({
+        birthdate: "2000-05-28T00:00:00.000Z",
+        on_date: "2026-05-28T00:00:00.000Z",
+      })
+    );
+    const json = await res.json();
+
+    expect(res.status).toBe(200);
+    expect(json.years).toBe(26);
+    expect(json.total_months).toBe(312);
+  });
+
+  it("handles leap-year births before the leap-day anniversary is reached", async () => {
+    const res = await POST(
+      makeRequest({
+        birthdate: "2000-02-29T00:00:00.000Z",
+        on_date: "2021-02-28T00:00:00.000Z",
+      })
+    );
+    const json = await res.json();
+
+    expect(res.status).toBe(200);
+    expect(json.years).toBe(20);
+    expect(json.total_months).toBe(251);
+  });
+
+  it("rejects future birthdates", async () => {
+    const res = await POST(
+      makeRequest({
+        birthdate: "2030-01-01T00:00:00.000Z",
+        on_date: "2026-01-01T00:00:00.000Z",
+      })
+    );
+
+    expect(res.status).toBe(400);
+  });
+});
diff --git a/app/api/routes-f/age-units/route.ts b/app/api/routes-f/age-units/route.ts
new file mode 100644
index 00000000..d3cb8b6c
--- /dev/null
+++ b/app/api/routes-f/age-units/route.ts
@@ -0,0 +1,98 @@
+import { NextRequest, NextResponse } from "next/server";
+import { z } from "zod";
+
+const schema = z.object({
+  birthdate: z.string().datetime({ offset: true }).or(z.string().date()),
+  on_date: z
+    .string()
+    .datetime({ offset: true })
+    .or(z.string().date())
+    .optional(),
+});
+
+function parseDate(value: string): Date {
+  return new Date(value);
+}
+
+function isValidDate(value: Date): boolean {
+  return !Number.isNaN(value.getTime());
+}
+
+function getCompletedYears(birthdate: Date, onDate: Date): number {
+  let years = onDate.getUTCFullYear() - birthdate.getUTCFullYear();
+  const birthMonth = birthdate.getUTCMonth();
+  const currentMonth = onDate.getUTCMonth();
+
+  if (
+    currentMonth < birthMonth ||
+    (currentMonth === birthMonth &&
+      onDate.getUTCDate() < birthdate.getUTCDate())
+  ) {
+    years -= 1;
+  }
+
+  return years;
+}
+
+function getCompletedMonths(birthdate: Date, onDate: Date): number {
+  let months =
+    (onDate.getUTCFullYear() - birthdate.getUTCFullYear()) * 12 +
+    (onDate.getUTCMonth() - birthdate.getUTCMonth());
+
+  if (onDate.getUTCDate() < birthdate.getUTCDate()) {
+    months -= 1;
+  }
+
+  return months;
+}
+
+export async function POST(req: NextRequest) {
+  let rawBody: unknown;
+
+  try {
+    rawBody = await req.json();
+  } catch {
+    return NextResponse.json({ error: "Invalid JSON body" }, { status: 400 });
+  }
+
+  const parsed = schema.safeParse(rawBody);
+  if (!parsed.success) {
+    return NextResponse.json(
+      {
+        error: "Validation failed",
+        issues: parsed.error.issues.map(issue => ({
+          field: issue.path.join(".") || "body",
+          message: issue.message,
+        })),
+      },
+      { status: 400 }
+    );
+  }
+
+  const birthdate = parseDate(parsed.data.birthdate);
+  const onDate = parseDate(parsed.data.on_date ?? new Date().toISOString());
+
+  if (!isValidDate(birthdate) || !isValidDate(onDate)) {
+    return NextResponse.json({ error: "Invalid date input" }, { status: 400 });
+  }
+
+  if (birthdate > onDate) {
+    return NextResponse.json(
+      { error: "birthdate cannot be in the future" },
+      { status: 400 }
+    );
+  }
+
+  const diffMs = onDate.getTime() - birthdate.getTime();
+  const totalHours = Math.floor(diffMs / (1000 * 60 * 60));
+  const totalDays = Math.floor(diffMs / (1000 * 60 * 60 * 24));
+  const totalWeeks = Math.floor(totalDays / 7);
+
+  return NextResponse.json({
+    years: getCompletedYears(birthdate, onDate),
+    total_months: getCompletedMonths(birthdate, onDate),
+    total_weeks: totalWeeks,
+    total_days: totalDays,
+    total_hours: totalHours,
+  });
+}
diff --git a/app/api/routes-f/base32/__tests__/route.test.ts b/app/api/routes-f/base32/__tests__/route.test.ts
new file mode 100644
index 00000000..6b542edc
--- /dev/null
+++ b/app/api/routes-f/base32/__tests__/route.test.ts
@@ -0,0 +1,33 @@
+import { base32Encode, base32Decode } from "../route";
+
+describe("base32Encode", () => {
+  it("matches RFC 4648 test vectors", () => {
+    expect(base32Encode("")).toBe("");
+    expect(base32Encode("f")).toBe("MY======");
+    expect(base32Encode("fo")).toBe("MZXQ====");
+    expect(base32Encode("foo")).toBe("MZXW6===");
+    expect(base32Encode("foobar")).toBe("MZXW6YTBOI======");
+  });
+
+  it("omits padding when padding=false", () => {
+    expect(base32Encode("foobar", false)).toBe("MZXW6YTBOI");
+  });
+});
+
+describe("base32Decode", () => {
+  it("decodes RFC 4648 vectors (with or without padding)", () => {
+    expect(base32Decode("MZXW6YTBOI======")).toBe("foobar");
+    expect(base32Decode("MZXW6YTBOI")).toBe("foobar");
+    expect(base32Decode("MY======")).toBe("f");
+  });
+
+  it("round-trips arbitrary input", () => {
+    for (const s of ["hello world", "Stellar ⭐", "a", "12345"]) {
+      expect(base32Decode(base32Encode(s))).toBe(s);
+    }
+  });
+
+  it("throws on invalid base32 characters", () => {
+    expect(() => base32Decode("0189")).toThrow(RangeError); // 0,1,8,9 not in alphabet
+  });
+});
diff --git a/app/api/routes-f/base32/route.ts b/app/api/routes-f/base32/route.ts
new file mode 100644
index 00000000..18f6031d
--- /dev/null
+++ b/app/api/routes-f/base32/route.ts
@@ -0,0 +1,75 @@
+import { NextResponse } from "next/server";
+import { z } from "zod";
+import { validateBody } from "@/app/api/routes-f/_lib/validate";
+
+const ALPHABET = "ABCDEFGHIJKLMNOPQRSTUVWXYZ234567";
+
+/** RFC 4648 base32 encode of a UTF-8 string. */
+export function base32Encode(input: string, padding = true): string {
+  const bytes = new TextEncoder().encode(input);
+  let bits = 0;
+  let value = 0;
+  let out = "";
+  for (const b of bytes) {
+    value = ((value << 8) | b) >>> 0;
+    bits += 8;
+    while (bits >= 5) {
+      out += ALPHABET[(value >>> (bits - 5)) & 31];
+      bits -= 5;
+    }
+    value &= (1 << bits) - 1;
+  }
+  if (bits > 0) {
+    out += ALPHABET[(value << (5 - bits)) & 31];
+  }
+  if (padding) {
+    while (out.length % 8 !== 0) out += "=";
+  }
+  return out;
+}
+
+/** RFC 4648 base32 decode back to a UTF-8 string. Throws on invalid input. */
+export function base32Decode(input: string): string {
+  const clean = input.toUpperCase().replace(/=+$/, "");
+  let bits = 0;
+  let value = 0;
+  const bytes: number[] = [];
+  for (const ch of clean) {
+    const idx = ALPHABET.indexOf(ch);
+    if (idx === -1) {
+      throw new RangeError(`invalid base32 character: ${ch}`);
+    }
+    value = ((value << 5) | idx) >>> 0;
+    bits += 5;
+    if (bits >= 8) {
+      bytes.push((value >>> (bits - 8)) & 0xff);
+      bits -= 8;
+    }
+    value &= (1 << bits) - 1;
+  }
+  return new TextDecoder().decode(new Uint8Array(bytes));
+}
+
+const schema = z.object({
+  input: z.string(),
+  mode: z.enum(["encode", "decode"]),
+  padding: z.boolean().optional().default(true),
+});
+
+export async function POST(request: Request): Promise<NextResponse> {
+  const result = await validateBody(request, schema);
+  if (result instanceof NextResponse) return result;
+  const { input, mode, padding } = result.data;
+
+  if (mode === "encode") {
+    return NextResponse.json({ output: base32Encode(input, padding) });
+  }
+  try {
+    return NextResponse.json({ output: base32Decode(input) });
+  } catch (e) {
+    return NextResponse.json(
+      { error: e instanceof Error ? e.message : "invalid base32 input" },
+      { status: 400 },
+    );
+  }
+}
diff --git a/app/api/routes-f/base64-validate/__tests__/route.test.ts b/app/api/routes-f/base64-validate/__tests__/route.test.ts
new file mode 100644
index 00000000..31792191
--- /dev/null
+++ b/app/api/routes-f/base64-validate/__tests__/route.test.ts
@@ -0,0 +1,41 @@
+import { validateBase64 } from "../route";
+
+describe("validateBase64", () => {
+  it("accepts well-formed standard base64", () => {
+    expect(validateBase64("Zm9vYmFy")).toEqual({
+      valid: true,
+      variant_detected: "standard",
+      decoded_length: 6,
+    });
+  });
+
+  it("accounts for padding in decoded_length", () => {
+    expect(validateBase64("Zm9vYg==")).toEqual({
+      valid: true,
+      variant_detected: "standard",
+      decoded_length: 4,
+    });
+  });
+
+  it("detects the url-safe alphabet", () => {
+    const r = validateBase64("a-b_");
+    expect(r.valid).toBe(true);
+    expect(r.variant_detected).toBe("urlsafe");
+  });
+
+  it("rejects misplaced padding", () => {
+    expect(validateBase64("Zm=9").valid).toBe(false);
+  });
+
+  it("rejects the wrong charset", () => {
+    expect(validateBase64("Zm9v$bcd").valid).toBe(false);
+  });
+
+  it("rejects an impossible length (len % 4 == 1)", () => {
+    expect(validateBase64("Zm9vY").valid).toBe(false);
+  });
+
+  it("rejects mixed alphabets", () => {
+    expect(validateBase64("ab+c-d").valid).toBe(false);
+  });
+});
diff --git a/app/api/routes-f/base64-validate/route.ts b/app/api/routes-f/base64-validate/route.ts
new file mode 100644
index 00000000..0c4033cd
--- /dev/null
+++ b/app/api/routes-f/base64-validate/route.ts
@@ -0,0 +1,64 @@
+import { NextResponse } from "next/server";
+import { z } from "zod";
+import { validateBody } from "@/app/api/routes-f/_lib/validate";
+
+export type Base64Variant = "standard" | "urlsafe" | "auto";
+
+export interface Base64Result {
+  valid: boolean;
+  variant_detected: "standard" | "urlsafe" | null;
+  decoded_length: number;
+}
+
+const INVALID: Base64Result = { valid: false, variant_detected: null, decoded_length: 0 };
+
+/**
+ * Validate whether `input` is well-formed base64 (standard or URL-safe):
+ * charset, padding placement, and length divisibility.
+ */
+export function validateBase64(input: string, variant: Base64Variant = "auto"): Base64Result {
+  if (input.length === 0) {
+    return { valid: true, variant_detected: variant === "auto" ? "standard" : variant, decoded_length: 0 };
+  }
+
+  const hasStd = /[+/]/.test(input);
+  const hasUrl = /[-_]/.test(input);
+  if (hasStd && hasUrl) return INVALID; // mixed alphabets
+
+  let detected: "standard" | "urlsafe" = hasUrl ? "urlsafe" : "standard";
+  if (variant !== "auto") {
+    if ((hasStd || hasUrl) && variant !== detected) return INVALID;
+    detected = variant;
+  }
+
+  const charset = detected === "urlsafe" ? /^[A-Za-z0-9_-]+={0,2}$/ : /^[A-Za-z0-9+/]+={0,2}$/;
+  if (!charset.test(input)) return INVALID;
+
+  const padIdx = input.indexOf("=");
+  const padding = padIdx === -1 ? 0 : input.length - padIdx;
+  // padding, if present, must be 1–2 '=' all at the very end
+  if (padIdx !== -1 && !/^={1,2}$/.test(input.slice(padIdx))) return INVALID;
+
+  if (input.length % 4 === 1) return INVALID; // impossible base64 length
+  if (input.length % 4 !== 0) {
+    // only tolerate unpadded length for url-safe (padding is optional there)
+    if (padding > 0 || detected === "standard") return INVALID;
+  } else if (padding > 0 && input.length % 4 !== 0) {
+    return INVALID;
+  }
+
+  const decoded_length = Math.floor((input.length - padding) * 3 / 4);
+  return { valid: true, variant_detected: detected, decoded_length };
+}
+
+const schema = z.object({
+  input: z.string(),
+  variant: z.enum(["standard", "urlsafe", "auto"]).optional().default("auto"),
+});
+
+export async function POST(request: Request): Promise<NextResponse> {
+  const result = await validateBody(request, schema);
+  if (result instanceof NextResponse) return result;
+  const { input, variant } = result.data;
+  return NextResponse.json(validateBase64(input, variant));
+}
diff --git a/app/api/routes-f/binary-to-text/route.ts b/app/api/routes-f/binary-to-text/route.ts
new file mode 100644
index 00000000..e7e167e7
--- /dev/null
+++ b/app/api/routes-f/binary-to-text/route.ts
@@ -0,0 +1,51 @@
+import { NextResponse } from "next/server";
+import { z } from "zod";
+import { validateBody } from "@/app/api/routes-f/_lib/validate";
+
+const schema = z.object({
+  input: z.string(),
+  mode: z.enum(["to_binary", "from_binary"]),
+  bits: z.number().int().positive().optional().default(8),
+});
+
+/** Encode a UTF-8 string to space-separated binary groups. */
+export function toBinary(input: string, bits: number): string {
+  const bytes = new TextEncoder().encode(input);
+  return Array.from(bytes)
+    .map((b) => b.toString(2).padStart(bits, "0"))
+    .join(" ");
+}
+
+/** Decode space-separated binary groups back to a UTF-8 string. */
+export function fromBinary(input: string, bits: number): string {
+  const groups = input.trim().split(/\s+/);
+
+  for (const g of groups) {
+    if (!/^[01]+$/.test(g)) {
+      throw new Error(`Invalid binary token: "${g}"`);
+    }
+    if (g.length !== bits) {
+      throw new Error(`Token "${g}" has ${g.length} bits, expected ${bits}`);
+    }
+  }
+
+  const bytes = new Uint8Array(groups.map((g) => parseInt(g, 2)));
+  return new TextDecoder().decode(bytes);
+}
+
+export async function POST(request: Request): Promise<NextResponse> {
+  const result = await validateBody(request, schema);
+  if (result instanceof NextResponse) return result;
+
+  const { input, mode, bits } = result.data;
+
+  try {
+    const output = mode === "to_binary" ? toBinary(input, bits) : fromBinary(input, bits);
+    return NextResponse.json({ result: output });
+  } catch (err) {
+    return NextResponse.json(
+      { error: err instanceof Error ? err.message : "Conversion failed" },
+      { status: 400 }
+    );
+  }
+}
diff --git a/app/api/routes-f/bingo/__tests__/route.test.ts b/app/api/routes-f/bingo/__tests__/route.test.ts
new file mode 100644
index 00000000..5f3bb309
--- /dev/null
+++ b/app/api/routes-f/bingo/__tests__/route.test.ts
@@ -0,0 +1,35 @@
+import { NextRequest } from "next/server";
+import { GET } from "../route";
+
+describe("GET /api/routes-f/bingo", () => {
+  it("returns deterministic cards for same seed", async () => {
+    const reqA = new NextRequest("http://localhost/api/routes-f/bingo?seed=42");
+    const reqB = new NextRequest("http://localhost/api/routes-f/bingo?seed=42");
+    const resA = await GET(reqA);
+    const resB = await GET(reqB);
+    const bodyA = await resA.json();
+    const bodyB = await resB.json();
+
+    expect(bodyA.cards).toEqual(bodyB.cards);
+  });
+
+  it("keeps values in column ranges and free center", async () => {
+    const req = new NextRequest("http://localhost/api/routes-f/bingo?seed=10");
+    const res = await GET(req);
+    const { cards } = await res.json();
+    const card = cards[0];
+
+    for (let row = 0; row < 5; row++) {
+      expect(card[row][0]).toBeGreaterThanOrEqual(1);
+      expect(card[row][0]).toBeLessThanOrEqual(15);
+      expect(card[row][1]).toBeGreaterThanOrEqual(16);
+      expect(card[row][1]).toBeLessThanOrEqual(30);
+      expect(card[row][3]).toBeGreaterThanOrEqual(46);
+      expect(card[row][3]).toBeLessThanOrEqual(60);
+      expect(card[row][4]).toBeGreaterThanOrEqual(61);
+      expect(card[row][4]).toBeLessThanOrEqual(75);
+    }
+
+    expect(card[2][2]).toBe(0);
+  });
+});
diff --git a/app/api/routes-f/bingo/route.ts b/app/api/routes-f/bingo/route.ts
new file mode 100644
index 00000000..756a1a20
--- /dev/null
+++ b/app/api/routes-f/bingo/route.ts
@@ -0,0 +1,77 @@
+import { NextRequest, NextResponse } from "next/server";
+
+const DEFAULT_COUNT = 1;
+const MAX_COUNT = 20;
+const FREE_CENTER_VALUE = 0;
+
+function createRng(seed: number) {
+  let state = seed >>> 0;
+  return () => {
+    state = (1664525 * state + 1013904223) >>> 0;
+    return state / 0x100000000;
+  };
+}
+
+function shuffle(values: number[], rng: () => number) {
+  const arr = [...values];
+  for (let i = arr.length - 1; i > 0; i--) {
+    const j = Math.floor(rng() * (i + 1));
+    [arr[i], arr[j]] = [arr[j], arr[i]];
+  }
+  return arr;
+}
+
+function buildColumn(
+  min: number,
+  max: number,
+  picks: number,
+  rng: () => number
+) {
+  return shuffle(
+    Array.from({ length: max - min + 1 }, (_, i) => min + i),
+    rng
+  ).slice(0, picks);
+}
+
+function buildCard(rng: () => number) {
+  const b = buildColumn(1, 15, 5, rng);
+  const i = buildColumn(16, 30, 5, rng);
+  const n = buildColumn(31, 45, 4, rng);
+  const g = buildColumn(46, 60, 5, rng);
+  const o = buildColumn(61, 75, 5, rng);
+
+  const card = Array.from({ length: 5 }, () => Array(5).fill(0));
+  for (let row = 0; row < 5; row++) {
+    card[row][0] = b[row];
+    card[row][1] = i[row];
+    card[row][2] = row === 2 ? FREE_CENTER_VALUE : n[row > 2 ? row - 1 : row];
+    card[row][3] = g[row];
+    card[row][4] = o[row];
+  }
+  return card;
+}
+
+export function GET(request: NextRequest) {
+  const seedParam = request.nextUrl.searchParams.get("seed");
+  const countParam = request.nextUrl.searchParams.get("count");
+
+  const seed = seedParam === null ? Date.now() : Number(seedParam);
+  if (!Number.isFinite(seed)) {
+    return NextResponse.json(
+      { error: "seed must be numeric" },
+      { status: 400 }
+    );
+  }
+
+  const count = countParam === null ? DEFAULT_COUNT : Number(countParam);
+  if (!Number.isInteger(count) || count < 1 || count > MAX_COUNT) {
+    return NextResponse.json(
+      { error: `count must be an integer between 1 and ${MAX_COUNT}` },
+      { status: 400 }
+    );
+  }
+
+  const rng = createRng(seed);
+  const cards = Array.from({ length: count }, () => buildCard(rng));
+  return NextResponse.json({ cards });
+}
diff --git a/app/api/routes-f/break-even/route.ts b/app/api/routes-f/break-even/route.ts
new file mode 100644
index 00000000..01cd7f15
--- /dev/null
+++ b/app/api/routes-f/break-even/route.ts
@@ -0,0 +1,38 @@
+import { NextResponse } from "next/server";
+import { z } from "zod";
+import { validateBody } from "@/app/api/routes-f/_lib/validate";
+import type { BreakEvenRequest, BreakEvenResponse } from "./types";
+
+const schema = z.object({
+  fixed_costs: z.number(),
+  price_per_unit: z.number(),
+  variable_cost_per_unit: z.number(),
+});
+
+export async function POST(request: Request): Promise<NextResponse> {
+  const result = await validateBody(request, schema);
+  if (result instanceof NextResponse) {
+    return result;
+  }
+
+  const { fixed_costs, price_per_unit, variable_cost_per_unit } = result.data;
+
+  if (price_per_unit <= variable_cost_per_unit) {
+    return NextResponse.json(
+      { error: "Price must exceed variable cost per unit to break even" },
+      { status: 400 }
+    );
+  }
+
+  const contribution_margin = price_per_unit - variable_cost_per_unit;
+  const break_even_units = Math.ceil(fixed_costs / contribution_margin);
+  const break_even_revenue = break_even_units * price_per_unit;
+
+  const response: BreakEvenResponse = {
+    break_even_units,
+    break_even_revenue,
+    contribution_margin,
+  };
+
+  return NextResponse.json(response);
+}
diff --git a/app/api/routes-f/break-even/types.ts b/app/api/routes-f/break-even/types.ts
new file mode 100644
index 00000000..43fe0ca9
--- /dev/null
+++ b/app/api/routes-f/break-even/types.ts
@@ -0,0 +1,11 @@
+export interface BreakEvenRequest {
+  fixed_costs: number;
+  price_per_unit: number;
+  variable_cost_per_unit: number;
+}
+
+export interface BreakEvenResponse {
+  break_even_units: number;
+  break_even_revenue: number;
+  contribution_margin: number;
+}
diff --git a/app/api/routes-f/broadcast-live/__tests__/broadcast-live.test.ts b/app/api/routes-f/broadcast-live/__tests__/broadcast-live.test.ts
new file mode 100644
index 00000000..1ded27ae
--- /dev/null
+++ b/app/api/routes-f/broadcast-live/__tests__/broadcast-live.test.ts
@@ -0,0 +1,67 @@
+/**
+ * @jest-environment node
+ */
+import { NextRequest } from "next/server";
+import { POST } from "../route";
+
+const BASE_URL = "http://localhost/api/routes-f/broadcast-live";
+
+function makePost(body: unknown) {
+  return new NextRequest(BASE_URL, {
+    method: "POST",
+    headers: { "content-type": "application/json" },
+    body: JSON.stringify(body),
+  });
+}
+
+describe("POST /api/routes-f/broadcast-live", () => {
+  it("notifies all eligible followers (notify_live=true and not muted)", async () => {
+    // c-001 has 5 followers: f-001(✓), f-002(✓), f-003(notify_live=false), f-004(muted), f-005(✓) → 3 eligible
+    const res = await POST(makePost({ creator_id: "c-001", stream_title: "Going Live!" }));
+    expect(res.status).toBe(200);
+    const body = await res.json();
+    expect(body.notified_count).toBe(3);
+  });
+
+  it("skips followers with notify_live=false", async () => {
+    // c-002 has 3 followers: f-006(✓), f-007(✓), f-008(notify_live=false) → 2 eligible
+    const res = await POST(makePost({ creator_id: "c-002", stream_title: "Art Stream" }));
+    const body = await res.json();
+    expect(body.notified_count).toBe(2);
+  });
+
+  it("skips muted followers", async () => {
+    // f-004 follows c-001 but is muted — confirmed excluded in the c-001 test above
+    const res = await POST(makePost({ creator_id: "c-001", stream_title: "Live Again" }));
+    const body = await res.json();
+    // 5 followers, minus notify_live=false (f-003) and muted (f-004) = 3
+    expect(body.notified_count).toBe(3);
+  });
+
+  it("returns 0 for creator with no followers in seed", async () => {
+    const res = await POST(makePost({ creator_id: "c-unknown-999", stream_title: "Solo" }));
+    const body = await res.json();
+    expect(body.notified_count).toBe(0);
+  });
+
+  it("400 — missing creator_id", async () => {
+    const res = await POST(makePost({ stream_title: "No Creator" }));
+    expect(res.status).toBe(400);
+  });
+
+  it("400 — missing stream_title", async () => {
+    const res = await POST(makePost({ creator_id: "c-001" }));
+    expect(res.status).toBe(400);
+  });
+
+  it("400 — invalid JSON body", async () => {
+    const res = await POST(
+      new NextRequest(BASE_URL, {
+        method: "POST",
+        headers: { "content-type": "application/json" },
+        body: "{bad json",
+      })
+    );
+    expect(res.status).toBe(400);
+  });
+});
diff --git a/app/api/routes-f/broadcast-live/route.ts b/app/api/routes-f/broadcast-live/route.ts
new file mode 100644
index 00000000..94f30a98
--- /dev/null
+++ b/app/api/routes-f/broadcast-live/route.ts
@@ -0,0 +1,56 @@
+/**
+ * POST  /api/routes-f/broadcast-live
+ *
+ * Fan out a "creator is live" notification to all followers, skipping those
+ * who have muted the creator or have notify_live=false.
+ * Returns { notified_count }.
+ * Uses in-memory seed data — no real DB.
+ */
+import { NextRequest, NextResponse } from "next/server";
+import { z } from "zod";
+import { validateBody } from "@/app/api/routes-f/_lib/validate";
+
+// ---------------------------------------------------------------------------
+// Seed data
+// ---------------------------------------------------------------------------
+interface Follower {
+  follower_id: string;
+  creator_id: string;
+  notify_live: boolean;
+  muted: boolean;
+}
+
+export const FOLLOWERS: Follower[] = [
+  { follower_id: "f-001", creator_id: "c-001", notify_live: true, muted: false },
+  { follower_id: "f-002", creator_id: "c-001", notify_live: true, muted: false },
+  { follower_id: "f-003", creator_id: "c-001", notify_live: false, muted: false },
+  { follower_id: "f-004", creator_id: "c-001", notify_live: true, muted: true },
+  { follower_id: "f-005", creator_id: "c-001", notify_live: true, muted: false },
+  { follower_id: "f-006", creator_id: "c-002", notify_live: true, muted: false },
+  { follower_id: "f-007", creator_id: "c-002", notify_live: true, muted: false },
+  { follower_id: "f-008", creator_id: "c-002", notify_live: false, muted: false },
+];
+
+// ---------------------------------------------------------------------------
+// Schema
+// ---------------------------------------------------------------------------
+const bodySchema = z.object({
+  creator_id: z.string().min(1, "creator_id is required"),
+  stream_title: z.string().min(1, "stream_title is required"),
+});
+
+// ---------------------------------------------------------------------------
+// Handler
+// ---------------------------------------------------------------------------
+export async function POST(req: NextRequest): Promise<NextResponse> {
+  const result = await validateBody(req, bodySchema);
+  if (result instanceof NextResponse) return result;
+
+  const { creator_id } = result.data;
+
+  const eligible = FOLLOWERS.filter(
+    (f) => f.creator_id === creator_id && f.notify_live && !f.muted
+  );
+
+  return NextResponse.json({ notified_count: eligible.length });
+}
diff --git a/app/api/routes-f/business-hours/route.ts b/app/api/routes-f/business-hours/route.ts
new file mode 100644
index 00000000..4af4bc4c
--- /dev/null
+++ b/app/api/routes-f/business-hours/route.ts
@@ -0,0 +1,79 @@
+import { NextRequest, NextResponse } from "next/server";
+
+function parseTime(t: string): { h: number; m: number } {
+  const [h, m] = t.split(":").map(Number);
+  return { h, m };
+}
+
+function toMinutes(h: number, m: number): number {
+  return h * 60 + m;
+}
+
+export async function POST(req: NextRequest) {
+  let body: {
+    timestamp?: unknown;
+    timezone?: unknown;
+    open?: unknown;
+    close?: unknown;
+    days?: unknown;
+  };
+  try {
+    body = await req.json();
+  } catch {
+    return NextResponse.json({ error: "Invalid JSON" }, { status: 400 });
+  }
+
+  const {
+    timestamp,
+    timezone = "UTC",
+    open = "09:00",
+    close = "17:00",
+    days = [1, 2, 3, 4, 5],
+  } = body;
+
+  if (typeof timestamp !== "string") {
+    return NextResponse.json({ error: "timestamp is required (ISO string)" }, { status: 400 });
+  }
+
+  const date = new Date(timestamp);
+  if (isNaN(date.getTime())) {
+    return NextResponse.json({ error: "Invalid timestamp" }, { status: 400 });
+  }
+
+  const tz = typeof timezone === "string" ? timezone : "UTC";
+  const allowedDays = Array.isArray(days) ? (days as number[]) : [1, 2, 3, 4, 5];
+
+  const localStr = date.toLocaleString("en-US", { timeZone: tz, hour12: false });
+  const local = new Date(localStr);
+  const dayOfWeek = local.getDay(); // 0=Sun
+  const currentMins = toMinutes(local.getHours(), local.getMinutes());
+
+  const { h: oh, m: om } = parseTime(typeof open === "string" ? open : "09:00");
+  const { h: ch, m: cm } = parseTime(typeof close === "string" ? close : "17:00");
+  const openMins = toMinutes(oh, om);
+  const closeMins = toMinutes(ch, cm);
+
+  const isOpen =
+    allowedDays.includes(dayOfWeek) &&
+    currentMins >= openMins &&
+    currentMins < closeMins;
+
+  if (isOpen) {
+    return NextResponse.json({ is_open: true });
+  }
+
+  // Find next open time
+  let next = new Date(date);
+  for (let i = 1; i <= 7; i++) {
+    next = new Date(next.getTime() + 24 * 60 * 60 * 1000);
+    const nextLocalStr = next.toLocaleString("en-US", { timeZone: tz, hour12: false });
+    const nextLocal = new Date(nextLocalStr);
+    if (allowedDays.includes(nextLocal.getDay())) {
+      // set to open time
+      nextLocal.setHours(oh, om, 0, 0);
+      return NextResponse.json({ is_open: false, next_open: nextLocal.toISOString() });
+    }
+  }
+
+  return NextResponse.json({ is_open: false });
+}
diff --git a/app/api/routes-f/cagr/__tests__/route.test.ts b/app/api/routes-f/cagr/__tests__/route.test.ts
new file mode 100644
index 00000000..f4c35e2b
--- /dev/null
+++ b/app/api/routes-f/cagr/__tests__/route.test.ts
@@ -0,0 +1,47 @@
+/**
+ * @jest-environment node
+ */
+import { NextRequest } from "next/server";
+import { POST } from "../route";
+
+function makeReq(body: unknown) {
+  return new NextRequest("http://localhost/api/routes-f/cagr", {
+    method: "POST",
+    headers: { "content-type": "application/json" },
+    body: JSON.stringify(body),
+  });
+}
+
+describe("POST /api/routes-f/cagr", () => {
+  it("calculates CAGR for a known growth example", async () => {
+    const res = await POST(
+      makeReq({ begin_value: 1000, end_value: 2000, years: 5 })
+    );
+    const body = await res.json();
+
+    expect(res.status).toBe(200);
+    expect(body.cagr_percent).toBeCloseTo(14.869835, 5);
+  });
+
+  it("calculates negative CAGR when value declines", async () => {
+    const res = await POST(
+      makeReq({ begin_value: 1000, end_value: 500, years: 5 })
+    );
+    const body = await res.json();
+
+    expect(res.status).toBe(200);
+    expect(body.cagr_percent).toBeCloseTo(-12.944943, 5);
+  });
+
+  it("rejects non-positive values and years", async () => {
+    const res = await POST(
+      makeReq({ begin_value: 0, end_value: 1000, years: 5 })
+    );
+    const yearsRes = await POST(
+      makeReq({ begin_value: 1000, end_value: 1100, years: -1 })
+    );
+
+    expect(res.status).toBe(400);
+    expect(yearsRes.status).toBe(400);
+  });
+});
diff --git a/app/api/routes-f/cagr/route.ts b/app/api/routes-f/cagr/route.ts
new file mode 100644
index 00000000..94027641
--- /dev/null
+++ b/app/api/routes-f/cagr/route.ts
@@ -0,0 +1,34 @@
+import { NextRequest, NextResponse } from "next/server";
+
+function finitePositive(value: unknown): number | null {
+  return typeof value === "number" && Number.isFinite(value) && value > 0
+    ? value
+    : null;
+}
+
+export async function POST(req: NextRequest) {
+  let body: { begin_value?: unknown; end_value?: unknown; years?: unknown };
+
+  try {
+    body = await req.json();
+  } catch {
+    return NextResponse.json({ error: "Invalid JSON body." }, { status: 400 });
+  }
+
+  const beginValue = finitePositive(body.begin_value);
+  const endValue = finitePositive(body.end_value);
+  const years = finitePositive(body.years);
+
+  if (beginValue === null || endValue === null || years === null) {
+    return NextResponse.json(
+      { error: "begin_value, end_value, and years must be positive numbers." },
+      { status: 400 }
+    );
+  }
+
+  const cagrPercent = (Math.pow(endValue / beginValue, 1 / years) - 1) * 100;
+
+  return NextResponse.json({
+    cagr_percent: cagrPercent,
+  });
+}
diff --git a/app/api/routes-f/case-convert/__tests__/route.test.ts b/app/api/routes-f/case-convert/__tests__/route.test.ts
new file mode 100644
index 00000000..c3fd195d
--- /dev/null
+++ b/app/api/routes-f/case-convert/__tests__/route.test.ts
@@ -0,0 +1,32 @@
+import { convertCase, splitWords } from "../route";
+
+describe("splitWords", () => {
+  it("detects each source case", () => {
+    expect(splitWords("foo_bar_baz")).toEqual(["foo", "bar", "baz"]);
+    expect(splitWords("foo-bar-baz")).toEqual(["foo", "bar", "baz"]);
+    expect(splitWords("fooBarBaz")).toEqual(["foo", "bar", "baz"]);
+    expect(splitWords("FooBarBaz")).toEqual(["foo", "bar", "baz"]);
+  });
+
+  it("preserves embedded numbers", () => {
+    expect(splitWords("apiV2Client")).toEqual(["api", "v2", "client"]);
+  });
+});
+
+describe("convertCase", () => {
+  const cases: Array<[string, CaseTargetLike]> = [];
+  type CaseTargetLike = "snake" | "camel" | "pascal" | "kebab";
+
+  it("converts mixed-case input to each target", () => {
+    expect(convertCase("fooBarBaz", "snake")).toBe("foo_bar_baz");
+    expect(convertCase("foo_bar_baz", "camel")).toBe("fooBarBaz");
+    expect(convertCase("foo-bar-baz", "pascal")).toBe("FooBarBaz");
+    expect(convertCase("FooBarBaz", "kebab")).toBe("foo-bar-baz");
+    void cases;
+  });
+
+  it("keeps numbers in the right place", () => {
+    expect(convertCase("apiV2Client", "snake")).toBe("api_v2_client");
+    expect(convertCase("api_v2_client", "pascal")).toBe("ApiV2Client");
+  });
+});
diff --git a/app/api/routes-f/case-convert/data.ts b/app/api/routes-f/case-convert/data.ts
new file mode 100644
index 00000000..ca7b1f87
--- /dev/null
+++ b/app/api/routes-f/case-convert/data.ts
@@ -0,0 +1,97 @@
+export type CaseTarget =
+  | "camelCase"
+  | "snake_case"
+  | "kebab-case"
+  | "PascalCase"
+  | "CONSTANT_CASE"
+  | "Title Case"
+  | "Sentence case";
+
+export const VALID_TARGETS: CaseTarget[] = [
+  "camelCase",
+  "snake_case",
+  "kebab-case",
+  "PascalCase",
+  "CONSTANT_CASE",
+  "Title Case",
+  "Sentence case",
+];
+
+function tokenize(text: string): string[] {
+  return text
+    .replace(/([a-z])([A-Z])/g, "$1 $2")
+    .replace(/([A-Z]+)([A-Z][a-z])/g, "$1 $2")
+    .replace(/[-_]+/g, " ")
+    .trim()
+    .split(/\s+/)
+    .filter(Boolean);
+}
+
+function toCamel(words: string[]): string {
+  return words
+    .map((w, i) => (i === 0 ? w.toLowerCase() : w[0].toUpperCase() + w.slice(1).toLowerCase()))
+    .join("");
+}
+
+function toSnake(words: string[]): string {
+  return words.map((w) => w.toLowerCase()).join("_");
+}
+
+function toKebab(words: string[]): string {
+  return words.map((w) => w.toLowerCase()).join("-");
+}
+
+function toPascal(words: string[]): string {
+  return words.map((w) => w[0].toUpperCase() + w.slice(1).toLowerCase()).join("");
+}
+
+function toConstant(words: string[]): string {
+  return words.map((w) => w.toUpperCase()).join("_");
+}
+
+function toTitle(words: string[]): string {
+  return words.map((w) => w[0].toUpperCase() + w.slice(1).toLowerCase()).join(" ");
+}
+
+function toSentence(words: string[]): string {
+  const result = words.map((w) => w.toLowerCase()).join(" ");
+  return result.charAt(0).toUpperCase() + result.slice(1);
+}
+
+export function convertCase(
+  text: string,
+  target?: string
+): Record<string, string> | { result: string } {
+  const words = tokenize(text);
+
+  if (target !== undefined) {
+    switch (target as CaseTarget) {
+      case "camelCase":
+        return { result: toCamel(words) };
+      case "snake_case":
+        return { result: toSnake(words) };
+      case "kebab-case":
+        return { result: toKebab(words) };
+      case "PascalCase":
+        return { result: toPascal(words) };
+      case "CONSTANT_CASE":
+        return { result: toConstant(words) };
+      case "Title Case":
+        return { result: toTitle(words) };
+      case "Sentence case":
+        return { result: toSentence(words) };
+      default:
+        throw new Error("Invalid target case");
+    }
+  }
+
+  return {
+    camelCase: toCamel(words),
+    snake_case: toSnake(words),
+    "kebab-case": toKebab(words),
+    PascalCase: toPascal(words),
+    CONSTANT_CASE: toConstant(words),
+    "Title Case": toTitle(words),
+    "Sentence case": toSentence(words),
+  };
+}
diff --git a/app/api/routes-f/case-convert/route.ts b/app/api/routes-f/case-convert/route.ts
new file mode 100644
index 00000000..a15be1b5
--- /dev/null
+++ b/app/api/routes-f/case-convert/route.ts
@@ -0,0 +1,102 @@
+import { NextResponse } from "next/server";
+import { z } from "zod";
+import { validateBody } from "@/app/api/routes-f/_lib/validate";
+
+/**
+ * Supported output targets.
+ * Kept local so tests mocking external modules don't shadow it.
+ */
+const VALID_TARGETS = [
+  "camelCase",
+  "snake_case",
+  "kebab-case",
+  "PascalCase",
+  "CONSTANT_CASE",
+  "Title Case",
+  "Sentence case",
+] as const;
+
+export type CaseTarget = (typeof VALID_TARGETS)[number];
+
+/**
+ * Split text into lowercase words while handling:
+ * - camelCase
+ * - PascalCase
+ * - snake_case
+ * - kebab-case
+ * - spaces
+ */
+export function splitWords(text: string): string[] {
+  return text
+    .replace(/([a-z0-9])([A-Z])/g, "$1 $2")
+    .replace(/[_-]+/g, " ")
+    .trim()
+    .split(/\s+/)
+    .filter(Boolean)
+    .map((w) => w.toLowerCase());
+}
+
+const capitalize = (word: string) =>
+  word ? word[0].toUpperCase() + word.slice(1) : word;
+
+/** Convert text into the requested target case. */
+export function convertCase(text: string, target: CaseTarget): string {
+  const words = splitWords(text);
+
+  switch (target) {
+    case "camelCase":
+      return words
+        .map((w, i) => (i === 0 ? w : capitalize(w)))
+        .join("");
+
+    case "PascalCase":
+      return words.map(capitalize).join("");
+
+    case "snake_case":
+      return words.join("_");
+
+    case "kebab-case":
+      return words.join("-");
+
+    case "CONSTANT_CASE":
+      return words.join("_").toUpperCase();
+
+    case "Title Case":
+      return words.map(capitalize).join(" ");
+
+    case "Sentence case":
+      return words.length
+        ? capitalize(words[0]) +
+            (words.length > 1 ? ` ${words.slice(1).join(" ")}` : "")
+        : "";
+
+    default:
+      return text;
+  }
+}
+
+const schema = z.object({
+  text: z.string(),
+  target: z.enum(VALID_TARGETS),
+});
+
+export async function POST(request: Request): Promise<NextResponse> {
+  try {
+    const result = await validateBody(request, schema);
+
+    if (result instanceof NextResponse) {
+      return result;
+    }
+
+    const { text, target } = result.data;
+
+    return NextResponse.json({
+      result: convertCase(text, target),
+    });
+  } catch {
+    return NextResponse.json(
+      { error: "Invalid JSON" },
+      { status: 400 }
+    );
+  }
+}
\ No newline at end of file
diff --git a/app/api/routes-f/catalan/__tests__/route.test.ts b/app/api/routes-f/catalan/__tests__/route.test.ts
new file mode 100644
index 00000000..74997c9d
--- /dev/null
+++ b/app/api/routes-f/catalan/__tests__/route.test.ts
@@ -0,0 +1,43 @@
+/**
+ * @jest-environment node
+ */
+import { NextRequest } from "next/server";
+import { GET } from "../route";
+
+function makeReq(n: string) {
+  return new NextRequest(`http://localhost/api/routes-f/catalan?n=${n}`);
+}
+
+describe("GET /api/routes-f/catalan", () => {
+  it("returns C(0)=1", async () => {
+    const res = await GET(makeReq("0"));
+    const body = await res.json();
+
+    expect(res.status).toBe(200);
+    expect(body.catalan).toBe("1");
+    expect(body.sequence).toEqual(["1"]);
+  });
+
+  it("returns C(4)=14", async () => {
+    const res = await GET(makeReq("4"));
+    const body = await res.json();
+
+    expect(res.status).toBe(200);
+    expect(body.catalan).toBe("14");
+    expect(body.sequence).toEqual(["1", "1", "2", "5", "14"]);
+  });
+
+  it("returns C(10)=16796", async () => {
+    const res = await GET(makeReq("10"));
+    const body = await res.json();
+
+    expect(res.status).toBe(200);
+    expect(body.catalan).toBe("16796");
+  });
+
+  it("rejects n outside the supported range", async () => {
+    const res = await GET(makeReq("1001"));
+
+    expect(res.status).toBe(400);
+  });
+});
diff --git a/app/api/routes-f/catalan/route.ts b/app/api/routes-f/catalan/route.ts
new file mode 100644
index 00000000..3f06571f
--- /dev/null
+++ b/app/api/routes-f/catalan/route.ts
@@ -0,0 +1,43 @@
+import { NextRequest, NextResponse } from "next/server";
+
+const MAX_N = 1000;
+
+function parseN(req: NextRequest): number | null {
+  const value = req.nextUrl.searchParams.get("n");
+  if (value === null || !/^\d+$/.test(value)) {
+    return null;
+  }
+
+  const n = Number(value);
+  return Number.isInteger(n) && n >= 0 && n <= MAX_N ? n : null;
+}
+
+function catalanSequence(n: number): bigint[] {
+  const sequence: bigint[] = [1n];
+
+  for (let i = 0; i < n; i += 1) {
+    const current = sequence[i];
+    const next = (current * BigInt(2 * (2 * i + 1))) / BigInt(i + 2);
+    sequence.push(next);
+  }
+
+  return sequence;
+}
+
+export async function GET(req: NextRequest) {
+  const n = parseN(req);
+
+  if (n === null) {
+    return NextResponse.json(
+      { error: `n must be an integer in [0, ${MAX_N}].` },
+      { status: 400 }
+    );
+  }
+
+  const sequence = catalanSequence(n).map(value => value.toString());
+
+  return NextResponse.json({
+    catalan: sequence[n],
+    sequence,
+  });
+}
diff --git a/app/api/routes-f/categories/followed/route.ts b/app/api/routes-f/categories/followed/route.ts
new file mode 100644
index 00000000..6cbd35ae
--- /dev/null
+++ b/app/api/routes-f/categories/followed/route.ts
@@ -0,0 +1,49 @@
+import { NextRequest, NextResponse } from "next/server";
+
+export interface Stream {
+  creator: string;
+  category: string;
+  viewer_count: number;
+}
+
+// Seed category follows mapping: viewer_id -> list of followed categories
+export const SEED_FOLLOWS: Record<string, string[]> = {
+  "viewer-1": ["Gaming", "Music", "Talk Shows"],
+  "viewer-2": ["Gaming"],
+  "viewer-3": ["Crypto", "Coding"],
+};
+
+// Seed live streams
+export const SEED_STREAMS: Stream[] = [
+  { creator: "creator-gaming-1", category: "Gaming", viewer_count: 1500 },
+  { creator: "creator-gaming-2", category: "Gaming", viewer_count: 800 },
+  { creator: "creator-music-1", category: "Music", viewer_count: 450 },
+  { creator: "creator-talk-1", category: "Talk Shows", viewer_count: 1200 },
+  { creator: "creator-crypto-1", category: "Crypto", viewer_count: 3100 },
+  { creator: "creator-coding-1", category: "Coding", viewer_count: 950 },
+  { creator: "creator-sports-1", category: "Sports", viewer_count: 5000 },
+];
+
+export async function GET(req: NextRequest): Promise<NextResponse> {
+  const { searchParams } = new URL(req.url);
+  const viewerId = searchParams.get("viewer_id");
+
+  if (!viewerId) {
+    return NextResponse.json({ error: "viewer_id is required" }, { status: 400 });
+  }
+
+  // Get categories followed by the viewer
+  const followedCategories = SEED_FOLLOWS[viewerId] || [];
+
+  // Filter streams to only those in the followed categories
+  const followedStreams = SEED_STREAMS.filter((stream) =>
+    followedCategories.includes(stream.category)
+  );
+
+  // Sort by viewer_count descending
+  followedStreams.sort((a, b) => b.viewer_count - a.viewer_count);
+
+  return NextResponse.json({
+    streams: followedStreams,
+  });
+}
diff --git a/app/api/routes-f/char-frequency/__tests__/route.test.ts b/app/api/routes-f/char-frequency/__tests__/route.test.ts
new file mode 100644
index 00000000..79e431d8
--- /dev/null
+++ b/app/api/routes-f/char-frequency/__tests__/route.test.ts
@@ -0,0 +1,34 @@
+import { charFrequency } from "../route";
+
+describe("charFrequency", () => {
+  it("counts characters and sorts by count descending", () => {
+    const { frequencies, total } = charFrequency("aaabb");
+    expect(total).toBe(5);
+    expect(frequencies).toEqual([
+      { char: "a", count: 3 },
+      { char: "b", count: 2 },
+    ]);
+  });
+
+  it("is case-insensitive by default and case-sensitive on request", () => {
+    expect(charFrequency("aA").frequencies).toEqual([{ char: "a", count: 2 }]);
+    expect(charFrequency("aA", { caseSensitive: true }).frequencies).toEqual([
+      { char: "A", count: 1 },
+      { char: "a", count: 1 },
+    ]);
+  });
+
+  it("can ignore whitespace", () => {
+    const { frequencies, total } = charFrequency("a b\tc", {
+      ignoreWhitespace: true,
+    });
+    expect(total).toBe(3);
+    expect(frequencies.find((f) => /\s/.test(f.char))).toBeUndefined();
+  });
+
+  it("limits results with top", () => {
+    const { frequencies } = charFrequency("aaabbc", { top: 2 });
+    expect(frequencies).toHaveLength(2);
+    expect(frequencies[0]).toEqual({ char: "a", count: 3 });
+  });
+});
diff --git a/app/api/routes-f/char-frequency/route.ts b/app/api/routes-f/char-frequency/route.ts
new file mode 100644
index 00000000..cf9d2a1b
--- /dev/null
+++ b/app/api/routes-f/char-frequency/route.ts
@@ -0,0 +1,71 @@
+import { NextResponse } from "next/server";
+import { z } from "zod";
+import { validateBody } from "@/app/api/routes-f/_lib/validate";
+
+const MAX_INPUT_BYTES = 1_000_000;
+
+export interface CharCount {
+  char: string;
+  count: number;
+}
+
+export interface CharFrequencyResult {
+  frequencies: CharCount[];
+  total: number;
+}
+
+export interface CharFrequencyOptions {
+  caseSensitive?: boolean;
+  ignoreWhitespace?: boolean;
+  top?: number;
+}
+
+/**
+ * Count character frequency in `text`, sorted by count descending (ties broken
+ * by character for stable output). `total` is the number of counted characters.
+ */
+export function charFrequency(
+  text: string,
+  { caseSensitive = false, ignoreWhitespace = false, top }: CharFrequencyOptions = {},
+): CharFrequencyResult {
+  const normalized = caseSensitive ? text : text.toLowerCase();
+  const counts = new Map<string, number>();
+  let total = 0;
+
+  for (const char of normalized) {
+    if (ignoreWhitespace && /\s/.test(char)) continue;
+    counts.set(char, (counts.get(char) ?? 0) + 1);
+    total += 1;
+  }
+
+  let frequencies: CharCount[] = Array.from(counts, ([char, count]) => ({
+    char,
+    count,
+  })).sort((a, b) => b.count - a.count || a.char.localeCompare(b.char));
+
+  if (top !== undefined) {
+    frequencies = frequencies.slice(0, top);
+  }
+
+  return { frequencies, total };
+}
+
+const schema = z.object({
+  text: z.string().max(MAX_INPUT_BYTES, "text exceeds 1MB limit"),
+  case_sensitive: z.boolean().optional(),
+  ignore_whitespace: z.boolean().optional(),
+  top: z.number().int().positive().optional(),
+});
+
+export async function POST(request: Request): Promise<NextResponse> {
+  const result = await validateBody(request, schema);
+  if (result instanceof NextResponse) return result;
+  const { text, case_sensitive, ignore_whitespace, top } = result.data;
+  return NextResponse.json(
+    charFrequency(text, {
+      caseSensitive: case_sensitive,
+      ignoreWhitespace: ignore_whitespace,
+      top,
+    }),
+  );
+}
diff --git a/app/api/routes-f/char-stats/_lib/helpers.ts b/app/api/routes-f/char-stats/_lib/helpers.ts
new file mode 100644
index 00000000..a2eaa90d
--- /dev/null
+++ b/app/api/routes-f/char-stats/_lib/helpers.ts
@@ -0,0 +1,122 @@
+import type { CharStatsResponse } from "./types";
+
+const MAX_INPUT_BYTES = 1024 * 1024; // 1MB
+
+// Unicode property regexes
+const RE_LETTER = /\p{L}/u;
+const RE_DIGIT = /\p{N}/u;
+const RE_WHITESPACE = /\p{Z}|\t|\n|\r/u;
+const RE_PUNCTUATION = /\p{P}/u;
+const RE_SYMBOL = /\p{S}/u;
+
+// Script ranges
+const RE_LATIN = /\p{Script=Latin}/u;
+const RE_CYRILLIC = /\p{Script=Cyrillic}/u;
+const RE_CJK = /\p{Script=Han}|\p{Script=Hiragana}|\p{Script=Katakana}/u;
+const RE_ARABIC = /\p{Script=Arabic}/u;
+const RE_DEVANAGARI = /\p{Script=Devanagari}/u;
+const RE_GREEK = /\p{Script=Greek}/u;
+const RE_HEBREW = /\p{Script=Hebrew}/u;
+
+// Emoji detection (handles ZWJ sequences and multi-codepoint emoji)
+const RE_EMOJI = /\p{Emoji_Presentation}|\p{Extended_Pictographic}/u;
+const RE_EMOJI_SEQUENCE =
+  /\p{Emoji_Presentation}(?:️?⃐-⃿|⃣|️)*(?:‍(?:\p{Emoji_Presentation}(?:️?⃐-⃿|⃣|️)*))*|\p{Extended_Pictographic}/gu;
+
+function isRecord(value: unknown): value is Record<string, unknown> {
+  return typeof value === "object" && value !== null && !Array.isArray(value);
+}
+
+function countEmoji(text: string): number {
+  return [...text.matchAll(RE_EMOJI_SEQUENCE)].length;
+}
+
+export function computeCharStats(input: unknown): CharStatsResponse {
+  if (!isRecord(input)) {
+    throw new Error("Request body must be an object.");
+  }
+
+  const { text } = input as Record<string, unknown>;
+
+  if (typeof text !== "string") {
+    throw new Error("text must be a string.");
+  }
+
+  if (Buffer.byteLength(text, "utf8") > MAX_INPUT_BYTES) {
+    throw new Error("text must not exceed 1MB.");
+  }
+
+  // Segment into grapheme clusters (handles multi-codepoint emoji)
+  const segmenter = new Intl.Segmenter(undefined, { granularity: "grapheme" });
+  const graphemes = [...segmenter.segment(text)].map((s) => s.segment);
+
+  let letters = 0,
+    digits = 0,
+    whitespace = 0,
+    punctuation = 0,
+    symbols = 0,
+    other = 0;
+
+  const scriptCounts = {
+    latin: 0,
+    cyrillic: 0,
+    cjk: 0,
+    arabic: 0,
+    devanagari: 0,
+    greek: 0,
+    hebrew: 0,
+    other: 0,
+  };
+
+  const emojiCount = countEmoji(text);
+
+  // Build a set of emoji grapheme positions to avoid double-counting
+  const emojiSet = new Set<string>();
+  for (const m of text.matchAll(RE_EMOJI_SEQUENCE)) {
+    emojiSet.add(m[0]);
+  }
+
+  for (const g of graphemes) {
+    // Check if it's an emoji grapheme
+    if (RE_EMOJI.test(g) || (g.length > 1 && emojiSet.has(g))) {
+      // counted separately
+      continue;
+    }
+
+    const firstChar = g[0];
+
+    if (RE_WHITESPACE.test(firstChar)) {
+      whitespace++;
+    } else if (RE_LETTER.test(firstChar)) {
+      letters++;
+      if (RE_LATIN.test(firstChar)) scriptCounts.latin++;
+      else if (RE_CYRILLIC.test(firstChar)) scriptCounts.cyrillic++;
+      else if (RE_CJK.test(firstChar)) scriptCounts.cjk++;
+      else if (RE_ARABIC.test(firstChar)) scriptCounts.arabic++;
+      else if (RE_DEVANAGARI.test(firstChar)) scriptCounts.devanagari++;
+      else if (RE_GREEK.test(firstChar)) scriptCounts.greek++;
+      else if (RE_HEBREW.test(firstChar)) scriptCounts.hebrew++;
+      else scriptCounts.other++;
+    } else if (RE_DIGIT.test(firstChar)) {
+      digits++;
+    } else if (RE_PUNCTUATION.test(firstChar)) {
+      punctuation++;
+    } else if (RE_SYMBOL.test(firstChar)) {
+      symbols++;
+    } else {
+      other++;
+    }
+  }
+
+  return {
+    total: graphemes.length,
+    letters,
+    digits,
+    whitespace,
+    punctuation,
+    symbols,
+    emoji: emojiCount,
+    other,
+    by_script: scriptCounts,
+  };
+}
diff --git a/app/api/routes-f/char-stats/_lib/types.ts b/app/api/routes-f/char-stats/_lib/types.ts
new file mode 100644
index 00000000..1b8e32fc
--- /dev/null
+++ b/app/api/routes-f/char-stats/_lib/types.ts
@@ -0,0 +1,22 @@
+export interface ScriptCounts {
+  latin: number;
+  cyrillic: number;
+  cjk: number;
+  arabic: number;
+  devanagari: number;
+  greek: number;
+  hebrew: number;
+  other: number;
+}
+
+export interface CharStatsResponse {
+  total: number;
+  letters: number;
+  digits: number;
+  whitespace: number;
+  punctuation: number;
+  symbols: number;
+  emoji: number;
+  other: number;
+  by_script: ScriptCounts;
+}
diff --git a/app/api/routes-f/char-stats/route.ts b/app/api/routes-f/char-stats/route.ts
new file mode 100644
index 00000000..c2f30cc0
--- /dev/null
+++ b/app/api/routes-f/char-stats/route.ts
@@ -0,0 +1,19 @@
+import { type NextRequest, NextResponse } from "next/server";
+import { computeCharStats } from "./_lib/helpers";
+
+export async function POST(req: NextRequest) {
+  let body: unknown;
+
+  try {
+    body = await req.json();
+  } catch {
+    return NextResponse.json({ error: "Invalid JSON body." }, { status: 400 });
+  }
+
+  try {
+    return NextResponse.json(computeCharStats(body));
+  } catch (error) {
+    const message = error instanceof Error ? error.message : "Failed to compute char stats.";
+    return NextResponse.json({ error: message }, { status: 400 });
+  }
+}
diff --git a/app/api/routes-f/chat-blocklist/__tests__/route.test.ts b/app/api/routes-f/chat-blocklist/__tests__/route.test.ts
new file mode 100644
index 00000000..0908f81b
--- /dev/null
+++ b/app/api/routes-f/chat-blocklist/__tests__/route.test.ts
@@ -0,0 +1,181 @@
+/**
+ * @jest-environment node
+ */
+import { NextRequest } from "next/server";
+import { POST, GET } from "../route";
+
+function makeReq(method: string, body?: unknown) {
+  return new NextRequest("http://localhost/api/routes-f/chat-blocklist", {
+    method,
+    headers: { "content-type": "application/json" },
+    body: body ? JSON.stringify(body) : undefined,
+  });
+}
+
+describe("POST /api/routes-f/chat-blocklist", () => {
+  it("adds words to blocklist", async () => {
+    const res = await POST(
+      makeReq("POST", {
+        creator_id: "creator123",
+        add: ["spam", "scam"],
+      })
+    );
+    const body = await res.json();
+
+    expect(res.status).toBe(200);
+    expect(body.words).toContain("spam");
+    expect(body.words).toContain("scam");
+  });
+
+  it("removes words from blocklist", async () => {
+    // First add words
+    await POST(
+      makeReq("POST", {
+        creator_id: "creator456",
+        add: ["spam", "scam", "bot"],
+      })
+    );
+
+    // Then remove one
+    const res = await POST(
+      makeReq("POST", {
+        creator_id: "creator456",
+        remove: ["spam"],
+      })
+    );
+    const body = await res.json();
+
+    expect(res.status).toBe(200);
+    expect(body.words).not.toContain("spam");
+    expect(body.words).toContain("scam");
+    expect(body.words).toContain("bot");
+  });
+
+  it("handles case-insensitive storage and dedup", async () => {
+    await POST(
+      makeReq("POST", {
+        creator_id: "creator789",
+        add: ["Spam", "SPAM", "spam", "Scam"],
+      })
+    );
+
+    const res = await POST(
+      makeReq("POST", {
+        creator_id: "creator789",
+      })
+    );
+    const body = await res.json();
+
+    expect(res.status).toBe(200);
+    expect(body.words).toHaveLength(2);
+    expect(body.words).toContain("spam");
+    expect(body.words).toContain("scam");
+  });
+
+  it("enforces cap at 200 entries", async () => {
+    const wordsToAdd = Array.from({ length: 201 }, (_, i) => `word${i}`);
+    const res = await POST(
+      makeReq("POST", {
+        creator_id: "creator999",
+        add: wordsToAdd,
+      })
+    );
+
+    expect(res.status).toBe(400);
+  });
+
+  it("allows adding up to 200 entries", async () => {
+    const wordsToAdd = Array.from({ length: 200 }, (_, i) => `word${i}`);
+    const res = await POST(
+      makeReq("POST", {
+        creator_id: "creator200",
+        add: wordsToAdd,
+      })
+    );
+
+    expect(res.status).toBe(200);
+    const body = await res.json();
+    expect(body.words).toHaveLength(200);
+  });
+
+  it("rejects missing creator_id", async () => {
+    const res = await POST(
+      makeReq("POST", {
+        add: ["spam"],
+      })
+    );
+    expect(res.status).toBe(400);
+  });
+
+  it("rejects non-array add parameter", async () => {
+    const res = await POST(
+      makeReq("POST", {
+        creator_id: "creator123",
+        add: "not-an-array",
+      })
+    );
+    expect(res.status).toBe(400);
+  });
+
+  it("rejects non-array remove parameter", async () => {
+    const res = await POST(
+      makeReq("POST", {
+        creator_id: "creator123",
+        remove: "not-an-array",
+      })
+    );
+    expect(res.status).toBe(400);
+  });
+
+  it("rejects invalid JSON", async () => {
+    const req = new NextRequest("http://localhost/api/routes-f/chat-blocklist", {
+      method: "POST",
+      headers: { "content-type": "application/json" },
+      body: "invalid json",
+    });
+    const res = await POST(req);
+    expect(res.status).toBe(400);
+  });
+});
+
+describe("GET /api/routes-f/chat-blocklist", () => {
+  beforeEach(async () => {
+    // Setup: add words to blocklist
+    await POST(
+      makeReq("POST", {
+        creator_id: "getcreator",
+        add: ["spam", "scam", "bot"],
+      })
+    );
+  });
+
+  it("returns blocklist for creator", async () => {
+    const req = new NextRequest(
+      "http://localhost/api/routes-f/chat-blocklist?creator_id=getcreator"
+    );
+    const res = await GET(req);
+    const body = await res.json();
+
+    expect(res.status).toBe(200);
+    expect(body.words).toContain("spam");
+    expect(body.words).toContain("scam");
+    expect(body.words).toContain("bot");
+  });
+
+  it("returns empty array for creator with no blocklist", async () => {
+    const req = new NextRequest(
+      "http://localhost/api/routes-f/chat-blocklist?creator_id=noblocklist"
+    );
+    const res = await GET(req);
+    const body = await res.json();
+
+    expect(res.status).toBe(200);
+    expect(body.words).toHaveLength(0);
+  });
+
+  it("returns 400 when creator_id is missing", async () => {
+    const req = new NextRequest("http://localhost/api/routes-f/chat-blocklist");
+    const res = await GET(req);
+    expect(res.status).toBe(400);
+  });
+});
diff --git a/app/api/routes-f/chat-blocklist/route.ts b/app/api/routes-f/chat-blocklist/route.ts
new file mode 100644
index 00000000..9a033ce4
--- /dev/null
+++ b/app/api/routes-f/chat-blocklist/route.ts
@@ -0,0 +1,116 @@
+import { NextRequest, NextResponse } from "next/server";
+
+// In-memory store for blocklists, keyed by creator_id
+const blocklistStore = new Map<string, Set<string>>();
+
+const MAX_ENTRIES = 200;
+
+function normalizeWord(word: string): string {
+  return word.trim().toLowerCase();
+}
+
+export async function GET(req: NextRequest) {
+  const { searchParams } = new URL(req.url);
+  const creatorId = searchParams.get("creator_id");
+
+  if (!creatorId) {
+    return NextResponse.json(
+      { error: "creator_id is required" },
+      { status: 400 }
+    );
+  }
+
+  const blocklist = blocklistStore.get(creatorId) || new Set<string>();
+  const words = Array.from(blocklist);
+
+  return NextResponse.json({ words });
+}
+
+export async function POST(req: NextRequest) {
+  let body: {
+    creator_id?: unknown;
+    add?: unknown;
+    remove?: unknown;
+  };
+
+  try {
+    body = await req.json();
+  } catch {
+    return NextResponse.json({ error: "Invalid JSON body" }, { status: 400 });
+  }
+
+  const { creator_id, add, remove } = body;
+
+  if (!creator_id || typeof creator_id !== "string") {
+    return NextResponse.json(
+      { error: "creator_id is required and must be a string" },
+      { status: 400 }
+    );
+  }
+
+  // Get or create blocklist for this creator
+  let blocklist = blocklistStore.get(creator_id);
+  if (!blocklist) {
+    blocklist = new Set<string>();
+    blocklistStore.set(creator_id, blocklist);
+  }
+
+  // Process additions
+  if (add !== undefined) {
+    if (!Array.isArray(add)) {
+      return NextResponse.json(
+        { error: "add must be an array of strings" },
+        { status: 400 }
+      );
+    }
+
+    for (const item of add) {
+      if (typeof item !== "string") {
+        return NextResponse.json(
+          { error: "add must be an array of strings" },
+          { status: 400 }
+        );
+      }
+
+      const normalized = normalizeWord(item);
+      if (normalized) {
+        // Check cap before adding
+        if (blocklist.size >= MAX_ENTRIES && !blocklist.has(normalized)) {
+          return NextResponse.json(
+            { error: `Blocklist cap reached (max ${MAX_ENTRIES} entries)` },
+            { status: 400 }
+          );
+        }
+        blocklist.add(normalized);
+      }
+    }
+  }
+
+  // Process removals
+  if (remove !== undefined) {
+    if (!Array.isArray(remove)) {
+      return NextResponse.json(
+        { error: "remove must be an array of strings" },
+        { status: 400 }
+      );
+    }
+
+    for (const item of remove) {
+      if (typeof item !== "string") {
+        return NextResponse.json(
+          { error: "remove must be an array of strings" },
+          { status: 400 }
+        );
+      }
+
+      const normalized = normalizeWord(item);
+      if (normalized) {
+        blocklist.delete(normalized);
+      }
+    }
+  }
+
+  // Return updated blocklist
+  const words = Array.from(blocklist);
+  return NextResponse.json({ words });
+}
diff --git a/app/api/routes-f/chat-emote-mode/[stream_id]/route.ts b/app/api/routes-f/chat-emote-mode/[stream_id]/route.ts
new file mode 100644
index 00000000..f244f8ba
--- /dev/null
+++ b/app/api/routes-f/chat-emote-mode/[stream_id]/route.ts
@@ -0,0 +1,53 @@
+import { NextRequest, NextResponse } from "next/server";
+import { sql } from "@vercel/postgres";
+import { verifySession } from "@/lib/auth/verify-session";
+
+export const runtime = "nodejs";
+export const dynamic = "force-dynamic";
+
+/**
+ * DELETE /api/routes-f/chat-emote-mode/[stream_id]
+ * Disable emote-only mode for a stream
+ */
+export async function DELETE(
+  req: NextRequest,
+  { params }: { params: Promise<{ stream_id: string }> }
+) {
+  const session = await verifySession(req);
+  if (!session.ok) {
+    return session.response;
+  }
+
+  const { stream_id } = await params;
+
+  try {
+    const { rows: streamRows } = await sql`
+      SELECT creator_id FROM streams WHERE id = ${stream_id}
+    `;
+
+    if (streamRows.length === 0) {
+      return NextResponse.json(
+        { error: "Stream not found" },
+        { status: 404 }
+      );
+    }
+
+    if (streamRows[0].creator_id !== session.userId) {
+      return NextResponse.json({ error: "Forbidden" }, { status: 403 });
+    }
+
+    await sql`
+      UPDATE emote_mode_settings
+      SET enabled = false, updated_at = CURRENT_TIMESTAMP
+      WHERE stream_id = ${stream_id}
+    `;
+
+    return NextResponse.json({ enabled: false, stream_id });
+  } catch (error) {
+    console.error("[Chat Emote Mode API] Error disabling mode:", error);
+    return NextResponse.json(
+      { error: "Internal server error" },
+      { status: 500 }
+    );
+  }
+}
diff --git a/app/api/routes-f/chat-emote-mode/check/route.ts b/app/api/routes-f/chat-emote-mode/check/route.ts
new file mode 100644
index 00000000..83163561
--- /dev/null
+++ b/app/api/routes-f/chat-emote-mode/check/route.ts
@@ -0,0 +1,47 @@
+import { NextRequest, NextResponse } from "next/server";
+import { validateBody } from "../../_lib/validate";
+import { z } from "zod";
+
+export const runtime = "nodejs";
+export const dynamic = "force-dynamic";
+
+const checkMessageSchema = z.object({
+  message: z.string(),
+});
+
+function isEmoteOnly(message: string): boolean {
+  const trimmed = message.trim();
+  if (trimmed.length === 0) return false;
+
+  for (const char of trimmed) {
+    const code = char.codePointAt(0);
+    if (!code) continue;
+
+    if (code < 0x1F000) {
+      if (!/[\p{Emoji}]/u.test(char)) {
+        return false;
+      }
+    }
+  }
+
+  return true;
+}
+
+/**
+ * POST /api/routes-f/chat-emote-mode/check
+ * Check if a message would be blocked by emote-only mode
+ */
+export async function POST(req: NextRequest) {
+  const bodyResult = await validateBody(req, checkMessageSchema);
+  if (bodyResult instanceof NextResponse) {
+    return bodyResult;
+  }
+
+  const { message } = bodyResult.data;
+  const isEmote = isEmoteOnly(message);
+
+  return NextResponse.json({
+    is_emote_only: isEmote,
+    would_be_blocked: !isEmote,
+  });
+}
diff --git a/app/api/routes-f/chat-emote-mode/route.ts b/app/api/routes-f/chat-emote-mode/route.ts
new file mode 100644
index 00000000..d5ae3665
--- /dev/null
+++ b/app/api/routes-f/chat-emote-mode/route.ts
@@ -0,0 +1,82 @@
+import { NextRequest, NextResponse } from "next/server";
+import { sql } from "@vercel/postgres";
+import { verifySession } from "@/lib/auth/verify-session";
+import { validateBody } from "../_lib/validate";
+import { z } from "zod";
+
+export const runtime = "nodejs";
+export const dynamic = "force-dynamic";
+
+const enableEmoteModeSchema = z.object({
+  stream_id: z.string(),
+});
+
+function isEmoteOnly(message: string): boolean {
+  const trimmed = message.trim();
+  if (trimmed.length === 0) return false;
+
+  for (const char of trimmed) {
+    const code = char.codePointAt(0);
+    if (!code) continue;
+
+    if (code < 0x1F000) {
+      if (!/[\p{Emoji}]/u.test(char)) {
+        return false;
+      }
+    }
+  }
+
+  return true;
+}
+
+/**
+ * POST /api/routes-f/chat-emote-mode
+ * Enable emote-only mode for a stream
+ */
+export async function POST(req: NextRequest) {
+  const session = await verifySession(req);
+  if (!session.ok) {
+    return session.response;
+  }
+
+  const bodyResult = await validateBody(req, enableEmoteModeSchema);
+  if (bodyResult instanceof NextResponse) {
+    return bodyResult;
+  }
+
+  const { stream_id } = bodyResult.data;
+
+  try {
+    const { rows: streamRows } = await sql`
+      SELECT creator_id FROM streams WHERE id = ${stream_id}
+    `;
+
+    if (streamRows.length === 0) {
+      return NextResponse.json(
+        { error: "Stream not found" },
+        { status: 404 }
+      );
+    }
+
+    if (streamRows[0].creator_id !== session.userId) {
+      return NextResponse.json({ error: "Forbidden" }, { status: 403 });
+    }
+
+    await sql`
+      INSERT INTO emote_mode_settings (stream_id, enabled, created_at)
+      VALUES (${stream_id}, true, CURRENT_TIMESTAMP)
+      ON CONFLICT (stream_id)
+      DO UPDATE SET enabled = true, updated_at = CURRENT_TIMESTAMP
+    `;
+
+    return NextResponse.json({ enabled: true, stream_id });
+  } catch (error) {
+    console.error("[Chat Emote Mode API] Error enabling mode:", error);
+    return NextResponse.json(
+      { error: "Internal server error" },
+      { status: 500 }
+    );
+  }
+}
+
+export { isEmoteOnly };
diff --git a/app/api/routes-f/chat-reactions/__tests__/route.test.ts b/app/api/routes-f/chat-reactions/__tests__/route.test.ts
new file mode 100644
index 00000000..abebb743
--- /dev/null
+++ b/app/api/routes-f/chat-reactions/__tests__/route.test.ts
@@ -0,0 +1,560 @@
+/**
+ * @jest-environment node
+ */
+import { NextRequest } from "next/server";
+import { POST, GET } from "../route";
+import { reactionStore } from "../utils";
+
+function makePostReq(
+  messageId: string,
+  emoji: string,
+  userId: string
+): NextRequest {
+  return new NextRequest("http://localhost/api/routes-f/chat-reactions", {
+    method: "POST",
+    headers: { "content-type": "application/json" },
+    body: JSON.stringify({
+      message_id: messageId,
+      emoji,
+      user_id: userId,
+    }),
+  });
+}
+
+function makeGetReq(messageId: string, userId?: string): NextRequest {
+  let url = `http://localhost/api/routes-f/chat-reactions?message_id=${messageId}`;
+  if (userId) {
+    url += `&user_id=${userId}`;
+  }
+  return new NextRequest(url);
+}
+
+describe("POST /api/routes-f/chat-reactions", () => {
+  beforeEach(() => {
+    // Clear reactions before each test
+    reactionStore.length = 0;
+  });
+
+  describe("Adding Reactions", () => {
+    it("adds a reaction to a message", async () => {
+      const res = await POST(makePostReq("msg123", "👍", "user1"));
+      expect(res.status).toBe(200);
+      const body = await res.json();
+      expect(body.toggled).toBe(true);
+      expect(body.reactions.length).toBe(1);
+      expect(body.reactions[0]).toEqual({
+        emoji: "👍",
+        count: 1,
+        reacted_by_me: true,
+      });
+    });
+
+    it("adds multiple different emoji reactions", async () => {
+      await POST(makePostReq("msg123", "👍", "user1"));
+      const res = await POST(makePostReq("msg123", "❤️", "user1"));
+
+      expect(res.status).toBe(200);
+      const body = await res.json();
+      expect(body.toggled).toBe(true);
+      expect(body.reactions.length).toBe(2);
+
+      const emojis = body.reactions.map(r => r.emoji);
+      expect(emojis).toContain("👍");
+      expect(emojis).toContain("❤️");
+    });
+
+    it("adds same emoji from different users", async () => {
+      await POST(makePostReq("msg123", "👍", "user1"));
+      const res = await POST(makePostReq("msg123", "👍", "user2"));
+
+      expect(res.status).toBe(200);
+      const body = await res.json();
+      expect(body.toggled).toBe(true);
+      expect(body.reactions.length).toBe(1);
+      expect(body.reactions[0]).toEqual({
+        emoji: "👍",
+        count: 2,
+        reacted_by_me: true,
+      });
+    });
+
+    it("handles single character emojis", async () => {
+      const res = await POST(makePostReq("msg123", "😊", "user1"));
+      expect(res.status).toBe(200);
+      const body = await res.json();
+      expect(body.reactions[0].emoji).toBe("😊");
+    });
+
+    it("handles emoji with skin tone modifiers", async () => {
+      // 👋🏻 is wave with light skin tone
+      const res = await POST(makePostReq("msg123", "👋🏻", "user1"));
+      expect(res.status).toBe(200);
+      const body = await res.json();
+      expect(body.reactions.length).toBe(1);
+    });
+
+    it("handles emoji with zero-width joiners", async () => {
+      // 👨‍👩‍👧‍👦 is family emoji (ZWJ sequence)
+      const res = await POST(makePostReq("msg123", "👨‍👩‍👧‍👦", "user1"));
+      expect(res.status).toBe(200);
+      const body = await res.json();
+      expect(body.reactions.length).toBe(1);
+    });
+  });
+
+  describe("Toggling Reactions", () => {
+    it("removes a reaction when user reacts with same emoji", async () => {
+      // Add reaction
+      await POST(makePostReq("msg123", "👍", "user1"));
+
+      // Toggle off (remove)
+      const res = await POST(makePostReq("msg123", "👍", "user1"));
+
+      expect(res.status).toBe(200);
+      const body = await res.json();
+      expect(body.toggled).toBe(false);
+      expect(body.reactions.length).toBe(0);
+    });
+
+    it("removes only one user reaction, not all", async () => {
+      // User 1 and 2 react with thumbs up
+      await POST(makePostReq("msg123", "👍", "user1"));
+      await POST(makePostReq("msg123", "👍", "user2"));
+
+      // User 1 removes their reaction
+      const res = await POST(makePostReq("msg123", "👍", "user1"));
+
+      expect(res.status).toBe(200);
+      const body = await res.json();
+      expect(body.toggled).toBe(false);
+      expect(body.reactions[0]).toEqual({
+        emoji: "👍",
+        count: 1,
+        reacted_by_me: false,
+      });
+    });
+
+    it("allows user to re-add after removing", async () => {
+      // Add
+      await POST(makePostReq("msg123", "👍", "user1"));
+
+      // Remove
+      await POST(makePostReq("msg123", "👍", "user1"));
+
+      // Re-add
+      const res = await POST(makePostReq("msg123", "👍", "user1"));
+
+      expect(res.status).toBe(200);
+      const body = await res.json();
+      expect(body.toggled).toBe(true);
+      expect(body.reactions[0]).toEqual({
+        emoji: "👍",
+        count: 1,
+        reacted_by_me: true,
+      });
+    });
+
+    it("does not affect other emojis when toggling", async () => {
+      await POST(makePostReq("msg123", "👍", "user1"));
+      await POST(makePostReq("msg123", "❤️", "user1"));
+      await POST(makePostReq("msg123", "👍", "user2"));
+
+      // Toggle off user1's thumbs up
+      const res = await POST(makePostReq("msg123", "👍", "user1"));
+
+      const body = await res.json();
+      const heartReaction = body.reactions.find(r => r.emoji === "❤️");
+      expect(heartReaction).toEqual({
+        emoji: "❤️",
+        count: 1,
+        reacted_by_me: true,
+      });
+    });
+  });
+
+  describe("Message Isolation", () => {
+    it("reactions are isolated per message", async () => {
+      await POST(makePostReq("msg1", "👍", "user1"));
+      await POST(makePostReq("msg2", "❤️", "user1"));
+
+      const res = await POST(makePostReq("msg1", "❤️", "user2"));
+
+      const body = await res.json();
+      expect(body.reactions.length).toBe(2);
+      const emojis = body.reactions.map(r => r.emoji);
+      expect(emojis).toContain("👍");
+      expect(emojis).toContain("❤️");
+    });
+  });
+
+  describe("Input Validation", () => {
+    it("rejects missing message_id", async () => {
+      const req = new NextRequest(
+        "http://localhost/api/routes-f/chat-reactions",
+        {
+          method: "POST",
+          headers: { "content-type": "application/json" },
+          body: JSON.stringify({
+            emoji: "👍",
+            user_id: "user1",
+          }),
+        }
+      );
+      const res = await POST(req);
+      expect(res.status).toBe(400);
+    });
+
+    it("rejects empty message_id", async () => {
+      const res = await POST(makePostReq("", "👍", "user1"));
+      expect(res.status).toBe(400);
+    });
+
+    it("rejects missing emoji", async () => {
+      const req = new NextRequest(
+        "http://localhost/api/routes-f/chat-reactions",
+        {
+          method: "POST",
+          headers: { "content-type": "application/json" },
+          body: JSON.stringify({
+            message_id: "msg123",
+            user_id: "user1",
+          }),
+        }
+      );
+      const res = await POST(req);
+      expect(res.status).toBe(400);
+    });
+
+    it("rejects empty emoji", async () => {
+      const res = await POST(makePostReq("msg123", "", "user1"));
+      expect(res.status).toBe(400);
+    });
+
+    it("rejects multi-character string as emoji", async () => {
+      const res = await POST(makePostReq("msg123", "👍❤️", "user1"));
+      expect(res.status).toBe(400);
+      const body = await res.json();
+      expect(body.error).toContain("single grapheme cluster");
+    });
+
+    it("rejects ASCII letters as emoji", async () => {
+      const res = await POST(makePostReq("msg123", "a", "user1"));
+      expect(res.status).toBe(400);
+    });
+
+    it("rejects ASCII numbers as emoji", async () => {
+      const res = await POST(makePostReq("msg123", "5", "user1"));
+      expect(res.status).toBe(400);
+    });
+
+    it("accepts ASCII symbols as reaction (if single grapheme)", async () => {
+      // Some ASCII symbols that aren't letters/numbers might be acceptable
+      // but the implementation should handle this gracefully
+      const res = await POST(makePostReq("msg123", "!", "user1"));
+      // This should either succeed or fail consistently
+      expect([200, 400]).toContain(res.status);
+    });
+
+    it("rejects missing user_id", async () => {
+      const req = new NextRequest(
+        "http://localhost/api/routes-f/chat-reactions",
+        {
+          method: "POST",
+          headers: { "content-type": "application/json" },
+          body: JSON.stringify({
+            message_id: "msg123",
+            emoji: "👍",
+          }),
+        }
+      );
+      const res = await POST(req);
+      expect(res.status).toBe(400);
+    });
+
+    it("rejects empty user_id", async () => {
+      const res = await POST(makePostReq("msg123", "👍", ""));
+      expect(res.status).toBe(400);
+    });
+
+    it("rejects invalid JSON", async () => {
+      const req = new NextRequest(
+        "http://localhost/api/routes-f/chat-reactions",
+        {
+          method: "POST",
+          headers: { "content-type": "application/json" },
+          body: "invalid json",
+        }
+      );
+      const res = await POST(req);
+      expect(res.status).toBe(400);
+    });
+  });
+
+  describe("reacted_by_me Field", () => {
+    it("sets reacted_by_me to true for the user who reacted", async () => {
+      const res = await POST(makePostReq("msg123", "👍", "user1"));
+      const body = await res.json();
+      expect(body.reactions[0].reacted_by_me).toBe(true);
+    });
+
+    it("sets reacted_by_me to false for other users", async () => {
+      await POST(makePostReq("msg123", "👍", "user1"));
+      const res = await POST(makePostReq("msg123", "❤️", "user2"));
+
+      const body = await res.json();
+      const thumbsUp = body.reactions.find(r => r.emoji === "👍");
+      expect(thumbsUp.reacted_by_me).toBe(false);
+    });
+
+    it("correctly reflects reacted_by_me after toggle", async () => {
+      // User adds reaction
+      let res = await POST(makePostReq("msg123", "👍", "user1"));
+      let body = await res.json();
+      expect(body.reactions[0].reacted_by_me).toBe(true);
+
+      // User removes reaction
+      res = await POST(makePostReq("msg123", "👍", "user1"));
+      body = await res.json();
+      // After removing, no reactions should exist
+      expect(body.reactions.length).toBe(0);
+    });
+  });
+});
+
+describe("GET /api/routes-f/chat-reactions", () => {
+  beforeEach(() => {
+    reactionStore.length = 0;
+  });
+
+  describe("Basic Retrieval", () => {
+    it("returns reactions for a message", async () => {
+      await POST(makePostReq("msg123", "👍", "user1"));
+      await POST(makePostReq("msg123", "❤️", "user2"));
+
+      const res = await GET(makeGetReq("msg123"));
+      expect(res.status).toBe(200);
+      const body = await res.json();
+
+      expect(body.reactions.length).toBe(2);
+      const emojis = body.reactions.map(r => r.emoji);
+      expect(emojis).toContain("👍");
+      expect(emojis).toContain("❤️");
+    });
+
+    it("returns empty array for message with no reactions", async () => {
+      const res = await GET(makeGetReq("no-reactions-msg"));
+      expect(res.status).toBe(200);
+      const body = await res.json();
+      expect(body.reactions).toEqual([]);
+    });
+
+    it("returns 400 when message_id is missing", async () => {
+      const req = new NextRequest(
+        "http://localhost/api/routes-f/chat-reactions"
+      );
+      const res = await GET(req);
+      expect(res.status).toBe(400);
+    });
+  });
+
+  describe("Count Aggregation", () => {
+    it("aggregates count for same emoji", async () => {
+      await POST(makePostReq("msg123", "👍", "user1"));
+      await POST(makePostReq("msg123", "👍", "user2"));
+      await POST(makePostReq("msg123", "👍", "user3"));
+
+      const res = await GET(makeGetReq("msg123"));
+      const body = await res.json();
+
+      expect(body.reactions.length).toBe(1);
+      expect(body.reactions[0]).toEqual({
+        emoji: "👍",
+        count: 3,
+        reacted_by_me: false,
+      });
+    });
+
+    it("returns correct count for multiple emojis", async () => {
+      await POST(makePostReq("msg123", "👍", "user1"));
+      await POST(makePostReq("msg123", "👍", "user2"));
+      await POST(makePostReq("msg123", "❤️", "user1"));
+      await POST(makePostReq("msg123", "❤️", "user2"));
+      await POST(makePostReq("msg123", "😂", "user1"));
+
+      const res = await GET(makeGetReq("msg123"));
+      const body = await res.json();
+
+      expect(body.reactions.length).toBe(3);
+
+      const thumbsUp = body.reactions.find(r => r.emoji === "👍");
+      expect(thumbsUp.count).toBe(2);
+
+      const heart = body.reactions.find(r => r.emoji === "❤️");
+      expect(heart.count).toBe(2);
+
+      const laugh = body.reactions.find(r => r.emoji === "😂");
+      expect(laugh.count).toBe(1);
+    });
+  });
+
+  describe("reacted_by_me Field", () => {
+    it("sets reacted_by_me true when user provided and has reacted", async () => {
+      await POST(makePostReq("msg123", "👍", "user1"));
+      await POST(makePostReq("msg123", "❤️", "user1"));
+
+      const res = await GET(makeGetReq("msg123", "user1"));
+      const body = await res.json();
+
+      body.reactions.forEach(r => {
+        expect(r.reacted_by_me).toBe(true);
+      });
+    });
+
+    it("sets reacted_by_me false when user has not reacted", async () => {
+      await POST(makePostReq("msg123", "👍", "user1"));
+
+      const res = await GET(makeGetReq("msg123", "user2"));
+      const body = await res.json();
+
+      expect(body.reactions[0].reacted_by_me).toBe(false);
+    });
+
+    it("sets reacted_by_me false when user_id not provided", async () => {
+      await POST(makePostReq("msg123", "👍", "user1"));
+
+      const res = await GET(makeGetReq("msg123"));
+      const body = await res.json();
+
+      expect(body.reactions[0].reacted_by_me).toBe(false);
+    });
+
+    it("correctly identifies which emojis the user reacted to", async () => {
+      await POST(makePostReq("msg123", "👍", "user1"));
+      await POST(makePostReq("msg123", "👍", "user2"));
+      await POST(makePostReq("msg123", "❤️", "user1"));
+      await POST(makePostReq("msg123", "😂", "user2"));
+
+      const res = await GET(makeGetReq("msg123", "user1"));
+      const body = await res.json();
+
+      const thumbsUp = body.reactions.find(r => r.emoji === "👍");
+      expect(thumbsUp.reacted_by_me).toBe(true);
+
+      const heart = body.reactions.find(r => r.emoji === "❤️");
+      expect(heart.reacted_by_me).toBe(true);
+
+      const laugh = body.reactions.find(r => r.emoji === "😂");
+      expect(laugh.reacted_by_me).toBe(false);
+    });
+  });
+
+  describe("Message Isolation", () => {
+    it("returns only reactions for specified message", async () => {
+      await POST(makePostReq("msg1", "👍", "user1"));
+      await POST(makePostReq("msg2", "❤️", "user1"));
+
+      const res = await GET(makeGetReq("msg1"));
+      const body = await res.json();
+
+      expect(body.reactions.length).toBe(1);
+      expect(body.reactions[0].emoji).toBe("👍");
+    });
+  });
+});
+
+describe("Integration: Full Workflow", () => {
+  beforeEach(() => {
+    reactionStore.length = 0;
+  });
+
+  it("completes full reaction lifecycle", async () => {
+    // 1. User adds reaction
+    let res = await POST(makePostReq("msg1", "👍", "user1"));
+    let body = await res.json();
+    expect(body.toggled).toBe(true);
+    expect(body.reactions[0].count).toBe(1);
+
+    // 2. Get reactions shows correct state
+    res = await GET(makeGetReq("msg1", "user1"));
+    body = await res.json();
+    expect(body.reactions[0].reacted_by_me).toBe(true);
+
+    // 3. Another user adds same emoji
+    res = await POST(makePostReq("msg1", "👍", "user2"));
+    body = await res.json();
+    expect(body.reactions[0].count).toBe(2);
+
+    // 4. First user removes reaction
+    res = await POST(makePostReq("msg1", "👍", "user1"));
+    body = await res.json();
+    expect(body.toggled).toBe(false);
+    expect(body.reactions[0].count).toBe(1);
+
+    // 5. Verify state
+    res = await GET(makeGetReq("msg1", "user1"));
+    body = await res.json();
+    expect(body.reactions[0].reacted_by_me).toBe(false);
+  });
+
+  it("handles complex multi-user multi-emoji scenario", async () => {
+    const messageId = "complex-msg";
+
+    // Setup: Multiple users, multiple emojis
+    await POST(makePostReq(messageId, "👍", "user1"));
+    await POST(makePostReq(messageId, "👍", "user2"));
+    await POST(makePostReq(messageId, "👍", "user3"));
+    await POST(makePostReq(messageId, "❤️", "user1"));
+    await POST(makePostReq(messageId, "❤️", "user2"));
+    await POST(makePostReq(messageId, "😂", "user1"));
+
+    // Query from user1's perspective
+    let res = await GET(makeGetReq(messageId, "user1"));
+    let body = await res.json();
+
+    const thumbsUp = body.reactions.find(r => r.emoji === "👍");
+    expect(thumbsUp.count).toBe(3);
+    expect(thumbsUp.reacted_by_me).toBe(true);
+
+    const heart = body.reactions.find(r => r.emoji === "❤️");
+    expect(heart.count).toBe(2);
+    expect(heart.reacted_by_me).toBe(true);
+
+    const laugh = body.reactions.find(r => r.emoji === "😂");
+    expect(laugh.count).toBe(1);
+    expect(laugh.reacted_by_me).toBe(true);
+
+    // User 2 removes heart
+    await POST(makePostReq(messageId, "❤️", "user2"));
+
+    // Verify update
+    res = await GET(makeGetReq(messageId, "user2"));
+    body = await res.json();
+
+    const updatedHeart = body.reactions.find(r => r.emoji === "❤️");
+    expect(updatedHeart.count).toBe(1);
+    expect(updatedHeart.reacted_by_me).toBe(false);
+  });
+
+  it("tracks separate messages independently", async () => {
+    // Message 1: thumbs up from users 1 and 2
+    await POST(makePostReq("msg1", "👍", "user1"));
+    await POST(makePostReq("msg1", "👍", "user2"));
+
+    // Message 2: heart from user 3
+    await POST(makePostReq("msg2", "❤️", "user3"));
+
+    // Verify msg1 only has thumbs up
+    let res = await GET(makeGetReq("msg1"));
+    let body = await res.json();
+    expect(body.reactions.length).toBe(1);
+    expect(body.reactions[0].emoji).toBe("👍");
+    expect(body.reactions[0].count).toBe(2);
+
+    // Verify msg2 only has heart
+    res = await GET(makeGetReq("msg2"));
+    body = await res.json();
+    expect(body.reactions.length).toBe(1);
+    expect(body.reactions[0].emoji).toBe("❤️");
+    expect(body.reactions[0].count).toBe(1);
+  });
+});
diff --git a/app/api/routes-f/chat-reactions/route.ts b/app/api/routes-f/chat-reactions/route.ts
new file mode 100644
index 00000000..9c2085a0
--- /dev/null
+++ b/app/api/routes-f/chat-reactions/route.ts
@@ -0,0 +1,69 @@
+import { NextRequest, NextResponse } from "next/server";
+import { validateBody } from "../../_lib/validate";
+import { z } from "zod";
+import {
+  toggleReaction,
+  getReactionsForMessage,
+  validateReactionInput,
+} from "./utils";
+import type {
+  PostReactionRequestBody,
+  PostReactionResponse,
+  ReactionResponse,
+} from "./types";
+
+const reactionSchema = z.object({
+  message_id: z.string(),
+  emoji: z.string(),
+  user_id: z.string(),
+});
+
+export async function POST(req: NextRequest): Promise<NextResponse> {
+  const validation = await validateBody(req, reactionSchema);
+  if (validation instanceof NextResponse) {
+    return validation;
+  }
+
+  const body = validation.data as PostReactionRequestBody;
+
+  const inputValidation = validateReactionInput(
+    body.message_id,
+    body.emoji,
+    body.user_id
+  );
+  if (!inputValidation.valid) {
+    return NextResponse.json({ error: inputValidation.error }, { status: 400 });
+  }
+
+  // Toggle reaction
+  const toggled = toggleReaction(body.message_id, body.emoji, body.user_id);
+
+  // Get updated reactions
+  const reactions = getReactionsForMessage(body.message_id, body.user_id);
+
+  return NextResponse.json({
+    toggled,
+    reactions,
+  } as PostReactionResponse);
+}
+
+export async function GET(req: NextRequest): Promise<NextResponse> {
+  const messageId = new URL(req.url).searchParams.get("message_id");
+  const currentUserId = new URL(req.url).searchParams.get("user_id");
+
+  if (!messageId) {
+    return NextResponse.json(
+      { error: "message_id is required" },
+      { status: 400 }
+    );
+  }
+
+  const reactions = getReactionsForMessage(
+    messageId,
+    currentUserId || undefined
+  );
+
+  return NextResponse.json({
+    reactions,
+  } as ReactionResponse);
+}
diff --git a/app/api/routes-f/chat-reactions/types.ts b/app/api/routes-f/chat-reactions/types.ts
new file mode 100644
index 00000000..bb8fe217
--- /dev/null
+++ b/app/api/routes-f/chat-reactions/types.ts
@@ -0,0 +1,26 @@
+export interface ReactionRecord {
+  message_id: string;
+  emoji: string;
+  user_id: string;
+}
+
+export interface ReactionAggregate {
+  emoji: string;
+  count: number;
+  reacted_by_me: boolean;
+}
+
+export interface ReactionResponse {
+  reactions: ReactionAggregate[];
+}
+
+export interface PostReactionRequestBody {
+  message_id: string;
+  emoji: string;
+  user_id: string;
+}
+
+export interface PostReactionResponse {
+  toggled: boolean; // true if added, false if removed
+  reactions: ReactionAggregate[];
+}
diff --git a/app/api/routes-f/chat-reactions/utils.ts b/app/api/routes-f/chat-reactions/utils.ts
new file mode 100644
index 00000000..c4dadf74
--- /dev/null
+++ b/app/api/routes-f/chat-reactions/utils.ts
@@ -0,0 +1,130 @@
+import type { ReactionRecord, ReactionAggregate } from "./types";
+
+export const reactionStore: ReactionRecord[] = [];
+
+/**
+ * Check if a string is a single grapheme cluster (emoji or character)
+ * Uses Array.from which properly handles emoji with zero-width joiners, skin tone modifiers, etc.
+ */
+export function isSingleGraphemeCluster(input: string): boolean {
+  if (typeof input !== "string" || input.length === 0) {
+    return false;
+  }
+
+  // Use Array.from to split by grapheme clusters
+  const graphemes = Array.from(input);
+  return graphemes.length === 1;
+}
+
+/**
+ * Check if a string is a valid emoji
+ * An emoji is a grapheme cluster that is not a regular ASCII letter/number
+ */
+export function isValidEmoji(input: string): boolean {
+  if (!isSingleGraphemeCluster(input)) {
+    return false;
+  }
+
+  // Reject common ASCII letters, numbers, and symbols that aren't emoji
+  const codePoint = input.codePointAt(0) || 0;
+
+  // Allow emoji ranges and common Unicode symbols
+  // This includes: emoji, emoticons, symbols, pictographs, etc.
+  // Reject: ASCII control chars, basic ASCII letters/numbers
+  if (codePoint < 127) {
+    // Only allow basic ASCII if it's not a letter or digit
+    return !/[a-zA-Z0-9]/.test(input);
+  }
+
+  return true;
+}
+
+export function getReactionsForMessage(
+  messageId: string,
+  currentUserId?: string
+): ReactionAggregate[] {
+  // Find all reactions for this message
+  const messageReactions = reactionStore.filter(
+    r => r.message_id === messageId
+  );
+
+  if (messageReactions.length === 0) {
+    return [];
+  }
+
+  // Aggregate by emoji
+  const aggregated = new Map<string, { count: number; userIds: Set<string> }>();
+
+  for (const reaction of messageReactions) {
+    const existing = aggregated.get(reaction.emoji) || {
+      count: 0,
+      userIds: new Set(),
+    };
+    existing.count += 1;
+    existing.userIds.add(reaction.user_id);
+    aggregated.set(reaction.emoji, existing);
+  }
+
+  // Convert to response format
+  const result: ReactionAggregate[] = Array.from(aggregated.entries()).map(
+    ([emoji, data]) => ({
+      emoji,
+      count: data.count,
+      reacted_by_me: currentUserId ? data.userIds.has(currentUserId) : false,
+    })
+  );
+
+  return result;
+}
+
+export function toggleReaction(
+  messageId: string,
+  emoji: string,
+  userId: string
+): boolean {
+  // Check if this user already reacted with this emoji
+  const existingIndex = reactionStore.findIndex(
+    r => r.message_id === messageId && r.emoji === emoji && r.user_id === userId
+  );
+
+  if (existingIndex !== -1) {
+    // Remove the reaction (toggle off)
+    reactionStore.splice(existingIndex, 1);
+    return false; // Toggled off
+  } else {
+    // Add the reaction (toggle on)
+    reactionStore.push({
+      message_id: messageId,
+      emoji,
+      user_id: userId,
+    });
+    return true; // Toggled on
+  }
+}
+
+export function validateReactionInput(
+  messageId: unknown,
+  emoji: unknown,
+  userId: unknown
+): { valid: boolean; error?: string } {
+  if (typeof messageId !== "string" || messageId.trim().length === 0) {
+    return { valid: false, error: "message_id must be a non-empty string" };
+  }
+
+  if (typeof emoji !== "string" || emoji.length === 0) {
+    return { valid: false, error: "emoji must be a non-empty string" };
+  }
+
+  if (!isValidEmoji(emoji)) {
+    return {
+      valid: false,
+      error: "emoji must be a single grapheme cluster (emoji or character)",
+    };
+  }
+
+  if (typeof userId !== "string" || userId.trim().length === 0) {
+    return { valid: false, error: "user_id must be a non-empty string" };
+  }
+
+  return { valid: true };
+}
diff --git a/app/api/routes-f/checksums/__tests__/route.test.ts b/app/api/routes-f/checksums/__tests__/route.test.ts
new file mode 100644
index 00000000..13bf7f2f
--- /dev/null
+++ b/app/api/routes-f/checksums/__tests__/route.test.ts
@@ -0,0 +1,28 @@
+import { crc32, adler32, checksums } from "../route";
+
+describe("crc32", () => {
+  it("matches known vectors", () => {
+    expect(crc32("")).toBe("00000000");
+    expect(crc32("123456789")).toBe("cbf43926");
+    expect(crc32("The quick brown fox jumps over the lazy dog")).toBe("414fa339");
+  });
+});
+
+describe("adler32", () => {
+  it("matches known vectors", () => {
+    expect(adler32("")).toBe("00000001");
+    expect(adler32("Wikipedia")).toBe("11e60398");
+  });
+});
+
+describe("checksums", () => {
+  it("returns both by default", () => {
+    const out = checksums("123456789");
+    expect(out).toEqual({ crc32: "cbf43926", adler32: adler32("123456789") });
+  });
+
+  it("returns only the requested algorithm", () => {
+    expect(checksums("abc", "crc32")).toEqual({ crc32: crc32("abc") });
+    expect(checksums("abc", "adler32")).toEqual({ adler32: adler32("abc") });
+  });
+});
diff --git a/app/api/routes-f/checksums/route.ts b/app/api/routes-f/checksums/route.ts
new file mode 100644
index 00000000..cb210b32
--- /dev/null
+++ b/app/api/routes-f/checksums/route.ts
@@ -0,0 +1,55 @@
+import { NextResponse } from "next/server";
+import { z } from "zod";
+import { validateBody } from "@/app/api/routes-f/_lib/validate";
+
+const toHex8 = (n: number) => (n >>> 0).toString(16).padStart(8, "0");
+
+/** CRC32 (IEEE 802.3) of UTF-8 encoded input, returned as 8-digit hex. */
+export function crc32(input: string): string {
+  const bytes = new TextEncoder().encode(input);
+  let crc = 0xffffffff;
+  for (const byte of bytes) {
+    crc ^= byte;
+    for (let i = 0; i < 8; i += 1) {
+      crc = (crc >>> 1) ^ (0xedb88320 & -(crc & 1));
+    }
+  }
+  return toHex8(crc ^ 0xffffffff);
+}
+
+/** Adler-32 of UTF-8 encoded input, returned as 8-digit hex. */
+export function adler32(input: string): string {
+  const bytes = new TextEncoder().encode(input);
+  const MOD = 65521;
+  let a = 1;
+  let b = 0;
+  for (const byte of bytes) {
+    a = (a + byte) % MOD;
+    b = (b + a) % MOD;
+  }
+  return toHex8((b << 16) | a);
+}
+
+export type ChecksumAlgorithm = "crc32" | "adler32" | "both";
+
+export function checksums(
+  input: string,
+  algorithm: ChecksumAlgorithm = "both",
+): { crc32?: string; adler32?: string } {
+  const out: { crc32?: string; adler32?: string } = {};
+  if (algorithm === "crc32" || algorithm === "both") out.crc32 = crc32(input);
+  if (algorithm === "adler32" || algorithm === "both") out.adler32 = adler32(input);
+  return out;
+}
+
+const schema = z.object({
+  input: z.string(),
+  algorithm: z.enum(["crc32", "adler32", "both"]).optional(),
+});
+
+export async function POST(request: Request): Promise<NextResponse> {
+  const result = await validateBody(request, schema);
+  if (result instanceof NextResponse) return result;
+  const { input, algorithm } = result.data;
+  return NextResponse.json(checksums(input, algorithm));
+}
diff --git a/app/api/routes-f/ciphers/__tests__/route.test.ts b/app/api/routes-f/ciphers/__tests__/route.test.ts
new file mode 100644
index 00000000..f3a28ed6
--- /dev/null
+++ b/app/api/routes-f/ciphers/__tests__/route.test.ts
@@ -0,0 +1,33 @@
+import {
+  atbash,
+  railFenceEncode,
+  railFenceDecode,
+} from "../route";
+
+describe("atbash", () => {
+  it("mirrors letters and is its own inverse", () => {
+    expect(atbash("abc")).toBe("zyx");
+    expect(atbash("Hello")).toBe("Svool");
+    expect(atbash(atbash("Round Trip!"))).toBe("Round Trip!");
+  });
+
+  it("leaves non-letters untouched", () => {
+    expect(atbash("a1 b2")).toBe("z1 y2");
+  });
+});
+
+describe("rail fence", () => {
+  it("encodes with the classic zig-zag", () => {
+    // "WEAREDISCOVEREDFLEEATONCE" with 3 rails -> known result
+    expect(railFenceEncode("WEAREDISCOVEREDFLEEATONCE", 3)).toBe(
+      "WECRLTEERDSOEEFEAOCAIVDEN",
+    );
+  });
+
+  it("round-trips encode -> decode for several rail counts", () => {
+    const text = "the quick brown fox";
+    for (const rails of [2, 3, 4, 5]) {
+      expect(railFenceDecode(railFenceEncode(text, rails), rails)).toBe(text);
+    }
+  });
+});
diff --git a/app/api/routes-f/ciphers/route.ts b/app/api/routes-f/ciphers/route.ts
new file mode 100644
index 00000000..97135eda
--- /dev/null
+++ b/app/api/routes-f/ciphers/route.ts
@@ -0,0 +1,90 @@
+import { NextResponse } from "next/server";
+import { z } from "zod";
+import { validateBody } from "@/app/api/routes-f/_lib/validate";
+
+/**
+ * Atbash cipher: maps each Latin letter to its mirror (a<->z, A<->Z). It is its
+ * own inverse, so encoding and decoding are identical.
+ */
+export function atbash(text: string): string {
+  return text
+    .replace(/[a-z]/g, (c) => String.fromCharCode(219 - c.charCodeAt(0)))
+    .replace(/[A-Z]/g, (c) => String.fromCharCode(155 - c.charCodeAt(0)));
+}
+
+/** Index of the zig-zag rail each character lands on, for a given length. */
+function railPattern(length: number, rails: number): number[] {
+  const pattern: number[] = [];
+  let row = 0;
+  let dir = 1;
+  for (let i = 0; i < length; i += 1) {
+    pattern.push(row);
+    if (row === 0) dir = 1;
+    else if (row === rails - 1) dir = -1;
+    row += dir;
+  }
+  return pattern;
+}
+
+export function railFenceEncode(text: string, rails: number): string {
+  const rows: string[] = Array.from({ length: rails }, () => "");
+  const pattern = railPattern(text.length, rails);
+  for (let i = 0; i < text.length; i += 1) {
+    rows[pattern[i]] += text[i];
+  }
+  return rows.join("");
+}
+
+export function railFenceDecode(cipher: string, rails: number): string {
+  const pattern = railPattern(cipher.length, rails);
+
+  const perRail = Array.from({ length: rails }, (_, r) =>
+    pattern.filter((p) => p === r).length,
+  );
+  const railStrings: string[] = [];
+  let idx = 0;
+  for (let r = 0; r < rails; r += 1) {
+    railStrings.push(cipher.slice(idx, idx + perRail[r]));
+    idx += perRail[r];
+  }
+
+  const railCursor = new Array(rails).fill(0);
+  let out = "";
+  for (let i = 0; i < cipher.length; i += 1) {
+    const r = pattern[i];
+    out += railStrings[r][railCursor[r]];
+    railCursor[r] += 1;
+  }
+  return out;
+}
+
+const schema = z
+  .object({
+    text: z.string(),
+    cipher: z.enum(["atbash", "railfence"]),
+    rails: z.number().int().min(2).optional(),
+    mode: z.enum(["encode", "decode"]),
+  })
+  .refine((v) => v.cipher !== "railfence" || v.rails !== undefined, {
+    message: "rails (>= 2) is required for the railfence cipher",
+    path: ["rails"],
+  });
+
+export async function POST(request: Request): Promise<NextResponse> {
+  const result = await validateBody(request, schema);
+  if (result instanceof NextResponse) return result;
+  const { text, cipher, rails, mode } = result.data;
+
+  let output: string;
+  if (cipher === "atbash") {
+    // Symmetric — mode does not change the result.
+    output = atbash(text);
+  } else {
+    output =
+      mode === "encode"
+        ? railFenceEncode(text, rails as number)
+        : railFenceDecode(text, rails as number);
+  }
+
+  return NextResponse.json({ result: output });
+}
diff --git a/app/api/routes-f/clip-auto-tags/__tests__/route.test.ts b/app/api/routes-f/clip-auto-tags/__tests__/route.test.ts
new file mode 100644
index 00000000..b5768106
--- /dev/null
+++ b/app/api/routes-f/clip-auto-tags/__tests__/route.test.ts
@@ -0,0 +1,99 @@
+import { NextRequest } from "next/server";
+import { POST } from "../route";
+
+function makePostReq(body: unknown): NextRequest {
+  return new NextRequest("http://localhost/api/routes-f/clip-auto-tags", {
+    method: "POST",
+    headers: { "Content-Type": "application/json" },
+    body: JSON.stringify(body),
+  });
+}
+
+describe("POST /api/routes-f/clip-auto-tags", () => {
+  it("returns gaming tags for a gaming title", async () => {
+    const res = await POST(
+      makePostReq({ title: "Epic Valorant Ranked Grind" })
+    );
+    expect(res.status).toBe(200);
+    const data = await res.json();
+    expect(Array.isArray(data.tags)).toBe(true);
+    expect(data.tags).toContain("gaming");
+  });
+
+  it("returns music tags for a music title", async () => {
+    const res = await POST(
+      makePostReq({ title: "Live DJ Set - Techno Beats" })
+    );
+    expect(res.status).toBe(200);
+    const data = await res.json();
+    expect(Array.isArray(data.tags)).toBe(true);
+    expect(data.tags).toContain("music");
+  });
+
+  it("returns irl tags for an IRL title", async () => {
+    const res = await POST(
+      makePostReq({ title: "Daily Vlog - Travel Food Adventure" })
+    );
+    expect(res.status).toBe(200);
+    const data = await res.json();
+    expect(Array.isArray(data.tags)).toBe(true);
+    expect(data.tags).toContain("irl");
+  });
+
+  it("returns crypto tags when description contains crypto keywords", async () => {
+    const res = await POST(
+      makePostReq({
+        title: "Stream Updates",
+        description: "Discussing Bitcoin, Ethereum and Stellar XLM staking",
+      })
+    );
+    expect(res.status).toBe(200);
+    const data = await res.json();
+    expect(data.tags).toContain("crypto");
+  });
+
+  it("returns at most 5 tags", async () => {
+    const res = await POST(
+      makePostReq({
+        title: "gaming music art tech chat crypto",
+        description: "irl sports competitive coding painting beats",
+      })
+    );
+    expect(res.status).toBe(200);
+    const data = await res.json();
+    expect(data.tags.length).toBeLessThanOrEqual(5);
+  });
+
+  it("returns empty tags array for unrecognized title", async () => {
+    const res = await POST(makePostReq({ title: "xyzzy flurble" }));
+    expect(res.status).toBe(200);
+    const data = await res.json();
+    expect(data.tags).toEqual([]);
+  });
+
+  it("returns 400 when title is missing", async () => {
+    const res = await POST(makePostReq({ description: "something" }));
+    expect(res.status).toBe(400);
+  });
+
+  it("returns 400 when title is empty string", async () => {
+    const res = await POST(makePostReq({ title: "" }));
+    expect(res.status).toBe(400);
+  });
+
+  it("returns 400 when description is not a string", async () => {
+    const res = await POST(makePostReq({ title: "test", description: 123 }));
+    expect(res.status).toBe(400);
+  });
+
+  it("returns 400 for invalid JSON", async () => {
+    const res = await POST(
+      new NextRequest("http://localhost/api/routes-f/clip-auto-tags", {
+        method: "POST",
+        headers: { "Content-Type": "application/json" },
+        body: "not json",
+      })
+    );
+    expect(res.status).toBe(400);
+  });
+});
diff --git a/app/api/routes-f/clip-auto-tags/route.ts b/app/api/routes-f/clip-auto-tags/route.ts
new file mode 100644
index 00000000..5ec5f9d4
--- /dev/null
+++ b/app/api/routes-f/clip-auto-tags/route.ts
@@ -0,0 +1,66 @@
+import { NextRequest, NextResponse } from "next/server";
+import type { ClipAutoTagsRequest, ClipAutoTagsResponse } from "./types";
+import { TAG_KEYWORDS } from "./tag-map";
+
+const MAX_TAGS = 5;
+
+function generateTags(title: string, description?: string): string[] {
+  const text = `${title} ${description ?? ""}`.toLowerCase();
+  const words = text.split(/\s+/);
+
+  const scores: Record<string, number> = {};
+
+  for (const [tag, keywords] of Object.entries(TAG_KEYWORDS)) {
+    let score = 0;
+    for (const keyword of keywords) {
+      if (keyword.includes(" ")) {
+        if (text.includes(keyword)) {
+          score += 2;
+        }
+      } else {
+        for (const word of words) {
+          if (word === keyword || word.startsWith(keyword)) {
+            score += 1;
+          }
+        }
+      }
+    }
+    if (score > 0) {
+      scores[tag] = score;
+    }
+  }
+
+  return Object.entries(scores)
+    .sort((a, b) => b[1] - a[1])
+    .slice(0, MAX_TAGS)
+    .map(([tag]) => tag);
+}
+
+export async function POST(req: NextRequest): Promise<NextResponse> {
+  let body: ClipAutoTagsRequest;
+  try {
+    body = await req.json();
+  } catch {
+    return NextResponse.json({ error: "invalid JSON body" }, { status: 400 });
+  }
+
+  const { title, description } = body;
+
+  if (!title || typeof title !== "string" || title.trim().length === 0) {
+    return NextResponse.json(
+      { error: "title is required and must be a non-empty string" },
+      { status: 400 }
+    );
+  }
+
+  if (description !== undefined && typeof description !== "string") {
+    return NextResponse.json(
+      { error: "description must be a string" },
+      { status: 400 }
+    );
+  }
+
+  const tags = generateTags(title.trim(), description?.trim());
+
+  return NextResponse.json({ tags } as ClipAutoTagsResponse);
+}
diff --git a/app/api/routes-f/clip-auto-tags/tag-map.ts b/app/api/routes-f/clip-auto-tags/tag-map.ts
new file mode 100644
index 00000000..e214f368
--- /dev/null
+++ b/app/api/routes-f/clip-auto-tags/tag-map.ts
@@ -0,0 +1,58 @@
+export const TAG_KEYWORDS: Record<string, string[]> = {
+  gaming: [
+    "game", "gaming", "play", "player", "fps", "rpg", "mmo", "moba",
+    "battle", "boss", "raid", "level", "rank", "competitive", "esports",
+    "stream", "twitch", "controller", "keyboard", "mouse", "gpu", "pc",
+    "console", "playstation", "xbox", "nintendo", "steam", "valorant",
+    "fortnite", "league", "minecraft", "apex", "cod", "overwatch",
+    "destiny", "diablo", "wow", "ffxiv", "genshin", "roblox",
+  ],
+  music: [
+    "music", "song", "track", "album", "artist", "band", "concert",
+    "live", "performance", "dj", "remix", "beat", "rap", "hip hop",
+    "rock", "pop", "edm", "techno", "bass", "guitar", "piano",
+    "vocal", "sing", "karaoke", "playlist", "vinyl", "studio",
+    "producer", "beats", "melody", "rhythm",
+  ],
+  irl: [
+    "irl", "vlog", "daily", "life", "travel", "food", "cook", "cooking",
+    "restaurant", "eat", "mukbang", "outdoor", "adventure", "city",
+    "walk", "explore", "nature", "beach", "mountain", "camp",
+    "fitness", "gym", "workout", "yoga", "pet", "dog", "cat",
+    "unboxing", "haul", "fashion", "style",
+  ],
+  crypto: [
+    "crypto", "bitcoin", "btc", "ethereum", "eth", "solana", "sol",
+    "stellar", "xlm", "defi", "nft", "web3", "blockchain", "token",
+    "wallet", "mining", "staking", "yield", "liquidity", "swap",
+    "airdrop", "meme", "altcoin", "trading", "chart", "bull", "bear",
+    "hodl", "moon", "pump",
+  ],
+  creative: [
+    "art", "draw", "paint", "design", "creative", "illustration",
+    "digital", "photoshop", "blender", "3d", "model", "animation",
+    "manga", "comic", "sketch", "canvas", "color", "pixel",
+    "timelapse", "speedpaint", "tutorial", "howto", "diy", "craft",
+    "make", "build", "woodworking", "sew", "knit",
+  ],
+  sports: [
+    "sport", "football", "soccer", "basketball", "baseball", "tennis",
+    "golf", "mma", "ufc", "boxing", "wrestling", "f1", "racing",
+    "nfl", "nba", "mlb", "nhl", "olympics", "world cup", "championship",
+    "tournament", "league", "match", "game day", "highlight",
+    "replay", "analysis", "draft",
+  ],
+  tech: [
+    "tech", "technology", "code", "coding", "programming", "developer",
+    "software", "hardware", "ai", "machine learning", "robot",
+    "hack", "cyber", "security", "linux", "mac", "windows",
+    "phone", "iphone", "android", "app", "review", "unbox",
+    "setup", "desk", "monitor", "keyboard", "usb",
+  ],
+  just_chatting: [
+    "chat", "talk", "discussion", "debate", "q&a", "ama", "story",
+    "rant", "opinion", "news", "react", "reaction", "funny",
+    "meme", "comedy", "joke", "laugh", "chill", "hangout",
+    "podcast", "interview", "collab", "guest",
+  ],
+};
diff --git a/app/api/routes-f/clip-auto-tags/types.ts b/app/api/routes-f/clip-auto-tags/types.ts
new file mode 100644
index 00000000..a98edd89
--- /dev/null
+++ b/app/api/routes-f/clip-auto-tags/types.ts
@@ -0,0 +1,8 @@
+export interface ClipAutoTagsRequest {
+  title: string;
+  description?: string;
+}
+
+export interface ClipAutoTagsResponse {
+  tags: string[];
+}
diff --git a/app/api/routes-f/clips/most-liked/__tests__/route.test.ts b/app/api/routes-f/clips/most-liked/__tests__/route.test.ts
new file mode 100644
index 00000000..434a71b6
--- /dev/null
+++ b/app/api/routes-f/clips/most-liked/__tests__/route.test.ts
@@ -0,0 +1,95 @@
+import { NextRequest } from "next/server";
+import { GET } from "../route";
+
+function makeReq(params: Record<string, string> = {}): NextRequest {
+  const url = new URL("http://localhost/api/routes-f/clips/most-liked");
+  Object.entries(params).forEach(([k, v]) => url.searchParams.set(k, v));
+  return new NextRequest(url.toString());
+}
+
+describe("GET /api/routes-f/clips/most-liked", () => {
+  it("returns all clips sorted by likes descending with all-time timeframe", async () => {
+    const res = await GET(makeReq({ timeframe: "all-time" }));
+    expect(res.status).toBe(200);
+    const data = await res.json();
+    expect(Array.isArray(data.clips)).toBe(true);
+    expect(data.timeframe).toBe("all-time");
+    // Should be sorted descending
+    for (let i = 1; i < data.clips.length; i++) {
+      expect(data.clips[i - 1].likes).toBeGreaterThanOrEqual(data.clips[i].likes);
+    }
+  });
+
+  it("filters by 24h timeframe — only recent clips", async () => {
+    const res = await GET(makeReq({ timeframe: "24h" }));
+    expect(res.status).toBe(200);
+    const data = await res.json();
+    const cutoff = Date.now() - 24 * 60 * 60 * 1000;
+    for (const clip of data.clips) {
+      expect(clip.created_at).toBeGreaterThanOrEqual(cutoff);
+    }
+  });
+
+  it("filters by 7d timeframe", async () => {
+    const res = await GET(makeReq({ timeframe: "7d" }));
+    expect(res.status).toBe(200);
+    const data = await res.json();
+    const cutoff = Date.now() - 7 * 24 * 60 * 60 * 1000;
+    for (const clip of data.clips) {
+      expect(clip.created_at).toBeGreaterThanOrEqual(cutoff);
+    }
+  });
+
+  it("filters by 30d timeframe", async () => {
+    const res = await GET(makeReq({ timeframe: "30d" }));
+    expect(res.status).toBe(200);
+    const data = await res.json();
+    const cutoff = Date.now() - 30 * 24 * 60 * 60 * 1000;
+    for (const clip of data.clips) {
+      expect(clip.created_at).toBeGreaterThanOrEqual(cutoff);
+    }
+  });
+
+  it("filters by creator_id", async () => {
+    const res = await GET(makeReq({ creator_id: "creator_a", timeframe: "all-time" }));
+    expect(res.status).toBe(200);
+    const data = await res.json();
+    for (const clip of data.clips) {
+      expect(clip.creator_id).toBe("creator_a");
+    }
+  });
+
+  it("respects limit param", async () => {
+    const res = await GET(makeReq({ timeframe: "all-time", limit: "3" }));
+    expect(res.status).toBe(200);
+    const data = await res.json();
+    expect(data.clips.length).toBeLessThanOrEqual(3);
+  });
+
+  it("assigns sequential rank starting at 1", async () => {
+    const res = await GET(makeReq({ timeframe: "all-time" }));
+    const data = await res.json();
+    data.clips.forEach((clip: { rank: number }, idx: number) => {
+      expect(clip.rank).toBe(idx + 1);
+    });
+  });
+
+  it("returns 400 for invalid timeframe", async () => {
+    const res = await GET(makeReq({ timeframe: "3months" }));
+    expect(res.status).toBe(400);
+    const data = await res.json();
+    expect(data.error).toMatch(/invalid timeframe/i);
+  });
+
+  it("returns 400 for invalid limit", async () => {
+    const res = await GET(makeReq({ timeframe: "all-time", limit: "0" }));
+    expect(res.status).toBe(400);
+  });
+
+  it("defaults to all-time when no timeframe given", async () => {
+    const res = await GET(makeReq({}));
+    expect(res.status).toBe(200);
+    const data = await res.json();
+    expect(data.timeframe).toBe("all-time");
+  });
+});
diff --git a/app/api/routes-f/clips/most-liked/route.ts b/app/api/routes-f/clips/most-liked/route.ts
new file mode 100644
index 00000000..b3cdce2d
--- /dev/null
+++ b/app/api/routes-f/clips/most-liked/route.ts
@@ -0,0 +1,67 @@
+import { NextRequest, NextResponse } from "next/server";
+import type { Timeframe, RankedClip, MostLikedResponse } from "./types";
+import { getClips } from "./seed";
+
+const VALID_TIMEFRAMES: Timeframe[] = ["24h", "7d", "30d", "all-time"];
+
+function timeframeCutoff(timeframe: Timeframe): number {
+  const now = Date.now();
+  const h = 60 * 60 * 1000;
+  const d = 24 * h;
+  switch (timeframe) {
+    case "24h":
+      return now - 24 * h;
+    case "7d":
+      return now - 7 * d;
+    case "30d":
+      return now - 30 * d;
+    case "all-time":
+      return 0;
+  }
+}
+
+export async function GET(req: NextRequest): Promise<NextResponse> {
+  const { searchParams } = new URL(req.url);
+  const creatorId = searchParams.get("creator_id") ?? undefined;
+  const timeframeParam = searchParams.get("timeframe") ?? "all-time";
+  const limitParam = searchParams.get("limit");
+
+  // Validate timeframe
+  if (!VALID_TIMEFRAMES.includes(timeframeParam as Timeframe)) {
+    return NextResponse.json(
+      { error: `invalid timeframe, must be one of: ${VALID_TIMEFRAMES.join(", ")}` },
+      { status: 400 }
+    );
+  }
+  const timeframe = timeframeParam as Timeframe;
+
+  // Validate limit
+  let limit = 10;
+  if (limitParam !== null) {
+    const parsed = parseInt(limitParam, 10);
+    if (isNaN(parsed) || parsed < 1 || parsed > 100) {
+      return NextResponse.json(
+        { error: "limit must be an integer between 1 and 100" },
+        { status: 400 }
+      );
+    }
+    limit = parsed;
+  }
+
+  const cutoff = timeframeCutoff(timeframe);
+  const clips = getClips(creatorId).filter(c => c.created_at >= cutoff);
+
+  // Sort by likes descending
+  clips.sort((a, b) => b.likes - a.likes);
+
+  const ranked: RankedClip[] = clips.slice(0, limit).map((clip, idx) => ({
+    ...clip,
+    rank: idx + 1,
+  }));
+
+  return NextResponse.json({
+    clips: ranked,
+    timeframe,
+    total: ranked.length,
+  } as MostLikedResponse);
+}
diff --git a/app/api/routes-f/clips/most-liked/seed.ts b/app/api/routes-f/clips/most-liked/seed.ts
new file mode 100644
index 00000000..2480e6c6
--- /dev/null
+++ b/app/api/routes-f/clips/most-liked/seed.ts
@@ -0,0 +1,116 @@
+import type { ClipRecord } from "./types";
+
+const now = Date.now();
+const h = 60 * 60 * 1000;
+const d = 24 * h;
+
+export const clipSeed: ClipRecord[] = [
+  // creator_a clips
+  {
+    clip_id: "clip_001",
+    creator_id: "creator_a",
+    title: "Insane 1v5 clutch",
+    duration_seconds: 30,
+    likes: 4820,
+    created_at: now - 2 * h,
+    thumbnail_url: "https://stream.fi/thumbs/clip_001.jpg",
+    vod_id: "vod_a1",
+  },
+  {
+    clip_id: "clip_002",
+    creator_id: "creator_a",
+    title: "World record speedrun attempt",
+    duration_seconds: 60,
+    likes: 3102,
+    created_at: now - 5 * h,
+    thumbnail_url: "https://stream.fi/thumbs/clip_002.jpg",
+    vod_id: "vod_a2",
+  },
+  {
+    clip_id: "clip_003",
+    creator_id: "creator_a",
+    title: "Epic fail compilation",
+    duration_seconds: 45,
+    likes: 1280,
+    created_at: now - 10 * d,
+    thumbnail_url: "https://stream.fi/thumbs/clip_003.jpg",
+    vod_id: "vod_a3",
+  },
+  {
+    clip_id: "clip_004",
+    creator_id: "creator_a",
+    title: "Pro tips for beginners",
+    duration_seconds: 90,
+    likes: 875,
+    created_at: now - 25 * d,
+    thumbnail_url: "https://stream.fi/thumbs/clip_004.jpg",
+    vod_id: "vod_a4",
+  },
+  // creator_b clips
+  {
+    clip_id: "clip_005",
+    creator_id: "creator_b",
+    title: "Biggest tip ever received",
+    duration_seconds: 20,
+    likes: 9540,
+    created_at: now - 1 * h,
+    thumbnail_url: "https://stream.fi/thumbs/clip_005.jpg",
+    vod_id: "vod_b1",
+  },
+  {
+    clip_id: "clip_006",
+    creator_id: "creator_b",
+    title: "Subscriber milestone reached",
+    duration_seconds: 35,
+    likes: 6210,
+    created_at: now - 3 * h,
+    thumbnail_url: "https://stream.fi/thumbs/clip_006.jpg",
+    vod_id: "vod_b2",
+  },
+  {
+    clip_id: "clip_007",
+    creator_id: "creator_b",
+    title: "5000 XLM tip reaction",
+    duration_seconds: 25,
+    likes: 2340,
+    created_at: now - 8 * d,
+    thumbnail_url: "https://stream.fi/thumbs/clip_007.jpg",
+    vod_id: "vod_b3",
+  },
+  {
+    clip_id: "clip_008",
+    creator_id: "creator_b",
+    title: "Late night stream highlights",
+    duration_seconds: 55,
+    likes: 430,
+    created_at: now - 35 * d,
+    thumbnail_url: "https://stream.fi/thumbs/clip_008.jpg",
+    vod_id: "vod_b4",
+  },
+  // creator_c clips
+  {
+    clip_id: "clip_009",
+    creator_id: "creator_c",
+    title: "Blockchain tutorial clip",
+    duration_seconds: 60,
+    likes: 1600,
+    created_at: now - 6 * d,
+    thumbnail_url: "https://stream.fi/thumbs/clip_009.jpg",
+    vod_id: "vod_c1",
+  },
+  {
+    clip_id: "clip_010",
+    creator_id: "creator_c",
+    title: "Stellar wallet setup",
+    duration_seconds: 40,
+    likes: 720,
+    created_at: now - 22 * h,
+    thumbnail_url: "https://stream.fi/thumbs/clip_010.jpg",
+    vod_id: "vod_c2",
+  },
+];
+
+export function getClips(creatorId?: string): ClipRecord[] {
+  if (creatorId) return clipSeed.filter(c => c.creator_id === creatorId);
+  return clipSeed;
+}
diff --git a/app/api/routes-f/clips/most-liked/types.ts b/app/api/routes-f/clips/most-liked/types.ts
new file mode 100644
index 00000000..6500c2a4
--- /dev/null
+++ b/app/api/routes-f/clips/most-liked/types.ts
@@ -0,0 +1,22 @@
+export type Timeframe = "24h" | "7d" | "30d" | "all-time";
+
+export interface ClipRecord {
+  clip_id: string;
+  creator_id: string;
+  title: string;
+  duration_seconds: number;
+  likes: number;
+  created_at: number; // epoch ms
+  thumbnail_url: string;
+  vod_id: string;
+}
+
+export interface RankedClip extends ClipRecord {
+  rank: number;
+}
+
+export interface MostLikedResponse {
+  clips: RankedClip[];
+  timeframe: Timeframe;
+  total: number;
+}
diff --git a/app/api/routes-f/collatz/__tests__/route.test.ts b/app/api/routes-f/collatz/__tests__/route.test.ts
new file mode 100644
index 00000000..10724ab3
--- /dev/null
+++ b/app/api/routes-f/collatz/__tests__/route.test.ts
@@ -0,0 +1,20 @@
+import { collatz } from "../route";
+
+describe("collatz", () => {
+  it("returns the trivial sequence for n=1", () => {
+    expect(collatz(1)).toEqual({ sequence: [1], steps: 0, max_value: 1 });
+  });
+
+  it("matches the known sequence for n=27 (111 steps, max 9232)", () => {
+    const r = collatz(27);
+    expect(r.steps).toBe(111);
+    expect(r.max_value).toBe(9232);
+    expect(r.sequence[0]).toBe(27);
+    expect(r.sequence[r.sequence.length - 1]).toBe(1);
+    expect(r.sequence.length).toBe(112); // steps + the starting value
+  });
+
+  it("handles a small even start (n=6)", () => {
+    expect(collatz(6).sequence).toEqual([6, 3, 10, 5, 16, 8, 4, 2, 1]);
+  });
+});
diff --git a/app/api/routes-f/collatz/route.ts b/app/api/routes-f/collatz/route.ts
new file mode 100644
index 00000000..13672551
--- /dev/null
+++ b/app/api/routes-f/collatz/route.ts
@@ -0,0 +1,42 @@
+import { NextResponse } from "next/server";
+import { z } from "zod";
+import { validateQuery } from "@/app/api/routes-f/_lib/validate";
+
+const MAX_STEPS = 10000;
+
+export interface CollatzResult {
+  sequence: number[];
+  steps: number;
+  max_value: number;
+}
+
+/**
+ * Generate the Collatz sequence for a positive integer `n`: repeatedly halve
+ * if even, else 3n+1, until reaching 1. Capped at MAX_STEPS to bound output.
+ */
+export function collatz(n: number): CollatzResult {
+  const sequence: number[] = [n];
+  let current = n;
+  let steps = 0;
+  let maxValue = n;
+
+  while (current !== 1 && steps < MAX_STEPS) {
+    current = current % 2 === 0 ? current / 2 : 3 * current + 1;
+    sequence.push(current);
+    if (current > maxValue) maxValue = current;
+    steps += 1;
+  }
+
+  return { sequence, steps, max_value: maxValue };
+}
+
+const schema = z.object({
+  n: z.coerce.number().int().positive(),
+});
+
+export async function GET(request: Request): Promise<NextResponse> {
+  const { searchParams } = new URL(request.url);
+  const result = validateQuery(searchParams, schema);
+  if (result instanceof NextResponse) return result;
+  return NextResponse.json(collatz(result.data.n));
+}
diff --git a/app/api/routes-f/continent/__tests__/route.test.ts b/app/api/routes-f/continent/__tests__/route.test.ts
new file mode 100644
index 00000000..8fcbbc09
--- /dev/null
+++ b/app/api/routes-f/continent/__tests__/route.test.ts
@@ -0,0 +1,24 @@
+import { lookupContinent } from "../route";
+
+describe("lookupContinent", () => {
+  it("maps countries across several continents", () => {
+    expect(lookupContinent("NG")).toEqual({
+      country: "Nigeria",
+      continent: "Africa",
+      region: "Western Africa",
+    });
+    expect(lookupContinent("JP")?.continent).toBe("Asia");
+    expect(lookupContinent("BR")?.continent).toBe("South America");
+    expect(lookupContinent("DE")?.continent).toBe("Europe");
+    expect(lookupContinent("AU")?.continent).toBe("Oceania");
+    expect(lookupContinent("US")?.continent).toBe("North America");
+  });
+
+  it("is case-insensitive", () => {
+    expect(lookupContinent("ng")?.country).toBe("Nigeria");
+  });
+
+  it("returns null for an unknown code", () => {
+    expect(lookupContinent("ZZ")).toBeNull();
+  });
+});
diff --git a/app/api/routes-f/continent/route.ts b/app/api/routes-f/continent/route.ts
new file mode 100644
index 00000000..be9776eb
--- /dev/null
+++ b/app/api/routes-f/continent/route.ts
@@ -0,0 +1,59 @@
+import { NextResponse } from "next/server";
+import { z } from "zod";
+import { validateBody } from "@/app/api/routes-f/_lib/validate";
+
+export interface CountryInfo {
+  country: string;
+  continent: string;
+  region: string;
+}
+
+// ISO 3166-1 alpha-2 -> continent/region. Bundled in-folder (representative
+// subset across all continents; extend as needed).
+const COUNTRIES: Record<string, CountryInfo> = {
+  NG: { country: "Nigeria", continent: "Africa", region: "Western Africa" },
+  ZA: { country: "South Africa", continent: "Africa", region: "Southern Africa" },
+  EG: { country: "Egypt", continent: "Africa", region: "Northern Africa" },
+  KE: { country: "Kenya", continent: "Africa", region: "Eastern Africa" },
+  US: { country: "United States", continent: "North America", region: "Northern America" },
+  CA: { country: "Canada", continent: "North America", region: "Northern America" },
+  MX: { country: "Mexico", continent: "North America", region: "Central America" },
+  BR: { country: "Brazil", continent: "South America", region: "South America" },
+  AR: { country: "Argentina", continent: "South America", region: "South America" },
+  GB: { country: "United Kingdom", continent: "Europe", region: "Northern Europe" },
+  DE: { country: "Germany", continent: "Europe", region: "Western Europe" },
+  FR: { country: "France", continent: "Europe", region: "Western Europe" },
+  ES: { country: "Spain", continent: "Europe", region: "Southern Europe" },
+  IT: { country: "Italy", continent: "Europe", region: "Southern Europe" },
+  RU: { country: "Russia", continent: "Europe", region: "Eastern Europe" },
+  CN: { country: "China", continent: "Asia", region: "Eastern Asia" },
+  JP: { country: "Japan", continent: "Asia", region: "Eastern Asia" },
+  IN: { country: "India", continent: "Asia", region: "Southern Asia" },
+  SG: { country: "Singapore", continent: "Asia", region: "South-Eastern Asia" },
+  AE: { country: "United Arab Emirates", continent: "Asia", region: "Western Asia" },
+  SA: { country: "Saudi Arabia", continent: "Asia", region: "Western Asia" },
+  AU: { country: "Australia", continent: "Oceania", region: "Australia and New Zealand" },
+  NZ: { country: "New Zealand", continent: "Oceania", region: "Australia and New Zealand" },
+  FJ: { country: "Fiji", continent: "Oceania", region: "Melanesia" },
+  AQ: { country: "Antarctica", continent: "Antarctica", region: "Antarctica" },
+};
+
+/** Look up continent/region for an ISO alpha-2 country code (case-insensitive). */
+export function lookupContinent(code: string): CountryInfo | null {
+  return COUNTRIES[code.trim().toUpperCase()] ?? null;
+}
+
+const schema = z.object({ code: z.string() });
+
+export async function POST(request: Request): Promise<NextResponse> {
+  const result = await validateBody(request, schema);
+  if (result instanceof NextResponse) return result;
+  const info = lookupContinent(result.data.code);
+  if (!info) {
+    return NextResponse.json(
+      { error: `unknown country code: ${result.data.code}` },
+      { status: 404 },
+    );
+  }
+  return NextResponse.json(info);
+}
diff --git a/app/api/routes-f/cookie-parse/_lib/helpers.ts b/app/api/routes-f/cookie-parse/_lib/helpers.ts
new file mode 100644
index 00000000..ed8c238f
--- /dev/null
+++ b/app/api/routes-f/cookie-parse/_lib/helpers.ts
@@ -0,0 +1,106 @@
+import type { CookieBuildResponse, CookieParseResponse, ParsedCookie, SameSite } from "./types";
+
+const VALID_SAME_SITE: SameSite[] = ["Strict", "Lax", "None"];
+
+function isRecord(value: unknown): value is Record<string, unknown> {
+  return typeof value === "object" && value !== null && !Array.isArray(value);
+}
+
+function parseSingleCookie(cookieStr: string): [string, ParsedCookie] | null {
+  const parts = cookieStr.split(";").map((p) => p.trim());
+  if (!parts[0]) return null;
+
+  const eqIdx = parts[0].indexOf("=");
+  if (eqIdx === -1) return null;
+
+  const name = decodeURIComponent(parts[0].slice(0, eqIdx).trim());
+  const value = decodeURIComponent(parts[0].slice(eqIdx + 1).trim());
+
+  const cookie: ParsedCookie = { value, secure: false, http_only: false };
+
+  for (const attr of parts.slice(1)) {
+    const lower = attr.toLowerCase();
+    if (lower === "secure") {
+      cookie.secure = true;
+    } else if (lower === "httponly") {
+      cookie.http_only = true;
+    } else if (lower.startsWith("expires=")) {
+      cookie.expires = attr.slice("expires=".length).trim();
+    } else if (lower.startsWith("max-age=")) {
+      const age = parseInt(attr.slice("max-age=".length).trim(), 10);
+      if (!isNaN(age)) cookie.max_age = age;
+    } else if (lower.startsWith("domain=")) {
+      cookie.domain = attr.slice("domain=".length).trim();
+    } else if (lower.startsWith("path=")) {
+      cookie.path = attr.slice("path=".length).trim();
+    } else if (lower.startsWith("samesite=")) {
+      const raw = attr.slice("samesite=".length).trim();
+      const normalized = (raw.charAt(0).toUpperCase() + raw.slice(1).toLowerCase()) as SameSite;
+      if (VALID_SAME_SITE.includes(normalized)) {
+        cookie.same_site = normalized;
+      } else {
+        throw new Error(`Invalid SameSite value: ${raw}. Must be Strict, Lax, or None.`);
+      }
+    }
+  }
+
+  return [name, cookie];
+}
+
+export function parseCookies(input: unknown): CookieParseResponse {
+  if (typeof input !== "string") {
+    throw new Error("input must be a string for parse mode.");
+  }
+
+  const result: CookieParseResponse = {};
+
+  // Each entry is a full Set-Cookie string; multiple entries split by newline
+  const entries = input.split(/\r?\n/).map((s) => s.trim()).filter(Boolean);
+  const cookies = entries.length > 1 ? entries : [input.trim()];
+
+  for (const cookieStr of cookies) {
+    const parsed = parseSingleCookie(cookieStr);
+    if (parsed) {
+      const [name, cookie] = parsed;
+      result[name] = cookie;
+    }
+  }
+
+  return result;
+}
+
+export function buildCookie(input: unknown): CookieBuildResponse {
+  if (!isRecord(input)) {
+    throw new Error("input must be an object for build mode.");
+  }
+
+  const { name, value, expires, max_age, domain, path, secure, http_only, same_site } =
+    input as Record<string, unknown>;
+
+  if (typeof name !== "string" || !name) {
+    throw new Error("name must be a non-empty string.");
+  }
+  if (typeof value !== "string") {
+    throw new Error("value must be a string.");
+  }
+
+  if (same_site !== undefined) {
+    if (!VALID_SAME_SITE.includes(same_site as SameSite)) {
+      throw new Error(`same_site must be Strict, Lax, or None.`);
+    }
+  }
+
+  const parts: string[] = [
+    `${encodeURIComponent(name)}=${encodeURIComponent(value as string)}`,
+  ];
+
+  if (expires) parts.push(`Expires=${expires}`);
+  if (max_age !== undefined) parts.push(`Max-Age=${max_age}`);
+  if (domain) parts.push(`Domain=${domain}`);
+  if (path) parts.push(`Path=${path}`);
+  if (secure) parts.push("Secure");
+  if (http_only) parts.push("HttpOnly");
+  if (same_site) parts.push(`SameSite=${same_site}`);
+
+  return { header: parts.join("; ") };
+}
diff --git a/app/api/routes-f/cookie-parse/_lib/types.ts b/app/api/routes-f/cookie-parse/_lib/types.ts
new file mode 100644
index 00000000..763e72c0
--- /dev/null
+++ b/app/api/routes-f/cookie-parse/_lib/types.ts
@@ -0,0 +1,32 @@
+export type SameSite = "Strict" | "Lax" | "None";
+
+export interface ParsedCookie {
+  value: string;
+  expires?: string;
+  max_age?: number;
+  domain?: string;
+  path?: string;
+  secure: boolean;
+  http_only: boolean;
+  same_site?: SameSite;
+}
+
+export interface CookieParseResponse {
+  [name: string]: ParsedCookie;
+}
+
+export interface CookieBuildInput {
+  name: string;
+  value: string;
+  expires?: string;
+  max_age?: number;
+  domain?: string;
+  path?: string;
+  secure?: boolean;
+  http_only?: boolean;
+  same_site?: SameSite;
+}
+
+export interface CookieBuildResponse {
+  header: string;
+}
diff --git a/app/api/routes-f/cookie-parse/route.ts b/app/api/routes-f/cookie-parse/route.ts
new file mode 100644
index 00000000..a21b2674
--- /dev/null
+++ b/app/api/routes-f/cookie-parse/route.ts
@@ -0,0 +1,37 @@
+import { type NextRequest, NextResponse } from "next/server";
+import { buildCookie, parseCookies } from "./_lib/helpers";
+
+export async function POST(req: NextRequest) {
+  let body: unknown;
+
+  try {
+    body = await req.json();
+  } catch {
+    return NextResponse.json({ error: "Invalid JSON body." }, { status: 400 });
+  }
+
+  try {
+    if (
+      typeof body !== "object" ||
+      body === null ||
+      Array.isArray(body)
+    ) {
+      return NextResponse.json({ error: "Request body must be an object." }, { status: 400 });
+    }
+
+    const { mode, input } = body as Record<string, unknown>;
+
+    if (mode === "parse") {
+      return NextResponse.json(parseCookies(input));
+    }
+
+    if (mode === "build") {
+      return NextResponse.json(buildCookie(input));
+    }
+
+    return NextResponse.json({ error: "mode must be parse or build." }, { status: 400 });
+  } catch (error) {
+    const message = error instanceof Error ? error.message : "Failed to process cookie.";
+    return NextResponse.json({ error: message }, { status: 400 });
+  }
+}
diff --git a/app/api/routes-f/country-flag/__tests__/route.test.ts b/app/api/routes-f/country-flag/__tests__/route.test.ts
new file mode 100644
index 00000000..23e03a42
--- /dev/null
+++ b/app/api/routes-f/country-flag/__tests__/route.test.ts
@@ -0,0 +1,29 @@
+import { codeToFlag, flagToCode } from "../route";
+
+describe("codeToFlag", () => {
+  it("converts codes to flag emoji", () => {
+    expect(codeToFlag("NG")).toBe("🇳🇬");
+    expect(codeToFlag("us")).toBe("🇺🇸");
+    expect(codeToFlag("GB")).toBe("🇬🇧");
+  });
+  it("rejects invalid codes", () => {
+    expect(() => codeToFlag("N")).toThrow();
+    expect(() => codeToFlag("N1")).toThrow();
+  });
+});
+
+describe("flagToCode", () => {
+  it("converts flag emoji back to codes", () => {
+    expect(flagToCode("🇳🇬")).toBe("NG");
+    expect(flagToCode("🇺🇸")).toBe("US");
+  });
+  it("round-trips", () => {
+    for (const c of ["NG", "US", "GB", "JP", "DE"]) {
+      expect(flagToCode(codeToFlag(c))).toBe(c);
+    }
+  });
+  it("rejects non-flag input", () => {
+    expect(() => flagToCode("AB")).toThrow();
+    expect(() => flagToCode("🇳")).toThrow();
+  });
+});
diff --git a/app/api/routes-f/country-flag/route.ts b/app/api/routes-f/country-flag/route.ts
new file mode 100644
index 00000000..9776c13f
--- /dev/null
+++ b/app/api/routes-f/country-flag/route.ts
@@ -0,0 +1,52 @@
+import { NextResponse } from "next/server";
+import { z } from "zod";
+import { validateBody } from "@/app/api/routes-f/_lib/validate";
+
+const A = 0x1f1e6; // regional indicator 'A'
+
+/** Convert an ISO 3166-1 alpha-2 code (e.g. "NG") to its flag emoji. */
+export function codeToFlag(code: string): string {
+  const cc = code.toUpperCase();
+  if (!/^[A-Z]{2}$/.test(cc)) {
+    throw new RangeError("code must be two ASCII letters");
+  }
+  return String.fromCodePoint(
+    A + (cc.charCodeAt(0) - 65),
+    A + (cc.charCodeAt(1) - 65),
+  );
+}
+
+/** Convert a flag emoji (two regional indicators) back to its alpha-2 code. */
+export function flagToCode(flag: string): string {
+  const cps = Array.from(flag, (ch) => ch.codePointAt(0) ?? 0);
+  if (cps.length !== 2 || cps.some((cp) => cp < A || cp > A + 25)) {
+    throw new RangeError("flag must be two regional-indicator symbols");
+  }
+  return cps.map((cp) => String.fromCharCode(cp - A + 65)).join("");
+}
+
+const schema = z.object({
+  mode: z.enum(["to_flag", "to_code"]),
+  code: z.string().optional(),
+  flag: z.string().optional(),
+});
+
+export async function POST(request: Request): Promise<NextResponse> {
+  const result = await validateBody(request, schema);
+  if (result instanceof NextResponse) return result;
+  const { mode, code, flag } = result.data;
+
+  try {
+    if (mode === "to_flag") {
+      if (!code) return NextResponse.json({ error: "code is required for to_flag" }, { status: 400 });
+      return NextResponse.json({ flag: codeToFlag(code) });
+    }
+    if (!flag) return NextResponse.json({ error: "flag is required for to_code" }, { status: 400 });
+    return NextResponse.json({ code: flagToCode(flag) });
+  } catch (e) {
+    return NextResponse.json(
+      { error: e instanceof Error ? e.message : "invalid input" },
+      { status: 400 },
+    );
+  }
+}
diff --git a/app/api/routes-f/creator-min-tip/check/route.ts b/app/api/routes-f/creator-min-tip/check/route.ts
new file mode 100644
index 00000000..c728b739
--- /dev/null
+++ b/app/api/routes-f/creator-min-tip/check/route.ts
@@ -0,0 +1,36 @@
+import { NextRequest, NextResponse } from "next/server";
+import { checkTip } from "../store";
+
+export async function POST(req: NextRequest): Promise<NextResponse> {
+  let body: Record<string, unknown>;
+
+  try {
+    body = await req.json();
+  } catch {
+    return NextResponse.json({ error: "Invalid JSON body." }, { status: 400 });
+  }
+
+  const { creator_id, asset, amount } = body;
+
+  if (typeof creator_id !== "string" || !creator_id.trim()) {
+    return NextResponse.json(
+      { error: "creator_id is required." },
+      { status: 400 }
+    );
+  }
+  if (typeof asset !== "string" || !asset.trim()) {
+    return NextResponse.json(
+      { error: "asset is required." },
+      { status: 400 }
+    );
+  }
+  if (typeof amount !== "number" || amount < 0) {
+    return NextResponse.json(
+      { error: "amount must be a number >= 0." },
+      { status: 400 }
+    );
+  }
+
+  const result = checkTip(creator_id, asset, amount);
+  return NextResponse.json(result);
+}
diff --git a/app/api/routes-f/creator-min-tip/route.ts b/app/api/routes-f/creator-min-tip/route.ts
new file mode 100644
index 00000000..200db828
--- /dev/null
+++ b/app/api/routes-f/creator-min-tip/route.ts
@@ -0,0 +1,66 @@
+import { NextRequest, NextResponse } from "next/server";
+import { getMinTip, setMinTip } from "./store";
+
+export async function GET(req: NextRequest): Promise<NextResponse> {
+  const creatorId = req.nextUrl.searchParams.get("creator_id");
+
+  if (!creatorId) {
+    return NextResponse.json(
+      { error: "creator_id is required." },
+      { status: 400 }
+    );
+  }
+
+  const config = getMinTip(creatorId);
+  return NextResponse.json({
+    min_xlm: config.min_xlm,
+    min_usdc: config.min_usdc,
+  });
+}
+
+export async function PUT(req: NextRequest): Promise<NextResponse> {
+  let body: Record<string, unknown>;
+
+  try {
+    body = await req.json();
+  } catch {
+    return NextResponse.json({ error: "Invalid JSON body." }, { status: 400 });
+  }
+
+  const { creator_id, min_xlm, min_usdc } = body;
+
+  if (typeof creator_id !== "string" || !creator_id.trim()) {
+    return NextResponse.json(
+      { error: "creator_id is required." },
+      { status: 400 }
+    );
+  }
+
+  if (min_xlm !== undefined) {
+    if (typeof min_xlm !== "number" || min_xlm < 0) {
+      return NextResponse.json(
+        { error: "min_xlm must be a number >= 0." },
+        { status: 400 }
+      );
+    }
+  }
+
+  if (min_usdc !== undefined) {
+    if (typeof min_usdc !== "number" || min_usdc < 0) {
+      return NextResponse.json(
+        { error: "min_usdc must be a number >= 0." },
+        { status: 400 }
+      );
+    }
+  }
+
+  const updated = setMinTip(
+    creator_id as string,
+    min_xlm as number | undefined,
+    min_usdc as number | undefined
+  );
+  return NextResponse.json({
+    min_xlm: updated.min_xlm,
+    min_usdc: updated.min_usdc,
+  });
+}
diff --git a/app/api/routes-f/creator-min-tip/store.ts b/app/api/routes-f/creator-min-tip/store.ts
new file mode 100644
index 00000000..c98c49f6
--- /dev/null
+++ b/app/api/routes-f/creator-min-tip/store.ts
@@ -0,0 +1,52 @@
+import type { MinTipConfig } from "./types";
+
+export const minTipStore = new Map<string, MinTipConfig>();
+
+export function getMinTip(creator_id: string): MinTipConfig {
+  return minTipStore.get(creator_id) ?? { creator_id, min_xlm: 0, min_usdc: 0 };
+}
+
+export function setMinTip(
+  creator_id: string,
+  min_xlm?: number,
+  min_usdc?: number
+): MinTipConfig {
+  const current = getMinTip(creator_id);
+  const updated: MinTipConfig = {
+    creator_id,
+    min_xlm: min_xlm ?? current.min_xlm,
+    min_usdc: min_usdc ?? current.min_usdc,
+  };
+  minTipStore.set(creator_id, updated);
+  return updated;
+}
+
+export function checkTip(
+  creator_id: string,
+  asset: string,
+  amount: number
+): { allowed: boolean; reason?: string } {
+  const config = getMinTip(creator_id);
+
+  if (asset === "XLM") {
+    if (amount < config.min_xlm) {
+      return {
+        allowed: false,
+        reason: `Minimum XLM tip is ${config.min_xlm}. You sent ${amount}.`,
+      };
+    }
+    return { allowed: true };
+  }
+
+  if (asset === "USDC") {
+    if (amount < config.min_usdc) {
+      return {
+        allowed: false,
+        reason: `Minimum USDC tip is ${config.min_usdc}. You sent ${amount}.`,
+      };
+    }
+    return { allowed: true };
+  }
+
+  return { allowed: false, reason: `Unsupported asset: "${asset}". Use XLM or USDC.` };
+}
diff --git a/app/api/routes-f/creator-min-tip/types.ts b/app/api/routes-f/creator-min-tip/types.ts
new file mode 100644
index 00000000..64727ab8
--- /dev/null
+++ b/app/api/routes-f/creator-min-tip/types.ts
@@ -0,0 +1,10 @@
+export interface MinTipConfig {
+  creator_id: string;
+  min_xlm: number;
+  min_usdc: number;
+}
+
+export interface CheckTipResult {
+  allowed: boolean;
+  reason?: string;
+}
diff --git a/app/api/routes-f/creator/analytics/route.ts b/app/api/routes-f/creator/analytics/route.ts
new file mode 100644
index 00000000..d1ee273b
--- /dev/null
+++ b/app/api/routes-f/creator/analytics/route.ts
@@ -0,0 +1,185 @@
+import { NextRequest, NextResponse } from "next/server";
+import { sql } from "@vercel/postgres";
+import { verifySession } from "@/lib/auth/verify-session";
+import { fetchPaymentsReceived } from "@/lib/stellar/horizon";
+import {
+  subDays,
+  startOfDay,
+  format,
+  eachDayOfInterval,
+  eachWeekOfInterval,
+  isSameDay,
+  isSameWeek,
+  parseISO,
+} from "date-fns";
+
+export const dynamic = "force-dynamic";
+
+type Metric = "revenue" | "viewers" | "followers" | "tips";
+type Period = "7d" | "30d" | "90d";
+type Granularity = "day" | "week";
+
+/**
+ * Converts a Stellar amount string to a BigInt of stroops (10^7)
+ * to prevent float precision loss.
+ */
+function toStroops(amount: string): bigint {
+  try {
+    const [whole, fraction = ""] = amount.split(".");
+    const paddedFraction = fraction.padEnd(7, "0").slice(0, 7);
+    return BigInt(whole + paddedFraction);
+  } catch {
+    return BigInt(0);
+  }
+}
+
+/**
+ * Converts stroops back to a string with 7 decimal places.
+ */
+function fromStroops(stroops: bigint): string {
+  const s = stroops.toString().padStart(8, "0");
+  const whole = s.slice(0, -7);
+  const fraction = s.slice(-7);
+  return `${whole}.${fraction}`;
+}
+
+export async function GET(req: NextRequest) {
+  // 1. Authenticate creator
+  const session = await verifySession(req);
+  if (!session.ok) return session.response;
+
+  const { userId } = session;
+
+  // 2. Parse and validate query parameters
+  const { searchParams } = new URL(req.url);
+  const metric = searchParams.get("metric") as Metric;
+  const period = (searchParams.get("period") || "7d") as Period;
+  const granularity = (searchParams.get("granularity") || "day") as Granularity;
+
+  if (!["revenue", "viewers", "followers", "tips"].includes(metric)) {
+    return NextResponse.json(
+      { error: "Invalid metric. Must be one of: revenue, viewers, followers, tips" },
+      { status: 400 }
+    );
+  }
+
+  if (!["7d", "30d", "90d"].includes(period)) {
+    return NextResponse.json(
+      { error: "Invalid period. Must be one of: 7d, 30d, 90d" },
+      { status: 400 }
+    );
+  }
+
+  if (!["day", "week"].includes(granularity)) {
+    return NextResponse.json(
+      { error: "Invalid granularity. Must be one of: day, week" },
+      { status: 400 }
+    );
+  }
+
+  try {
+    // 3. Define time range
+    const now = new Date();
+    const daysToSub = period === "7d" ? 7 : period === "30d" ? 30 : 90;
+    const startDate = startOfDay(subDays(now, daysToSub));
+    const endDate = now;
+
+    // Generate date range points
+    const datePoints =
+      granularity === "day"
+        ? eachDayOfInterval({ start: startDate, end: endDate })
+        : eachWeekOfInterval({ start: startDate, end: endDate }, { weekStartsOn: 1 });
+
+    let data: { date: string; value: string | number }[] = [];
+
+    if (metric === "viewers") {
+      // Fetch viewer analytics from DB
+      // We use a subquery to handle the date_trunc safely
+      const { rows } = await sql`
+        SELECT 
+          date_trunc(${granularity}, sv.joined_at) as point_date,
+          COUNT(DISTINCT sv.user_id) as viewer_count
+        FROM stream_viewers sv
+        JOIN stream_sessions ss ON sv.stream_session_id = ss.id
+        WHERE ss.user_id = ${userId}
+          AND sv.joined_at >= ${startDate.toISOString()}
+        GROUP BY point_date
+        ORDER BY point_date ASC
+      `;
+
+      data = datePoints.map((point: Date) => {
+        const match = rows.find((r: any) => 
+          granularity === "day" 
+            ? isSameDay(new Date(r.point_date), point)
+            : isSameWeek(new Date(r.point_date), point, { weekStartsOn: 1 })
+        );
+        return {
+          date: format(point, "yyyy-MM-dd"),
+          value: match ? Number(match.viewer_count) : 0
+        };
+      });
+
+    } else if (metric === "revenue" || metric === "tips") {
+      // Fetch creator's Stellar public key (stored in 'wallet' column)
+      const userRes = await sql`SELECT wallet FROM users WHERE id = ${userId}`;
+      const publicKey = userRes.rows[0]?.wallet;
+
+      if (!publicKey || !publicKey.startsWith("G")) {
+        data = datePoints.map((point: Date) => ({ date: format(point, "yyyy-MM-dd"), value: "0.0000000" }));
+      } else {
+        // Fetch tips from Stellar
+        const { tips } = await fetchPaymentsReceived({
+          publicKey,
+          limit: 200, 
+        });
+
+        // Group tips by date
+        data = datePoints.map((point: Date) => {
+          const dailyTips = tips.filter((tip: any) => {
+            const tipDate = parseISO(tip.timestamp);
+            return granularity === "day" 
+              ? isSameDay(tipDate, point)
+              : isSameWeek(tipDate, point, { weekStartsOn: 1 });
+          });
+
+          const totalStroops = dailyTips.reduce((sum: bigint, tip: any) => sum + toStroops(tip.amount), BigInt(0));
+          return {
+            date: format(point, "yyyy-MM-dd"),
+            value: fromStroops(totalStroops)
+          };
+        });
+      }
+
+    } else if (metric === "followers") {
+      // Fetch current follower count
+      const { rows } = await sql`
+        SELECT array_length(followers, 1) as follower_count 
+        FROM users 
+        WHERE id = ${userId}
+      `;
+      const currentCount = Number(rows[0]?.follower_count || 0);
+
+      // Baseline implementation for followers history (current count for all points)
+      data = datePoints.map((point: Date) => ({
+        date: format(point, "yyyy-MM-dd"),
+        value: currentCount
+      }));
+    }
+
+    // 4. Return response with caching headers
+    return new NextResponse(JSON.stringify(data), {
+      status: 200,
+      headers: {
+        "Content-Type": "application/json",
+        "Cache-Control": "public, s-maxage=300, stale-while-revalidate=300",
+      },
+    });
+
+  } catch (error) {
+    console.error("[creator/analytics] Error:", error);
+    return NextResponse.json(
+      { error: "Internal server error" },
+      { status: 500 }
+    );
+  }
+}
diff --git a/app/api/routes-f/creator/anniversary/__tests__/route.test.ts b/app/api/routes-f/creator/anniversary/__tests__/route.test.ts
new file mode 100644
index 00000000..47ed92ef
--- /dev/null
+++ b/app/api/routes-f/creator/anniversary/__tests__/route.test.ts
@@ -0,0 +1,90 @@
+import { NextRequest } from "next/server";
+import { GET } from "../route";
+
+function makeReq(params: Record<string, string> = {}): NextRequest {
+  const url = new URL("http://localhost/api/routes-f/creator/anniversary");
+  Object.entries(params).forEach(([k, v]) => url.searchParams.set(k, v));
+  return new NextRequest(url.toString());
+}
+
+// creator_c joined exactly 365 days ago with 100 streams/1000 followers — milestones today
+const onDateToday = new Date().toISOString().split("T")[0];
+
+// A date 10 days from now
+function daysFromNow(n: number): string {
+  const d = new Date();
+  d.setDate(d.getDate() + n);
+  return d.toISOString().split("T")[0];
+}
+
+describe("GET /api/routes-f/creator/anniversary", () => {
+  it("returns 400 when creator_id is missing", async () => {
+    const res = await GET(makeReq({}));
+    expect(res.status).toBe(400);
+    const data = await res.json();
+    expect(data.error).toMatch(/creator_id/i);
+  });
+
+  it("returns 404 for unknown creator", async () => {
+    const res = await GET(makeReq({ creator_id: "creator_unknown" }));
+    expect(res.status).toBe(404);
+  });
+
+  it("returns 400 for invalid on_date", async () => {
+    const res = await GET(makeReq({ creator_id: "creator_a", on_date: "not-a-date" }));
+    expect(res.status).toBe(400);
+  });
+
+  it("responds with today and upcoming arrays", async () => {
+    const res = await GET(makeReq({ creator_id: "creator_a" }));
+    expect(res.status).toBe(200);
+    const data = await res.json();
+    expect(Array.isArray(data.today)).toBe(true);
+    expect(Array.isArray(data.upcoming)).toBe(true);
+    expect(typeof data.on_date).toBe("string");
+  });
+
+  it("creator_c has 1-year anniversary today", async () => {
+    const res = await GET(makeReq({ creator_id: "creator_c", on_date: onDateToday }));
+    expect(res.status).toBe(200);
+    const data = await res.json();
+    const hasBirthday = data.today.some(
+      (m: { kind: string }) => m.kind === "1_year_anniversary"
+    );
+    expect(hasBirthday).toBe(true);
+  });
+
+  it("creator_d has no milestones in window (too new)", async () => {
+    const res = await GET(makeReq({ creator_id: "creator_d" }));
+    expect(res.status).toBe(200);
+    const data = await res.json();
+    expect(data.today.length).toBe(0);
+    expect(data.upcoming.length).toBe(0);
+  });
+
+  it("on_date in the past works for creator_b 2-year anniversary", async () => {
+    // creator_b joined 730 days ago so their 2-year anniversary was ~today
+    const res = await GET(makeReq({ creator_id: "creator_b" }));
+    expect(res.status).toBe(200);
+    const data = await res.json();
+    // May be in today or within upcoming window; just confirm valid response shape
+    expect(Array.isArray(data.today)).toBe(true);
+    expect(Array.isArray(data.upcoming)).toBe(true);
+  });
+
+  it("all milestones in today array have date matching on_date", async () => {
+    const res = await GET(makeReq({ creator_id: "creator_c", on_date: onDateToday }));
+    const data = await res.json();
+    for (const m of data.today) {
+      expect(m.date).toBe(data.on_date);
+    }
+  });
+
+  it("all upcoming milestones have date after on_date", async () => {
+    const res = await GET(makeReq({ creator_id: "creator_a" }));
+    const data = await res.json();
+    for (const m of data.upcoming) {
+      expect(m.date > data.on_date).toBe(true);
+    }
+  });
+});
diff --git a/app/api/routes-f/creator/anniversary/route.ts b/app/api/routes-f/creator/anniversary/route.ts
new file mode 100644
index 00000000..940f67ff
--- /dev/null
+++ b/app/api/routes-f/creator/anniversary/route.ts
@@ -0,0 +1,119 @@
+import { NextRequest, NextResponse } from "next/server";
+import type { CreatorStats, Milestone, MilestoneKind, AnniversaryResponse } from "./types";
+import { getCreatorStats } from "./seed";
+
+const LOOK_AHEAD_DAYS = 14;
+const DAY_MS = 24 * 60 * 60 * 1000;
+
+// Stream count milestones
+const STREAM_MILESTONES = [100, 500, 1000];
+// Follower milestones
+const FOLLOWER_MILESTONES = [100, 1000, 10000];
+// Year anniversaries to check
+const YEAR_ANNIVERSARIES = [1, 2, 3];
+
+function isoDate(epochMs: number): string {
+  return new Date(epochMs).toISOString().split("T")[0];
+}
+
+function computeMilestones(stats: CreatorStats, onDate: number): Milestone[] {
+  const milestones: Milestone[] = [];
+  const windowEnd = onDate + LOOK_AHEAD_DAYS * DAY_MS;
+
+  // Year anniversaries: look at the anniversary date for each year
+  for (const years of YEAR_ANNIVERSARIES) {
+    const anniversaryDate = stats.joined_at + years * 365 * DAY_MS;
+    if (anniversaryDate >= onDate && anniversaryDate <= windowEnd) {
+      milestones.push({
+        kind: `${years}_year_anniversary` as MilestoneKind,
+        label: `${years} Year Anniversary`,
+        date: isoDate(anniversaryDate),
+        creator_id: stats.creator_id,
+        creator_name: stats.display_name,
+      });
+    }
+  }
+
+  // Stream count milestones: if they're within a plausible range (already hit or hit today)
+  for (const target of STREAM_MILESTONES) {
+    if (stats.stream_count >= target) {
+      // Estimate when they hit this — assume ~1 stream/day rate
+      const streamsAgo = stats.stream_count - target;
+      const estimatedDate = onDate - streamsAgo * DAY_MS;
+      if (estimatedDate >= onDate && estimatedDate <= windowEnd) {
+        milestones.push({
+          kind: `${target}th_stream` as MilestoneKind,
+          label: `${target}th Stream`,
+          date: isoDate(estimatedDate),
+          creator_id: stats.creator_id,
+          creator_name: stats.display_name,
+        });
+      }
+    }
+  }
+
+  // Follower milestones: same logic
+  for (const target of FOLLOWER_MILESTONES) {
+    if (stats.follower_count >= target) {
+      const followersAgo = stats.follower_count - target;
+      // Rough estimate: 10 followers/day growth rate
+      const estimatedDate = onDate - (followersAgo / 10) * DAY_MS;
+      if (estimatedDate >= onDate && estimatedDate <= windowEnd) {
+        milestones.push({
+          kind: `${target}th_follower` as MilestoneKind,
+          label: `${target}th Follower`,
+          date: isoDate(estimatedDate),
+          creator_id: stats.creator_id,
+          creator_name: stats.display_name,
+        });
+      }
+    }
+  }
+
+  return milestones;
+}
+
+export async function GET(req: NextRequest): Promise<NextResponse> {
+  const { searchParams } = new URL(req.url);
+  const creatorId = searchParams.get("creator_id");
+  const onDateParam = searchParams.get("on_date");
+
+  if (!creatorId) {
+    return NextResponse.json({ error: "creator_id is required" }, { status: 400 });
+  }
+
+  const stats = getCreatorStats(creatorId);
+  if (!stats) {
+    return NextResponse.json(
+      { error: `creator '${creatorId}' not found` },
+      { status: 404 }
+    );
+  }
+
+  // Resolve the reference date
+  let onDate: number;
+  if (onDateParam) {
+    const parsed = Date.parse(onDateParam);
+    if (isNaN(parsed)) {
+      return NextResponse.json(
+        { error: "on_date must be a valid ISO date string (e.g. 2025-06-01)" },
+        { status: 400 }
+      );
+    }
+    onDate = parsed;
+  } else {
+    onDate = new Date().setHours(0, 0, 0, 0);
+  }
+
+  const allMilestones = computeMilestones(stats, onDate);
+  const todayStr = isoDate(onDate);
+
+  const today = allMilestones.filter(m => m.date === todayStr);
+  const upcoming = allMilestones.filter(m => m.date !== todayStr);
+
+  return NextResponse.json({
+    today,
+    upcoming,
+    on_date: todayStr,
+  } as AnniversaryResponse);
+}
diff --git a/app/api/routes-f/creator/anniversary/seed.ts b/app/api/routes-f/creator/anniversary/seed.ts
new file mode 100644
index 00000000..3013f893
--- /dev/null
+++ b/app/api/routes-f/creator/anniversary/seed.ts
@@ -0,0 +1,48 @@
+import type { CreatorStats } from "./types";
+
+const now = Date.now();
+const d = 24 * 60 * 60 * 1000;
+
+// Seed creator stats with a variety of ages and milestones
+export const creatorStats: CreatorStats[] = [
+  {
+    creator_id: "creator_a",
+    display_name: "AlphaStreamer",
+    // Joined exactly 1 year ago + 14 days so upcoming anniversary is in 14 days
+    joined_at: now - (365 - 14) * d,
+    stream_count: 98,      // near 100th stream
+    follower_count: 985,   // near 1000th follower
+    last_updated: now,
+  },
+  {
+    creator_id: "creator_b",
+    display_name: "BetaCaster",
+    // Joined exactly 2 years ago today
+    joined_at: now - 730 * d,
+    stream_count: 502,
+    follower_count: 12000,
+    last_updated: now,
+  },
+  {
+    creator_id: "creator_c",
+    display_name: "GammaBroadcast",
+    // Joined 1 year ago today - anniversary is today
+    joined_at: now - 365 * d,
+    stream_count: 100, // hits 100th stream today
+    follower_count: 1000, // hits 1000th follower today
+    last_updated: now,
+  },
+  {
+    creator_id: "creator_d",
+    display_name: "DeltaLive",
+    // Joined 10 days ago — no anniversaries upcoming in 14-day window
+    joined_at: now - 10 * d,
+    stream_count: 5,
+    follower_count: 45,
+    last_updated: now,
+  },
+];
+
+export function getCreatorStats(creatorId: string): CreatorStats | undefined {
+  return creatorStats.find(c => c.creator_id === creatorId);
+}
diff --git a/app/api/routes-f/creator/anniversary/types.ts b/app/api/routes-f/creator/anniversary/types.ts
new file mode 100644
index 00000000..f4943fc5
--- /dev/null
+++ b/app/api/routes-f/creator/anniversary/types.ts
@@ -0,0 +1,33 @@
+export interface CreatorStats {
+  creator_id: string;
+  display_name: string;
+  joined_at: number; // epoch ms
+  stream_count: number;
+  follower_count: number;
+  last_updated: number; // epoch ms
+}
+
+export type MilestoneKind =
+  | "1_year_anniversary"
+  | "2_year_anniversary"
+  | "3_year_anniversary"
+  | "100th_stream"
+  | "500th_stream"
+  | "1000th_stream"
+  | "100th_follower"
+  | "1000th_follower"
+  | "10000th_follower";
+
+export interface Milestone {
+  kind: MilestoneKind;
+  label: string;
+  date: string; // ISO date string
+  creator_id: string;
+  creator_name: string;
+}
+
+export interface AnniversaryResponse {
+  today: Milestone[];
+  upcoming: Milestone[];
+  on_date: string; // the date queried
+}
diff --git a/app/api/routes-f/deck/__tests__/route.test.ts b/app/api/routes-f/deck/__tests__/route.test.ts
new file mode 100644
index 00000000..389081fe
--- /dev/null
+++ b/app/api/routes-f/deck/__tests__/route.test.ts
@@ -0,0 +1,66 @@
+jest.mock("next/server", () => ({
+  NextResponse: {
+    json: (body: unknown, init?: ResponseInit) =>
+      new Response(JSON.stringify(body), {
+        ...init,
+        headers: { "Content-Type": "application/json" },
+      }),
+  },
+}));
+
+import { POST } from "../route";
+
+function makeRequest(body: object) {
+  return new Request("http://localhost/api/routes-f/deck", {
+    method: "POST",
+    headers: { "Content-Type": "application/json" },
+    body: JSON.stringify(body),
+  }) as unknown as import("next/server").NextRequest;
+}
+
+describe("routes-f deck", () => {
+  it("shuffles deterministically with the same seed", async () => {
+    const body = {
+      hands: 2,
+      cards_per_hand: 5,
+      seed: "streamfi-seed",
+      jokers: false,
+    };
+
+    const firstRes = await POST(makeRequest(body));
+    const secondRes = await POST(makeRequest(body));
+    const first = await firstRes.json();
+    const second = await secondRes.json();
+
+    expect(first).toEqual(second);
+  });
+
+  it("deals unique cards without duplicates", async () => {
+    const res = await POST(
+      makeRequest({
+        hands: 4,
+        cards_per_hand: 5,
+        seed: 42,
+        jokers: true,
+      })
+    );
+    const json = await res.json();
+    const dealt = [...json.hands.flat(), ...json.remaining];
+    const unique = new Set(dealt);
+
+    expect(res.status).toBe(200);
+    expect(dealt).toHaveLength(54);
+    expect(unique.size).toBe(54);
+  });
+
+  it("rejects requests that exceed deck size", async () => {
+    const res = await POST(
+      makeRequest({
+        hands: 11,
+        cards_per_hand: 5,
+      })
+    );
+
+    expect(res.status).toBe(400);
+  });
+});
diff --git a/app/api/routes-f/deck/route.ts b/app/api/routes-f/deck/route.ts
new file mode 100644
index 00000000..9749452e
--- /dev/null
+++ b/app/api/routes-f/deck/route.ts
@@ -0,0 +1,117 @@
+import { NextRequest, NextResponse } from "next/server";
+import { z } from "zod";
+
+const schema = z.object({
+  hands: z.number().int().min(1).max(54).optional().default(1),
+  cards_per_hand: z.number().int().min(1).max(54).optional().default(5),
+  seed: z.union([z.string(), z.number()]).optional(),
+  jokers: z.boolean().optional().default(false),
+});
+
+const SUITS = ["C", "D", "H", "S"] as const;
+const RANKS = [
+  "A",
+  "2",
+  "3",
+  "4",
+  "5",
+  "6",
+  "7",
+  "8",
+  "9",
+  "10",
+  "J",
+  "Q",
+  "K",
+] as const;
+
+function buildDeck(includeJokers: boolean): string[] {
+  const deck = SUITS.flatMap(suit => RANKS.map(rank => `${rank}${suit}`));
+  return includeJokers ? [...deck, "BLACK_JOKER", "RED_JOKER"] : deck;
+}
+
+function hashSeed(seed: string): number {
+  let hash = 2166136261;
+
+  for (let index = 0; index < seed.length; index += 1) {
+    hash ^= seed.charCodeAt(index);
+    hash = Math.imul(hash, 16777619);
+  }
+
+  return hash >>> 0;
+}
+
+function createSeededRandom(seed: string | number | undefined): () => number {
+  if (seed === undefined) {
+    return Math.random;
+  }
+
+  let state = hashSeed(String(seed));
+
+  return () => {
+    state += 0x6d2b79f5;
+    let next = state;
+    next = Math.imul(next ^ (next >>> 15), next | 1);
+    next ^= next + Math.imul(next ^ (next >>> 7), next | 61);
+    return ((next ^ (next >>> 14)) >>> 0) / 4294967296;
+  };
+}
+
+function shuffleDeck(deck: string[], random: () => number): string[] {
+  const copy = [...deck];
+
+  for (let index = copy.length - 1; index > 0; index -= 1) {
+    const swapIndex = Math.floor(random() * (index + 1));
+    [copy[index], copy[swapIndex]] = [copy[swapIndex], copy[index]];
+  }
+
+  return copy;
+}
+
+export async function POST(req: NextRequest) {
+  let rawBody: unknown;
+
+  try {
+    rawBody = await req.json();
+  } catch {
+    return NextResponse.json({ error: "Invalid JSON body" }, { status: 400 });
+  }
+
+  const parsed = schema.safeParse(rawBody);
+  if (!parsed.success) {
+    return NextResponse.json(
+      {
+        error: "Validation failed",
+        issues: parsed.error.issues.map(issue => ({
+          field: issue.path.join(".") || "body",
+          message: issue.message,
+        })),
+      },
+      { status: 400 }
+    );
+  }
+
+  const { hands, cards_per_hand, seed, jokers } = parsed.data;
+  const deck = buildDeck(jokers);
+
+  if (hands * cards_per_hand > deck.length) {
+    return NextResponse.json(
+      { error: "hands * cards_per_hand cannot exceed deck size" },
+      { status: 400 }
+    );
+  }
+
+  const shuffled = shuffleDeck(deck, createSeededRandom(seed));
+  const dealtHands: string[][] = [];
+  let cursor = 0;
+
+  for (let handIndex = 0; handIndex < hands; handIndex += 1) {
+    dealtHands.push(shuffled.slice(cursor, cursor + cards_per_hand));
+    cursor += cards_per_hand;
+  }
+
+  return NextResponse.json({
+    hands: dealtHands,
+    remaining: shuffled.slice(cursor),
+  });
+}
diff --git a/app/api/routes-f/deep-merge/route.ts b/app/api/routes-f/deep-merge/route.ts
new file mode 100644
index 00000000..1e535fd9
--- /dev/null
+++ b/app/api/routes-f/deep-merge/route.ts
@@ -0,0 +1,86 @@
+import { NextResponse } from "next/server";
+import { z } from "zod";
+import { validateBody } from "@/app/api/routes-f/_lib/validate";
+
+type ArrayStrategy = "replace" | "concat" | "union";
+
+const schema = z.object({
+  objects: z.array(z.record(z.unknown())).min(1),
+  array_strategy: z.enum(["replace", "concat", "union"]).optional().default("replace"),
+});
+
+const MAX_SIZE = 2 * 1024 * 1024; // 2MB
+
+function isObject(val: unknown): val is Record<string, unknown> {
+  return typeof val === "object" && val !== null && !Array.isArray(val);
+}
+
+export function deepMerge(
+  objects: Record<string, unknown>[],
+  arrayStrategy: ArrayStrategy
+): Record<string, unknown> {
+  if (objects.length === 0) return {};
+  if (objects.length === 1) return objects[0];
+
+  const result: Record<string, unknown> = {};
+
+  for (const obj of objects) {
+    for (const key in obj) {
+      const val = obj[key];
+      
+      if (!(key in result)) {
+        result[key] = val;
+        continue;
+      }
+
+      const existing = result[key];
+
+      if (Array.isArray(existing) && Array.isArray(val)) {
+        if (arrayStrategy === "replace") {
+          result[key] = val;
+        } else if (arrayStrategy === "concat") {
+          result[key] = existing.concat(val);
+        } else if (arrayStrategy === "union") {
+          result[key] = Array.from(new Set([...existing, ...val]));
+        }
+      } else if (isObject(existing) && isObject(val)) {
+        result[key] = deepMerge([existing, val], arrayStrategy);
+      } else {
+        result[key] = val;
+      }
+    }
+  }
+
+  return result;
+}
+
+export async function POST(request: Request): Promise<NextResponse> {
+  const bodyText = await request.text();
+  
+  if (bodyText.length > MAX_SIZE) {
+    return NextResponse.json(
+      { error: `Request body exceeds ${MAX_SIZE / 1024 / 1024}MB limit` },
+      { status: 400 }
+    );
+  }
+
+  let body: unknown;
+  try {
+    body = JSON.parse(bodyText);
+  } catch {
+    return NextResponse.json({ error: "Invalid JSON body" }, { status: 400 });
+  }
+
+  const parsed = schema.safeParse(body);
+  if (!parsed.success) {
+    return NextResponse.json(
+      { error: "Invalid request body", details: parsed.error.flatten() },
+      { status: 400 }
+    );
+  }
+
+  const { objects, array_strategy } = parsed.data;
+  const merged = deepMerge(objects, array_strategy);
+
+  return NextResponse.json({ merged });
+}
diff --git a/app/api/routes-f/dice-coefficient/__tests__/route.test.ts b/app/api/routes-f/dice-coefficient/__tests__/route.test.ts
new file mode 100644
index 00000000..9e88e21d
--- /dev/null
+++ b/app/api/routes-f/dice-coefficient/__tests__/route.test.ts
@@ -0,0 +1,31 @@
+import { NextRequest } from "next/server";
+import { POST } from "../route";
+
+function makeReq(body: object) {
+  return new NextRequest("http://localhost/api/routes-f/dice-coefficient", {
+    method: "POST",
+    body: JSON.stringify(body),
+    headers: { "Content-Type": "application/json" },
+  });
+}
+
+describe("POST /api/routes-f/dice-coefficient", () => {
+  it("returns 1 for identical strings", async () => {
+    const res = await POST(makeReq({ a: "Hello", b: "hello" }));
+    const body = await res.json();
+    expect(body.coefficient).toBe(1);
+  });
+
+  it("returns 0 for disjoint strings", async () => {
+    const res = await POST(makeReq({ a: "ab", b: "xy" }));
+    const body = await res.json();
+    expect(body.coefficient).toBe(0);
+  });
+
+  it("returns fractional value for partial overlap", async () => {
+    const res = await POST(makeReq({ a: "night", b: "nacht" }));
+    const body = await res.json();
+    expect(body.coefficient).toBeGreaterThan(0);
+    expect(body.coefficient).toBeLessThan(1);
+  });
+});
diff --git a/app/api/routes-f/dice-coefficient/route.ts b/app/api/routes-f/dice-coefficient/route.ts
new file mode 100644
index 00000000..aa29cb22
--- /dev/null
+++ b/app/api/routes-f/dice-coefficient/route.ts
@@ -0,0 +1,54 @@
+import { NextRequest, NextResponse } from "next/server";
+
+function getBigrams(value: string) {
+  const normalized = value.toLowerCase();
+  if (normalized.length < 2) {
+    return [normalized];
+  }
+  const out: string[] = [];
+  for (let i = 0; i < normalized.length - 1; i++) {
+    out.push(normalized.slice(i, i + 2));
+  }
+  return out;
+}
+
+function diceCoefficient(a: string, b: string) {
+  if (a === b) return 1;
+  const aBigrams = getBigrams(a);
+  const bBigrams = getBigrams(b);
+
+  const counts = new Map<string, number>();
+  for (const gram of aBigrams) {
+    counts.set(gram, (counts.get(gram) ?? 0) + 1);
+  }
+
+  let intersection = 0;
+  for (const gram of bBigrams) {
+    const count = counts.get(gram) ?? 0;
+    if (count > 0) {
+      intersection += 1;
+      counts.set(gram, count - 1);
+    }
+  }
+
+  const denom = aBigrams.length + bBigrams.length;
+  return denom === 0 ? 1 : (2 * intersection) / denom;
+}
+
+export async function POST(request: NextRequest) {
+  let body: { a?: string; b?: string };
+  try {
+    body = await request.json();
+  } catch {
+    return NextResponse.json({ error: "Invalid JSON body" }, { status: 400 });
+  }
+
+  if (typeof body.a !== "string" || typeof body.b !== "string") {
+    return NextResponse.json(
+      { error: "a and b must be strings" },
+      { status: 400 }
+    );
+  }
+
+  return NextResponse.json({ coefficient: diceCoefficient(body.a, body.b) });
+}
diff --git a/app/api/routes-f/digital-root/__tests__/route.test.ts b/app/api/routes-f/digital-root/__tests__/route.test.ts
new file mode 100644
index 00000000..a4ac8410
--- /dev/null
+++ b/app/api/routes-f/digital-root/__tests__/route.test.ts
@@ -0,0 +1,48 @@
+jest.mock("next/server", () => ({
+  NextResponse: {
+    json: (body: unknown, init?: ResponseInit) =>
+      new Response(JSON.stringify(body), {
+        ...init,
+        headers: { "Content-Type": "application/json" },
+      }),
+  },
+}));
+
+import { GET } from "../route";
+
+function makeRequest(path: string) {
+  return new Request(
+    `http://localhost${path}`
+  ) as unknown as import("next/server").NextRequest;
+}
+
+describe("routes-f digital-root", () => {
+  it("returns zero for 0", async () => {
+    const res = await GET(makeRequest("/api/routes-f/digital-root?n=0"));
+    const json = await res.json();
+
+    expect(res.status).toBe(200);
+    expect(json).toEqual({ digital_root: 0, persistence: 0 });
+  });
+
+  it("returns zero persistence for a single-digit number", async () => {
+    const res = await GET(makeRequest("/api/routes-f/digital-root?n=7"));
+    const json = await res.json();
+
+    expect(res.status).toBe(200);
+    expect(json).toEqual({ digital_root: 7, persistence: 0 });
+  });
+
+  it("computes digital root and additive persistence for multi-step input", async () => {
+    const res = await GET(makeRequest("/api/routes-f/digital-root?n=12345"));
+    const json = await res.json();
+
+    expect(res.status).toBe(200);
+    expect(json).toEqual({ digital_root: 6, persistence: 2 });
+  });
+
+  it("rejects invalid input", async () => {
+    const res = await GET(makeRequest("/api/routes-f/digital-root?n=-9"));
+    expect(res.status).toBe(400);
+  });
+});
diff --git a/app/api/routes-f/digital-root/route.ts b/app/api/routes-f/digital-root/route.ts
new file mode 100644
index 00000000..a6a08016
--- /dev/null
+++ b/app/api/routes-f/digital-root/route.ts
@@ -0,0 +1,42 @@
+import { NextRequest, NextResponse } from "next/server";
+
+function sumDigits(value: string): number {
+  return value.split("").reduce((sum, digit) => sum + Number(digit), 0);
+}
+
+function getPersistence(value: string): number {
+  let current = value;
+  let steps = 0;
+
+  while (current.length > 1) {
+    current = String(sumDigits(current));
+    steps += 1;
+  }
+
+  return steps;
+}
+
+function getDigitalRoot(value: string): number {
+  if (value === "0") {
+    return 0;
+  }
+
+  const numericValue = Number(value);
+  return 1 + ((numericValue - 1) % 9);
+}
+
+export async function GET(req: NextRequest) {
+  const n = new URL(req.url).searchParams.get("n");
+
+  if (!n || !/^\d+$/.test(n)) {
+    return NextResponse.json(
+      { error: "n must be a non-negative integer" },
+      { status: 400 }
+    );
+  }
+
+  return NextResponse.json({
+    digital_root: getDigitalRoot(n),
+    persistence: getPersistence(n),
+  });
+}
diff --git a/app/api/routes-f/dms-converter/__tests__/route.test.ts b/app/api/routes-f/dms-converter/__tests__/route.test.ts
new file mode 100644
index 00000000..3d8feabd
--- /dev/null
+++ b/app/api/routes-f/dms-converter/__tests__/route.test.ts
@@ -0,0 +1,210 @@
+/**
+ * @jest-environment node
+ */
+import { NextRequest } from "next/server";
+import { POST } from "../route";
+
+function makeReq(body: unknown) {
+  return new NextRequest("http://localhost/api/routes-f/dms-converter", {
+    method: "POST",
+    headers: { "content-type": "application/json" },
+    body: JSON.stringify(body),
+  });
+}
+
+describe("POST /api/routes-f/dms-converter", () => {
+  describe("to_decimal mode", () => {
+    it("converts DMS latitude to decimal (North)", async () => {
+      const res = await POST(
+        makeReq({
+          mode: "to_decimal",
+          dms: { degrees: 40, minutes: 26, seconds: 46, direction: "N" },
+        })
+      );
+      const body = await res.json();
+
+      expect(res.status).toBe(200);
+      expect(body.decimal).toBeCloseTo(40.446111, 5);
+    });
+
+    it("converts DMS latitude to decimal (South)", async () => {
+      const res = await POST(
+        makeReq({
+          mode: "to_decimal",
+          dms: { degrees: 33, minutes: 51, seconds: 30, direction: "S" },
+        })
+      );
+      const body = await res.json();
+
+      expect(res.status).toBe(200);
+      expect(body.decimal).toBeCloseTo(-33.858333, 5);
+    });
+
+    it("converts DMS longitude to decimal (East)", async () => {
+      const res = await POST(
+        makeReq({
+          mode: "to_decimal",
+          dms: { degrees: 151, minutes: 12, seconds: 30, direction: "E" },
+        })
+      );
+      const body = await res.json();
+
+      expect(res.status).toBe(200);
+      expect(body.decimal).toBeCloseTo(151.208333, 5);
+    });
+
+    it("converts DMS longitude to decimal (West)", async () => {
+      const res = await POST(
+        makeReq({
+          mode: "to_decimal",
+          dms: { degrees: 74, minutes: 0, seconds: 21, direction: "W" },
+        })
+      );
+      const body = await res.json();
+
+      expect(res.status).toBe(200);
+      expect(body.decimal).toBeCloseTo(-74.005833, 5);
+    });
+
+    it("rejects invalid direction or coordinate types", async () => {
+      // Invalid direction string
+      let res = await POST(
+        makeReq({
+          mode: "to_decimal",
+          dms: { degrees: 40, minutes: 26, seconds: 46, direction: "X" },
+        })
+      );
+      expect(res.status).toBe(400);
+
+      // Latitude with longitude direction
+      res = await POST(
+        makeReq({
+          mode: "to_decimal",
+          type: "lat",
+          dms: { degrees: 40, minutes: 26, seconds: 46, direction: "W" },
+        })
+      );
+      expect(res.status).toBe(400);
+    });
+
+    it("rejects invalid minutes/seconds ranges", async () => {
+      let res = await POST(
+        makeReq({
+          mode: "to_decimal",
+          dms: { degrees: 40, minutes: 61, seconds: 46, direction: "N" },
+        })
+      );
+      expect(res.status).toBe(400);
+
+      res = await POST(
+        makeReq({
+          mode: "to_decimal",
+          dms: { degrees: 40, minutes: 26, seconds: -1, direction: "N" },
+        })
+      );
+      expect(res.status).toBe(400);
+    });
+
+    it("rejects latitude out of bounds (> 90)", async () => {
+      const res = await POST(
+        makeReq({
+          mode: "to_decimal",
+          dms: { degrees: 95, minutes: 0, seconds: 0, direction: "N" },
+        })
+      );
+      expect(res.status).toBe(400);
+    });
+  });
+
+  describe("to_dms mode", () => {
+    it("converts decimal latitude to DMS (North)", async () => {
+      const res = await POST(
+        makeReq({
+          mode: "to_dms",
+          decimal: 40.446111,
+          type: "lat",
+        })
+      );
+      const body = await res.json();
+
+      expect(res.status).toBe(200);
+      expect(body.degrees).toBe(40);
+      expect(body.minutes).toBe(26);
+      expect(body.seconds).toBeCloseTo(46.0, 1);
+      expect(body.direction).toBe("N");
+    });
+
+    it("converts decimal latitude to DMS (South)", async () => {
+      const res = await POST(
+        makeReq({
+          mode: "to_dms",
+          decimal: -33.858333,
+          type: "lat",
+        })
+      );
+      const body = await res.json();
+
+      expect(res.status).toBe(200);
+      expect(body.degrees).toBe(33);
+      expect(body.minutes).toBe(51);
+      expect(body.seconds).toBeCloseTo(30.0, 1);
+      expect(body.direction).toBe("S");
+    });
+
+    it("converts decimal longitude to DMS (East)", async () => {
+      const res = await POST(
+        makeReq({
+          mode: "to_dms",
+          decimal: 151.208333,
+          type: "lng",
+        })
+      );
+      const body = await res.json();
+
+      expect(res.status).toBe(200);
+      expect(body.degrees).toBe(151);
+      expect(body.minutes).toBe(12);
+      expect(body.seconds).toBeCloseTo(30.0, 1);
+      expect(body.direction).toBe("E");
+    });
+
+    it("handles rollover precision edge cases", async () => {
+      // 40.99999999 should round up and not cause seconds >= 60
+      const res = await POST(
+        makeReq({
+          mode: "to_dms",
+          decimal: 40.99999999,
+          type: "lat",
+        })
+      );
+      const body = await res.json();
+
+      expect(res.status).toBe(200);
+      expect(body.degrees).toBe(41);
+      expect(body.minutes).toBe(0);
+      expect(body.seconds).toBe(0);
+    });
+
+    it("rejects latitude out of bounds (> 90)", async () => {
+      const res = await POST(
+        makeReq({
+          mode: "to_dms",
+          decimal: 95.0,
+          type: "lat",
+        })
+      );
+      expect(res.status).toBe(400);
+    });
+
+    it("rejects longitude out of bounds (> 180)", async () => {
+      const res = await POST(
+        makeReq({
+          mode: "to_dms",
+          decimal: -185.0,
+          type: "lng",
+        })
+      );
+      expect(res.status).toBe(400);
+    });
+  });
+});
diff --git a/app/api/routes-f/dms-converter/route.ts b/app/api/routes-f/dms-converter/route.ts
new file mode 100644
index 00000000..003e8dee
--- /dev/null
+++ b/app/api/routes-f/dms-converter/route.ts
@@ -0,0 +1,185 @@
+import { NextRequest, NextResponse } from "next/server";
+
+type DMS = {
+  degrees: number;
+  minutes: number;
+  seconds: number;
+  direction: string;
+};
+
+export async function POST(req: NextRequest) {
+  let body: {
+    mode?: unknown;
+    dms?: Partial<DMS>;
+    decimal?: unknown;
+    type?: unknown;
+  };
+
+  try {
+    body = await req.json();
+  } catch {
+    return NextResponse.json({ error: "Invalid JSON body." }, { status: 400 });
+  }
+
+  const { mode, dms, decimal, type } = body;
+
+  if (mode !== "to_decimal" && mode !== "to_dms") {
+    return NextResponse.json(
+      { error: "mode must be either 'to_decimal' or 'to_dms'." },
+      { status: 400 }
+    );
+  }
+
+  if (type !== undefined && type !== "lat" && type !== "lng") {
+    return NextResponse.json(
+      { error: "type must be either 'lat' or 'lng' if provided." },
+      { status: 400 }
+    );
+  }
+
+  if (mode === "to_decimal") {
+    if (dms === undefined || typeof dms !== "object" || dms === null) {
+      return NextResponse.json(
+        { error: "dms object is required for to_decimal mode." },
+        { status: 400 }
+      );
+    }
+
+    const degrees = Number(dms.degrees);
+    const minutes = Number(dms.minutes);
+    const seconds = Number(dms.seconds);
+    const direction = dms.direction;
+
+    if (
+      dms.degrees === undefined ||
+      dms.minutes === undefined ||
+      dms.seconds === undefined ||
+      direction === undefined ||
+      isNaN(degrees) ||
+      isNaN(minutes) ||
+      isNaN(seconds) ||
+      typeof direction !== "string"
+    ) {
+      return NextResponse.json(
+        { error: "dms must contain degrees, minutes, seconds as numbers, and direction as a string." },
+        { status: 400 }
+      );
+    }
+
+    const dirUpper = direction.trim().toUpperCase();
+    if (!["N", "S", "E", "W"].includes(dirUpper)) {
+      return NextResponse.json(
+        { error: "direction must be 'N', 'S', 'E', or 'W'." },
+        { status: 400 }
+      );
+    }
+
+    if (degrees < 0 || minutes < 0 || minutes >= 60 || seconds < 0 || seconds >= 60) {
+      return NextResponse.json(
+        { error: "degrees/minutes/seconds must be positive, with minutes and seconds less than 60." },
+        { status: 400 }
+      );
+    }
+
+    // Determine type from direction if type is not provided
+    const resolvedType = type || (["N", "S"].includes(dirUpper) ? "lat" : "lng");
+
+    if (resolvedType === "lat" && !["N", "S"].includes(dirUpper)) {
+      return NextResponse.json(
+        { error: "Latitude direction must be 'N' or 'S'." },
+        { status: 400 }
+      );
+    }
+
+    if (resolvedType === "lng" && !["E", "W"].includes(dirUpper)) {
+      return NextResponse.json(
+        { error: "Longitude direction must be 'E' or 'W'." },
+        { status: 400 }
+      );
+    }
+
+    let decimalVal = degrees + minutes / 60 + seconds / 3600;
+    if (dirUpper === "S" || dirUpper === "W") {
+      decimalVal = -decimalVal;
+    }
+
+    // Validate range limits
+    if (resolvedType === "lat" && (decimalVal < -90 || decimalVal > 90)) {
+      return NextResponse.json(
+        { error: "Latitude decimal degrees must be between -90 and 90." },
+        { status: 400 }
+      );
+    }
+
+    if (resolvedType === "lng" && (decimalVal < -180 || decimalVal > 180)) {
+      return NextResponse.json(
+        { error: "Longitude decimal degrees must be between -180 and 180." },
+        { status: 400 }
+      );
+    }
+
+    return NextResponse.json({ decimal: decimalVal });
+  } else {
+    // mode === 'to_dms'
+    if (decimal === undefined || isNaN(Number(decimal)) || typeof decimal === "boolean") {
+      return NextResponse.json(
+        { error: "decimal is required and must be a number for to_dms mode." },
+        { status: 400 }
+      );
+    }
+
+    const decimalVal = Number(decimal);
+
+    // Resolve type: default to lat unless out of lat bounds, or type is specified
+    const resolvedType = type || (Math.abs(decimalVal) > 90 ? "lng" : "lat");
+
+    // Validate range limits
+    if (resolvedType === "lat" && (decimalVal < -90 || decimalVal > 90)) {
+      return NextResponse.json(
+        { error: "Latitude decimal degrees must be between -90 and 90." },
+        { status: 400 }
+      );
+    }
+
+    if (resolvedType === "lng" && (decimalVal < -180 || decimalVal > 180)) {
+      return NextResponse.json(
+        { error: "Longitude decimal degrees must be between -180 and 180." },
+        { status: 400 }
+      );
+    }
+
+    const absVal = Math.abs(decimalVal);
+    const degrees = Math.floor(absVal);
+    const minutesDecimal = (absVal - degrees) * 60;
+    const minutes = Math.floor(minutesDecimal);
+    let seconds = (minutesDecimal - minutes) * 60;
+
+    // Handle numerical precision, round to 4 decimal places
+    seconds = Math.round(seconds * 10000) / 10000;
+    let minutesVal = minutes;
+    let degreesVal = degrees;
+
+    if (seconds >= 60) {
+      seconds = 0;
+      minutesVal += 1;
+    }
+    if (minutesVal >= 60) {
+      minutesVal = 0;
+      degreesVal += 1;
+    }
+
+    let direction = "";
+    if (resolvedType === "lat") {
+      direction = decimalVal >= 0 ? "N" : "S";
+    } else {
+      direction = decimalVal >= 0 ? "E" : "W";
+    }
+
+    return NextResponse.json({
+      degrees: degreesVal,
+      minutes: minutesVal,
+      seconds,
+      direction,
+    });
+  }
+}
diff --git a/app/api/routes-f/donations/history/__tests__/route.test.ts b/app/api/routes-f/donations/history/__tests__/route.test.ts
new file mode 100644
index 00000000..c2e98b97
--- /dev/null
+++ b/app/api/routes-f/donations/history/__tests__/route.test.ts
@@ -0,0 +1,79 @@
+jest.mock("next/server", () => ({
+  NextResponse: {
+    json: (body: unknown, init?: ResponseInit) =>
+      new Response(JSON.stringify(body), {
+        ...init,
+        headers: { "Content-Type": "application/json" },
+      }),
+  },
+}));
+jest.mock("@vercel/postgres", () => ({ sql: { query: jest.fn() } }));
+jest.mock("@/lib/auth/verify-session", () => ({ verifySession: jest.fn() }));
+
+import { sql } from "@vercel/postgres";
+import { verifySession } from "@/lib/auth/verify-session";
+import { GET } from "../route";
+
+const sqlQuery = (sql as unknown as { query: jest.Mock }).query;
+const verify = verifySession as unknown as jest.Mock;
+
+function req(qs = ""): any {
+  return new Request(`http://localhost/api/routes-f/donations/history${qs}`);
+}
+
+const row = {
+  id: "t1",
+  amount_usdc: "5.00",
+  message: "thanks!",
+  tx_hash: "hash1",
+  created_at: "2026-05-01T00:00:00.000Z",
+  sender_username: "alice",
+  recipient_username: "bob",
+};
+
+beforeEach(() => {
+  jest.clearAllMocks();
+  verify.mockResolvedValue({ ok: true, userId: "user-1" });
+});
+
+describe("GET /api/routes-f/donations/history", () => {
+  it("returns the session's 401 response when unauthenticated", async () => {
+    verify.mockResolvedValue({ ok: false, response: new Response("no", { status: 401 }) });
+    const res = await GET(req());
+    expect(res.status).toBe(401);
+  });
+
+  it("rejects an invalid direction", async () => {
+    const res = await GET(req("?direction=weird"));
+    expect(res.status).toBe(400);
+  });
+
+  it("rejects a non-ISO from date", async () => {
+    const res = await GET(req("?from=not-a-date"));
+    expect(res.status).toBe(400);
+  });
+
+  it("returns the user's donation history", async () => {
+    sqlQuery.mockResolvedValue({ rows: [row] });
+    const res = await GET(req("?direction=all&limit=20"));
+    expect(res.status).toBe(200);
+    const json = await res.json();
+    expect(json.donations).toHaveLength(1);
+    expect(json.donations[0]).toMatchObject({
+      amount_usdc: "5.00",
+      sender_username: "alice",
+      recipient_username: "bob",
+    });
+    expect(json.pagination.hasMore).toBe(false);
+  });
+
+  it("sets hasMore + nextCursor when an extra row is returned", async () => {
+    const rows = Array.from({ length: 3 }, (_, k) => ({ ...row, id: `t${k}` }));
+    sqlQuery.mockResolvedValue({ rows });
+    const res = await GET(req("?limit=2"));
+    const json = await res.json();
+    expect(json.donations).toHaveLength(2);
+    expect(json.pagination.hasMore).toBe(true);
+    expect(json.pagination.nextCursor).toBe("2026-05-01T00:00:00.000Z");
+  });
+});
diff --git a/app/api/routes-f/donations/history/route.ts b/app/api/routes-f/donations/history/route.ts
new file mode 100644
index 00000000..6f42fc0e
--- /dev/null
+++ b/app/api/routes-f/donations/history/route.ts
@@ -0,0 +1,116 @@
+import { NextRequest, NextResponse } from "next/server";
+import { sql } from "@vercel/postgres";
+import { verifySession } from "@/lib/auth/verify-session";
+
+export const dynamic = "force-dynamic";
+
+/**
+ * GET /api/routes-f/donations/history (#466)
+ *
+ * Returns the authenticated user's tip/donation history (sent and/or received),
+ * with date-range filtering and keyset (created_at) cursor pagination.
+ *
+ * Query: ?direction=sent|received|all&limit=20&cursor=<ISO>&from=<ISO>&to=<ISO>
+ */
+export async function GET(req: NextRequest): Promise<NextResponse> {
+  const session = await verifySession(req);
+  if (!session.ok) return session.response;
+  const userId = session.userId;
+
+  const { searchParams } = new URL(req.url);
+
+  const direction = (searchParams.get("direction") ?? "all").toLowerCase();
+  if (!["sent", "received", "all"].includes(direction)) {
+    return NextResponse.json(
+      { error: "direction must be one of sent | received | all" },
+      { status: 400 },
+    );
+  }
+
+  const limit = Math.min(
+    100,
+    Math.max(1, Number.parseInt(searchParams.get("limit") ?? "20", 10) || 20),
+  );
+
+  const from = searchParams.get("from");
+  const to = searchParams.get("to");
+  const cursor = searchParams.get("cursor");
+  for (const [name, value] of [["from", from], ["to", to], ["cursor", cursor]] as const) {
+    if (value && Number.isNaN(Date.parse(value))) {
+      return NextResponse.json({ error: `${name} must be an ISO timestamp` }, { status: 400 });
+    }
+  }
+
+  const conditions: string[] = [];
+  const params: unknown[] = [];
+  let i = 1;
+
+  if (direction === "sent") {
+    conditions.push(`t.sender_id = $${i++}`);
+    params.push(userId);
+  } else if (direction === "received") {
+    conditions.push(`t.recipient_id = $${i++}`);
+    params.push(userId);
+  } else {
+    conditions.push(`(t.sender_id = $${i} OR t.recipient_id = $${i})`);
+    i += 1;
+    params.push(userId);
+  }
+  if (from) {
+    conditions.push(`t.created_at >= $${i++}`);
+    params.push(from);
+  }
+  if (to) {
+    conditions.push(`t.created_at <= $${i++}`);
+    params.push(to);
+  }
+  if (cursor) {
+    conditions.push(`t.created_at < $${i++}`);
+    params.push(cursor);
+  }
+
+  // Fetch one extra row to determine the next cursor.
+  const queryText = `
+    SELECT t.id,
+           t.amount_usdc,
+           t.message,
+           t.tx_hash,
+           t.created_at,
+           s.username AS sender_username,
+           r.username AS recipient_username
+    FROM tips t
+    LEFT JOIN users s ON s.id = t.sender_id
+    LEFT JOIN users r ON r.id = t.recipient_id
+    WHERE ${conditions.join(" AND ")}
+    ORDER BY t.created_at DESC
+    LIMIT $${i}`;
+  params.push(limit + 1);
+
+  try {
+    const { rows } = await sql.query(queryText, params);
+    const hasMore = rows.length > limit;
+    const items = hasMore ? rows.slice(0, limit) : rows;
+    const nextCursor =
+      hasMore && items.length > 0
+        ? new Date(items[items.length - 1].created_at).toISOString()
+        : null;
+
+    return NextResponse.json({
+      donations: items.map((row) => ({
+        id: row.id,
+        amount_usdc: row.amount_usdc,
+        sender_username: row.sender_username,
+        recipient_username: row.recipient_username,
+        message: row.message ?? null,
+        tx_hash: row.tx_hash ?? null,
+        created_at: row.created_at,
+      })),
+      pagination: { limit, nextCursor, hasMore },
+    });
+  } catch {
+    return NextResponse.json(
+      { error: "Failed to load donation history" },
+      { status: 500 },
+    );
+  }
+}
diff --git a/app/api/routes-f/duration/route.ts b/app/api/routes-f/duration/route.ts
new file mode 100644
index 00000000..424d69da
--- /dev/null
+++ b/app/api/routes-f/duration/route.ts
@@ -0,0 +1,73 @@
+// @ts-nocheck
+import { type NextRequest, NextResponse } from "next/server";
+import { z } from "zod";
+import { validateBody } from "@/app/api/routes-f/_lib/validate";
+import {
+  DurationComponents,
+  durationToSeconds,
+  formatDuration,
+  parseDuration,
+} from "@/app/api/routes-f/_lib/duration";
+
+const durationComponentsSchema = z.object({
+  years: z.number().min(0).optional(),
+  months: z.number().min(0).optional(),
+  weeks: z.number().min(0).optional(),
+  days: z.number().min(0).optional(),
+  hours: z.number().min(0).optional(),
+  minutes: z.number().min(0).optional(),
+  seconds: z.number().min(0).optional(),
+});
+
+const durationBodySchema = z.discriminatedUnion("mode", [
+  z.object({ mode: z.literal("parse"), text: z.string() }),
+  z.object({ mode: z.literal("format"), components: durationComponentsSchema }),
+]);
+
+export async function POST(req: NextRequest) {
+  const validated = await validateBody(req, durationBodySchema);
+  if (validated instanceof NextResponse) {
+    return validated;
+  }
+
+  const { mode } = validated.data;
+
+  if (mode === "parse") {
+    const { text } = validated.data;
+    try {
+      const parsed = parseDuration(text);
+      return NextResponse.json({
+        text,
+        components: parsed,
+        total_seconds: durationToSeconds(parsed),
+      });
+    } catch (error) {
+      return NextResponse.json(
+        {
+          error:
+            error instanceof Error ? error.message : "Invalid ISO duration.",
+        },
+        { status: 400 }
+      );
+    }
+  }
+
+  try {
+    const { components } = validated.data;
+    const formatted = formatDuration(components as DurationComponents);
+    const normalized = parseDuration(formatted);
+    return NextResponse.json({
+      text: formatted,
+      components: normalized,
+      total_seconds: durationToSeconds(normalized),
+    });
+  } catch (error) {
+    return NextResponse.json(
+      {
+        error:
+          error instanceof Error ? error.message : "Failed to format duration.",
+      },
+      { status: 400 }
+    );
+  }
+}
diff --git a/app/api/routes-f/easter/route.ts b/app/api/routes-f/easter/route.ts
new file mode 100644
index 00000000..480734dc
--- /dev/null
+++ b/app/api/routes-f/easter/route.ts
@@ -0,0 +1,53 @@
+import { NextRequest, NextResponse } from 'next/server';
+
+function computeEaster(year: number): { easter: string; good_friday: string; easter_monday: string } {
+  const a = year % 19;
+  const b = Math.floor(year / 100);
+  const c = year % 100;
+  const d = Math.floor(b / 4);
+  const e = b % 4;
+  const f = Math.floor((b + 8) / 25);
+  const g = Math.floor((b - f + 1) / 3);
+  const h = (19 * a + b - d - g + 15) % 30;
+  const i = Math.floor(c / 4);
+  const k = c % 4;
+  const l = (32 + 2 * e + 2 * i - h - k) % 7;
+  const m = Math.floor((a + 11 * h + 22 * l) / 451);
+  const month = Math.floor((h + l - 7 * m + 114) / 31);
+  const day = ((h + l - 7 * m + 114) % 31) + 1;
+
+  const easterDate = new Date(year, month - 1, day);
+  const easterString = easterDate.toISOString().split('T')[0];
+
+  const goodFridayDate = new Date(easterDate);
+  goodFridayDate.setDate(goodFridayDate.getDate() - 2);
+  const goodFridayString = goodFridayDate.toISOString().split('T')[0];
+
+  const easterMondayDate = new Date(easterDate);
+  easterMondayDate.setDate(easterMondayDate.getDate() + 1);
+  const easterMondayString = easterMondayDate.toISOString().split('T')[0];
+
+  return {
+    easter: easterString,
+    good_friday: goodFridayString,
+    easter_monday: easterMondayString,
+  };
+}
+
+export async function GET(req: NextRequest) {
+  const year = parseInt(new URL(req.url).searchParams.get('year') || '', 10);
+
+  if (isNaN(year)) {
+    return NextResponse.json({ error: 'year query param is required' }, { status: 400 });
+  }
+
+  if (year < 1583 || year > 4099) {
+    return NextResponse.json(
+      { error: 'year must be in range [1583, 4099]' },
+      { status: 400 }
+    );
+  }
+
+  const result = computeEaster(year);
+  return NextResponse.json(result);
+}
diff --git a/app/api/routes-f/etag/__tests__/route.test.ts b/app/api/routes-f/etag/__tests__/route.test.ts
new file mode 100644
index 00000000..57a87307
--- /dev/null
+++ b/app/api/routes-f/etag/__tests__/route.test.ts
@@ -0,0 +1,110 @@
+/**
+ * @jest-environment node
+ */
+import { NextRequest } from "next/server";
+import { POST } from "../route";
+
+function makeReq(body: unknown) {
+  return new NextRequest("http://localhost/api/routes-f/etag", {
+    method: "POST",
+    headers: { "content-type": "application/json" },
+    body: JSON.stringify(body),
+  });
+}
+
+describe("POST /api/routes-f/etag", () => {
+  it("generates a strong ETag by default", async () => {
+    const res = await POST(makeReq({ content: "hello world" }));
+    const body = await res.json();
+
+    expect(res.status).toBe(200);
+    // SHA-256 of "hello world" is "b94d27b9934d3e08a52e52d7da7dabfac484efe37a5380ee9088f7ace2efcde9"
+    // Truncated to 32 chars: "b94d27b9934d3e08a52e52d7da7dabfa"
+    expect(body.etag).toBe('"b94d27b9934d3e08a52e52d7da7dabfa"');
+    expect(body.matches).toBeUndefined();
+  });
+
+  it("generates a weak ETag when weak is true", async () => {
+    const res = await POST(makeReq({ content: "hello world", weak: true }));
+    const body = await res.json();
+
+    expect(res.status).toBe(200);
+    expect(body.etag).toBe('W/"b94d27b9934d3e08a52e52d7da7dabfa"');
+  });
+
+  it("validates If-None-Match with exact match", async () => {
+    const etag = '"b94d27b9934d3e08a52e52d7da7dabfa"';
+    const res = await POST(
+      makeReq({ content: "hello world", if_none_match: etag })
+    );
+    const body = await res.json();
+
+    expect(res.status).toBe(200);
+    expect(body.etag).toBe(etag);
+    expect(body.matches).toBe(true);
+  });
+
+  it("validates If-None-Match with wildcard *", async () => {
+    const res = await POST(
+      makeReq({ content: "hello world", if_none_match: "*" })
+    );
+    const body = await res.json();
+
+    expect(res.status).toBe(200);
+    expect(body.matches).toBe(true);
+  });
+
+  it("validates If-None-Match with weak comparison (weak vs strong)", async () => {
+    const strongEtag = '"b94d27b9934d3e08a52e52d7da7dabfa"';
+    const weakEtag = 'W/"b94d27b9934d3e08a52e52d7da7dabfa"';
+
+    // Client sends weak, server generates strong
+    let res = await POST(
+      makeReq({ content: "hello world", if_none_match: weakEtag })
+    );
+    let body = await res.json();
+    expect(res.status).toBe(200);
+    expect(body.etag).toBe(strongEtag);
+    expect(body.matches).toBe(true);
+
+    // Client sends strong, server generates weak
+    res = await POST(
+      makeReq({ content: "hello world", weak: true, if_none_match: strongEtag })
+    );
+    body = await res.json();
+    expect(res.status).toBe(200);
+    expect(body.etag).toBe(weakEtag);
+    expect(body.matches).toBe(true);
+  });
+
+  it("validates If-None-Match with comma-separated list of ETags", async () => {
+    const list = '"other-tag", W/"b94d27b9934d3e08a52e52d7da7dabfa", "another"';
+    const res = await POST(
+      makeReq({ content: "hello world", if_none_match: list })
+    );
+    const body = await res.json();
+
+    expect(res.status).toBe(200);
+    expect(body.matches).toBe(true);
+  });
+
+  it("returns matches: false for non-matching ETags", async () => {
+    const res = await POST(
+      makeReq({ content: "hello world", if_none_match: '"non-matching-tag"' })
+    );
+    const body = await res.json();
+
+    expect(res.status).toBe(200);
+    expect(body.matches).toBe(false);
+  });
+
+  it("rejects invalid input content", async () => {
+    // Missing content
+    let res = await POST(makeReq({}));
+    expect(res.status).toBe(400);
+
+    // Non-string content
+    res = await POST(makeReq({ content: 12345 }));
+    expect(res.status).toBe(400);
+  });
+});
diff --git a/app/api/routes-f/etag/route.ts b/app/api/routes-f/etag/route.ts
new file mode 100644
index 00000000..21826c91
--- /dev/null
+++ b/app/api/routes-f/etag/route.ts
@@ -0,0 +1,65 @@
+import { NextRequest, NextResponse } from "next/server";
+import crypto from "crypto";
+
+function cleanEtag(tag: string): string {
+  let t = tag.trim();
+  if (t.startsWith("W/")) {
+    t = t.substring(2);
+  }
+  if (t.startsWith('"') && t.endsWith('"')) {
+    t = t.substring(1, t.length - 1);
+  }
+  return t;
+}
+
+export async function POST(req: NextRequest) {
+  let body: { content?: unknown; weak?: unknown; if_none_match?: unknown };
+
+  try {
+    body = await req.json();
+  } catch {
+    return NextResponse.json({ error: "Invalid JSON body." }, { status: 400 });
+  }
+
+  if (body.content === undefined || typeof body.content !== "string") {
+    return NextResponse.json(
+      { error: "content is required and must be a string." },
+      { status: 400 }
+    );
+  }
+
+  const isWeak = body.weak === true;
+  const ifNoneMatch = body.if_none_match;
+
+  if (ifNoneMatch !== undefined && typeof ifNoneMatch !== "string") {
+    return NextResponse.json(
+      { error: "if_none_match must be a string if provided." },
+      { status: 400 }
+    );
+  }
+
+  // Generate SHA-256 hash and truncate to 32 characters
+  const hash = crypto.createHash("sha256").update(body.content).digest("hex");
+  const truncatedHash = hash.substring(0, 32);
+
+  const etag = isWeak ? `W/"${truncatedHash}"` : `"${truncatedHash}"`;
+
+  const responseBody: { etag: string; matches?: boolean } = { etag };
+
+  if (ifNoneMatch !== undefined) {
+    let matches = false;
+    const trimmedIfNoneMatch = ifNoneMatch.trim();
+
+    if (trimmedIfNoneMatch === "*") {
+      matches = true;
+    } else {
+      const clientTags = trimmedIfNoneMatch.split(",").map(cleanEtag);
+      const generatedClean = cleanEtag(etag);
+      matches = clientTags.includes(generatedClean);
+    }
+
+    responseBody.matches = matches;
+  }
+
+  return NextResponse.json(responseBody);
+}
diff --git a/app/api/routes-f/explore-feed/__tests__/explore-feed.test.ts b/app/api/routes-f/explore-feed/__tests__/explore-feed.test.ts
new file mode 100644
index 00000000..a72ed836
--- /dev/null
+++ b/app/api/routes-f/explore-feed/__tests__/explore-feed.test.ts
@@ -0,0 +1,71 @@
+/**
+ * @jest-environment node
+ */
+import { NextRequest } from "next/server";
+import { GET } from "../route";
+
+const BASE_URL = "http://localhost/api/routes-f/explore-feed";
+
+function makeGet(params: Record<string, string>) {
+  const url = new URL(BASE_URL);
+  for (const [k, v] of Object.entries(params)) url.searchParams.set(k, v);
+  return new NextRequest(url.toString(), { method: "GET" });
+}
+
+describe("GET /api/routes-f/explore-feed", () => {
+  it("returns four sections with correct titles", async () => {
+    const res = await GET(makeGet({ viewer_id: "v-rich-001" }));
+    expect(res.status).toBe(200);
+    const { sections } = await res.json();
+    const titles = sections.map((s: { title: string }) => s.title);
+    expect(titles).toEqual([
+      "For You",
+      "Continue Watching",
+      "Clips You Might Like",
+      "New Creators",
+    ]);
+  });
+
+  it("viewer with rich history gets personalised For You results", async () => {
+    const res = await GET(makeGet({ viewer_id: "v-rich-001" }));
+    const { sections } = await res.json();
+    const forYou = sections.find((s: { title: string }) => s.title === "For You");
+    expect(forYou.items.length).toBeGreaterThan(0);
+    // Rich viewer follows c-001, c-002, c-003 — at least one should appear first
+    const firstCreatorId = forYou.items[0].creator_id;
+    expect(["c-001", "c-002", "c-003"]).toContain(firstCreatorId);
+  });
+
+  it("viewer with rich history gets Continue Watching with progress", async () => {
+    const res = await GET(makeGet({ viewer_id: "v-rich-001" }));
+    const { sections } = await res.json();
+    const cont = sections.find((s: { title: string }) => s.title === "Continue Watching");
+    expect(cont.items.length).toBeGreaterThan(0);
+    for (const item of cont.items) {
+      expect(typeof item.progress_pct).toBe("number");
+    }
+  });
+
+  it("cold-start viewer gets empty Continue Watching", async () => {
+    const res = await GET(makeGet({ viewer_id: "v-cold-new" }));
+    const { sections } = await res.json();
+    const cont = sections.find((s: { title: string }) => s.title === "Continue Watching");
+    expect(cont.items).toHaveLength(0);
+  });
+
+  it("cold-start viewer still gets For You, Clips, and New Creators populated", async () => {
+    const res = await GET(makeGet({ viewer_id: "v-cold-new" }));
+    const { sections } = await res.json();
+    const forYou = sections.find((s: { title: string }) => s.title === "For You");
+    const clips = sections.find((s: { title: string }) => s.title === "Clips You Might Like");
+    const newCreators = sections.find((s: { title: string }) => s.title === "New Creators");
+    expect(forYou.items.length).toBeGreaterThan(0);
+    expect(clips.items.length).toBeGreaterThan(0);
+    expect(newCreators.items.length).toBeGreaterThan(0);
+  });
+
+  it("400 — missing viewer_id", async () => {
+    const res = await GET(makeGet({}));
+    expect(res.status).toBe(400);
+  });
+});
diff --git a/app/api/routes-f/explore-feed/route.ts b/app/api/routes-f/explore-feed/route.ts
new file mode 100644
index 00000000..f04e2320
--- /dev/null
+++ b/app/api/routes-f/explore-feed/route.ts
@@ -0,0 +1,107 @@
+/**
+ * GET  /api/routes-f/explore-feed?viewer_id=
+ *
+ * Returns a personalized explore feed mixing live streams, VODs, clips, and
+ * new creators. Seed data is bundled inline. A cold-start viewer (no history)
+ * gets a generic trending feed.
+ */
+import { NextRequest, NextResponse } from "next/server";
+import { z } from "zod";
+import { validateQuery } from "@/app/api/routes-f/_lib/validate";
+
+// ---------------------------------------------------------------------------
+// Seed data
+// ---------------------------------------------------------------------------
+const LIVE_STREAMS = [
+  { id: "ls-001", creator_id: "c-001", creator_name: "CryptoKing", title: "Stellar DeFi Deep Dive", viewers_now: 1420 },
+  { id: "ls-002", creator_id: "c-002", creator_name: "ArtByLena", title: "Live Generative Art", viewers_now: 830 },
+  { id: "ls-003", creator_id: "c-003", creator_name: "GamingGuru", title: "Speedrun Saturday", viewers_now: 3200 },
+  { id: "ls-004", creator_id: "c-004", creator_name: "MusicMaven", title: "Lo-fi Coding Session", viewers_now: 560 },
+];
+
+const VODS = [
+  { id: "vod-001", creator_id: "c-001", title: "Intro to Stellar AMMs", duration_s: 1800, progress_pct: 0 },
+  { id: "vod-002", creator_id: "c-003", title: "Top 10 Speedrun Fails", duration_s: 900, progress_pct: 0 },
+  { id: "vod-003", creator_id: "c-005", creator_name: "DevDojo", title: "Smart Contracts 101", duration_s: 3600, progress_pct: 0 },
+];
+
+const CLIPS = [
+  { id: "clip-001", creator_id: "c-002", title: "Pixel-perfect generative circle", duration_s: 45 },
+  { id: "clip-002", creator_id: "c-003", title: "World-record split", duration_s: 30 },
+  { id: "clip-003", creator_id: "c-004", title: "Chillest lofi drop ever", duration_s: 60 },
+];
+
+const NEW_CREATORS = [
+  { id: "c-010", name: "StellarSam", followers: 12, streams_count: 3, category: "Finance" },
+  { id: "c-011", name: "PixelPaula", followers: 8, streams_count: 1, category: "Art" },
+  { id: "c-012", name: "CodeWithKai", followers: 20, streams_count: 5, category: "Dev" },
+];
+
+// viewer_id → set of creator_ids the viewer has watched
+const VIEWER_HISTORY: Record<string, string[]> = {
+  "v-rich-001": ["c-001", "c-002", "c-003"],
+  "v-rich-002": ["c-003", "c-004"],
+};
+
+// ---------------------------------------------------------------------------
+// Helpers
+// ---------------------------------------------------------------------------
+function personalizedLive(viewerHistory: string[]) {
+  if (!viewerHistory.length) return LIVE_STREAMS.slice(0, 3);
+  const preferred = LIVE_STREAMS.filter((s) => viewerHistory.includes(s.creator_id));
+  const rest = LIVE_STREAMS.filter((s) => !viewerHistory.includes(s.creator_id));
+  return [...preferred, ...rest].slice(0, 3);
+}
+
+function continueWatching(viewerHistory: string[]) {
+  return VODS.filter((v) => viewerHistory.includes(v.creator_id)).map((v) => ({
+    ...v,
+    // Simulate partial progress for known creators.
+    progress_pct: 42,
+  }));
+}
+
+// ---------------------------------------------------------------------------
+// Schema
+// ---------------------------------------------------------------------------
+const querySchema = z.object({
+  viewer_id: z.string().min(1, "viewer_id is required"),
+});
+
+// ---------------------------------------------------------------------------
+// Handler
+// ---------------------------------------------------------------------------
+export async function GET(req: NextRequest): Promise<NextResponse> {
+  const { searchParams } = new URL(req.url);
+  const result = validateQuery(searchParams, querySchema);
+  if (result instanceof NextResponse) return result;
+
+  const { viewer_id } = result.data;
+  const history = VIEWER_HISTORY[viewer_id] ?? [];
+  const isColdStart = history.length === 0;
+
+  const sections = [
+    {
+      title: "For You",
+      items: personalizedLive(history),
+    },
+    {
+      title: "Continue Watching",
+      items: isColdStart ? [] : continueWatching(history),
+    },
+    {
+      title: "Clips You Might Like",
+      items: isColdStart
+        ? CLIPS
+        : CLIPS.filter((c) => history.includes(c.creator_id)).concat(
+            CLIPS.filter((c) => !history.includes(c.creator_id))
+          ),
+    },
+    {
+      title: "New Creators",
+      items: NEW_CREATORS,
+    },
+  ];
+
+  return NextResponse.json({ sections });
+}
diff --git a/app/api/routes-f/exponential-smoothing/__tests__/route.test.ts b/app/api/routes-f/exponential-smoothing/__tests__/route.test.ts
new file mode 100644
index 00000000..706197a1
--- /dev/null
+++ b/app/api/routes-f/exponential-smoothing/__tests__/route.test.ts
@@ -0,0 +1,63 @@
+/**
+ * @jest-environment node
+ */
+import { NextRequest } from "next/server";
+import { POST } from "../route";
+import { exponentialSmooth } from "../smoothing";
+
+function makeReq(body: unknown) {
+  return new NextRequest("http://localhost/api/routes-f/exponential-smoothing", {
+    method: "POST",
+    headers: { "content-type": "application/json" },
+    body: JSON.stringify(body),
+  });
+}
+
+describe("/api/routes-f/exponential-smoothing", () => {
+  it("follows the exponential smoothing recurrence", async () => {
+    const data = [10, 12, 13, 15];
+    const alpha = 0.3;
+    const res = await POST(makeReq({ data, alpha, forecast: 2 }));
+    const body = await res.json();
+
+    expect(res.status).toBe(200);
+    expect(body.smoothed[0]).toBe(data[0]);
+
+    for (let i = 1; i < data.length; i += 1) {
+      expect(body.smoothed[i]).toBeCloseTo(
+        alpha * data[i] + (1 - alpha) * body.smoothed[i - 1],
+        10
+      );
+    }
+
+    expect(body.forecast).toEqual([body.smoothed.at(-1), body.smoothed.at(-1)]);
+  });
+
+  it("defaults alpha to 0.3 and forecast to 1", async () => {
+    const res = await POST(makeReq({ data: [1, 2, 3] }));
+    const body = await res.json();
+
+    expect(res.status).toBe(200);
+    expect(body.forecast).toHaveLength(1);
+    expect(body.smoothed[1]).toBeCloseTo(0.3 * 2 + 0.7 * 1, 10);
+  });
+
+  it("rejects alpha outside (0, 1)", async () => {
+    const invalid = await POST(makeReq({ data: [1, 2], alpha: 1 }));
+    const zero = await POST(makeReq({ data: [1, 2], alpha: 0 }));
+
+    expect(invalid.status).toBe(400);
+    expect(zero.status).toBe(400);
+  });
+
+  it("rejects empty data", async () => {
+    const res = await POST(makeReq({ data: [] }));
+    expect(res.status).toBe(400);
+  });
+});
+
+describe("exponentialSmooth", () => {
+  it("returns an empty smoothed array for empty input", () => {
+    expect(exponentialSmooth([], 0.5, 2)).toEqual({ smoothed: [], forecast: [0, 0] });
+  });
+});
diff --git a/app/api/routes-f/exponential-smoothing/route.ts b/app/api/routes-f/exponential-smoothing/route.ts
new file mode 100644
index 00000000..86be1a72
--- /dev/null
+++ b/app/api/routes-f/exponential-smoothing/route.ts
@@ -0,0 +1,53 @@
+// @ts-nocheck
+import { type NextRequest, NextResponse } from "next/server";
+import { exponentialSmooth } from "./smoothing";
+
+type SmoothingBody = {
+  data?: unknown;
+  alpha?: unknown;
+  forecast?: unknown;
+};
+
+function badRequest(message: string) {
+  return NextResponse.json({ error: message }, { status: 400 });
+}
+
+export async function POST(req: NextRequest) {
+  let body: SmoothingBody;
+
+  try {
+    body = (await req.json()) as SmoothingBody;
+  } catch {
+    return badRequest("Invalid JSON body.");
+  }
+
+  const { data, alpha = 0.3, forecast = 1 } = body;
+
+  if (
+    !Array.isArray(data) ||
+    data.length === 0 ||
+    data.some(value => typeof value !== "number" || !Number.isFinite(value))
+  ) {
+    return badRequest("data must be a non-empty array of finite numbers.");
+  }
+
+  if (
+    typeof alpha !== "number" ||
+    !Number.isFinite(alpha) ||
+    alpha <= 0 ||
+    alpha >= 1
+  ) {
+    return badRequest("alpha must be a number in the open interval (0, 1).");
+  }
+
+  if (
+    typeof forecast !== "number" ||
+    !Number.isInteger(forecast) ||
+    forecast < 0
+  ) {
+    return badRequest("forecast must be a non-negative integer.");
+  }
+
+  const result = exponentialSmooth(data, alpha, forecast);
+  return NextResponse.json(result);
+}
diff --git a/app/api/routes-f/exponential-smoothing/smoothing.ts b/app/api/routes-f/exponential-smoothing/smoothing.ts
new file mode 100644
index 00000000..43752596
--- /dev/null
+++ b/app/api/routes-f/exponential-smoothing/smoothing.ts
@@ -0,0 +1,20 @@
+export function exponentialSmooth(
+  data: number[],
+  alpha: number,
+  forecastSteps: number
+): { smoothed: number[]; forecast: number[] } {
+  if (data.length === 0) {
+    return { smoothed: [], forecast: Array.from({ length: forecastSteps }, () => 0) };
+  }
+
+  const smoothed: number[] = [data[0]];
+
+  for (let i = 1; i < data.length; i += 1) {
+    smoothed.push(alpha * data[i] + (1 - alpha) * smoothed[i - 1]);
+  }
+
+  const lastLevel = smoothed[smoothed.length - 1];
+  const forecast = Array.from({ length: forecastSteps }, () => lastLevel);
+
+  return { smoothed, forecast };
+}
diff --git a/app/api/routes-f/extensions/catalog/route.ts b/app/api/routes-f/extensions/catalog/route.ts
new file mode 100644
index 00000000..4fe338ef
--- /dev/null
+++ b/app/api/routes-f/extensions/catalog/route.ts
@@ -0,0 +1,31 @@
+import { NextResponse } from "next/server";
+import { sql } from "@vercel/postgres";
+
+export const runtime = "nodejs";
+export const dynamic = "force-dynamic";
+
+/**
+ * GET /api/routes-f/extensions/catalog
+ * Returns all active extensions available for streamers.
+ */
+export async function GET() {
+    try {
+        const { rows } = await sql`
+      SELECT id, name, description, json_schema as "jsonSchema", icon_url as "iconUrl"
+      FROM extension_catalog
+      WHERE is_active = TRUE
+      ORDER BY name ASC
+    `;
+
+        return NextResponse.json({
+            extensions: rows,
+            count: rows.length
+        });
+    } catch (error) {
+        console.error("[Catalog API] Error fetching extensions:", error);
+        return NextResponse.json(
+            { error: "Failed to fetch extension catalog" },
+            { status: 500 }
+        );
+    }
+}
diff --git a/app/api/routes-f/fibonacci/__tests__/route.test.ts b/app/api/routes-f/fibonacci/__tests__/route.test.ts
new file mode 100644
index 00000000..f519fdff
--- /dev/null
+++ b/app/api/routes-f/fibonacci/__tests__/route.test.ts
@@ -0,0 +1,68 @@
+import { NextRequest } from "next/server";
+import { POST, fibNth } from "../route";
+
+function req(body: unknown) {
+  return new NextRequest("http://localhost/api/routes-f/fibonacci", {
+    method: "POST",
+    body: JSON.stringify(body),
+  });
+}
+
+describe("fibNth", () => {
+  it("matches known values", () => {
+    expect(fibNth(1)).toBe(BigInt(1));
+    expect(fibNth(2)).toBe(BigInt(1));
+    expect(fibNth(10)).toBe(BigInt(55));
+    expect(fibNth(20)).toBe(BigInt(6765));
+  });
+
+  it("uses BigInt-safe outputs beyond precision boundary", () => {
+    expect(fibNth(78)).toBe(BigInt("8944394323791464"));
+    expect(fibNth(79)).toBe(BigInt("14472334024676221"));
+  });
+});
+
+describe("POST /api/routes-f/fibonacci", () => {
+  it("returns first n sequence in count mode", async () => {
+    const res = await POST(req({ mode: "count", n: 7, format: "array" }));
+    expect(res.status).toBe(200);
+    expect((await res.json()).sequence).toEqual([
+      "1",
+      "1",
+      "2",
+      "3",
+      "5",
+      "8",
+      "13",
+    ]);
+  });
+
+  it("returns nth value in count mode", async () => {
+    const res = await POST(req({ mode: "count", n: 10, format: "nth" }));
+    expect(res.status).toBe(200);
+    expect((await res.json()).value).toBe("55");
+  });
+
+  it("returns all values <= max in until mode", async () => {
+    const res = await POST(req({ mode: "until", max: "34", format: "array" }));
+    expect(res.status).toBe(200);
+    expect((await res.json()).sequence).toEqual([
+      "1",
+      "1",
+      "2",
+      "3",
+      "5",
+      "8",
+      "13",
+      "21",
+      "34",
+    ]);
+  });
+
+  it("validates input bounds", async () => {
+    const resN = await POST(req({ mode: "count", n: 0 }));
+    const resMax = await POST(req({ mode: "until", max: 0 }));
+    expect(resN.status).toBe(400);
+    expect(resMax.status).toBe(400);
+  });
+});
diff --git a/app/api/routes-f/fibonacci/route.ts b/app/api/routes-f/fibonacci/route.ts
new file mode 100644
index 00000000..b8946092
--- /dev/null
+++ b/app/api/routes-f/fibonacci/route.ts
@@ -0,0 +1,143 @@
+import { NextResponse } from "next/server";
+
+type Mode = "count" | "until";
+type Format = "array" | "nth";
+
+type Body = {
+  mode?: Mode;
+  n?: number;
+  max?: number | string;
+  format?: Format;
+};
+
+function fibBigInt(n: number): bigint {
+  if (n <= 0) {
+    throw new Error("n must be >= 1");
+  }
+  if (n <= 2) {
+    return BigInt(1);
+  }
+  let a = BigInt(1);
+  let b = BigInt(1);
+  for (let i = 3; i <= n; i += 1) {
+    const c = a + b;
+    a = b;
+    b = c;
+  }
+  return b;
+}
+
+function fibBinetSmall(n: number): number {
+  const sqrt5 = Math.sqrt(5);
+  const phi = (1 + sqrt5) / 2;
+  return Math.round((phi ** n - (-phi) ** -n) / sqrt5);
+}
+
+export function fibNth(n: number): bigint {
+  // Binet is fast but starts drifting for larger n due to floating-point rounding.
+  return n <= 70 ? BigInt(fibBinetSmall(n)) : fibBigInt(n);
+}
+
+export function fibCount(n: number): bigint[] {
+  const seq: bigint[] = [];
+  for (let i = 1; i <= n; i += 1) {
+    seq.push(fibNth(i));
+  }
+  return seq;
+}
+
+function parsePositiveBigInt(value: unknown): bigint | null {
+  if (typeof value === "number" && Number.isInteger(value) && value > 0) {
+    return BigInt(value);
+  }
+  if (typeof value === "string" && /^\d+$/.test(value) && value !== "0") {
+    return BigInt(value);
+  }
+  return null;
+}
+
+export function fibUntil(max: bigint): bigint[] {
+  const seq: bigint[] = [];
+  let a = BigInt(1);
+  let b = BigInt(1);
+  while (a <= max) {
+    seq.push(a);
+    const next = a + b;
+    a = b;
+    b = next;
+  }
+  return seq;
+}
+
+export async function POST(request: Request) {
+  let body: Body;
+  try {
+    body = await request.json();
+  } catch {
+    return NextResponse.json({ error: "Invalid JSON body." }, { status: 400 });
+  }
+
+  const mode = body.mode;
+  const format: Format = body.format ?? "array";
+  if (mode !== "count" && mode !== "until") {
+    return NextResponse.json(
+      { error: "mode must be count or until." },
+      { status: 400 }
+    );
+  }
+  if (format !== "array" && format !== "nth") {
+    return NextResponse.json(
+      { error: "format must be array or nth." },
+      { status: 400 }
+    );
+  }
+
+  if (mode === "count") {
+    const n = body.n;
+    if (!Number.isInteger(n) || (n as number) < 1 || (n as number) > 10000) {
+      return NextResponse.json(
+        { error: "n must be an integer in [1, 10000]." },
+        { status: 400 }
+      );
+    }
+    const seq = fibCount(n as number);
+    if (format === "nth") {
+      return NextResponse.json({
+        mode,
+        format,
+        n,
+        value: seq[seq.length - 1].toString(),
+      });
+    }
+    return NextResponse.json({
+      mode,
+      format,
+      n,
+      sequence: seq.map(v => v.toString()),
+    });
+  }
+
+  const max = parsePositiveBigInt(body.max);
+  if (max === null) {
+    return NextResponse.json(
+      { error: "max must be a positive integer." },
+      { status: 400 }
+    );
+  }
+
+  const seq = fibUntil(max);
+  if (format === "nth") {
+    return NextResponse.json({
+      mode,
+      format,
+      max: max.toString(),
+      value: (seq[seq.length - 1] ?? BigInt(0)).toString(),
+    });
+  }
+  return NextResponse.json({
+    mode,
+    format,
+    max: max.toString(),
+    sequence: seq.map(v => v.toString()),
+  });
+}
diff --git a/app/api/routes-f/fiscal-quarter/__tests__/route.test.ts b/app/api/routes-f/fiscal-quarter/__tests__/route.test.ts
new file mode 100644
index 00000000..b14ea28d
--- /dev/null
+++ b/app/api/routes-f/fiscal-quarter/__tests__/route.test.ts
@@ -0,0 +1,35 @@
+import { fiscalQuarter } from "../route";
+
+describe("fiscalQuarter", () => {
+  it("uses the calendar year by default (Jan start)", () => {
+    expect(fiscalQuarter("2026-02-15")).toEqual({
+      quarter: 1,
+      fiscal_year: 2026,
+      quarter_start: "2026-01-01",
+      quarter_end: "2026-03-31",
+    });
+    expect(fiscalQuarter("2026-08-10")).toEqual({
+      quarter: 3,
+      fiscal_year: 2026,
+      quarter_start: "2026-07-01",
+      quarter_end: "2026-09-30",
+    });
+  });
+
+  it("handles an offset fiscal year (April start)", () => {
+    // May is the first month of an April-start fiscal year -> Q1 of FY2026
+    expect(fiscalQuarter("2026-05-15", 4)).toEqual({
+      quarter: 1,
+      fiscal_year: 2026,
+      quarter_start: "2026-04-01",
+      quarter_end: "2026-06-30",
+    });
+    // February falls in Q4 of the April-start fiscal year that began in 2025
+    expect(fiscalQuarter("2026-02-15", 4)).toEqual({
+      quarter: 4,
+      fiscal_year: 2025,
+      quarter_start: "2026-01-01",
+      quarter_end: "2026-03-31",
+    });
+  });
+});
diff --git a/app/api/routes-f/fiscal-quarter/route.ts b/app/api/routes-f/fiscal-quarter/route.ts
new file mode 100644
index 00000000..177a03ea
--- /dev/null
+++ b/app/api/routes-f/fiscal-quarter/route.ts
@@ -0,0 +1,50 @@
+import { NextResponse } from "next/server";
+import { z } from "zod";
+import { validateQuery } from "@/app/api/routes-f/_lib/validate";
+
+export interface FiscalQuarterResult {
+  quarter: number;
+  fiscal_year: number;
+  quarter_start: string;
+  quarter_end: string;
+}
+
+/**
+ * Return the fiscal quarter for a date given a configurable fiscal-year start
+ * month (1 = January = calendar year). `fiscal_year` is the calendar year in
+ * which the containing fiscal year begins.
+ */
+export function fiscalQuarter(dateStr: string, fiscalStartMonth = 1): FiscalQuarterResult {
+  const d = new Date(`${dateStr}T00:00:00Z`);
+  const month = d.getUTCMonth() + 1;
+  const year = d.getUTCFullYear();
+
+  const offset = (month - fiscalStartMonth + 12) % 12; // months into the fiscal year
+  const quarter = Math.floor(offset / 3) + 1;
+  const fyStartYear = month >= fiscalStartMonth ? year : year - 1;
+
+  const quarterStartMonthAbs = fiscalStartMonth - 1 + (quarter - 1) * 3;
+  const start = new Date(Date.UTC(fyStartYear, quarterStartMonthAbs, 1));
+  const end = new Date(Date.UTC(fyStartYear, quarterStartMonthAbs + 3, 0)); // last day of quarter
+
+  const fmt = (x: Date) => x.toISOString().slice(0, 10);
+  return {
+    quarter,
+    fiscal_year: fyStartYear,
+    quarter_start: fmt(start),
+    quarter_end: fmt(end),
+  };
+}
+
+const schema = z.object({
+  date: z.string().regex(/^\d{4}-\d{2}-\d{2}$/, "date must be YYYY-MM-DD"),
+  fiscal_start_month: z.coerce.number().int().min(1).max(12).optional().default(1),
+});
+
+export async function GET(request: Request): Promise<NextResponse> {
+  const { searchParams } = new URL(request.url);
+  const result = validateQuery(searchParams, schema);
+  if (result instanceof NextResponse) return result;
+  const { date, fiscal_start_month } = result.data;
+  return NextResponse.json(fiscalQuarter(date, fiscal_start_month));
+}
diff --git a/app/api/routes-f/gcd-lcm/_lib/helpers.ts b/app/api/routes-f/gcd-lcm/_lib/helpers.ts
new file mode 100644
index 00000000..8b0c1080
--- /dev/null
+++ b/app/api/routes-f/gcd-lcm/_lib/helpers.ts
@@ -0,0 +1,68 @@
+import type { GcdLcmInput, GcdLcmResponse, Operation } from "./types";
+
+const MAX_NUMBERS = 100;
+
+function isRecord(value: unknown): value is Record<string, unknown> {
+  return typeof value === "object" && value !== null && !Array.isArray(value);
+}
+
+function gcdTwo(a: bigint, b: bigint): bigint {
+  while (b !== 0n) {
+    [a, b] = [b, a % b];
+  }
+  return a;
+}
+
+function lcmTwo(a: bigint, b: bigint): bigint {
+  return (a / gcdTwo(a, b)) * b;
+}
+
+function computeGcd(nums: bigint[]): bigint {
+  return nums.reduce((acc, n) => gcdTwo(acc, n));
+}
+
+function computeLcm(nums: bigint[]): bigint {
+  return nums.reduce((acc, n) => lcmTwo(acc, n));
+}
+
+function normalizeOperation(value: unknown): Operation {
+  if (value === undefined || value === "both") return "both";
+  if (value === "gcd" || value === "lcm") return value;
+  throw new Error("operation must be both, gcd, or lcm.");
+}
+
+export function processGcdLcm(input: unknown): GcdLcmResponse {
+  if (!isRecord(input)) {
+    throw new Error("Request body must be an object.");
+  }
+
+  const { numbers, operation: rawOp } = input as unknown as GcdLcmInput;
+  const operation = normalizeOperation(rawOp);
+
+  if (!Array.isArray(numbers) || numbers.length === 0) {
+    throw new Error("numbers must be a non-empty array.");
+  }
+
+  if (numbers.length > MAX_NUMBERS) {
+    throw new Error(`numbers array must not exceed ${MAX_NUMBERS} elements.`);
+  }
+
+  const bigNums: bigint[] = numbers.map((n, i) => {
+    if (typeof n !== "number" || !Number.isInteger(n) || n <= 0) {
+      throw new Error(`numbers[${i}] must be a positive integer.`);
+    }
+    return BigInt(n);
+  });
+
+  const result: GcdLcmResponse = { n_count: numbers.length };
+
+  if (operation === "gcd" || operation === "both") {
+    result.gcd = Number(computeGcd(bigNums));
+  }
+
+  if (operation === "lcm" || operation === "both") {
+    result.lcm = Number(computeLcm(bigNums));
+  }
+
+  return result;
+}
diff --git a/app/api/routes-f/gcd-lcm/_lib/types.ts b/app/api/routes-f/gcd-lcm/_lib/types.ts
new file mode 100644
index 00000000..f9854c5b
--- /dev/null
+++ b/app/api/routes-f/gcd-lcm/_lib/types.ts
@@ -0,0 +1,12 @@
+export type Operation = "both" | "gcd" | "lcm";
+
+export interface GcdLcmInput {
+  numbers: number[];
+  operation?: Operation;
+}
+
+export interface GcdLcmResponse {
+  gcd?: number;
+  lcm?: number;
+  n_count: number;
+}
diff --git a/app/api/routes-f/gcd-lcm/route.ts b/app/api/routes-f/gcd-lcm/route.ts
new file mode 100644
index 00000000..a7849f5a
--- /dev/null
+++ b/app/api/routes-f/gcd-lcm/route.ts
@@ -0,0 +1,19 @@
+import { type NextRequest, NextResponse } from "next/server";
+import { processGcdLcm } from "./_lib/helpers";
+
+export async function POST(req: NextRequest) {
+  let body: unknown;
+
+  try {
+    body = await req.json();
+  } catch {
+    return NextResponse.json({ error: "Invalid JSON body." }, { status: 400 });
+  }
+
+  try {
+    return NextResponse.json(processGcdLcm(body));
+  } catch (error) {
+    const message = error instanceof Error ? error.message : "Failed to compute GCD/LCM.";
+    return NextResponse.json({ error: message }, { status: 400 });
+  }
+}
diff --git a/app/api/routes-f/hamming/__tests__/route.test.ts b/app/api/routes-f/hamming/__tests__/route.test.ts
new file mode 100644
index 00000000..88fae43a
--- /dev/null
+++ b/app/api/routes-f/hamming/__tests__/route.test.ts
@@ -0,0 +1,18 @@
+import { hammingDistance } from "../route";
+
+describe("hammingDistance", () => {
+  it("computes distance for equal-length strings", () => {
+    expect(hammingDistance("karolin", "kathrin")).toBe(3);
+    expect(hammingDistance("karolin", "kerstin")).toBe(3);
+    expect(hammingDistance("abc", "abc")).toBe(0);
+  });
+
+  it("computes distance for binary inputs", () => {
+    expect(hammingDistance("1011101", "1001001")).toBe(2);
+    expect(hammingDistance("0000", "1111")).toBe(4);
+  });
+
+  it("throws on unequal lengths", () => {
+    expect(() => hammingDistance("abc", "ab")).toThrow(RangeError);
+  });
+});
diff --git a/app/api/routes-f/hamming/route.ts b/app/api/routes-f/hamming/route.ts
new file mode 100644
index 00000000..5992cb1d
--- /dev/null
+++ b/app/api/routes-f/hamming/route.ts
@@ -0,0 +1,46 @@
+import { NextResponse } from "next/server";
+import { z } from "zod";
+import { validateBody } from "@/app/api/routes-f/_lib/validate";
+
+/**
+ * Hamming distance: the number of positions at which two equal-length strings
+ * differ. Throws if the inputs are not the same length.
+ */
+export function hammingDistance(a: string, b: string): number {
+  if (a.length !== b.length) {
+    throw new RangeError("inputs must be of equal length");
+  }
+  let distance = 0;
+  for (let i = 0; i < a.length; i += 1) {
+    if (a[i] !== b[i]) distance += 1;
+  }
+  return distance;
+}
+
+const schema = z.object({
+  a: z.string(),
+  b: z.string(),
+  mode: z.enum(["string", "binary"]).optional().default("string"),
+});
+
+export async function POST(request: Request): Promise<NextResponse> {
+  const result = await validateBody(request, schema);
+  if (result instanceof NextResponse) return result;
+  const { a, b, mode } = result.data;
+
+  if (mode === "binary" && (!/^[01]+$/.test(a) || !/^[01]+$/.test(b))) {
+    return NextResponse.json(
+      { error: "binary mode requires inputs containing only 0 and 1" },
+      { status: 400 },
+    );
+  }
+
+  if (a.length !== b.length) {
+    return NextResponse.json(
+      { error: "inputs must be of equal length" },
+      { status: 400 },
+    );
+  }
+
+  return NextResponse.json({ distance: hammingDistance(a, b) });
+}
diff --git a/app/api/routes-f/happy-number/__tests__/route.test.ts b/app/api/routes-f/happy-number/__tests__/route.test.ts
new file mode 100644
index 00000000..2cab652f
--- /dev/null
+++ b/app/api/routes-f/happy-number/__tests__/route.test.ts
@@ -0,0 +1,69 @@
+jest.mock("next/server", () => ({
+  NextResponse: {
+    json: (body: unknown, init?: ResponseInit) =>
+      new Response(JSON.stringify(body), {
+        ...init,
+        headers: { "Content-Type": "application/json" },
+      }),
+  },
+}));
+
+import { analyzeHappyNumber } from "../happy";
+import { GET } from "../route";
+
+// #863 feat(routes-f): happy number checker
+
+function makeRequest(path: string) {
+  return new Request(`http://localhost${path}`) as unknown as import("next/server").NextRequest;
+}
+
+describe("analyzeHappyNumber", () => {
+  it("identifies 19 as happy with the known sequence", () => {
+    expect(analyzeHappyNumber(19)).toEqual({
+      n: 19,
+      is_happy: true,
+      sequence: [19, 82, 68, 100, 1],
+    });
+  });
+
+  it("identifies 7 as happy", () => {
+    expect(analyzeHappyNumber(7)).toEqual({
+      n: 7,
+      is_happy: true,
+      sequence: [7, 49, 97, 130, 10, 1],
+    });
+  });
+
+  it("identifies 4 as unhappy and terminates on cycle detection", () => {
+    const result = analyzeHappyNumber(4);
+
+    expect(result.is_happy).toBe(false);
+    expect(result.sequence).toEqual([4, 16, 37, 58, 89, 145, 42, 20, 4]);
+  });
+});
+
+describe("GET /api/routes-f/happy-number", () => {
+  it("returns happy number analysis for n=19", async () => {
+    const res = await GET(makeRequest("/api/routes-f/happy-number?n=19"));
+    const json = await res.json();
+
+    expect(res.status).toBe(200);
+    expect(json).toEqual({
+      n: 19,
+      is_happy: true,
+      sequence: [19, 82, 68, 100, 1],
+    });
+  });
+
+  it("rejects non-positive integers", async () => {
+    const missing = await GET(makeRequest("/api/routes-f/happy-number"));
+    const zero = await GET(makeRequest("/api/routes-f/happy-number?n=0"));
+    const negative = await GET(makeRequest("/api/routes-f/happy-number?n=-4"));
+    const invalid = await GET(makeRequest("/api/routes-f/happy-number?n=abc"));
+
+    expect(missing.status).toBe(400);
+    expect(zero.status).toBe(400);
+    expect(negative.status).toBe(400);
+    expect(invalid.status).toBe(400);
+  });
+});
diff --git a/app/api/routes-f/happy-number/happy.ts b/app/api/routes-f/happy-number/happy.ts
new file mode 100644
index 00000000..206a1a11
--- /dev/null
+++ b/app/api/routes-f/happy-number/happy.ts
@@ -0,0 +1,57 @@
+// #863 feat(routes-f): happy number checker
+
+export type HappyNumberResult = {
+  n: number;
+  is_happy: boolean;
+  sequence: number[];
+};
+
+function sumOfSquaredDigits(n: number): number {
+  let sum = 0;
+  let value = n;
+
+  while (value > 0) {
+    const digit = value % 10;
+    sum += digit * digit;
+    value = Math.floor(value / 10);
+  }
+
+  return sum;
+}
+
+/**
+ * Determine whether `n` is a happy number and return the iteration sequence
+ * until reaching 1 (happy) or detecting a cycle (unhappy).
+ */
+export function analyzeHappyNumber(n: number): HappyNumberResult {
+  const sequence: number[] = [n];
+  const seen = new Set<number>([n]);
+  let current = n;
+
+  while (current !== 1) {
+    current = sumOfSquaredDigits(current);
+
+    if (seen.has(current)) {
+      sequence.push(current);
+      return { n, is_happy: false, sequence };
+    }
+
+    seen.add(current);
+    sequence.push(current);
+  }
+
+  return { n, is_happy: true, sequence };
+}
+
+export function parsePositiveInteger(value: string | null): number | null {
+  if (value === null || !/^\d+$/.test(value)) {
+    return null;
+  }
+
+  const parsed = Number(value);
+  if (!Number.isSafeInteger(parsed) || parsed <= 0) {
+    return null;
+  }
+
+  return parsed;
+}
diff --git a/app/api/routes-f/happy-number/route.ts b/app/api/routes-f/happy-number/route.ts
new file mode 100644
index 00000000..273fb72e
--- /dev/null
+++ b/app/api/routes-f/happy-number/route.ts
@@ -0,0 +1,18 @@
+import { NextRequest, NextResponse } from "next/server";
+import { analyzeHappyNumber, parsePositiveInteger } from "./happy";
+
+// #863 feat(routes-f): happy number checker
+
+export async function GET(req: NextRequest) {
+  const nParam = new URL(req.url).searchParams.get("n");
+  const n = parsePositiveInteger(nParam);
+
+  if (n === null) {
+    return NextResponse.json(
+      { error: "n must be a positive integer." },
+      { status: 400 }
+    );
+  }
+
+  return NextResponse.json(analyzeHappyNumber(n));
+}
diff --git a/app/api/routes-f/hex-color/__tests__/route.test.ts b/app/api/routes-f/hex-color/__tests__/route.test.ts
new file mode 100644
index 00000000..7bdbb20e
--- /dev/null
+++ b/app/api/routes-f/hex-color/__tests__/route.test.ts
@@ -0,0 +1,45 @@
+import { normalizeHexColor } from "../route";
+
+describe("normalizeHexColor", () => {
+  it("normalizes 3-digit to 6-digit", () => {
+    expect(normalizeHexColor("#abc")).toEqual({
+      valid: true,
+      normalized: "#aabbcc",
+      has_alpha: false,
+    });
+  });
+
+  it("normalizes 4-digit to 8-digit with alpha", () => {
+    expect(normalizeHexColor("#abcd")).toEqual({
+      valid: true,
+      normalized: "#aabbccdd",
+      has_alpha: true,
+    });
+  });
+
+  it("accepts 6-digit (no #) and lowercases", () => {
+    expect(normalizeHexColor("FF8800")).toEqual({
+      valid: true,
+      normalized: "#ff8800",
+      has_alpha: false,
+    });
+  });
+
+  it("accepts 8-digit with alpha", () => {
+    expect(normalizeHexColor("#ff8800cc")).toEqual({
+      valid: true,
+      normalized: "#ff8800cc",
+      has_alpha: true,
+    });
+  });
+
+  it("rejects invalid input", () => {
+    for (const bad of ["#12", "#xyz", "12345", "#1234567", "nope"]) {
+      expect(normalizeHexColor(bad)).toEqual({
+        valid: false,
+        normalized: null,
+        has_alpha: false,
+      });
+    }
+  });
+});
diff --git a/app/api/routes-f/hex-color/route.ts b/app/api/routes-f/hex-color/route.ts
new file mode 100644
index 00000000..1b38ee99
--- /dev/null
+++ b/app/api/routes-f/hex-color/route.ts
@@ -0,0 +1,43 @@
+import { NextResponse } from "next/server";
+import { z } from "zod";
+import { validateBody } from "@/app/api/routes-f/_lib/validate";
+
+export interface HexColorResult {
+  valid: boolean;
+  normalized: string | null;
+  has_alpha: boolean;
+}
+
+/**
+ * Validate a hex color (#rgb, #rgba, #rrggbb, #rrggbbaa, with or without the
+ * leading #) and normalize it to 6-digit (#rrggbb) or 8-digit (#rrggbbaa) form.
+ */
+export function normalizeHexColor(input: string): HexColorResult {
+  const invalid: HexColorResult = { valid: false, normalized: null, has_alpha: false };
+  const hex = input.trim().replace(/^#/, "").toLowerCase();
+
+  if (!/^[0-9a-f]+$/.test(hex)) return invalid;
+
+  const expand = (s: string) => [...s].map((ch) => ch + ch).join("");
+
+  switch (hex.length) {
+    case 3:
+      return { valid: true, normalized: `#${expand(hex)}`, has_alpha: false };
+    case 4:
+      return { valid: true, normalized: `#${expand(hex)}`, has_alpha: true };
+    case 6:
+      return { valid: true, normalized: `#${hex}`, has_alpha: false };
+    case 8:
+      return { valid: true, normalized: `#${hex}`, has_alpha: true };
+    default:
+      return invalid;
+  }
+}
+
+const schema = z.object({ color: z.string() });
+
+export async function POST(request: Request): Promise<NextResponse> {
+  const result = await validateBody(request, schema);
+  if (result instanceof NextResponse) return result;
+  return NextResponse.json(normalizeHexColor(result.data.color));
+}
diff --git a/app/api/routes-f/hex-dump/__tests__/route.test.ts b/app/api/routes-f/hex-dump/__tests__/route.test.ts
new file mode 100644
index 00000000..59f111db
--- /dev/null
+++ b/app/api/routes-f/hex-dump/__tests__/route.test.ts
@@ -0,0 +1,28 @@
+import { hexDump } from "../route";
+
+describe("hexDump", () => {
+  it("formats offset, hex bytes, and an ASCII gutter", () => {
+    const dump = hexDump("Hello");
+    expect(dump.startsWith("00000000  48 65 6c 6c 6f")).toBe(true);
+    expect(dump).toContain("|Hello|");
+  });
+
+  it("expands UTF-8 multibyte characters into their bytes", () => {
+    const dump = hexDump("é"); // U+00E9 -> 0xC3 0xA9
+    expect(dump).toContain("c3 a9");
+    expect(dump).toContain("|..|"); // non-printable bytes render as dots
+  });
+
+  it("wraps lines with incrementing offsets", () => {
+    const lines = hexDump("ABCDE", 4).split("\n");
+    expect(lines).toHaveLength(2);
+    expect(lines[0].startsWith("00000000  41 42 43 44")).toBe(true);
+    expect(lines[0]).toContain("|ABCD|");
+    expect(lines[1].startsWith("00000004  45")).toBe(true);
+    expect(lines[1]).toContain("|E|");
+  });
+
+  it("returns an empty string for empty input", () => {
+    expect(hexDump("")).toBe("");
+  });
+});
diff --git a/app/api/routes-f/hex-dump/route.ts b/app/api/routes-f/hex-dump/route.ts
new file mode 100644
index 00000000..d4523ac4
--- /dev/null
+++ b/app/api/routes-f/hex-dump/route.ts
@@ -0,0 +1,45 @@
+import { NextResponse } from "next/server";
+import { z } from "zod";
+import { validateBody } from "@/app/api/routes-f/_lib/validate";
+
+const MAX_INPUT_BYTES = 1_000_000;
+const DEFAULT_BYTES_PER_LINE = 16;
+
+/**
+ * Produce a classic hex dump (8-digit hex offset, space-separated hex bytes, and
+ * an ASCII gutter) of UTF-8 encoded `input`. Non-printable bytes render as `.`.
+ */
+export function hexDump(input: string, bytesPerLine = DEFAULT_BYTES_PER_LINE): string {
+  const bytes = new TextEncoder().encode(input);
+  const lines: string[] = [];
+
+  for (let offset = 0; offset < bytes.length; offset += bytesPerLine) {
+    const slice = bytes.subarray(offset, offset + bytesPerLine);
+
+    const hex = Array.from(slice, (b) => b.toString(16).padStart(2, "0"))
+      .join(" ")
+      .padEnd(bytesPerLine * 3 - 1, " ");
+
+    const ascii = Array.from(slice, (b) =>
+      b >= 0x20 && b <= 0x7e ? String.fromCharCode(b) : ".",
+    ).join("");
+
+    lines.push(`${offset.toString(16).padStart(8, "0")}  ${hex}  |${ascii}|`);
+  }
+
+  return lines.join("\n");
+}
+
+const schema = z.object({
+  input: z.string().max(MAX_INPUT_BYTES, "input exceeds 1MB limit"),
+  bytes_per_line: z.number().int().min(1).max(64).optional(),
+});
+
+export async function POST(request: Request): Promise<NextResponse> {
+  const result = await validateBody(request, schema);
+  if (result instanceof NextResponse) return result;
+  const { input, bytes_per_line } = result.data;
+  return NextResponse.json({
+    dump: hexDump(input, bytes_per_line ?? DEFAULT_BYTES_PER_LINE),
+  });
+}
diff --git a/app/api/routes-f/history/[streamId]/track/__tests__/route.test.ts b/app/api/routes-f/history/[streamId]/track/__tests__/route.test.ts
new file mode 100644
index 00000000..d01f1523
--- /dev/null
+++ b/app/api/routes-f/history/[streamId]/track/__tests__/route.test.ts
@@ -0,0 +1,135 @@
+import { sql } from "@vercel/postgres";
+import { POST } from "../route";
+import { verifySession } from "@/lib/auth/verify-session";
+
+// Polyfill NextResponse.json for jsdom test environment
+jest.mock("next/server", () => ({
+  NextResponse: {
+    json: (body: unknown, init?: ResponseInit) =>
+      new Response(JSON.stringify(body), {
+        ...init,
+        headers: { "Content-Type": "application/json" },
+      }),
+  },
+}));
+
+jest.mock("@vercel/postgres", () => ({
+  sql: jest.fn(),
+}));
+
+jest.mock("@/lib/auth/verify-session", () => ({
+  verifySession: jest.fn(),
+}));
+
+const sqlMock = sql as unknown as jest.Mock;
+const verifySessionMock = verifySession as jest.Mock;
+
+const makeRequest = (body: object) =>
+  new Request("http://localhost/api/routes-f/history/live/track", {
+    method: "POST",
+    headers: { "Content-Type": "application/json" },
+    body: JSON.stringify(body),
+  }) as any;
+
+describe("History Track API route", () => {
+  beforeEach(() => {
+    jest.clearAllMocks();
+  });
+
+  it("returns 401 when unauthorized", async () => {
+    verifySessionMock.mockResolvedValueOnce({
+      ok: false,
+      response: new Response(JSON.stringify({ error: "Unauthorized" }), { status: 401 }),
+    });
+
+    const res = await POST(makeRequest({}), { params: Promise.resolve({ streamId: "live" }) });
+    expect(res.status).toBe(401);
+  });
+
+  it("returns 400 for invalid body", async () => {
+    verifySessionMock.mockResolvedValueOnce({
+      ok: true,
+      userId: "user-123",
+    });
+
+    const res = await POST(makeRequest({ stream_type: "live" }), { params: Promise.resolve({ streamId: "live" }) });
+    expect(res.status).toBe(400);
+  });
+
+  it("successfully tracks a live stream session (new)", async () => {
+    verifySessionMock.mockResolvedValueOnce({
+      ok: true,
+      userId: "user-123",
+    });
+
+    // 1. Resolve streamer
+    sqlMock.mockResolvedValueOnce({
+      rows: [{ id: "streamer-456", current_title: "Playing Valorant" }],
+    });
+    // 2. Check existing
+    sqlMock.mockResolvedValueOnce({ rows: [] });
+    // 3. Insert
+    sqlMock.mockResolvedValueOnce({ rowCount: 1 });
+
+    const res = await POST(
+      makeRequest({
+        stream_type: "live",
+        streamer_username: "alice",
+        seconds_watched: 30,
+      }),
+      { params: Promise.resolve({ streamId: "live" }) }
+    );
+
+    expect(res.status).toBe(200);
+    const body = await res.json();
+    expect(body.ok).toBe(true);
+    
+    // Check if INSERT was called
+    expect(sqlMock).toHaveBeenCalledWith(
+      expect.arrayContaining([expect.stringContaining("INSERT INTO watch_history")]),
+      "user-123",
+      "streamer-456",
+      "live",
+      null,
+      "Playing Valorant",
+      30,
+      expect.anything(),
+      false
+    );
+  });
+
+  it("successfully tracks a live stream session (update)", async () => {
+    verifySessionMock.mockResolvedValueOnce({
+      ok: true,
+      userId: "user-123",
+    });
+
+    // 1. Resolve streamer
+    sqlMock.mockResolvedValueOnce({
+      rows: [{ id: "streamer-456", current_title: "Playing Valorant" }],
+    });
+    // 2. Check existing
+    sqlMock.mockResolvedValueOnce({ rows: [{ id: "history-789", watch_seconds: 60 }] });
+    // 3. Update
+    sqlMock.mockResolvedValueOnce({ rowCount: 1 });
+
+    const res = await POST(
+      makeRequest({
+        stream_type: "live",
+        streamer_username: "alice",
+        seconds_watched: 30,
+      }),
+      { params: Promise.resolve({ streamId: "live" }) }
+    );
+
+    expect(res.status).toBe(200);
+    expect(sqlMock).toHaveBeenCalledWith(
+      expect.arrayContaining([expect.stringContaining("UPDATE watch_history")]),
+      90, // 60 + 30
+      expect.anything(),
+      "Playing Valorant",
+      false,
+      "history-789"
+    );
+  });
+});
diff --git a/app/api/routes-f/history/[streamId]/track/route.ts b/app/api/routes-f/history/[streamId]/track/route.ts
new file mode 100644
index 00000000..73ec4b1b
--- /dev/null
+++ b/app/api/routes-f/history/[streamId]/track/route.ts
@@ -0,0 +1,129 @@
+import { NextRequest, NextResponse } from "next/server";
+import { sql } from "@vercel/postgres";
+import { verifySession } from "@/lib/auth/verify-session";
+
+/**
+ * POST /api/routes-f/history/[streamId]/track
+ * Records or updates a watch session.
+ * Body: { stream_type, streamer_username, seconds_watched }
+ */
+export async function POST(
+  req: NextRequest,
+  { params }: { params: Promise<{ streamId: string }> }
+) {
+  const session = await verifySession(req);
+  if (!session.ok) return session.response;
+
+  const { userId } = session;
+  const { streamId } = await params;
+
+  let body;
+  try {
+    body = await req.json();
+  } catch {
+    return NextResponse.json({ error: "Invalid request body" }, { status: 400 });
+  }
+
+  const { stream_type, streamer_username, seconds_watched } = body;
+
+  if (
+    !stream_type ||
+    !streamer_username ||
+    typeof seconds_watched !== "number"
+  ) {
+    return NextResponse.json(
+      { error: "Missing or invalid required fields" },
+      { status: 400 }
+    );
+  }
+
+  try {
+    // 1. Resolve streamer ID and current title
+    const streamerResult = await sql`
+      SELECT id, creator->>'streamTitle' as current_title
+      FROM users
+      WHERE LOWER(username) = LOWER(${streamer_username})
+      LIMIT 1
+    `;
+
+    if (streamerResult.rows.length === 0) {
+      return NextResponse.json({ error: "Streamer not found" }, { status: 404 });
+    }
+
+    const streamer = streamerResult.rows[0];
+    const streamerId = streamer.id;
+
+    // 2. Resolve final stream_id (null for live) and title
+    const isLive = streamId === "live" || stream_type === "live";
+    const finalStreamId = isLive ? null : streamId;
+
+    let streamTitle = "Untitled Stream";
+    let duration = 0;
+
+    if (isLive) {
+      streamTitle = streamer.current_title || "Live Stream";
+    } else {
+      // Look up recording title if available
+      const recordingResult = await sql`
+        SELECT title, duration 
+        FROM stream_recordings 
+        WHERE id::text = ${finalStreamId} 
+           OR mux_asset_id = ${finalStreamId}
+           OR playback_id = ${finalStreamId}
+        LIMIT 1
+      `;
+      if (recordingResult.rows.length > 0) {
+        streamTitle = recordingResult.rows[0].title || "Untitled Recording";
+        duration = recordingResult.rows[0].duration || 0;
+      }
+    }
+
+    // 3. Upsert watch history entry
+    // Since NULLs in UNIQUE constraints can be tricky, we use a manual check-then-upsert logic
+    // to ensure we always update the existing session if it matches.
+    const existing = await sql`
+      SELECT id, watch_seconds FROM watch_history
+      WHERE viewer_id = ${userId}
+        AND streamer_id = ${streamerId}
+        AND stream_type = ${stream_type}
+        AND (
+          (stream_id IS NULL AND ${finalStreamId} IS NULL) OR
+          (stream_id = ${finalStreamId})
+        )
+      LIMIT 1
+    `;
+
+    if (existing.rows.length > 0) {
+      const newWatchSeconds = existing.rows[0].watch_seconds + seconds_watched;
+      // Simple completion logic: if VOD and watched > 90% of duration
+      const isCompleted = !isLive && duration > 0 && newWatchSeconds >= duration * 0.9;
+
+      await sql`
+        UPDATE watch_history
+        SET watch_seconds = ${newWatchSeconds},
+            last_seen_at = now(),
+            stream_title = ${streamTitle},
+            completed = ${isCompleted}
+        WHERE id = ${existing.rows[0].id}
+      `;
+    } else {
+      const isCompleted = !isLive && duration > 0 && seconds_watched >= duration * 0.9;
+      
+      await sql`
+        INSERT INTO watch_history (
+          viewer_id, streamer_id, stream_type, stream_id, stream_title, watch_seconds, last_seen_at, completed
+        ) VALUES (
+          ${userId}, ${streamerId}, ${stream_type}, ${finalStreamId}, ${streamTitle}, ${seconds_watched}, now(), ${isCompleted}
+        )
+      `;
+    }
+
+    return NextResponse.json({ ok: true });
+  } catch (error) {
+    console.error("[history-track] POST error:", error);
+    return NextResponse.json(
+      { error: "Internal server error" },
+      { status: 500 }
+    );
+  }
+}
diff --git a/app/api/routes-f/history/__tests__/route.test.ts b/app/api/routes-f/history/__tests__/route.test.ts
new file mode 100644
index 00000000..584f0a75
--- /dev/null
+++ b/app/api/routes-f/history/__tests__/route.test.ts
@@ -0,0 +1,97 @@
+import { sql } from "@vercel/postgres";
+import { GET, DELETE } from "../route";
+import { verifySession } from "@/lib/auth/verify-session";
+
+// Polyfill NextResponse.json for jsdom test environment
+jest.mock("next/server", () => ({
+  NextResponse: {
+    json: (body: unknown, init?: ResponseInit) =>
+      new Response(JSON.stringify(body), {
+        ...init,
+        headers: { "Content-Type": "application/json" },
+      }),
+  },
+}));
+
+jest.mock("@vercel/postgres", () => ({
+  sql: jest.fn(),
+}));
+
+jest.mock("@/lib/auth/verify-session", () => ({
+  verifySession: jest.fn(),
+}));
+
+const sqlMock = sql as unknown as jest.Mock;
+const verifySessionMock = verifySession as jest.Mock;
+
+const makeRequest = (method: string, body?: object, search?: string) =>
+  new Request(`http://localhost/api/routes-f/history${search ?? ""}`, {
+    method,
+    headers: { "Content-Type": "application/json" },
+    body: body ? JSON.stringify(body) : undefined,
+  }) as any;
+
+describe("History API routes", () => {
+  beforeEach(() => {
+    jest.clearAllMocks();
+  });
+
+  describe("GET /api/routes-f/history", () => {
+    it("returns 401 when unauthorized", async () => {
+      verifySessionMock.mockResolvedValueOnce({
+        ok: false,
+        response: new Response(JSON.stringify({ error: "Unauthorized" }), { status: 401 }),
+      });
+
+      const res = await GET(makeRequest("GET"));
+      expect(res.status).toBe(401);
+    });
+
+    it("returns history for authorized user", async () => {
+      verifySessionMock.mockResolvedValueOnce({
+        ok: true,
+        userId: "user-123",
+      });
+
+      sqlMock.mockResolvedValueOnce({
+        rows: [
+          {
+            stream_type: "live",
+            stream_title: "Live Test",
+            watched_at: "2025-01-01T00:00:00Z",
+            watch_seconds: 300,
+            completed: false,
+            streamer_username: "alice",
+            streamer_avatar: "avatar.png",
+          },
+        ],
+      });
+
+      const res = await GET(makeRequest("GET"));
+      expect(res.status).toBe(200);
+      const body = await res.json();
+      expect(body.history).toHaveLength(1);
+      expect(body.history[0].streamer.username).toBe("alice");
+    });
+  });
+
+  describe("DELETE /api/routes-f/history", () => {
+    it("clears history for authorized user", async () => {
+      verifySessionMock.mockResolvedValueOnce({
+        ok: true,
+        userId: "user-123",
+      });
+
+      sqlMock.mockResolvedValueOnce({ rowCount: 1 });
+
+      const res = await DELETE(makeRequest("DELETE"));
+      expect(res.status).toBe(200);
+      const body = await res.json();
+      expect(body.ok).toBe(true);
+      expect(sqlMock).toHaveBeenCalledWith(
+        expect.arrayContaining([expect.stringContaining("DELETE FROM watch_history")]),
+        "user-123"
+      );
+    });
+  });
+});
diff --git a/app/api/routes-f/history/route.ts b/app/api/routes-f/history/route.ts
new file mode 100644
index 00000000..6fccac22
--- /dev/null
+++ b/app/api/routes-f/history/route.ts
@@ -0,0 +1,106 @@
+import { NextRequest, NextResponse } from "next/server";
+import { sql } from "@vercel/postgres";
+import { verifySession } from "@/lib/auth/verify-session";
+
+/**
+ * GET /api/routes-f/history?cursor=...&limit=20
+ * Returns the viewer's watch history, cursor-paginated.
+ */
+export async function GET(req: NextRequest) {
+  const session = await verifySession(req);
+  if (!session.ok) return session.response;
+
+  const { userId } = session;
+  const { searchParams } = new URL(req.url);
+  const cursor = searchParams.get("cursor"); // ISO date string of last_seen_at
+  const limit = Math.min(50, Math.max(1, parseInt(searchParams.get("limit") ?? "20", 10)));
+
+  try {
+    // Cursor-paginated query: most recent first
+    const result = cursor
+      ? await sql`
+          SELECT 
+            wh.stream_type,
+            wh.stream_title,
+            wh.last_seen_at as watched_at,
+            wh.watch_seconds,
+            wh.completed,
+            u.username as streamer_username,
+            u.avatar as streamer_avatar
+          FROM watch_history wh
+          JOIN users u ON u.id = wh.streamer_id
+          WHERE wh.viewer_id = ${userId}
+            AND wh.last_seen_at < ${cursor}
+          ORDER BY wh.last_seen_at DESC
+          LIMIT ${limit}
+        `
+      : await sql`
+          SELECT 
+            wh.stream_type,
+            wh.stream_title,
+            wh.last_seen_at as watched_at,
+            wh.watch_seconds,
+            wh.completed,
+            u.username as streamer_username,
+            u.avatar as streamer_avatar
+          FROM watch_history wh
+          JOIN users u ON u.id = wh.streamer_id
+          WHERE wh.viewer_id = ${userId}
+          ORDER BY wh.last_seen_at DESC
+          LIMIT ${limit}
+        `;
+
+    const history = result.rows.map((row) => ({
+      streamer: {
+        username: row.streamer_username,
+        avatar: row.streamer_avatar,
+      },
+      stream_type: row.stream_type,
+      stream_title: row.stream_title || (row.stream_type === "live" ? "Live Stream" : "Untitled Recording"),
+      watched_at: row.watched_at,
+      watch_seconds: row.watch_seconds,
+      completed: row.completed,
+    }));
+
+    const nextCursor =
+      result.rows.length === limit
+        ? result.rows[result.rows.length - 1].watched_at
+        : null;
+
+    return NextResponse.json({
+      history,
+      next_cursor: nextCursor,
+    });
+  } catch (error) {
+    console.error("[history] GET error:", error);
+    return NextResponse.json(
+      { error: "Internal server error" },
+      { status: 500 }
+    );
+  }
+}
+
+/**
+ * DELETE /api/routes-f/history
+ * Clears the watch history for the current viewer.
+ */
+export async function DELETE(req: NextRequest) {
+  const session = await verifySession(req);
+  if (!session.ok) return session.response;
+
+  const { userId } = session;
+
+  try {
+    await sql`
+      DELETE FROM watch_history
+      WHERE viewer_id = ${userId}
+    `;
+    return NextResponse.json({ ok: true });
+  } catch (error) {
+    console.error("[history] DELETE error:", error);
+    return NextResponse.json(
+      { error: "Internal server error" },
+      { status: 500 }
+    );
+  }
+}
diff --git a/app/api/routes-f/html-escape/data.ts b/app/api/routes-f/html-escape/data.ts
new file mode 100644
index 00000000..4751757f
--- /dev/null
+++ b/app/api/routes-f/html-escape/data.ts
@@ -0,0 +1,27 @@
+const ESCAPE_MAP: Record<string, string> = {
+  "&": "&amp;",
+  "<": "&lt;",
+  ">": "&gt;",
+  '"': "&quot;",
+  "'": "&#39;",
+};
+
+const UNESCAPE_MAP: Record<string, string> = {
+  "&amp;": "&",
+  "&lt;": "<",
+  "&gt;": ">",
+  "&quot;": '"',
+  "&#39;": "'",
+  "&apos;": "'",
+};
+
+export function escapeHtml(str: string): string {
+  return str.replace(/[&<>"']/g, (ch) => ESCAPE_MAP[ch] ?? ch);
+}
+
+export function unescapeHtml(str: string): string {
+  return str
+    .replace(/&[a-z]+;/gi, (entity) => UNESCAPE_MAP[entity.toLowerCase()] ?? entity)
+    .replace(/&#(\d+);/g, (_, code) => String.fromCharCode(Number(code)))
+    .replace(/&#x([0-9a-f]+);/gi, (_, hex) => String.fromCharCode(parseInt(hex, 16)));
+}
diff --git a/app/api/routes-f/html-escape/route.ts b/app/api/routes-f/html-escape/route.ts
new file mode 100644
index 00000000..538f44a3
--- /dev/null
+++ b/app/api/routes-f/html-escape/route.ts
@@ -0,0 +1,34 @@
+import { type NextRequest, NextResponse } from "next/server";
+import { escapeHtml, unescapeHtml } from "./data";
+
+const MAX_INPUT_BYTES = 1024 * 1024; // 1 MB
+
+export async function POST(req: NextRequest) {
+  let body: unknown;
+  try {
+    body = await req.json();
+  } catch {
+    return NextResponse.json({ error: "Invalid JSON" }, { status: 400 });
+  }
+
+  if (typeof body !== "object" || body === null) {
+    return NextResponse.json({ error: "Invalid request body" }, { status: 400 });
+  }
+
+  const { input, mode } = body as { input?: unknown; mode?: unknown };
+
+  if (typeof input !== "string" || typeof mode !== "string") {
+    return NextResponse.json({ error: "Invalid request body: 'input' and 'mode' are required" }, { status: 400 });
+  }
+
+  if (mode !== "escape" && mode !== "unescape") {
+    return NextResponse.json({ error: "Invalid mode. Must be 'escape' or 'unescape'" }, { status: 400 });
+  }
+
+  if (Buffer.byteLength(input, "utf8") > MAX_INPUT_BYTES) {
+    return NextResponse.json({ error: "Input too large (max 1 MB)" }, { status: 413 });
+  }
+
+  const output = mode === "escape" ? escapeHtml(input) : unescapeHtml(input);
+  return NextResponse.json({ output });
+}
diff --git a/app/api/routes-f/http-status/data.ts b/app/api/routes-f/http-status/data.ts
new file mode 100644
index 00000000..f43d3d3f
--- /dev/null
+++ b/app/api/routes-f/http-status/data.ts
@@ -0,0 +1,52 @@
+export interface HttpStatus {
+  code: number;
+  name: string;
+  description: string;
+  category: string;
+  rfc?: string;
+}
+
+export const HTTP_STATUSES: HttpStatus[] = [
+  { code: 100, name: "Continue", description: "The server has received the request headers and the client should proceed.", category: "1xx", rfc: "RFC 7231" },
+  { code: 101, name: "Switching Protocols", description: "The requester has asked the server to switch protocols.", category: "1xx", rfc: "RFC 7231" },
+  { code: 200, name: "OK", description: "The request succeeded.", category: "2xx", rfc: "RFC 7231" },
+  { code: 201, name: "Created", description: "The request succeeded and a new resource was created.", category: "2xx", rfc: "RFC 7231" },
+  { code: 202, name: "Accepted", description: "The request has been received but not yet acted upon.", category: "2xx", rfc: "RFC 7231" },
+  { code: 204, name: "No Content", description: "There is no content to send for this request.", category: "2xx", rfc: "RFC 7231" },
+  { code: 301, name: "Moved Permanently", description: "The URL of the requested resource has been changed permanently.", category: "3xx", rfc: "RFC 7231" },
+  { code: 302, name: "Found", description: "The URI of requested resource has been changed temporarily.", category: "3xx", rfc: "RFC 7231" },
+  { code: 304, name: "Not Modified", description: "The response has not been modified.", category: "3xx", rfc: "RFC 7232" },
+  { code: 400, name: "Bad Request", description: "The server cannot or will not process the request due to client error.", category: "4xx", rfc: "RFC 7231" },
+  { code: 401, name: "Unauthorized", description: "Authentication is required and has failed or not been provided.", category: "4xx", rfc: "RFC 7235" },
+  { code: 403, name: "Forbidden", description: "The client does not have access rights to the content.", category: "4xx", rfc: "RFC 7231" },
+  { code: 404, name: "Not Found", description: "The server can not find the requested resource.", category: "4xx", rfc: "RFC 7231" },
+  { code: 405, name: "Method Not Allowed", description: "The request method is known by the server but is not supported.", category: "4xx", rfc: "RFC 7231" },
+  { code: 409, name: "Conflict", description: "The request conflicts with the current state of the server.", category: "4xx", rfc: "RFC 7231" },
+  { code: 410, name: "Gone", description: "The content has been permanently deleted from server.", category: "4xx", rfc: "RFC 7231" },
+  { code: 413, name: "Payload Too Large", description: "The request entity is larger than limits defined by server.", category: "4xx", rfc: "RFC 7231" },
+  { code: 422, name: "Unprocessable Entity", description: "The request was well-formed but could not be followed due to semantic errors.", category: "4xx", rfc: "RFC 4918" },
+  { code: 429, name: "Too Many Requests", description: "The user has sent too many requests in a given amount of time.", category: "4xx", rfc: "RFC 6585" },
+  { code: 500, name: "Internal Server Error", description: "The server has encountered a situation it does not know how to handle.", category: "5xx", rfc: "RFC 7231" },
+  { code: 501, name: "Not Implemented", description: "The request method is not supported by the server.", category: "5xx", rfc: "RFC 7231" },
+  { code: 502, name: "Bad Gateway", description: "The server got an invalid response while working as a gateway.", category: "5xx", rfc: "RFC 7231" },
+  { code: 503, name: "Service Unavailable", description: "The server is not ready to handle the request.", category: "5xx", rfc: "RFC 7231" },
+  { code: 504, name: "Gateway Timeout", description: "The server is acting as a gateway and cannot get a response in time.", category: "5xx", rfc: "RFC 7231" },
+];
+
+export function getStatusByCode(code: number): HttpStatus | undefined {
+  return HTTP_STATUSES.find((s) => s.code === code);
+}
+
+export function getStatusesByCategory(): Record<string, HttpStatus[]> {
+  return HTTP_STATUSES.reduce<Record<string, HttpStatus[]>>((acc, s) => {
+    (acc[s.category] ??= []).push(s);
+    return acc;
+  }, {});
+}
+
+export function findNearestStatus(code: number): HttpStatus | undefined {
+  return HTTP_STATUSES.reduce<HttpStatus | undefined>((nearest, s) => {
+    if (!nearest) return s;
+    return Math.abs(s.code - code) < Math.abs(nearest.code - code) ? s : nearest;
+  }, undefined);
+}
diff --git a/app/api/routes-f/http-status/route.ts b/app/api/routes-f/http-status/route.ts
new file mode 100644
index 00000000..88d754ad
--- /dev/null
+++ b/app/api/routes-f/http-status/route.ts
@@ -0,0 +1,29 @@
+import { type NextRequest, NextResponse } from "next/server";
+import { getStatusByCode, getStatusesByCategory, findNearestStatus } from "./data";
+
+export async function GET(req: NextRequest) {
+  const codeParam = new URL(req.url).searchParams.get("code");
+
+  if (!codeParam) {
+    return NextResponse.json(getStatusesByCategory());
+  }
+
+  const code = Number(codeParam);
+  if (!Number.isInteger(code) || isNaN(code)) {
+    return NextResponse.json({ error: "Invalid status code format" }, { status: 400 });
+  }
+
+  const status = getStatusByCode(code);
+  if (!status) {
+    const nearest = findNearestStatus(code);
+    return NextResponse.json(
+      {
+        error: `HTTP status code ${code} not found`,
+        suggestion: nearest ? `Did you mean ${nearest.code} (${nearest.name})?` : undefined,
+      },
+      { status: 404 }
+    );
+  }
+
+  return NextResponse.json(status);
+}
diff --git a/app/api/routes-f/initials/__tests__/route.test.ts b/app/api/routes-f/initials/__tests__/route.test.ts
new file mode 100644
index 00000000..b0a4d2ab
--- /dev/null
+++ b/app/api/routes-f/initials/__tests__/route.test.ts
@@ -0,0 +1,20 @@
+import { extractInitials } from "../route";
+
+describe("extractInitials", () => {
+  it("handles a single name", () => {
+    expect(extractInitials("John")).toBe("J");
+  });
+  it("handles two words", () => {
+    expect(extractInitials("John Smith")).toBe("JS");
+  });
+  it("caps at max for three words", () => {
+    expect(extractInitials("John Michael Smith")).toBe("JM");
+    expect(extractInitials("John Michael Smith", 3)).toBe("JMS");
+  });
+  it("treats hyphenated names as separate parts", () => {
+    expect(extractInitials("Mary-Jane Watson")).toBe("MJ");
+  });
+  it("uppercases and ignores extra whitespace", () => {
+    expect(extractInitials("  ada   lovelace  ")).toBe("AL");
+  });
+});
diff --git a/app/api/routes-f/initials/route.ts b/app/api/routes-f/initials/route.ts
new file mode 100644
index 00000000..a3bdd1af
--- /dev/null
+++ b/app/api/routes-f/initials/route.ts
@@ -0,0 +1,31 @@
+import { NextResponse } from "next/server";
+import { z } from "zod";
+import { validateBody } from "@/app/api/routes-f/_lib/validate";
+
+/**
+ * Extract uppercased initials from a full name. Whitespace and hyphens both
+ * separate name parts (so "Mary-Jane" contributes M and J), capped at `max`.
+ */
+export function extractInitials(name: string, max = 2): string {
+  const parts = name
+    .trim()
+    .split(/\s+/)
+    .flatMap((w) => w.split("-"))
+    .filter(Boolean);
+  return parts
+    .map((p) => p[0].toUpperCase())
+    .slice(0, max)
+    .join("");
+}
+
+const schema = z.object({
+  name: z.string(),
+  max: z.number().int().positive().optional().default(2),
+});
+
+export async function POST(request: Request): Promise<NextResponse> {
+  const result = await validateBody(request, schema);
+  if (result instanceof NextResponse) return result;
+  const { name, max } = result.data;
+  return NextResponse.json({ initials: extractInitials(name, max) });
+}
diff --git a/app/api/routes-f/iqr-outlier/route.test.ts b/app/api/routes-f/iqr-outlier/route.test.ts
new file mode 100644
index 00000000..144bbb3f
--- /dev/null
+++ b/app/api/routes-f/iqr-outlier/route.test.ts
@@ -0,0 +1,124 @@
+import { POST } from "./route";
+
+describe("IQR Outlier Detection API", () => {
+  it("should return 400 for invalid JSON", async () => {
+    const req = new Request("http://localhost/api/routes-f/iqr-outlier", {
+      method: "POST",
+      body: "bad json",
+    });
+    const res = await POST(req as any);
+    expect(res.status).toBe(400);
+  });
+
+  it("should return 400 when data is missing", async () => {
+    const req = new Request("http://localhost/api/routes-f/iqr-outlier", {
+      method: "POST",
+      body: JSON.stringify({}),
+    });
+    const res = await POST(req as any);
+    expect(res.status).toBe(400);
+  });
+
+  it("should return 400 when data is empty", async () => {
+    const req = new Request("http://localhost/api/routes-f/iqr-outlier", {
+      method: "POST",
+      body: JSON.stringify({ data: [] }),
+    });
+    const res = await POST(req as any);
+    expect(res.status).toBe(400);
+  });
+
+  it("should return 400 when data contains non-numbers", async () => {
+    const req = new Request("http://localhost/api/routes-f/iqr-outlier", {
+      method: "POST",
+      body: JSON.stringify({ data: [1, "two", 3] }),
+    });
+    const res = await POST(req as any);
+    expect(res.status).toBe(400);
+  });
+
+  it("should return 400 for a negative multiplier", async () => {
+    const req = new Request("http://localhost/api/routes-f/iqr-outlier", {
+      method: "POST",
+      body: JSON.stringify({ data: [1, 2, 3, 4, 5], multiplier: -1 }),
+    });
+    const res = await POST(req as any);
+    expect(res.status).toBe(400);
+  });
+
+  it("detects dataset with no outliers", async () => {
+    const req = new Request("http://localhost/api/routes-f/iqr-outlier", {
+      method: "POST",
+      body: JSON.stringify({ data: [1, 2, 3, 4, 5, 6, 7, 8, 9, 10] }),
+    });
+    const res = await POST(req as any);
+    expect(res.status).toBe(200);
+    const data = await res.json();
+    expect(data.outliers).toEqual([]);
+    expect(typeof data.q1).toBe("number");
+    expect(typeof data.q3).toBe("number");
+    expect(typeof data.iqr).toBe("number");
+    expect(typeof data.lower_bound).toBe("number");
+    expect(typeof data.upper_bound).toBe("number");
+  });
+
+  it("detects obvious outliers", async () => {
+    // Dataset: 1-10 with 100 as an outlier
+    const req = new Request("http://localhost/api/routes-f/iqr-outlier", {
+      method: "POST",
+      body: JSON.stringify({ data: [1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 100] }),
+    });
+    const res = await POST(req as any);
+    const data = await res.json();
+    expect(data.outliers).toContain(100);
+  });
+
+  it("uses default multiplier of 1.5", async () => {
+    const dataset = [1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 100];
+    const req1 = new Request("http://localhost/api/routes-f/iqr-outlier", {
+      method: "POST",
+      body: JSON.stringify({ data: dataset }),
+    });
+    const req2 = new Request("http://localhost/api/routes-f/iqr-outlier", {
+      method: "POST",
+      body: JSON.stringify({ data: dataset, multiplier: 1.5 }),
+    });
+    const [res1, res2] = await Promise.all([POST(req1 as any), POST(req2 as any)]);
+    const [d1, d2] = await Promise.all([res1.json(), res2.json()]);
+    expect(d1).toEqual(d2);
+  });
+
+  it("custom multiplier changes bounds", async () => {
+    const data = [1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 15];
+    const reqDefault = new Request("http://localhost/api/routes-f/iqr-outlier", {
+      method: "POST",
+      body: JSON.stringify({ data, multiplier: 1.5 }),
+    });
+    const reqStrict = new Request("http://localhost/api/routes-f/iqr-outlier", {
+      method: "POST",
+      body: JSON.stringify({ data, multiplier: 0.5 }),
+    });
+    const [resDefault, resStrict] = await Promise.all([
+      POST(reqDefault as any),
+      POST(reqStrict as any),
+    ]);
+    const [dDefault, dStrict] = await Promise.all([resDefault.json(), resStrict.json()]);
+    // Stricter multiplier yields narrower bounds, more outliers
+    expect(dStrict.upper_bound).toBeLessThan(dDefault.upper_bound);
+  });
+
+  it("computes correct IQR values for a known dataset", async () => {
+    // sorted: [2, 4, 6, 8, 10] → Q1=4, Q3=8, IQR=4
+    const req = new Request("http://localhost/api/routes-f/iqr-outlier", {
+      method: "POST",
+      body: JSON.stringify({ data: [10, 2, 6, 8, 4] }),
+    });
+    const res = await POST(req as any);
+    const data = await res.json();
+    expect(data.q1).toBeCloseTo(4);
+    expect(data.q3).toBeCloseTo(8);
+    expect(data.iqr).toBeCloseTo(4);
+    expect(data.lower_bound).toBeCloseTo(4 - 1.5 * 4); // -2
+    expect(data.upper_bound).toBeCloseTo(8 + 1.5 * 4); // 14
+  });
+});
diff --git a/app/api/routes-f/iqr-outlier/route.ts b/app/api/routes-f/iqr-outlier/route.ts
new file mode 100644
index 00000000..22136d60
--- /dev/null
+++ b/app/api/routes-f/iqr-outlier/route.ts
@@ -0,0 +1,54 @@
+import { type NextRequest, NextResponse } from "next/server";
+
+/**
+ * Calculates the quartile value for a sorted dataset using linear interpolation.
+ * Uses the inclusive method (same as Excel's QUARTILE.INC / NumPy default).
+ */
+function quartile(sorted: number[], q: 0.25 | 0.75): number {
+  const pos = q * (sorted.length - 1);
+  const lower = Math.floor(pos);
+  const upper = Math.ceil(pos);
+  const frac = pos - lower;
+  return sorted[lower] + frac * (sorted[upper] - sorted[lower]);
+}
+
+export async function POST(req: NextRequest) {
+  let body: unknown;
+  try {
+    body = await req.json();
+  } catch {
+    return NextResponse.json({ error: "Invalid JSON body." }, { status: 400 });
+  }
+
+  if (typeof body !== "object" || body === null || Array.isArray(body)) {
+    return NextResponse.json({ error: "Request body must be an object." }, { status: 400 });
+  }
+
+  const { data, multiplier } = body as Record<string, unknown>;
+
+  if (!Array.isArray(data) || data.length === 0 || data.some((v) => typeof v !== "number")) {
+    return NextResponse.json(
+      { error: "data must be a non-empty array of numbers." },
+      { status: 400 }
+    );
+  }
+
+  const m = multiplier !== undefined ? multiplier : 1.5;
+  if (typeof m !== "number" || m < 0) {
+    return NextResponse.json(
+      { error: "multiplier must be a non-negative number." },
+      { status: 400 }
+    );
+  }
+
+  const sorted = [...(data as number[])].sort((a, b) => a - b);
+
+  const q1 = quartile(sorted, 0.25);
+  const q3 = quartile(sorted, 0.75);
+  const iqr = q3 - q1;
+  const lower_bound = q1 - m * iqr;
+  const upper_bound = q3 + m * iqr;
+  const outliers = sorted.filter((v) => v < lower_bound || v > upper_bound);
+
+  return NextResponse.json({ q1, q3, iqr, lower_bound, upper_bound, outliers });
+}
diff --git a/app/api/routes-f/items/[id]/route.ts b/app/api/routes-f/items/[id]/route.ts
new file mode 100644
index 00000000..68e1dfce
--- /dev/null
+++ b/app/api/routes-f/items/[id]/route.ts
@@ -0,0 +1,106 @@
+// @ts-nocheck
+import { NextRequest, NextResponse } from "next/server";
+import { db } from "@/lib/db";
+import { redis } from "@/lib/redis";
+import { getAuthUser } from "@/lib/auth";
+
+const CATALOG_CACHE_KEY = "items_catalog";
+
+async function invalidateCatalogCache() {
+  await redis.del(CATALOG_CACHE_KEY);
+  const keys = await redis.keys("items_catalog:type:*");
+  if (keys.length > 0) {
+    await redis.del(...keys);
+  }
+}
+
+/**
+ * GET /api/routes-f/items/[id]
+ * Returns a single catalog item by UUID.
+ */
+export async function GET(
+  _req: NextRequest,
+  context: { params: Promise<{ id: string }> }
+) {
+  const { id } = await context.params;
+
+  const cacheKey = `items_catalog:item:${id}`;
+  const cached = await redis.get(cacheKey);
+  if (cached) {
+    return NextResponse.json(JSON.parse(cached as string), {
+      headers: { "X-Cache": "HIT" },
+    });
+  }
+
+  const { rows } = await db.query(
+    `SELECT id, type, name, slug, description, emoji, image_url,
+            price_usd, price_usdc, animation, tier, active, metadata
+     FROM items_catalog
+     WHERE id = $1`,
+    [id]
+  );
+
+  if (rows.length === 0) {
+    return NextResponse.json({ error: "Item not found" }, { status: 404 });
+  }
+
+  const response = { item: rows[0] };
+  await redis.setex(cacheKey, 300, JSON.stringify(response));
+
+  return NextResponse.json(response, { headers: { "X-Cache": "MISS" } });
+}
+
+/**
+ * PATCH /api/routes-f/items/[id]
+ * Admin-only: update a catalog item.
+ */
+export async function PATCH(
+  req: NextRequest,
+  context: { params: Promise<{ id: string }> }
+) {
+  const user = await getAuthUser(req);
+  if (!user || user.role !== "admin") {
+    return NextResponse.json({ error: "Forbidden" }, { status: 403 });
+  }
+
+  const { id } = await context.params;
+  const body = await req.json();
+
+  const allowed = [
+    "type", "name", "slug", "description", "emoji", "image_url",
+    "price_usd", "price_usdc", "animation", "tier", "sort_order",
+    "active", "metadata",
+  ];
+
+  const fields: string[] = [];
+  const values: unknown[] = [];
+  let idx = 1;
+
+  for (const key of allowed) {
+    if (key in body) {
+      fields.push(`${key} = $${idx}`);
+      values.push(key === "metadata" && body[key] ? JSON.stringify(body[key]) : body[key]);
+      idx++;
+    }
+  }
+
+  if (fields.length === 0) {
+    return NextResponse.json({ error: "No valid fields to update" }, { status: 400 });
+  }
+
+  values.push(id);
+  const { rows } = await db.query(
+    `UPDATE items_catalog SET ${fields.join(", ")} WHERE id = $${idx} RETURNING *`,
+    values
+  );
+
+  if (rows.length === 0) {
+    return NextResponse.json({ error: "Item not found" }, { status: 404 });
+  }
+
+  // Invalidate caches
+  await invalidateCatalogCache();
+  await redis.del(`items_catalog:item:${id}`);
+
+  return NextResponse.json({ item: rows[0] });
+}
diff --git a/app/api/routes-f/items/_catalog.ts b/app/api/routes-f/items/_catalog.ts
new file mode 100644
index 00000000..c251271b
--- /dev/null
+++ b/app/api/routes-f/items/_catalog.ts
@@ -0,0 +1,124 @@
+import { NextRequest } from "next/server";
+
+// ----- Shared catalog store -----
+export const ITEMS_CATALOG: {
+  id: string;
+  type: string;
+  name: string;
+  slug: string;
+  description: string | null;
+  emoji: string | null;
+  image_url: string | null;
+  price_usd: number | null;
+  price_usdc: number | null;
+  animation: string | null;
+  tier: string | null;
+  sort_order: number;
+  active: boolean;
+  metadata: Record<string, unknown>;
+}[] = [
+  {
+    id: "a1b2c3d4-0001-0000-0000-000000000001",
+    type: "gift",
+    name: "Flower",
+    slug: "gift-flower",
+    description: "A beautiful flower gift.",
+    emoji: "🌸",
+    image_url: null,
+    price_usd: 1.0,
+    price_usdc: 1.0,
+    animation: "flower",
+    tier: "common",
+    sort_order: 1,
+    active: true,
+    metadata: {},
+  },
+  {
+    id: "a1b2c3d4-0002-0000-0000-000000000002",
+    type: "gift",
+    name: "Candy",
+    slug: "gift-candy",
+    description: "Sweet candy for your favourite streamer.",
+    emoji: "🍬",
+    image_url: null,
+    price_usd: 5.0,
+    price_usdc: 5.0,
+    animation: "candy",
+    tier: "common",
+    sort_order: 2,
+    active: true,
+    metadata: {},
+  },
+  {
+    id: "a1b2c3d4-0003-0000-0000-000000000003",
+    type: "gift",
+    name: "Crown",
+    slug: "gift-crown",
+    description: "A rare crown fit for royalty.",
+    emoji: "👑",
+    image_url: null,
+    price_usd: 25.0,
+    price_usdc: 25.0,
+    animation: "crown",
+    tier: "rare",
+    sort_order: 3,
+    active: true,
+    metadata: {},
+  },
+  {
+    id: "a1b2c3d4-0004-0000-0000-000000000004",
+    type: "gift",
+    name: "Lion",
+    slug: "gift-lion",
+    description: "A majestic lion gift.",
+    emoji: "🦁",
+    image_url: null,
+    price_usd: 100.0,
+    price_usdc: 100.0,
+    animation: "lion",
+    tier: "rare",
+    sort_order: 4,
+    active: true,
+    metadata: {},
+  },
+  {
+    id: "a1b2c3d4-0005-0000-0000-000000000005",
+    type: "gift",
+    name: "Dragon",
+    slug: "gift-dragon",
+    description: "The legendary dragon — the ultimate gift.",
+    emoji: "🐉",
+    image_url: null,
+    price_usd: 500.0,
+    price_usdc: 500.0,
+    animation: "dragon",
+    tier: "legendary",
+    sort_order: 5,
+    active: true,
+    metadata: {},
+  },
+];
+
+// Simulated Redis cache (in-memory, 5 min TTL)
+let catalogCache: { data: typeof ITEMS_CATALOG; expiresAt: number } | null = null;
+const CACHE_TTL_MS = 5 * 60 * 1000;
+
+export function getCachedCatalog() {
+  if (catalogCache && Date.now() < catalogCache.expiresAt) {
+    return catalogCache.data;
+  }
+  return null;
+}
+
+export function setCatalogCache(data: typeof ITEMS_CATALOG) {
+  catalogCache = { data, expiresAt: Date.now() + CACHE_TTL_MS };
+}
+
+export function invalidateCatalogCache() {
+  catalogCache = null;
+}
+
+export function isAdmin(request: NextRequest): boolean {
+  const adminToken = request.headers.get("x-admin-token");
+  return adminToken === process.env.ADMIN_SECRET_TOKEN;
+}
diff --git a/app/api/routes-f/items/route.ts b/app/api/routes-f/items/route.ts
new file mode 100644
index 00000000..77dd4533
--- /dev/null
+++ b/app/api/routes-f/items/route.ts
@@ -0,0 +1,153 @@
+// @ts-nocheck
+import { NextRequest, NextResponse } from "next/server";
+
+// ---------------------------------------------------------------------------
+// DB schema (apply once via migration):
+//
+// CREATE TYPE item_type AS ENUM ('gift', 'sticker', 'effect', 'badge_frame', 'chat_color');
+//
+// CREATE TABLE items_catalog (
+//   id            UUID PRIMARY KEY DEFAULT gen_random_uuid(),
+//   type          item_type NOT NULL,
+//   name          TEXT NOT NULL,
+//   slug          TEXT NOT NULL UNIQUE,
+//   description   TEXT,
+//   emoji         TEXT,
+//   image_url     TEXT,
+//   price_usd     NUMERIC(10,2),
+//   price_usdc    NUMERIC(10,2),
+//   animation     TEXT,
+//   tier          TEXT,
+//   sort_order    INT DEFAULT 0,
+//   active        BOOLEAN DEFAULT true,
+//   metadata      JSONB
+// );
+//
+// Seed data (run once):
+// INSERT INTO items_catalog (type, name, slug, emoji, price_usd, price_usdc, animation, tier, sort_order)
+// VALUES
+//   ('gift', 'Flower', 'gift-flower', '🌸', 1.00,   1.00,   'flower',  'common',    1),
+//   ('gift', 'Candy',  'gift-candy',  '🍬', 5.00,   5.00,   'candy',   'common',    2),
+//   ('gift', 'Crown',  'gift-crown',  '👑', 25.00,  25.00,  'crown',   'rare',      3),
+//   ('gift', 'Lion',   'gift-lion',   '🦁', 100.00, 100.00, 'lion',    'rare',      4),
+//   ('gift', 'Dragon', 'gift-dragon', '🐉', 500.00, 500.00, 'dragon',  'legendary', 5);
+// ---------------------------------------------------------------------------
+
+import { db } from "@/lib/db";
+import { redis } from "@/lib/redis";
+import { getAuthUser } from "@/lib/auth";
+
+const CACHE_KEY = "items_catalog";
+const CACHE_TTL = 300; // 5 minutes
+
+async function invalidateCatalogCache() {
+  await redis.del(CACHE_KEY);
+  // Invalidate any type-scoped keys
+  const keys = await redis.keys("items_catalog:type:*");
+  if (keys.length > 0) {
+    await redis.del(...keys);
+  }
+}
+
+/**
+ * GET /api/routes-f/items
+ * Returns all active items, optionally filtered by ?type=gift|sticker|effect|...
+ * Full catalog cached in Redis with 5-minute TTL.
+ */
+export async function GET(req: NextRequest) {
+  const { searchParams } = new URL(req.url);
+  const type = searchParams.get("type");
+
+  const cacheKey = type ? `items_catalog:type:${type}` : CACHE_KEY;
+
+  // 1. Try cache
+  const cached = await redis.get(cacheKey);
+  if (cached) {
+    return NextResponse.json(JSON.parse(cached as string), {
+      headers: { "X-Cache": "HIT" },
+    });
+  }
+
+  // 2. Query DB
+  const params: unknown[] = [];
+  let query =
+    "SELECT id, type, name, slug, emoji, image_url, price_usd, price_usdc, animation, tier, active FROM items_catalog WHERE active = true";
+
+  if (type) {
+    params.push(type);
+    query += ` AND type = $${params.length}`;
+  }
+
+  query += " ORDER BY sort_order ASC, name ASC";
+
+  const { rows } = await db.query(query, params);
+
+  const response = { items: rows };
+
+  // 3. Cache result
+  await redis.setex(cacheKey, CACHE_TTL, JSON.stringify(response));
+
+  return NextResponse.json(response, {
+    headers: { "X-Cache": "MISS" },
+  });
+}
+
+/**
+ * POST /api/routes-f/items
+ * Admin-only: create a new catalog item.
+ */
+export async function POST(req: NextRequest) {
+  const user = await getAuthUser(req);
+  if (!user || user.role !== "admin") {
+    return NextResponse.json({ error: "Forbidden" }, { status: 403 });
+  }
+
+  const body = await req.json();
+  const {
+    type,
+    name,
+    slug,
+    description,
+    emoji,
+    image_url,
+    price_usd,
+    price_usdc,
+    animation,
+    tier,
+    sort_order = 0,
+    metadata,
+  } = body;
+
+  if (!type || !name || !slug) {
+    return NextResponse.json(
+      { error: "type, name, and slug are required" },
+      { status: 400 }
+    );
+  }
+
+  const { rows } = await db.query(
+    `INSERT INTO items_catalog
+       (type, name, slug, description, emoji, image_url, price_usd, price_usdc, animation, tier, sort_order, metadata)
+     VALUES ($1,$2,$3,$4,$5,$6,$7,$8,$9,$10,$11,$12)
+     RETURNING *`,
+    [
+      type,
+      name,
+      slug,
+      description ?? null,
+      emoji ?? null,
+      image_url ?? null,
+      price_usd ?? null,
+      price_usdc ?? null,
+      animation ?? null,
+      tier ?? null,
+      sort_order,
+      metadata ? JSON.stringify(metadata) : null,
+    ]
+  );
+
+  // Invalidate catalog cache
+  await invalidateCatalogCache();
+
+  return NextResponse.json({ item: rows[0] }, { status: 201 });
+}
diff --git a/app/api/routes-f/jest.config.simple.cjs b/app/api/routes-f/jest.config.simple.cjs
new file mode 100644
index 00000000..e8dbed9d
--- /dev/null
+++ b/app/api/routes-f/jest.config.simple.cjs
@@ -0,0 +1,13 @@
+module.exports = {
+  testEnvironment: "node",
+  transform: {
+    "^.+\\.(js|jsx|ts|tsx)$": ["babel-jest", { presets: ["next/babel"] }],
+  },
+  moduleNameMapper: {
+    "^@/(.*)$": "<rootDir>/$1",
+  },
+  rootDir: "../../..",
+  testMatch: [
+    "<rootDir>/app/api/routes-f/__tests__/relative-date.test.ts"
+  ],
+};
diff --git a/app/api/routes-f/json-format/route.ts b/app/api/routes-f/json-format/route.ts
new file mode 100644
index 00000000..721da622
--- /dev/null
+++ b/app/api/routes-f/json-format/route.ts
@@ -0,0 +1,53 @@
+import { NextRequest, NextResponse } from "next/server";
+
+const MAX_BYTES = 5 * 1024 * 1024;
+
+function sortKeys(obj: unknown): unknown {
+  if (Array.isArray(obj)) return obj.map(sortKeys);
+  if (obj !== null && typeof obj === "object") {
+    return Object.fromEntries(
+      Object.keys(obj as Record<string, unknown>)
+        .sort()
+        .map((k) => [k, sortKeys((obj as Record<string, unknown>)[k])])
+    );
+  }
+  return obj;
+}
+
+export async function POST(req: NextRequest) {
+  const contentLength = Number(req.headers.get("content-length") ?? 0);
+  if (contentLength > MAX_BYTES) {
+    return NextResponse.json({ error: "Input exceeds 5MB limit" }, { status: 413 });
+  }
+
+  let body: { input?: unknown; mode?: unknown; indent?: unknown; sort_keys?: unknown };
+  try {
+    body = await req.json();
+  } catch {
+    return NextResponse.json({ error: "Invalid JSON body" }, { status: 400 });
+  }
+
+  const { input, mode, indent = 2, sort_keys = false } = body;
+
+  if (typeof input !== "string") {
+    return NextResponse.json({ valid: false, error: "input must be a string" }, { status: 400 });
+  }
+  if (mode !== "minify" && mode !== "prettify") {
+    return NextResponse.json({ error: "mode must be minify or prettify" }, { status: 400 });
+  }
+
+  let parsed: unknown;
+  try {
+    parsed = JSON.parse(input);
+  } catch (e) {
+    return NextResponse.json({ valid: false, error: (e as Error).message });
+  }
+
+  const data = sort_keys ? sortKeys(parsed) : parsed;
+  const output =
+    mode === "minify"
+      ? JSON.stringify(data)
+      : JSON.stringify(data, null, typeof indent === "number" ? indent : 2);
+
+  return NextResponse.json({ output });
+}
diff --git a/app/api/routes-f/json-schema-validate/__tests__/route.test.ts b/app/api/routes-f/json-schema-validate/__tests__/route.test.ts
new file mode 100644
index 00000000..24bb1037
--- /dev/null
+++ b/app/api/routes-f/json-schema-validate/__tests__/route.test.ts
@@ -0,0 +1,59 @@
+import { validateAgainstSchema } from "../route";
+
+describe("validateAgainstSchema", () => {
+  it("passes a valid object", () => {
+    const schema = {
+      type: "object",
+      required: ["name", "age"],
+      properties: {
+        name: { type: "string", minLength: 1, maxLength: 50 },
+        age: { type: "integer", minimum: 0, maximum: 130 },
+        role: { type: "string", enum: ["admin", "user"] },
+      },
+    };
+    const r = validateAgainstSchema(schema, { name: "Ada", age: 36, role: "admin" });
+    expect(r.valid).toBe(true);
+    expect(r.errors).toEqual([]);
+  });
+
+  it("flags a type mismatch", () => {
+    const r = validateAgainstSchema({ type: "number" }, "nope");
+    expect(r.valid).toBe(false);
+    expect(r.errors[0].message).toMatch(/expected type number/);
+  });
+
+  it("flags missing required properties", () => {
+    const r = validateAgainstSchema(
+      { type: "object", required: ["id"], properties: {} },
+      {},
+    );
+    expect(r.valid).toBe(false);
+    expect(r.errors[0]).toEqual({ path: "id", message: "required property is missing" });
+  });
+
+  it("enforces minimum/maximum", () => {
+    expect(validateAgainstSchema({ type: "number", minimum: 10 }, 5).valid).toBe(false);
+    expect(validateAgainstSchema({ type: "number", maximum: 10 }, 20).valid).toBe(false);
+    expect(validateAgainstSchema({ type: "number", minimum: 0, maximum: 10 }, 5).valid).toBe(true);
+  });
+
+  it("enforces minLength/maxLength", () => {
+    expect(validateAgainstSchema({ type: "string", minLength: 3 }, "ab").valid).toBe(false);
+    expect(validateAgainstSchema({ type: "string", maxLength: 3 }, "abcd").valid).toBe(false);
+  });
+
+  it("enforces enum", () => {
+    expect(validateAgainstSchema({ enum: ["a", "b"] }, "c").valid).toBe(false);
+    expect(validateAgainstSchema({ enum: ["a", "b"] }, "a").valid).toBe(true);
+  });
+
+  it("reports nested property paths", () => {
+    const schema = {
+      type: "object",
+      properties: { user: { type: "object", properties: { age: { type: "integer", minimum: 0 } } } },
+    };
+    const r = validateAgainstSchema(schema, { user: { age: -1 } });
+    expect(r.valid).toBe(false);
+    expect(r.errors[0].path).toBe("user.age");
+  });
+});
diff --git a/app/api/routes-f/json-schema-validate/route.ts b/app/api/routes-f/json-schema-validate/route.ts
new file mode 100644
index 00000000..fa3a6b61
--- /dev/null
+++ b/app/api/routes-f/json-schema-validate/route.ts
@@ -0,0 +1,97 @@
+import { NextResponse } from "next/server";
+import { z } from "zod";
+import { validateBody } from "@/app/api/routes-f/_lib/validate";
+
+// Minimal JSON-schema subset validator (no ajv): supports type, required,
+// properties, minimum/maximum, minLength/maxLength, enum.
+
+export interface SchemaError {
+  path: string;
+  message: string;
+}
+
+type JsonSchema = Record<string, unknown>;
+
+function typeOf(v: unknown): string {
+  if (v === null) return "null";
+  if (Array.isArray(v)) return "array";
+  return typeof v;
+}
+
+const join = (path: string, key: string) => (path ? `${path}.${key}` : key);
+
+function walk(schema: JsonSchema, data: unknown, path: string, errors: SchemaError[]): void {
+  if (typeof schema !== "object" || schema === null) return;
+
+  if (schema.type !== undefined) {
+    const expected = Array.isArray(schema.type) ? (schema.type as string[]) : [schema.type as string];
+    const actual = typeOf(data);
+    const ok = expected.some((t) =>
+      t === "integer" ? actual === "number" && Number.isInteger(data) : t === actual,
+    );
+    if (!ok) {
+      errors.push({ path, message: `expected type ${expected.join(" | ")}, got ${actual}` });
+      return; // further keyword checks are meaningless on a type mismatch
+    }
+  }
+
+  if (Array.isArray(schema.enum)) {
+    const match = (schema.enum as unknown[]).some(
+      (e) => JSON.stringify(e) === JSON.stringify(data),
+    );
+    if (!match) errors.push({ path, message: "value is not one of the allowed enum values" });
+  }
+
+  if (typeof data === "number") {
+    if (typeof schema.minimum === "number" && data < schema.minimum) {
+      errors.push({ path, message: `must be >= ${schema.minimum}` });
+    }
+    if (typeof schema.maximum === "number" && data > schema.maximum) {
+      errors.push({ path, message: `must be <= ${schema.maximum}` });
+    }
+  }
+
+  if (typeof data === "string") {
+    if (typeof schema.minLength === "number" && data.length < schema.minLength) {
+      errors.push({ path, message: `length must be >= ${schema.minLength}` });
+    }
+    if (typeof schema.maxLength === "number" && data.length > schema.maxLength) {
+      errors.push({ path, message: `length must be <= ${schema.maxLength}` });
+    }
+  }
+
+  if (typeOf(data) === "object") {
+    const obj = data as Record<string, unknown>;
+    if (Array.isArray(schema.required)) {
+      for (const key of schema.required as string[]) {
+        if (!(key in obj)) errors.push({ path: join(path, key), message: "required property is missing" });
+      }
+    }
+    if (schema.properties && typeof schema.properties === "object") {
+      for (const [key, sub] of Object.entries(schema.properties as Record<string, JsonSchema>)) {
+        if (key in obj) walk(sub, obj[key], join(path, key), errors);
+      }
+    }
+  }
+}
+
+export function validateAgainstSchema(
+  schema: JsonSchema,
+  data: unknown,
+): { valid: boolean; errors: SchemaError[] } {
+  const errors: SchemaError[] = [];
+  walk(schema, data, "", errors);
+  return { valid: errors.length === 0, errors };
+}
+
+const schema = z.object({
+  schema: z.record(z.any()),
+  data: z.any(),
+});
+
+export async function POST(request: Request): Promise<NextResponse> {
+  const result = await validateBody(request, schema);
+  if (result instanceof NextResponse) return result;
+  const { schema: jsonSchema, data } = result.data;
+  return NextResponse.json(validateAgainstSchema(jsonSchema as JsonSchema, data));
+}
diff --git a/app/api/routes-f/leap-year/route.ts b/app/api/routes-f/leap-year/route.ts
new file mode 100644
index 00000000..70c443a0
--- /dev/null
+++ b/app/api/routes-f/leap-year/route.ts
@@ -0,0 +1,37 @@
+import { NextRequest, NextResponse } from "next/server";
+
+function isLeapYear(year: number): boolean {
+  return (year % 4 === 0 && year % 100 !== 0) || year % 400 === 0;
+}
+
+function getNextLeapYears(from: number, count = 5): number[] {
+  const result: number[] = [];
+  let y = from + 1;
+  while (result.length < count) {
+    if (isLeapYear(y)) result.push(y);
+    y++;
+  }
+  return result;
+}
+
+function leapReason(year: number): string {
+  if (year % 400 === 0) return "Divisible by 400";
+  if (year % 100 === 0) return "Divisible by 100 but not 400 — not a leap year";
+  if (year % 4 === 0) return "Divisible by 4 but not 100";
+  return "Not divisible by 4";
+}
+
+export async function GET(req: NextRequest) {
+  const yearParam = new URL(req.url).searchParams.get("year");
+  const year = yearParam ? parseInt(yearParam, 10) : NaN;
+
+  if (!yearParam || isNaN(year)) {
+    return NextResponse.json({ error: "year query param is required" }, { status: 400 });
+  }
+
+  return NextResponse.json({
+    is_leap: isLeapYear(year),
+    reason: leapReason(year),
+    next_leap_years: getNextLeapYears(year),
+  });
+}
diff --git a/app/api/routes-f/live/raid/incoming/route.ts b/app/api/routes-f/live/raid/incoming/route.ts
new file mode 100644
index 00000000..3d6a0e11
--- /dev/null
+++ b/app/api/routes-f/live/raid/incoming/route.ts
@@ -0,0 +1,52 @@
+import { NextRequest, NextResponse } from "next/server";
+import { sql } from "@vercel/postgres";
+import { verifySession } from "@/lib/auth/verify-session";
+
+export const runtime = "nodejs";
+export const dynamic = "force-dynamic";
+
+/**
+ * GET /api/routes-f/live/raid/incoming
+ * Target creator polls for incoming raid.
+ */
+export async function GET(req: NextRequest) {
+    const session = await verifySession(req);
+    if (!session.ok) {
+        return session.response;
+    }
+
+    try {
+        // Find latest unacknowledged raid
+        const { rows } = await sql`
+      SELECT 
+        r.id, 
+        u.username as "raiderUsername", 
+        r.viewer_count as "viewerCount", 
+        r.raided_at as "raidedAt"
+      FROM raids r
+      JOIN users u ON r.raider_id = u.id
+      WHERE r.target_id = ${session.userId} 
+      AND r.is_acknowledged = FALSE
+      ORDER BY r.raided_at DESC
+      LIMIT 1
+    `;
+
+        if (rows.length === 0) {
+            return NextResponse.json({ raid: null });
+        }
+
+        const latestRaid = rows[0];
+
+        // Mark as acknowledged
+        await sql`
+      UPDATE raids
+      SET is_acknowledged = TRUE
+      WHERE id = ${latestRaid.id}
+    `;
+
+        return NextResponse.json({ raid: latestRaid });
+    } catch (error) {
+        console.error("[Raid API] Error fetching incoming raid:", error);
+        return NextResponse.json({ error: "Internal server error" }, { status: 500 });
+    }
+}
diff --git a/app/api/routes-f/live/raid/route.ts b/app/api/routes-f/live/raid/route.ts
new file mode 100644
index 00000000..9ec57303
--- /dev/null
+++ b/app/api/routes-f/live/raid/route.ts
@@ -0,0 +1,69 @@
+import { NextRequest, NextResponse } from "next/server";
+import { sql } from "@vercel/postgres";
+import { verifySession } from "@/lib/auth/verify-session";
+import { z } from "zod";
+
+export const runtime = "nodejs";
+export const dynamic = "force-dynamic";
+
+const raidSchema = z.object({
+    targetUsername: z.string().min(1),
+    viewerCount: z.number().int().nonnegative(),
+});
+
+/**
+ * POST /api/routes-f/live/raid
+ * Initiate a raid.
+ */
+export async function POST(req: NextRequest) {
+    const session = await verifySession(req);
+    if (!session.ok) {
+        return session.response;
+    }
+
+    try {
+        const body = await req.json();
+        const result = raidSchema.safeParse(body);
+        if (!result.success) {
+            return NextResponse.json({ error: "Invalid request body", details: result.error.format() }, { status: 400 });
+        }
+
+        const { targetUsername, viewerCount } = result.data;
+
+        // Check if raider is live
+        const { rows: raiderStatus } = await sql`
+      SELECT is_live FROM users WHERE id = ${session.userId} LIMIT 1
+    `;
+        if (!raiderStatus[0]?.is_live) {
+            return NextResponse.json({ error: "Only active streamers can initiate a raid" }, { status: 400 });
+        }
+
+        // Find target
+        const { rows: target } = await sql`
+      SELECT id, is_live FROM users WHERE username = ${targetUsername} LIMIT 1
+    `;
+
+        if (target.length === 0) {
+            return NextResponse.json({ error: "Target user not found" }, { status: 404 });
+        }
+
+        if (target[0].id === session.userId) {
+            return NextResponse.json({ error: "You cannot raid yourself" }, { status: 400 });
+        }
+
+        if (!target[0].is_live) {
+            return NextResponse.json({ error: "Target streamer must be live to be raided" }, { status: 400 });
+        }
+
+        // Record the raid
+        await sql`
+      INSERT INTO raids (raider_id, target_id, viewer_count)
+      VALUES (${session.userId}, ${target[0].id}, ${viewerCount})
+    `;
+
+        return NextResponse.json({ message: `Raid initiated to ${targetUsername} with ${viewerCount} viewers` });
+    } catch (error) {
+        console.error("[Raid API] Error initiating raid:", error);
+        return NextResponse.json({ error: "Internal server error" }, { status: 500 });
+    }
+}
diff --git a/app/api/routes-f/loan-amortization/route.ts b/app/api/routes-f/loan-amortization/route.ts
new file mode 100644
index 00000000..cc3a6067
--- /dev/null
+++ b/app/api/routes-f/loan-amortization/route.ts
@@ -0,0 +1,88 @@
+import { type NextRequest, NextResponse } from "next/server";
+
+interface AmortizationRow {
+  month: number;
+  payment: number;
+  principal: number;
+  interest: number;
+  balance: number;
+}
+
+interface AmortizationInput {
+  principal: number;
+  annual_rate: number;
+  years: number;
+  extra_monthly_payment?: number;
+}
+
+function round2(n: number): number {
+  return Math.round(n * 100) / 100;
+}
+
+function computeSchedule(input: AmortizationInput) {
+  const { principal, annual_rate, years, extra_monthly_payment = 0 } = input;
+  const monthlyRate = annual_rate / 100 / 12;
+  const totalMonths = years * 12;
+
+  let monthly_payment: number;
+  if (monthlyRate === 0) {
+    monthly_payment = round2(principal / totalMonths);
+  } else {
+    const factor = Math.pow(1 + monthlyRate, totalMonths);
+    monthly_payment = round2((principal * monthlyRate * factor) / (factor - 1));
+  }
+
+  const schedule: AmortizationRow[] = [];
+  let balance = principal;
+  let month = 0;
+
+  while (balance > 0) {
+    month++;
+    const interest = round2(balance * monthlyRate);
+    const principalPart = round2(Math.min(monthly_payment - interest + extra_monthly_payment, balance));
+    const payment = round2(interest + principalPart);
+    balance = round2(balance - principalPart);
+    schedule.push({ month, payment, principal: principalPart, interest, balance: Math.max(0, balance) });
+    if (month > totalMonths + 1000) break; // safety guard
+  }
+
+  const total_interest = round2(schedule.reduce((sum, r) => sum + r.interest, 0));
+
+  return { monthly_payment, payoff_months: schedule.length, total_interest, schedule };
+}
+
+function isRecord(v: unknown): v is Record<string, unknown> {
+  return typeof v === "object" && v !== null && !Array.isArray(v);
+}
+
+export async function POST(req: NextRequest) {
+  let body: unknown;
+  try {
+    body = await req.json();
+  } catch {
+    return NextResponse.json({ error: "Invalid JSON body." }, { status: 400 });
+  }
+
+  if (!isRecord(body)) {
+    return NextResponse.json({ error: "Request body must be an object." }, { status: 400 });
+  }
+
+  const { principal, annual_rate, years, extra_monthly_payment } = body as Record<string, unknown>;
+
+  if (typeof principal !== "number" || principal <= 0) {
+    return NextResponse.json({ error: "principal must be a positive number." }, { status: 400 });
+  }
+  if (typeof annual_rate !== "number" || annual_rate < 0) {
+    return NextResponse.json({ error: "annual_rate must be a non-negative number." }, { status: 400 });
+  }
+  if (typeof years !== "number" || years <= 0 || years > 50) {
+    return NextResponse.json({ error: "years must be a positive number not exceeding 50." }, { status: 400 });
+  }
+  if (extra_monthly_payment !== undefined && (typeof extra_monthly_payment !== "number" || extra_monthly_payment < 0)) {
+    return NextResponse.json({ error: "extra_monthly_payment must be a non-negative number." }, { status: 400 });
+  }
+
+  return NextResponse.json(
+    computeSchedule({ principal, annual_rate, years, extra_monthly_payment: extra_monthly_payment as number | undefined })
+  );
+}
diff --git a/app/api/routes-f/markdown-preview/__tests__/route.test.ts b/app/api/routes-f/markdown-preview/__tests__/route.test.ts
new file mode 100644
index 00000000..2ee2eb04
--- /dev/null
+++ b/app/api/routes-f/markdown-preview/__tests__/route.test.ts
@@ -0,0 +1,299 @@
+import { POST } from "../route";
+import { NextRequest } from "next/server";
+
+function makeReq(body: object) {
+  return new NextRequest("http://localhost/api/routes-f/markdown-preview", {
+    method: "POST",
+    body: JSON.stringify(body),
+  });
+}
+
+describe("POST /api/routes-f/markdown-preview", () => {
+  describe("markdown rendering", () => {
+    it("renders headings", async () => {
+      const res = await POST(
+        makeReq({
+          markdown: "# Title\n## Subtitle\n### Sub-subtitle",
+        })
+      );
+      expect(res.status).toBe(200);
+      const body = await res.json();
+      expect(body.html).toContain("<h1>Title</h1>");
+      expect(body.html).toContain("<h2>Subtitle</h2>");
+      expect(body.html).toContain("<h3>Sub-subtitle</h3>");
+    });
+
+    it("renders bold text", async () => {
+      const res = await POST(
+        makeReq({
+          markdown: "This is **bold** text",
+        })
+      );
+      expect(res.status).toBe(200);
+      const body = await res.json();
+      expect(body.html).toContain("<strong>bold</strong>");
+    });
+
+    it("renders italic text", async () => {
+      const res = await POST(
+        makeReq({
+          markdown: "This is *italic* text",
+        })
+      );
+      expect(res.status).toBe(200);
+      const body = await res.json();
+      expect(body.html).toContain("<em>italic</em>");
+    });
+
+    it("renders inline code", async () => {
+      const res = await POST(
+        makeReq({
+          markdown: "Use `const x = 5` in JavaScript",
+        })
+      );
+      expect(res.status).toBe(200);
+      const body = await res.json();
+      expect(body.html).toContain("<code>const x = 5</code>");
+    });
+
+    it("renders code blocks", async () => {
+      const res = await POST(
+        makeReq({
+          markdown: "```\nconst x = 5;\nconst y = 10;\n```",
+        })
+      );
+      expect(res.status).toBe(200);
+      const body = await res.json();
+      expect(body.html).toContain("<pre><code>");
+      expect(body.html).toContain("const x = 5;");
+      expect(body.html).toContain("const y = 10;");
+    });
+
+    it("preserves code block content exactly", async () => {
+      const res = await POST(
+        makeReq({
+          markdown: "```\n<script>alert('test')</script>\n```",
+        })
+      );
+      expect(res.status).toBe(200);
+      const body = await res.json();
+      expect(body.html).toContain("&lt;script&gt;");
+    });
+
+    it("renders links", async () => {
+      const res = await POST(
+        makeReq({
+          markdown: "Check [this link](https://example.com)",
+        })
+      );
+      expect(res.status).toBe(200);
+      const body = await res.json();
+      expect(body.html).toContain('<a href="https://example.com">this link</a>');
+    });
+
+    it("renders unordered lists", async () => {
+      const res = await POST(
+        makeReq({
+          markdown: "- Item 1\n- Item 2\n- Item 3",
+        })
+      );
+      expect(res.status).toBe(200);
+      const body = await res.json();
+      expect(body.html).toContain("<ul>");
+      expect(body.html).toContain("<li>Item 1</li>");
+      expect(body.html).toContain("<li>Item 2</li>");
+      expect(body.html).toContain("</ul>");
+    });
+
+    it("renders ordered lists", async () => {
+      const res = await POST(
+        makeReq({
+          markdown: "1. First\n2. Second\n3. Third",
+        })
+      );
+      expect(res.status).toBe(200);
+      const body = await res.json();
+      expect(body.html).toContain("<ol>");
+      expect(body.html).toContain("<li>First</li>");
+      expect(body.html).toContain("</ol>");
+    });
+
+    it("renders paragraphs", async () => {
+      const res = await POST(
+        makeReq({
+          markdown: "This is a paragraph.\n\nThis is another.",
+        })
+      );
+      expect(res.status).toBe(200);
+      const body = await res.json();
+      expect(body.html).toContain("<p>This is a paragraph.</p>");
+      expect(body.html).toContain("<p>This is another.</p>");
+    });
+  });
+
+  describe("heading extraction", () => {
+    it("extracts headings with correct levels", async () => {
+      const res = await POST(
+        makeReq({
+          markdown: "# H1\n## H2\n### H3",
+        })
+      );
+      expect(res.status).toBe(200);
+      const body = await res.json();
+      expect(body.headings).toEqual([
+        { level: 1, text: "H1" },
+        { level: 2, text: "H2" },
+        { level: 3, text: "H3" },
+      ]);
+    });
+
+    it("preserves heading order", async () => {
+      const res = await POST(
+        makeReq({
+          markdown: "# Title\nSome text\n## Section\nMore text\n### Subsection",
+        })
+      );
+      expect(res.status).toBe(200);
+      const body = await res.json();
+      expect(body.headings.map((h: { text: string }) => h.text)).toEqual([
+        "Title",
+        "Section",
+        "Subsection",
+      ]);
+    });
+  });
+
+  describe("word count", () => {
+    it("counts words correctly", async () => {
+      const res = await POST(
+        makeReq({
+          markdown: "This is a test with seven words here",
+        })
+      );
+      expect(res.status).toBe(200);
+      const body = await res.json();
+      expect(body.word_count).toBe(7);
+    });
+
+    it("counts words across multiple lines", async () => {
+      const res = await POST(
+        makeReq({
+          markdown: "Hello world\nfoo bar",
+        })
+      );
+      expect(res.status).toBe(200);
+      const body = await res.json();
+      expect(body.word_count).toBe(4);
+    });
+  });
+
+  describe("sanitization", () => {
+    it("strips script tags by default", async () => {
+      const res = await POST(
+        makeReq({
+          markdown: "<script>alert('xss')</script>Hello",
+        })
+      );
+      expect(res.status).toBe(200);
+      const body = await res.json();
+      expect(body.html).not.toContain("<script>");
+    });
+
+    it("strips event handlers by default", async () => {
+      const res = await POST(
+        makeReq({
+          markdown: "[link](https://example.com)",
+        })
+      );
+      expect(res.status).toBe(200);
+      const body = await res.json();
+      expect(body.html).not.toContain("onclick");
+    });
+
+    it("replaces javascript: links with # by default", async () => {
+      const res = await POST(
+        makeReq({
+          markdown: "[click](javascript:alert('xss'))",
+        })
+      );
+      expect(res.status).toBe(200);
+      const body = await res.json();
+      expect(body.html).not.toContain("javascript:");
+      expect(body.html).toContain('href="#"');
+    });
+
+    it("disables sanitization when sanitize=false", async () => {
+      const testHtml = "<div>content</div>";
+      const res = await POST(
+        makeReq({
+          markdown: testHtml,
+          sanitize: false,
+        })
+      );
+      expect(res.status).toBe(200);
+      const body = await res.json();
+      expect(body.html).toContain("<div>");
+    });
+
+    it("still sanitizes in unsanitized mode for script tags", async () => {
+      const res = await POST(
+        makeReq({
+          markdown: "<script>alert('xss')</script>",
+          sanitize: false,
+        })
+      );
+      expect(res.status).toBe(200);
+      const body = await res.json();
+      // Script tags should still be removed even with sanitize=false
+      expect(body.html).not.toContain("<script>");
+    });
+  });
+
+  describe("validation", () => {
+    it("returns 400 for missing markdown", async () => {
+      const res = await POST(makeReq({}));
+      expect(res.status).toBe(400);
+    });
+
+    it("returns 400 for non-string markdown", async () => {
+      const res = await POST(makeReq({ markdown: 123 }));
+      expect(res.status).toBe(400);
+    });
+  });
+
+  describe("edge cases", () => {
+    it("handles empty markdown", async () => {
+      const res = await POST(makeReq({ markdown: "" }));
+      expect(res.status).toBe(200);
+      const body = await res.json();
+      expect(body.html).toBe("");
+      expect(body.word_count).toBe(0);
+    });
+
+    it("handles malformed markdown gracefully", async () => {
+      const res = await POST(
+        makeReq({
+          markdown: "**unclosed bold\n*unclosed italic",
+        })
+      );
+      expect(res.status).toBe(200);
+      const body = await res.json();
+      expect(typeof body.html).toBe("string");
+    });
+
+    it("handles mixed markdown syntax", async () => {
+      const res = await POST(
+        makeReq({
+          markdown: "# Main Title\n\nHello **world** with *emphasis*.\n\n- List item\n\n[Link](https://example.com)",
+        })
+      );
+      expect(res.status).toBe(200);
+      const body = await res.json();
+      expect(body.html).toContain("<h1>");
+      expect(body.html).toContain("<strong>");
+      expect(body.html).toContain("<em>");
+      expect(body.html).toContain("<ul>");
+      expect(body.html).toContain("<a href=");
+    });
+  });
+});
diff --git a/app/api/routes-f/markdown-preview/_lib/helpers.ts b/app/api/routes-f/markdown-preview/_lib/helpers.ts
new file mode 100644
index 00000000..c58ec973
--- /dev/null
+++ b/app/api/routes-f/markdown-preview/_lib/helpers.ts
@@ -0,0 +1,184 @@
+import type { Heading } from "./types";
+
+interface ParsedMarkdown {
+  html: string;
+  headings: Heading[];
+}
+
+function escapeHtml(text: string): string {
+  const map: Record<string, string> = {
+    "&": "&amp;",
+    "<": "&lt;",
+    ">": "&gt;",
+    '"': "&quot;",
+    "'": "&#39;",
+  };
+  return text.replace(/[&<>"']/g, (char) => map[char]);
+}
+
+function stripEventHandlers(html: string): string {
+  // Remove event handler attributes like onclick, onload, etc.
+  return html.replace(/\s+on[a-z]+="[^"]*"/gi, "");
+}
+
+function stripScriptTags(html: string): string {
+  // Remove <script> tags and their content
+  return html.replace(/<script\b[^<]*(?:(?!<\/script>)<[^<]*)*<\/script>/gi, "");
+}
+
+function stripJavascriptLinks(html: string): string {
+  // Replace javascript: URLs with #
+  return html.replace(/href="javascript:[^"]*"/gi, 'href="#"');
+}
+
+export function sanitizeHtml(html: string): string {
+  let sanitized = html;
+  sanitized = stripScriptTags(sanitized);
+  sanitized = stripEventHandlers(sanitized);
+  sanitized = stripJavascriptLinks(sanitized);
+  return sanitized;
+}
+
+function parseInlineMarkdown(text: string): string {
+  // Bold: **text** or __text__
+  text = text.replace(/\*\*([^*]+)\*\*/g, "<strong>$1</strong>");
+  text = text.replace(/__([^_]+)__/g, "<strong>$1</strong>");
+
+  // Italic: *text* or _text_
+  text = text.replace(/\*([^*]+)\*/g, "<em>$1</em>");
+  text = text.replace(/_([^_]+)_/g, "<em>$1</em>");
+
+  // Inline code: `text`
+  text = text.replace(/`([^`]+)`/g, "<code>$1</code>");
+
+  // Links: [text](url)
+  text = text.replace(/\[([^\]]+)\]\(([^)]+)\)/g, '<a href="$2">$1</a>');
+
+  return text;
+}
+
+function countWords(text: string): number {
+  const cleaned = text.replace(/[^\w\s]/g, " ");
+  const words = cleaned.split(/\s+/).filter((word) => word.length > 0);
+  return words.length;
+}
+
+export function parseMarkdown(markdown: string): ParsedMarkdown {
+  const lines = markdown.split("\n");
+  const headings: Heading[] = [];
+  const htmlLines: string[] = [];
+  let inCodeBlock = false;
+  let codeBlockContent = "";
+  let inList = false;
+  let listType: "ul" | "ol" | null = null;
+
+  for (let i = 0; i < lines.length; i++) {
+    const line = lines[i];
+
+    // Check for code block markers
+    if (line.startsWith("```")) {
+      if (!inCodeBlock) {
+        inCodeBlock = true;
+        codeBlockContent = "";
+        continue;
+      } else {
+        inCodeBlock = false;
+        const escaped = escapeHtml(codeBlockContent.trim());
+        htmlLines.push(`<pre><code>${escaped}</code></pre>`);
+        continue;
+      }
+    }
+
+    // Accumulate code block content
+    if (inCodeBlock) {
+      codeBlockContent += line + "\n";
+      continue;
+    }
+
+    // Close list if needed
+    if (inList && !line.match(/^[\s]*[-*+]\s/i) && !line.match(/^[\s]*\d+\.\s/)) {
+      htmlLines.push(listType === "ol" ? "</ol>" : "</ul>");
+      inList = false;
+      listType = null;
+    }
+
+    // Headings: # text through ###### text
+    const headingMatch = line.match(/^(#{1,6})\s+(.+)$/);
+    if (headingMatch) {
+      const level = headingMatch[1].length;
+      const text = headingMatch[2];
+      headings.push({ level, text });
+      const processed = parseInlineMarkdown(text);
+      htmlLines.push(`<h${level}>${processed}</h${level}>`);
+      continue;
+    }
+
+    // Unordered lists: - item, * item, + item
+    const ulMatch = line.match(/^[\s]*[-*+]\s+(.+)$/);
+    if (ulMatch) {
+      if (!inList || listType !== "ul") {
+        if (inList && listType === "ol") {
+          htmlLines.push("</ol>");
+        }
+        htmlLines.push("<ul>");
+        inList = true;
+        listType = "ul";
+      }
+      const content = parseInlineMarkdown(ulMatch[1]);
+      htmlLines.push(`<li>${content}</li>`);
+      continue;
+    }
+
+    // Ordered lists: 1. item, 2. item, etc.
+    const olMatch = line.match(/^[\s]*\d+\.\s+(.+)$/);
+    if (olMatch) {
+      if (!inList || listType !== "ol") {
+        if (inList && listType === "ul") {
+          htmlLines.push("</ul>");
+        }
+        htmlLines.push("<ol>");
+        inList = true;
+        listType = "ol";
+      }
+      const content = parseInlineMarkdown(olMatch[1]);
+      htmlLines.push(`<li>${content}</li>`);
+      continue;
+    }
+
+    // Skip empty lines
+    if (line.trim() === "") {
+      continue;
+    }
+
+    // Regular paragraphs
+    const processed = parseInlineMarkdown(line);
+    htmlLines.push(`<p>${processed}</p>`);
+  }
+
+  // Close any open list
+  if (inList) {
+    htmlLines.push(listType === "ol" ? "</ol>" : "</ul>");
+  }
+
+  // Close any unclosed code block
+  if (inCodeBlock) {
+    const escaped = escapeHtml(codeBlockContent.trim());
+    htmlLines.push(`<pre><code>${escaped}</code></pre>`);
+  }
+
+  const html = htmlLines.join("\n");
+
+  return { html, headings };
+}
+
+export function processMarkdown(markdown: string, sanitize: boolean = true): {
+  html: string;
+  headings: Heading[];
+  word_count: number;
+} {
+  const { html: rawHtml, headings } = parseMarkdown(markdown);
+  const html = sanitize ? sanitizeHtml(rawHtml) : rawHtml;
+  const wordCount = countWords(markdown);
+
+  return { html, headings, word_count: wordCount };
+}
diff --git a/app/api/routes-f/markdown-preview/_lib/types.ts b/app/api/routes-f/markdown-preview/_lib/types.ts
new file mode 100644
index 00000000..25ebcf2b
--- /dev/null
+++ b/app/api/routes-f/markdown-preview/_lib/types.ts
@@ -0,0 +1,15 @@
+export interface MarkdownPreviewRequest {
+  markdown: string;
+  sanitize?: boolean;
+}
+
+export interface Heading {
+  level: number;
+  text: string;
+}
+
+export interface MarkdownPreviewResponse {
+  html: string;
+  headings: Heading[];
+  word_count: number;
+}
diff --git a/app/api/routes-f/markdown-preview/route.ts b/app/api/routes-f/markdown-preview/route.ts
new file mode 100644
index 00000000..1bfaffe9
--- /dev/null
+++ b/app/api/routes-f/markdown-preview/route.ts
@@ -0,0 +1,26 @@
+import { NextRequest, NextResponse } from "next/server";
+import { processMarkdown } from "./_lib/helpers";
+import type { MarkdownPreviewRequest, MarkdownPreviewResponse } from "./_lib/types";
+
+export async function POST(req: NextRequest) {
+  let body: MarkdownPreviewRequest;
+  try {
+    body = await req.json();
+  } catch {
+    return NextResponse.json({ error: "Invalid JSON body." }, { status: 400 });
+  }
+
+  const { markdown, sanitize = true } = body;
+
+  if (typeof markdown !== "string") {
+    return NextResponse.json({ error: "markdown must be a string." }, { status: 400 });
+  }
+
+  try {
+    const result = processMarkdown(markdown, sanitize);
+    return NextResponse.json(result as MarkdownPreviewResponse);
+  } catch (error) {
+    const message = error instanceof Error ? error.message : "Processing failed";
+    return NextResponse.json({ error: message }, { status: 400 });
+  }
+}
diff --git a/app/api/routes-f/matrix-multiply/__tests__/route.test.ts b/app/api/routes-f/matrix-multiply/__tests__/route.test.ts
new file mode 100644
index 00000000..290e4182
--- /dev/null
+++ b/app/api/routes-f/matrix-multiply/__tests__/route.test.ts
@@ -0,0 +1,92 @@
+/**
+ * @jest-environment node
+ */
+import { NextRequest } from "next/server";
+import { POST } from "../route";
+
+function makeReq(body: unknown) {
+  return new NextRequest("http://localhost/api/routes-f/matrix-multiply", {
+    method: "POST",
+    headers: { "content-type": "application/json" },
+    body: JSON.stringify(body),
+  });
+}
+
+describe("POST /api/routes-f/matrix-multiply", () => {
+  it("multiplies square matrices", async () => {
+    const res = await POST(
+      makeReq({
+        a: [
+          [1, 2],
+          [3, 4],
+        ],
+        b: [
+          [5, 6],
+          [7, 8],
+        ],
+      })
+    );
+    const body = await res.json();
+
+    expect(res.status).toBe(200);
+    expect(body.result).toEqual([
+      [19, 22],
+      [43, 50],
+    ]);
+    expect(body.dimensions.result).toEqual({ rows: 2, columns: 2 });
+  });
+
+  it("multiplies rectangular matrices", async () => {
+    const res = await POST(
+      makeReq({
+        a: [
+          [1, 2, 3],
+          [4, 5, 6],
+        ],
+        b: [
+          [7, 8],
+          [9, 10],
+          [11, 12],
+        ],
+      })
+    );
+    const body = await res.json();
+
+    expect(res.status).toBe(200);
+    expect(body.result).toEqual([
+      [58, 64],
+      [139, 154],
+    ]);
+  });
+
+  it("preserves a matrix multiplied by identity", async () => {
+    const matrix = [
+      [2, -1],
+      [0, 3],
+    ];
+    const res = await POST(
+      makeReq({
+        a: matrix,
+        b: [
+          [1, 0],
+          [0, 1],
+        ],
+      })
+    );
+    const body = await res.json();
+
+    expect(res.status).toBe(200);
+    expect(body.result).toEqual(matrix);
+  });
+
+  it("rejects incompatible dimensions", async () => {
+    const res = await POST(
+      makeReq({
+        a: [[1, 2]],
+        b: [[1, 2]],
+      })
+    );
+
+    expect(res.status).toBe(400);
+  });
+});
diff --git a/app/api/routes-f/matrix-multiply/route.ts b/app/api/routes-f/matrix-multiply/route.ts
new file mode 100644
index 00000000..391c7f84
--- /dev/null
+++ b/app/api/routes-f/matrix-multiply/route.ts
@@ -0,0 +1,97 @@
+import { NextRequest, NextResponse } from "next/server";
+
+const MAX_DIMENSION = 100;
+
+type Matrix = number[][];
+
+function badRequest(message: string) {
+  return NextResponse.json({ error: message }, { status: 400 });
+}
+
+function validateMatrix(value: unknown, name: string): Matrix | string {
+  if (!Array.isArray(value) || value.length === 0) {
+    return `${name} must be a non-empty number matrix.`;
+  }
+
+  if (value.length > MAX_DIMENSION) {
+    return `${name} cannot exceed ${MAX_DIMENSION} rows.`;
+  }
+
+  const firstRow = value[0];
+  if (!Array.isArray(firstRow) || firstRow.length === 0) {
+    return `${name} must contain non-empty rows.`;
+  }
+
+  const columnCount = firstRow.length;
+  if (columnCount > MAX_DIMENSION) {
+    return `${name} cannot exceed ${MAX_DIMENSION} columns.`;
+  }
+
+  for (const row of value) {
+    if (!Array.isArray(row) || row.length !== columnCount) {
+      return `${name} must be rectangular.`;
+    }
+
+    if (!row.every(cell => typeof cell === "number" && Number.isFinite(cell))) {
+      return `${name} must contain only finite numbers.`;
+    }
+  }
+
+  return value as Matrix;
+}
+
+function multiplyMatrices(a: Matrix, b: Matrix): Matrix {
+  const rows = a.length;
+  const inner = b.length;
+  const columns = b[0].length;
+  const result: Matrix = Array.from({ length: rows }, () =>
+    Array.from({ length: columns }, () => 0)
+  );
+
+  for (let row = 0; row < rows; row += 1) {
+    for (let col = 0; col < columns; col += 1) {
+      let sum = 0;
+      for (let i = 0; i < inner; i += 1) {
+        sum += a[row][i] * b[i][col];
+      }
+      result[row][col] = sum;
+    }
+  }
+
+  return result;
+}
+
+export async function POST(req: NextRequest) {
+  let body: { a?: unknown; b?: unknown };
+
+  try {
+    body = await req.json();
+  } catch {
+    return badRequest("Invalid JSON body.");
+  }
+
+  const a = validateMatrix(body.a, "a");
+  if (typeof a === "string") {
+    return badRequest(a);
+  }
+
+  const b = validateMatrix(body.b, "b");
+  if (typeof b === "string") {
+    return badRequest(b);
+  }
+
+  if (a[0].length !== b.length) {
+    return badRequest("Matrix dimensions are incompatible for multiplication.");
+  }
+
+  const result = multiplyMatrices(a, b);
+
+  return NextResponse.json({
+    result,
+    dimensions: {
+      a: { rows: a.length, columns: a[0].length },
+      b: { rows: b.length, columns: b[0].length },
+      result: { rows: result.length, columns: result[0]?.length ?? 0 },
+    },
+  });
+}
diff --git a/app/api/routes-f/moon-phase/__tests__/route.test.ts b/app/api/routes-f/moon-phase/__tests__/route.test.ts
new file mode 100644
index 00000000..3278cb56
--- /dev/null
+++ b/app/api/routes-f/moon-phase/__tests__/route.test.ts
@@ -0,0 +1,102 @@
+/**
+ * @jest-environment node
+ */
+import { NextRequest } from "next/server";
+import { GET, moonPhaseAt, SYNODIC_MONTH, PHASE_NAMES } from "../route";
+
+function callGet(query: string) {
+  return GET(
+    new NextRequest(`http://localhost/api/routes-f/moon-phase${query}`)
+  );
+}
+
+describe("moonPhaseAt", () => {
+  it("reports a near-new moon on known new-moon dates", () => {
+    // NASA: new moon on 2024-01-11 and 2025-01-29.
+    for (const day of ["2024-01-11", "2025-01-29"]) {
+      const result = moonPhaseAt(new Date(`${day}T00:00:00Z`));
+      expect(result.phase_name).toBe("new");
+      expect(result.illumination_percent).toBeLessThan(2);
+    }
+  });
+
+  it("reports a near-full moon on known full-moon dates", () => {
+    // NASA: full moon on 2024-01-25 and 2025-01-13.
+    for (const day of ["2024-01-25", "2025-01-13"]) {
+      const result = moonPhaseAt(new Date(`${day}T00:00:00Z`));
+      expect(result.phase_name).toBe("full");
+      expect(result.illumination_percent).toBeGreaterThan(95);
+    }
+  });
+
+  it("reports ~0% illumination at the reference new moon epoch", () => {
+    // The epoch itself: 2000-01-06 18:14 UTC. age_days wraps to ~0.
+    const result = moonPhaseAt(new Date(Date.UTC(2000, 0, 6, 18, 14, 0)));
+    expect(result.age_days).toBeCloseTo(0, 1);
+    expect(result.illumination_percent).toBeCloseTo(0, 1);
+    expect(result.phase_name).toBe("new");
+  });
+
+  it("reports ~100% illumination half a synodic month after new moon", () => {
+    const epoch = Date.UTC(2000, 0, 6, 18, 14, 0);
+    const halfCycle = new Date(epoch + (SYNODIC_MONTH / 2) * 86_400_000);
+    const result = moonPhaseAt(halfCycle);
+    expect(result.phase_name).toBe("full");
+    expect(result.illumination_percent).toBeCloseTo(100, 1);
+    expect(result.age_days).toBeCloseTo(SYNODIC_MONTH / 2, 1);
+  });
+
+  it("walks through the eight phases across one synodic month", () => {
+    const epoch = Date.UTC(2000, 0, 6, 18, 14, 0);
+    const seen = new Set<string>();
+    for (let i = 0; i < 8; i++) {
+      const t = new Date(epoch + ((i * SYNODIC_MONTH) / 8) * 86_400_000);
+      seen.add(moonPhaseAt(t).phase_name);
+    }
+    expect(seen.size).toBe(8);
+    for (const name of PHASE_NAMES) {
+      expect(seen.has(name)).toBe(true);
+    }
+  });
+
+  it("keeps age_days within [0, synodic month)", () => {
+    for (const day of ["1999-06-01", "2000-01-06", "2030-12-31"]) {
+      const { age_days } = moonPhaseAt(new Date(`${day}T00:00:00Z`));
+      expect(age_days).toBeGreaterThanOrEqual(0);
+      expect(age_days).toBeLessThan(SYNODIC_MONTH);
+    }
+  });
+});
+
+describe("GET /api/routes-f/moon-phase", () => {
+  it("returns the phase for a valid date", async () => {
+    const res = await callGet("?date=2024-01-25");
+    expect(res.status).toBe(200);
+    const body = await res.json();
+    expect(body).toEqual({
+      phase_name: "full",
+      illumination_percent: expect.any(Number),
+      age_days: expect.any(Number),
+    });
+    expect(body.illumination_percent).toBeGreaterThan(95);
+  });
+
+  it("rejects a missing date param", async () => {
+    const res = await callGet("");
+    expect(res.status).toBe(400);
+    const body = await res.json();
+    expect(body.error).toBe("Invalid query parameters");
+  });
+
+  it("rejects a malformed date param", async () => {
+    const res = await callGet("?date=Jan-25-2024");
+    expect(res.status).toBe(400);
+  });
+
+  it("rejects a well-formed but impossible calendar date", async () => {
+    const res = await callGet("?date=2024-02-30");
+    expect(res.status).toBe(400);
+    const body = await res.json();
+    expect(body.error).toBe("Invalid query parameters");
+  });
+});
diff --git a/app/api/routes-f/moon-phase/route.ts b/app/api/routes-f/moon-phase/route.ts
new file mode 100644
index 00000000..a220d60f
--- /dev/null
+++ b/app/api/routes-f/moon-phase/route.ts
@@ -0,0 +1,122 @@
+import { NextResponse } from "next/server";
+import { z } from "zod";
+import { validateQuery } from "@/app/api/routes-f/_lib/validate";
+
+/**
+ * Mean length of a synodic month (one new-moon-to-new-moon cycle), in days.
+ * Source: Jean Meeus, "Astronomical Algorithms" (2nd ed.), the mean synodic
+ * month is 29.530588853 days. We use the commonly cited 29.53058867 value.
+ */
+export const SYNODIC_MONTH = 29.53058867;
+
+/**
+ * A well-documented reference new moon: 2000-01-06 18:14 UTC. Lunar age for any
+ * other instant is the elapsed time since this epoch reduced modulo the synodic
+ * month. This is the standard "synodic-month approximation" — it ignores the
+ * small irregularities in the Moon's orbit and is accurate to within ~1 day.
+ */
+export const REFERENCE_NEW_MOON_UTC = Date.UTC(2000, 0, 6, 18, 14, 0);
+
+/**
+ * The eight conventional moon phases, ordered from new moon through a full
+ * cycle. The four "principal" phases (new, first quarter, full, last quarter)
+ * sit at exact 1/4 points; the four intermediate phases fill the gaps.
+ */
+export const PHASE_NAMES = [
+  "new",
+  "waxing crescent",
+  "first quarter",
+  "waxing gibbous",
+  "full",
+  "waning gibbous",
+  "last quarter",
+  "waning crescent",
+] as const;
+
+export type PhaseName = (typeof PHASE_NAMES)[number];
+
+export interface MoonPhaseResult {
+  phase_name: PhaseName;
+  illumination_percent: number;
+  age_days: number;
+}
+
+/**
+ * Compute the moon phase for the given UTC instant.
+ *
+ * `age_days` is the time elapsed since the most recent new moon (0 .. synodic
+ * month). `illumination_percent` is the fraction of the lunar disc that appears
+ * lit, derived from the age via (1 - cos(2π·age/synodic)) / 2. `phase_name` is
+ * the nearest of the eight conventional phases, so each principal phase is
+ * centred on its exact age.
+ */
+export function moonPhaseAt(date: Date): MoonPhaseResult {
+  const elapsedDays = (date.getTime() - REFERENCE_NEW_MOON_UTC) / 86_400_000;
+
+  // Reduce into [0, SYNODIC_MONTH). `%` keeps the sign of the dividend, so add
+  // a synodic month before the final modulo to handle dates before the epoch.
+  const ageDays =
+    ((elapsedDays % SYNODIC_MONTH) + SYNODIC_MONTH) % SYNODIC_MONTH;
+
+  const cyclePosition = ageDays / SYNODIC_MONTH; // 0 .. 1
+  const illumination = (1 - Math.cos(2 * Math.PI * cyclePosition)) / 2;
+
+  // Round to the nearest eighth so principal phases occupy a narrow window
+  // centred on their exact age; `% 8` folds the wrap-around back onto "new".
+  const phaseIndex = Math.round(cyclePosition * 8) % 8;
+
+  return {
+    phase_name: PHASE_NAMES[phaseIndex],
+    illumination_percent: Math.round(illumination * 1000) / 10,
+    age_days: Math.round(ageDays * 100) / 100,
+  };
+}
+
+/**
+ * Parse a strict `YYYY-MM-DD` string as a UTC midnight instant, returning
+ * `null` for impossible calendar dates. `new Date(...)` silently rolls
+ * overflowing days into the next month (e.g. "2024-02-30" → Mar 1), so we
+ * verify the parsed components round-trip back to the input.
+ */
+export function parseCalendarDate(value: string): Date | null {
+  const match = /^(\d{4})-(\d{2})-(\d{2})$/.exec(value);
+  if (!match) {
+    return null;
+  }
+
+  const [, year, month, day] = match.map(Number);
+  const date = new Date(Date.UTC(year, month - 1, day));
+  if (
+    date.getUTCFullYear() !== year ||
+    date.getUTCMonth() !== month - 1 ||
+    date.getUTCDate() !== day
+  ) {
+    return null;
+  }
+  return date;
+}
+
+const schema = z.object({
+  date: z.string().regex(/^\d{4}-\d{2}-\d{2}$/, "date must be YYYY-MM-DD"),
+});
+
+export async function GET(request: Request): Promise<NextResponse> {
+  const { searchParams } = new URL(request.url);
+  const result = validateQuery(searchParams, schema);
+  if (result instanceof NextResponse) {
+    return result;
+  }
+
+  const date = parseCalendarDate(result.data.date);
+  if (!date) {
+    return NextResponse.json(
+      {
+        error: "Invalid query parameters",
+        details: "date is not a real calendar date",
+      },
+      { status: 400 }
+    );
+  }
+
+  return NextResponse.json(moonPhaseAt(date));
+}
diff --git a/app/api/routes-f/mortgage/route.ts b/app/api/routes-f/mortgage/route.ts
new file mode 100644
index 00000000..72569d59
--- /dev/null
+++ b/app/api/routes-f/mortgage/route.ts
@@ -0,0 +1,91 @@
+import { type NextRequest, NextResponse } from "next/server";
+
+function round2(n: number): number {
+  return Math.round(n * 100) / 100;
+}
+
+function isRecord(v: unknown): v is Record<string, unknown> {
+  return typeof v === "object" && v !== null && !Array.isArray(v);
+}
+
+export async function POST(req: NextRequest) {
+  let body: unknown;
+  try {
+    body = await req.json();
+  } catch {
+    return NextResponse.json({ error: "Invalid JSON body." }, { status: 400 });
+  }
+
+  if (!isRecord(body)) {
+    return NextResponse.json({ error: "Request body must be an object." }, { status: 400 });
+  }
+
+  const {
+    home_price,
+    down_payment,
+    annual_rate,
+    years,
+    property_tax_annual,
+    insurance_annual,
+    hoa_monthly,
+  } = body as Record<string, unknown>;
+
+  if (typeof home_price !== "number" || home_price <= 0) {
+    return NextResponse.json({ error: "home_price must be a positive number." }, { status: 400 });
+  }
+  if (typeof down_payment !== "number" || down_payment < 0) {
+    return NextResponse.json({ error: "down_payment must be non-negative." }, { status: 400 });
+  }
+  if (down_payment >= home_price) {
+    return NextResponse.json({ error: "down_payment must be less than home_price." }, { status: 400 });
+  }
+  if (typeof annual_rate !== "number" || annual_rate < 0) {
+    return NextResponse.json({ error: "annual_rate must be a non-negative number." }, { status: 400 });
+  }
+  if (typeof years !== "number" || years <= 0 || years > 50) {
+    return NextResponse.json({ error: "years must be between 1 and 50." }, { status: 400 });
+  }
+
+  const loan_amount = round2(home_price - down_payment);
+  const monthlyRate = annual_rate / 100 / 12;
+  const totalMonths = years * 12;
+
+  let monthly_pi: number;
+  if (monthlyRate === 0) {
+    monthly_pi = round2(loan_amount / totalMonths);
+  } else {
+    const factor = Math.pow(1 + monthlyRate, totalMonths);
+    monthly_pi = round2((loan_amount * monthlyRate * factor) / (factor - 1));
+  }
+
+  const total_paid_pi = round2(monthly_pi * totalMonths);
+  const total_interest = round2(total_paid_pi - loan_amount);
+
+  const monthly_taxes = round2(
+    typeof property_tax_annual === "number" ? property_tax_annual / 12 : 0
+  );
+  const monthly_insurance = round2(
+    typeof insurance_annual === "number" ? insurance_annual / 12 : 0
+  );
+  const monthly_hoa = typeof hoa_monthly === "number" ? round2(hoa_monthly) : 0;
+
+  const monthly_total = round2(monthly_pi + monthly_taxes + monthly_insurance + monthly_hoa);
+  const ltv_ratio = round2((loan_amount / home_price) * 100);
+
+  const payoffDate = new Date();
+  payoffDate.setMonth(payoffDate.getMonth() + totalMonths);
+  const payoff_date = payoffDate.toISOString().slice(0, 7);
+
+  return NextResponse.json({
+    loan_amount,
+    monthly_principal_interest: monthly_pi,
+    monthly_taxes,
+    monthly_insurance,
+    monthly_hoa,
+    monthly_total,
+    total_interest,
+    total_paid: round2(total_paid_pi + (monthly_taxes + monthly_insurance + monthly_hoa) * totalMonths),
+    ltv_ratio,
+    payoff_date,
+  });
+}
diff --git a/app/api/routes-f/mute-creator/__tests__/route.test.ts b/app/api/routes-f/mute-creator/__tests__/route.test.ts
new file mode 100644
index 00000000..2a56a49e
--- /dev/null
+++ b/app/api/routes-f/mute-creator/__tests__/route.test.ts
@@ -0,0 +1,105 @@
+import { GET, POST, DELETE } from "../route";
+import { __resetMuteStore } from "../_lib/store";
+import { NextRequest } from "next/server";
+
+const BASE = "http://localhost/api/routes-f/mute-creator";
+
+function req(method: string, body?: object, search?: string) {
+  const url = search ? `${BASE}?${search}` : BASE;
+  return new NextRequest(url, {
+    method,
+    ...(body
+      ? { body: JSON.stringify(body), headers: { "Content-Type": "application/json" } }
+      : {}),
+  });
+}
+
+beforeEach(() => {
+  __resetMuteStore();
+});
+
+describe("POST /mute-creator — mute", () => {
+  it("mutes a creator and returns muted_at", async () => {
+    const res = await POST(req("POST", { follower_id: "user-1", creator_id: "creator-1" }));
+    expect(res.status).toBe(201);
+    const body = await res.json();
+    expect(typeof body.muted_at).toBe("string");
+    expect(new Date(body.muted_at).getTime()).not.toBeNaN();
+  });
+
+  it("returns 409 when already muted", async () => {
+    await POST(req("POST", { follower_id: "user-1", creator_id: "creator-1" }));
+    const res = await POST(req("POST", { follower_id: "user-1", creator_id: "creator-1" }));
+    expect(res.status).toBe(409);
+    expect((await res.json()).error).toMatch(/already muted/i);
+  });
+
+  it("returns 400 when a user tries to mute themselves", async () => {
+    const res = await POST(req("POST", { follower_id: "user-1", creator_id: "user-1" }));
+    expect(res.status).toBe(400);
+    expect((await res.json()).error).toMatch(/cannot mute themselves/i);
+  });
+
+  it("returns 400 when follower_id is missing", async () => {
+    const res = await POST(req("POST", { creator_id: "creator-1" }));
+    expect(res.status).toBe(400);
+  });
+
+  it("returns 400 when creator_id is missing", async () => {
+    const res = await POST(req("POST", { follower_id: "user-1" }));
+    expect(res.status).toBe(400);
+  });
+});
+
+describe("DELETE /mute-creator — unmute", () => {
+  it("unmutes a previously muted creator", async () => {
+    await POST(req("POST", { follower_id: "user-1", creator_id: "creator-1" }));
+    const res = await DELETE(req("DELETE", { follower_id: "user-1", creator_id: "creator-1" }));
+    expect(res.status).toBe(200);
+    expect((await res.json()).message).toMatch(/unmuted/i);
+  });
+
+  it("returns 404 when the mute record does not exist", async () => {
+    const res = await DELETE(req("DELETE", { follower_id: "user-1", creator_id: "ghost-creator" }));
+    expect(res.status).toBe(404);
+    expect((await res.json()).error).toMatch(/not found/i);
+  });
+});
+
+describe("GET /mute-creator — list muted creators", () => {
+  it("returns an empty list when no creators are muted", async () => {
+    const res = await GET(req("GET", undefined, "follower_id=user-1"));
+    expect(res.status).toBe(200);
+    const body = await res.json();
+    expect(body.muted).toHaveLength(0);
+    expect(body.count).toBe(0);
+  });
+
+  it("lists all muted creators for the given follower", async () => {
+    await POST(req("POST", { follower_id: "user-1", creator_id: "creator-a" }));
+    await POST(req("POST", { follower_id: "user-1", creator_id: "creator-b" }));
+    await POST(req("POST", { follower_id: "user-2", creator_id: "creator-a" }));
+
+    const res = await GET(req("GET", undefined, "follower_id=user-1"));
+    const body = await res.json();
+
+    expect(body.count).toBe(2);
+    expect(body.muted.map((r: { creator_id: string }) => r.creator_id).sort()).toEqual([
+      "creator-a",
+      "creator-b",
+    ]);
+  });
+
+  it("does not include creators muted after an unmute", async () => {
+    await POST(req("POST", { follower_id: "user-1", creator_id: "creator-a" }));
+    await DELETE(req("DELETE", { follower_id: "user-1", creator_id: "creator-a" }));
+
+    const res = await GET(req("GET", undefined, "follower_id=user-1"));
+    expect((await res.json()).count).toBe(0);
+  });
+
+  it("returns 400 when follower_id query param is missing", async () => {
+    const res = await GET(req("GET"));
+    expect(res.status).toBe(400);
+  });
+});
diff --git a/app/api/routes-f/mute-creator/_lib/store.ts b/app/api/routes-f/mute-creator/_lib/store.ts
new file mode 100644
index 00000000..4ce54227
--- /dev/null
+++ b/app/api/routes-f/mute-creator/_lib/store.ts
@@ -0,0 +1,53 @@
+import type { MuteRecord } from "./types";
+
+// Keyed by `${follower_id}:${creator_id}` for O(1) lookups
+const mutes = new Map<string, MuteRecord>();
+
+function muteKey(followerId: string, creatorId: string): string {
+  return `${followerId}:${creatorId}`;
+}
+
+export function muteCreator(
+  followerId: string,
+  creatorId: string,
+): { ok: true; record: MuteRecord } | { ok: false; error: string; status: number } {
+  if (followerId === creatorId) {
+    return { ok: false, error: "A user cannot mute themselves.", status: 400 };
+  }
+
+  const key = muteKey(followerId, creatorId);
+  if (mutes.has(key)) {
+    return { ok: false, error: "Creator is already muted.", status: 409 };
+  }
+
+  const record: MuteRecord = {
+    follower_id: followerId,
+    creator_id: creatorId,
+    muted_at: new Date().toISOString(),
+  };
+
+  mutes.set(key, record);
+  return { ok: true, record };
+}
+
+export function unmuteCreator(
+  followerId: string,
+  creatorId: string,
+): { ok: true } | { ok: false; error: string; status: number } {
+  const key = muteKey(followerId, creatorId);
+  if (!mutes.has(key)) {
+    return { ok: false, error: "Mute record not found.", status: 404 };
+  }
+  mutes.delete(key);
+  return { ok: true };
+}
+
+export function listMutedCreators(followerId: string): MuteRecord[] {
+  return Array.from(mutes.values())
+    .filter((r) => r.follower_id === followerId)
+    .sort((a, b) => a.muted_at.localeCompare(b.muted_at));
+}
+
+export function __resetMuteStore(): void {
+  mutes.clear();
+}
diff --git a/app/api/routes-f/mute-creator/_lib/types.ts b/app/api/routes-f/mute-creator/_lib/types.ts
new file mode 100644
index 00000000..f606fc46
--- /dev/null
+++ b/app/api/routes-f/mute-creator/_lib/types.ts
@@ -0,0 +1,5 @@
+export interface MuteRecord {
+  follower_id: string;
+  creator_id: string;
+  muted_at: string;
+}
diff --git a/app/api/routes-f/mute-creator/route.ts b/app/api/routes-f/mute-creator/route.ts
new file mode 100644
index 00000000..cec49b87
--- /dev/null
+++ b/app/api/routes-f/mute-creator/route.ts
@@ -0,0 +1,87 @@
+import { NextRequest, NextResponse } from "next/server";
+import { muteCreator, unmuteCreator, listMutedCreators } from "./_lib/store";
+
+// GET /api/routes-f/mute-creator?follower_id=<id>
+export async function GET(req: NextRequest) {
+  const followerId = req.nextUrl.searchParams.get("follower_id");
+
+  if (!followerId || followerId.trim().length === 0) {
+    return NextResponse.json(
+      { error: "follower_id query parameter is required." },
+      { status: 400 },
+    );
+  }
+
+  const muted = listMutedCreators(followerId.trim());
+  return NextResponse.json({ muted, count: muted.length });
+}
+
+// POST /api/routes-f/mute-creator
+// Body: { follower_id, creator_id }
+export async function POST(req: NextRequest) {
+  let body: { follower_id?: unknown; creator_id?: unknown };
+  try {
+    body = await req.json();
+  } catch {
+    return NextResponse.json({ error: "Invalid JSON body." }, { status: 400 });
+  }
+
+  const { follower_id, creator_id } = body;
+
+  if (typeof follower_id !== "string" || follower_id.trim().length === 0) {
+    return NextResponse.json(
+      { error: "follower_id is required and must be a non-empty string." },
+      { status: 400 },
+    );
+  }
+
+  if (typeof creator_id !== "string" || creator_id.trim().length === 0) {
+    return NextResponse.json(
+      { error: "creator_id is required and must be a non-empty string." },
+      { status: 400 },
+    );
+  }
+
+  const result = muteCreator(follower_id.trim(), creator_id.trim());
+
+  if (!result.ok) {
+    return NextResponse.json({ error: result.error }, { status: result.status });
+  }
+
+  return NextResponse.json({ muted_at: result.record.muted_at }, { status: 201 });
+}
+
+// DELETE /api/routes-f/mute-creator
+// Body: { follower_id, creator_id }
+export async function DELETE(req: NextRequest) {
+  let body: { follower_id?: unknown; creator_id?: unknown };
+  try {
+    body = await req.json();
+  } catch {
+    return NextResponse.json({ error: "Invalid JSON body." }, { status: 400 });
+  }
+
+  const { follower_id, creator_id } = body;
+
+  if (typeof follower_id !== "string" || follower_id.trim().length === 0) {
+    return NextResponse.json(
+      { error: "follower_id is required and must be a non-empty string." },
+      { status: 400 },
+    );
+  }
+
+  if (typeof creator_id !== "string" || creator_id.trim().length === 0) {
+    return NextResponse.json(
+      { error: "creator_id is required and must be a non-empty string." },
+      { status: 400 },
+    );
+  }
+
+  const result = unmuteCreator(follower_id.trim(), creator_id.trim());
+
+  if (!result.ok) {
+    return NextResponse.json({ error: result.error }, { status: result.status });
+  }
+
+  return NextResponse.json({ message: "Creator unmuted successfully." });
+}
diff --git a/app/api/routes-f/nanoid/_lib/helpers.ts b/app/api/routes-f/nanoid/_lib/helpers.ts
new file mode 100644
index 00000000..80a249a8
--- /dev/null
+++ b/app/api/routes-f/nanoid/_lib/helpers.ts
@@ -0,0 +1,76 @@
+import { randomBytes } from "crypto";
+
+const DEFAULT_ALPHABET =
+  "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789_-";
+const DEFAULT_SIZE = 21;
+const DEFAULT_COUNT = 1;
+const MAX_COUNT = 100;
+
+function isRecord(value: unknown): value is Record<string, unknown> {
+  return typeof value === "object" && value !== null && !Array.isArray(value);
+}
+
+export function generateId(size: number, alphabet: string): string {
+  const alphabetLength = alphabet.length;
+  // Use rejection sampling to avoid modulo bias
+  const mask = Math.pow(2, Math.ceil(Math.log2(alphabetLength))) - 1;
+  const bytesNeeded = Math.ceil((size * 1.6) / 1); // slight overallocation
+  let id = "";
+
+  while (id.length < size) {
+    const bytes = randomBytes(bytesNeeded);
+    for (let i = 0; i < bytes.length && id.length < size; i++) {
+      const byte = bytes[i] & mask;
+      if (byte < alphabetLength) {
+        id += alphabet[byte];
+      }
+    }
+  }
+
+  return id;
+}
+
+export function parseAndGenerate(input: unknown): { ids: string[] } {
+  if (!isRecord(input)) {
+    throw new Error("Request body must be an object.");
+  }
+
+  let count = DEFAULT_COUNT;
+  let size = DEFAULT_SIZE;
+  let alphabet = DEFAULT_ALPHABET;
+
+  if (input.count !== undefined) {
+    if (
+      typeof input.count !== "number" ||
+      !Number.isInteger(input.count) ||
+      input.count < 1
+    ) {
+      throw new Error("count must be a positive integer.");
+    }
+    if (input.count > MAX_COUNT) {
+      throw new Error(`count must not exceed ${MAX_COUNT}.`);
+    }
+    count = input.count;
+  }
+
+  if (input.size !== undefined) {
+    if (
+      typeof input.size !== "number" ||
+      !Number.isInteger(input.size) ||
+      input.size < 1
+    ) {
+      throw new Error("size must be a positive integer.");
+    }
+    size = input.size;
+  }
+
+  if (input.alphabet !== undefined) {
+    if (typeof input.alphabet !== "string" || input.alphabet.length < 2) {
+      throw new Error("alphabet must be a string with at least 2 characters.");
+    }
+    alphabet = input.alphabet;
+  }
+
+  const ids = Array.from({ length: count }, () => generateId(size, alphabet));
+  return { ids };
+}
diff --git a/app/api/routes-f/nanoid/_lib/types.ts b/app/api/routes-f/nanoid/_lib/types.ts
new file mode 100644
index 00000000..96fe4681
--- /dev/null
+++ b/app/api/routes-f/nanoid/_lib/types.ts
@@ -0,0 +1,3 @@
+export interface NanoidResponse {
+  ids: string[];
+}
diff --git a/app/api/routes-f/nanoid/route.ts b/app/api/routes-f/nanoid/route.ts
new file mode 100644
index 00000000..2852b4ab
--- /dev/null
+++ b/app/api/routes-f/nanoid/route.ts
@@ -0,0 +1,22 @@
+import { type NextRequest, NextResponse } from "next/server";
+import { parseAndGenerate } from "./_lib/helpers";
+import type { NanoidResponse } from "./_lib/types";
+
+export async function POST(req: NextRequest) {
+  let body: unknown;
+
+  try {
+    body = await req.json();
+  } catch {
+    return NextResponse.json({ error: "Invalid JSON body." }, { status: 400 });
+  }
+
+  try {
+    const result = parseAndGenerate(body);
+    return NextResponse.json(result satisfies NanoidResponse);
+  } catch (error) {
+    const message =
+      error instanceof Error ? error.message : "Failed to generate IDs.";
+    return NextResponse.json({ error: message }, { status: 400 });
+  }
+}
diff --git a/app/api/routes-f/notification-preferences/__tests__/notification-preferences.test.ts b/app/api/routes-f/notification-preferences/__tests__/notification-preferences.test.ts
new file mode 100644
index 00000000..1777473f
--- /dev/null
+++ b/app/api/routes-f/notification-preferences/__tests__/notification-preferences.test.ts
@@ -0,0 +1,120 @@
+/**
+ * @jest-environment node
+ */
+import { NextRequest } from "next/server";
+import { GET, PUT, prefsStore } from "../route";
+
+const BASE_URL = "http://localhost/api/routes-f/notification-preferences";
+const VIEWER_ID = "v-0001-0000-4000-8000-000000000001";
+const OTHER_VIEWER = "v-0002-0000-4000-8000-000000000002";
+
+function makeGet(params: Record<string, string>) {
+  const url = new URL(BASE_URL);
+  for (const [k, v] of Object.entries(params)) url.searchParams.set(k, v);
+  return new NextRequest(url.toString(), { method: "GET" });
+}
+
+function makePut(body: unknown) {
+  return new NextRequest(BASE_URL, {
+    method: "PUT",
+    headers: { "content-type": "application/json" },
+    body: JSON.stringify(body),
+  });
+}
+
+describe("GET /api/routes-f/notification-preferences", () => {
+  beforeEach(() => prefsStore.clear());
+
+  it("returns defaults (all true except email_digest) for unknown viewer", async () => {
+    const res = await GET(makeGet({ viewer_id: VIEWER_ID }));
+    expect(res.status).toBe(200);
+    const body = await res.json();
+    expect(body).toEqual({
+      live_alerts: true,
+      tips_received: true,
+      chat_mentions: true,
+      email_digest: false,
+    });
+  });
+
+  it("returns stored prefs after a PUT", async () => {
+    await PUT(makePut({ viewer_id: VIEWER_ID, live_alerts: false, email_digest: true }));
+    const res = await GET(makeGet({ viewer_id: VIEWER_ID }));
+    const body = await res.json();
+    expect(body.live_alerts).toBe(false);
+    expect(body.email_digest).toBe(true);
+    // untouched fields keep their defaults
+    expect(body.tips_received).toBe(true);
+    expect(body.chat_mentions).toBe(true);
+  });
+
+  it("different viewers have independent prefs", async () => {
+    await PUT(makePut({ viewer_id: VIEWER_ID, live_alerts: false }));
+    const res = await GET(makeGet({ viewer_id: OTHER_VIEWER }));
+    const body = await res.json();
+    expect(body.live_alerts).toBe(true);
+  });
+
+  it("400 — missing viewer_id", async () => {
+    const res = await GET(makeGet({}));
+    expect(res.status).toBe(400);
+  });
+});
+
+describe("PUT /api/routes-f/notification-preferences", () => {
+  beforeEach(() => prefsStore.clear());
+
+  it("updates a single field, leaves others at defaults", async () => {
+    const res = await PUT(makePut({ viewer_id: VIEWER_ID, chat_mentions: false }));
+    expect(res.status).toBe(200);
+    const body = await res.json();
+    expect(body.chat_mentions).toBe(false);
+    expect(body.live_alerts).toBe(true);
+    expect(body.tips_received).toBe(true);
+    expect(body.email_digest).toBe(false);
+  });
+
+  it("updates all four fields at once", async () => {
+    const res = await PUT(
+      makePut({
+        viewer_id: VIEWER_ID,
+        live_alerts: false,
+        tips_received: false,
+        chat_mentions: false,
+        email_digest: true,
+      })
+    );
+    const body = await res.json();
+    expect(body).toEqual({
+      live_alerts: false,
+      tips_received: false,
+      chat_mentions: false,
+      email_digest: true,
+    });
+  });
+
+  it("second PUT merges on top of first", async () => {
+    await PUT(makePut({ viewer_id: VIEWER_ID, live_alerts: false }));
+    await PUT(makePut({ viewer_id: VIEWER_ID, email_digest: true }));
+    const res = await GET(makeGet({ viewer_id: VIEWER_ID }));
+    const body = await res.json();
+    expect(body.live_alerts).toBe(false);
+    expect(body.email_digest).toBe(true);
+  });
+
+  it("400 — missing viewer_id", async () => {
+    const res = await PUT(makePut({ live_alerts: false }));
+    expect(res.status).toBe(400);
+  });
+
+  it("400 — invalid JSON body", async () => {
+    const res = await PUT(
+      new NextRequest(BASE_URL, {
+        method: "PUT",
+        headers: { "content-type": "application/json" },
+        body: "not-json",
+      })
+    );
+    expect(res.status).toBe(400);
+  });
+});
diff --git a/app/api/routes-f/notification-preferences/route.ts b/app/api/routes-f/notification-preferences/route.ts
new file mode 100644
index 00000000..685ce376
--- /dev/null
+++ b/app/api/routes-f/notification-preferences/route.ts
@@ -0,0 +1,61 @@
+/**
+ * GET  /api/routes-f/notification-preferences?viewer_id=
+ * PUT  /api/routes-f/notification-preferences
+ *
+ * Per-viewer notification preferences for live alerts, tips, mentions, email digest.
+ * Defaults: all true except email_digest (false).
+ * Uses in-memory storage — no real DB.
+ */
+import { NextRequest, NextResponse } from "next/server";
+import { z } from "zod";
+import { validateQuery, validateBody } from "@/app/api/routes-f/_lib/validate";
+
+export interface NotificationPrefs {
+  viewer_id: string;
+  live_alerts: boolean;
+  tips_received: boolean;
+  chat_mentions: boolean;
+  email_digest: boolean;
+}
+
+export const prefsStore: Map<string, NotificationPrefs> = new Map();
+
+function defaults(viewer_id: string): NotificationPrefs {
+  return { viewer_id, live_alerts: true, tips_received: true, chat_mentions: true, email_digest: false };
+}
+
+const getQuerySchema = z.object({
+  viewer_id: z.string().min(1, "viewer_id is required"),
+});
+
+const putBodySchema = z.object({
+  viewer_id: z.string().min(1, "viewer_id is required"),
+  live_alerts: z.boolean().optional(),
+  tips_received: z.boolean().optional(),
+  chat_mentions: z.boolean().optional(),
+  email_digest: z.boolean().optional(),
+});
+
+export async function GET(req: NextRequest): Promise<NextResponse> {
+  const { searchParams } = new URL(req.url);
+  const result = validateQuery(searchParams, getQuerySchema);
+  if (result instanceof NextResponse) return result;
+
+  const { viewer_id } = result.data;
+  const prefs = prefsStore.get(viewer_id) ?? defaults(viewer_id);
+  const { live_alerts, tips_received, chat_mentions, email_digest } = prefs;
+  return NextResponse.json({ live_alerts, tips_received, chat_mentions, email_digest });
+}
+
+export async function PUT(req: NextRequest): Promise<NextResponse> {
+  const result = await validateBody(req, putBodySchema);
+  if (result instanceof NextResponse) return result;
+
+  const { viewer_id, ...updates } = result.data;
+  const existing = prefsStore.get(viewer_id) ?? defaults(viewer_id);
+  const updated: NotificationPrefs = { ...existing, ...updates };
+  prefsStore.set(viewer_id, updated);
+
+  const { live_alerts, tips_received, chat_mentions, email_digest } = updated;
+  return NextResponse.json({ live_alerts, tips_received, chat_mentions, email_digest });
+}
diff --git a/app/api/routes-f/notifications/preferences/__tests__/preferences.test.ts b/app/api/routes-f/notifications/preferences/__tests__/preferences.test.ts
new file mode 100644
index 00000000..fad177d7
--- /dev/null
+++ b/app/api/routes-f/notifications/preferences/__tests__/preferences.test.ts
@@ -0,0 +1,187 @@
+/**
+ * @jest-environment node
+ */
+import { NextRequest } from "next/server";
+import { GET, PUT, preferencesStore } from "../route";
+
+const BASE_URL = "http://localhost/api/routes-f/notifications/preferences";
+
+const FOLLOWER_ID = "f0110000-0000-4000-8000-000000000001";
+const CREATOR_ID = "c0110000-0000-4000-8000-000000000002";
+const OTHER_CREATOR = "c0110000-0000-4000-8000-000000000003";
+
+function makeGetReq(params: Record<string, string>) {
+  const url = new URL(BASE_URL);
+  for (const [k, v] of Object.entries(params)) {
+    url.searchParams.set(k, v);
+  }
+  return new NextRequest(url.toString(), { method: "GET" });
+}
+
+function makePutReq(body: unknown) {
+  return new NextRequest(BASE_URL, {
+    method: "PUT",
+    headers: { "content-type": "application/json" },
+    body: JSON.stringify(body),
+  });
+}
+
+describe("GET + PUT /api/routes-f/notifications/preferences", () => {
+  beforeEach(() => {
+    preferencesStore.clear();
+  });
+
+  // -------------------------------------------------------------------------
+  // GET
+  // -------------------------------------------------------------------------
+  describe("GET", () => {
+    it("returns defaults (both true) when no preference has been stored", async () => {
+      const res = await GET(
+        makeGetReq({ follower_id: FOLLOWER_ID, creator_id: CREATOR_ID })
+      );
+      expect(res.status).toBe(200);
+      const body = await res.json();
+      expect(body).toEqual({ notify_live: true, notify_vods: true });
+    });
+
+    it("returns stored preference after a PUT", async () => {
+      // PUT first
+      await PUT(
+        makePutReq({
+          follower_id: FOLLOWER_ID,
+          creator_id: CREATOR_ID,
+          notify_live: false,
+          notify_vods: true,
+        })
+      );
+
+      const res = await GET(
+        makeGetReq({ follower_id: FOLLOWER_ID, creator_id: CREATOR_ID })
+      );
+      expect(res.status).toBe(200);
+      const body = await res.json();
+      expect(body).toEqual({ notify_live: false, notify_vods: true });
+    });
+
+    it("400 — missing follower_id", async () => {
+      const res = await GET(makeGetReq({ creator_id: CREATOR_ID }));
+      expect(res.status).toBe(400);
+      const body = await res.json();
+      expect(body.error).toBeTruthy();
+    });
+
+    it("400 — missing creator_id", async () => {
+      const res = await GET(makeGetReq({ follower_id: FOLLOWER_ID }));
+      expect(res.status).toBe(400);
+    });
+
+    it("400 — both params missing", async () => {
+      const res = await GET(makeGetReq({}));
+      expect(res.status).toBe(400);
+    });
+
+    it("isolates preferences per creator — defaults still apply for an unset creator", async () => {
+      // Store prefs for CREATOR_ID
+      await PUT(
+        makePutReq({
+          follower_id: FOLLOWER_ID,
+          creator_id: CREATOR_ID,
+          notify_live: false,
+          notify_vods: false,
+        })
+      );
+
+      // OTHER_CREATOR should still have defaults
+      const res = await GET(
+        makeGetReq({ follower_id: FOLLOWER_ID, creator_id: OTHER_CREATOR })
+      );
+      const body = await res.json();
+      expect(body).toEqual({ notify_live: true, notify_vods: true });
+    });
+  });
+
+  // -------------------------------------------------------------------------
+  // PUT
+  // -------------------------------------------------------------------------
+  describe("PUT", () => {
+    it("stores and returns the updated preferences", async () => {
+      const res = await PUT(
+        makePutReq({
+          follower_id: FOLLOWER_ID,
+          creator_id: CREATOR_ID,
+          notify_live: false,
+          notify_vods: true,
+        })
+      );
+      expect(res.status).toBe(200);
+      const body = await res.json();
+      expect(body).toEqual({ notify_live: false, notify_vods: true });
+    });
+
+    it("partial update merges with existing — unset fields keep their prior value", async () => {
+      // Set both to false
+      await PUT(
+        makePutReq({
+          follower_id: FOLLOWER_ID,
+          creator_id: CREATOR_ID,
+          notify_live: false,
+          notify_vods: false,
+        })
+      );
+
+      // Update only notify_live
+      const res = await PUT(
+        makePutReq({
+          follower_id: FOLLOWER_ID,
+          creator_id: CREATOR_ID,
+          notify_live: true,
+        })
+      );
+      expect(res.status).toBe(200);
+      const body = await res.json();
+      expect(body).toEqual({ notify_live: true, notify_vods: false });
+    });
+
+    it("subsequent GET reflects the PUT change", async () => {
+      await PUT(
+        makePutReq({
+          follower_id: FOLLOWER_ID,
+          creator_id: CREATOR_ID,
+          notify_live: false,
+          notify_vods: false,
+        })
+      );
+
+      const res = await GET(
+        makeGetReq({ follower_id: FOLLOWER_ID, creator_id: CREATOR_ID })
+      );
+      const body = await res.json();
+      expect(body).toEqual({ notify_live: false, notify_vods: false });
+    });
+
+    it("400 — missing follower_id", async () => {
+      const res = await PUT(
+        makePutReq({ creator_id: CREATOR_ID, notify_live: false })
+      );
+      expect(res.status).toBe(400);
+    });
+
+    it("400 — missing creator_id", async () => {
+      const res = await PUT(
+        makePutReq({ follower_id: FOLLOWER_ID, notify_live: false })
+      );
+      expect(res.status).toBe(400);
+    });
+
+    it("400 — notify_live is not a boolean", async () => {
+      const res = await PUT(
+        makePutReq({
+          follower_id: FOLLOWER_ID,
+          creator_id: CREATOR_ID,
+          notify_live: "yes",
+        })
+      );
+      expect(res.status).toBe(400);
+    });
+  });
+});
diff --git a/app/api/routes-f/notifications/preferences/route.ts b/app/api/routes-f/notifications/preferences/route.ts
new file mode 100644
index 00000000..d43bf15d
--- /dev/null
+++ b/app/api/routes-f/notifications/preferences/route.ts
@@ -0,0 +1,96 @@
+/**
+ * GET  /api/routes-f/notifications/preferences?follower_id=&creator_id=
+ * PUT  /api/routes-f/notifications/preferences
+ *
+ * Manages per-follower notification preferences for a given creator.
+ * Uses in-memory storage (mock) — no real DB.
+ */
+import { NextRequest, NextResponse } from "next/server";
+import { z } from "zod";
+import { validateBody, validateQuery } from "@/app/api/routes-f/_lib/validate";
+
+// ---------------------------------------------------------------------------
+// Types
+// ---------------------------------------------------------------------------
+export interface NotificationPreference {
+  follower_id: string;
+  creator_id: string;
+  notify_live: boolean;
+  notify_vods: boolean;
+}
+
+// ---------------------------------------------------------------------------
+// In-memory storage
+// Key: `${follower_id}:${creator_id}`
+// Exported so tests can reset between runs.
+// ---------------------------------------------------------------------------
+export const preferencesStore: Map<string, NotificationPreference> = new Map();
+
+function storeKey(followerId: string, creatorId: string): string {
+  return `${followerId}:${creatorId}`;
+}
+
+// ---------------------------------------------------------------------------
+// Validation schemas
+// ---------------------------------------------------------------------------
+const getQuerySchema = z.object({
+  follower_id: z.string().min(1, "follower_id is required"),
+  creator_id: z.string().min(1, "creator_id is required"),
+});
+
+const putBodySchema = z.object({
+  follower_id: z.string().min(1, "follower_id is required"),
+  creator_id: z.string().min(1, "creator_id is required"),
+  notify_live: z.boolean().optional(),
+  notify_vods: z.boolean().optional(),
+});
+
+// ---------------------------------------------------------------------------
+// Route handlers
+// ---------------------------------------------------------------------------
+export async function GET(req: NextRequest): Promise<NextResponse> {
+  const { searchParams } = new URL(req.url);
+  const queryResult = validateQuery(searchParams, getQuerySchema);
+  if (queryResult instanceof NextResponse) {
+    return queryResult;
+  }
+
+  const { follower_id, creator_id } = queryResult.data;
+  const key = storeKey(follower_id, creator_id);
+
+  const stored = preferencesStore.get(key);
+
+  // Default both to true when no preference has been stored yet.
+  const prefs: Pick<NotificationPreference, "notify_live" | "notify_vods"> = {
+    notify_live: stored?.notify_live ?? true,
+    notify_vods: stored?.notify_vods ?? true,
+  };
+
+  return NextResponse.json(prefs);
+}
+
+export async function PUT(req: NextRequest): Promise<NextResponse> {
+  const bodyResult = await validateBody(req, putBodySchema);
+  if (bodyResult instanceof NextResponse) {
+    return bodyResult;
+  }
+
+  const { follower_id, creator_id, notify_live, notify_vods } = bodyResult.data;
+  const key = storeKey(follower_id, creator_id);
+
+  // Merge with existing prefs (defaulting to true for any un-set field).
+  const existing = preferencesStore.get(key);
+  const updated: NotificationPreference = {
+    follower_id,
+    creator_id,
+    notify_live: notify_live ?? existing?.notify_live ?? true,
+    notify_vods: notify_vods ?? existing?.notify_vods ?? true,
+  };
+
+  preferencesStore.set(key, updated);
+
+  return NextResponse.json({
+    notify_live: updated.notify_live,
+    notify_vods: updated.notify_vods,
+  });
+}
diff --git a/app/api/routes-f/nth-prime/route.ts b/app/api/routes-f/nth-prime/route.ts
new file mode 100644
index 00000000..bc3e1e03
--- /dev/null
+++ b/app/api/routes-f/nth-prime/route.ts
@@ -0,0 +1,33 @@
+import { type NextRequest, NextResponse } from "next/server";
+import { z } from "zod";
+import { validateQuery } from "@/app/api/routes-f/_lib/validate";
+import { findNthPrime } from "@/app/api/routes-f/_lib/prime";
+
+const querySchema = z.object({
+  n: z.string(),
+});
+
+export async function GET(req: NextRequest) {
+  const validated = validateQuery(req.nextUrl.searchParams, querySchema);
+  if (validated instanceof NextResponse) {
+    return validated;
+  }
+
+  const n = Number(validated.data.n);
+  if (!Number.isInteger(n) || n < 1 || n > 100000) {
+    return NextResponse.json(
+      { error: "n must be an integer between 1 and 100000." },
+      { status: 400 }
+    );
+  }
+
+  try {
+    const prime = findNthPrime(n);
+    return NextResponse.json({ n, prime });
+  } catch (error) {
+    return NextResponse.json(
+      { error: error instanceof Error ? error.message : "Failed to compute nth prime." },
+      { status: 400 }
+    );
+  }
+}
diff --git a/app/api/routes-f/onboarding/complete/route.ts b/app/api/routes-f/onboarding/complete/route.ts
new file mode 100644
index 00000000..21926aad
--- /dev/null
+++ b/app/api/routes-f/onboarding/complete/route.ts
@@ -0,0 +1,102 @@
+// @ts-nocheck
+import { NextRequest, NextResponse } from "next/server";
+import { db } from "@/lib/db";
+import { getAuthUser } from "@/lib/auth";
+
+const VALID_STEPS = [
+  "set_avatar",
+  "set_bio",
+  "set_stream_title",
+  "add_category",
+  "first_stream",
+  "connect_wallet",
+  "first_follower",
+  "first_tip",
+];
+
+/**
+ * POST /api/routes-f/onboarding/complete
+ * Mark a step as manually complete (for edge cases like wallet connection).
+ * Also handles { dismiss: true } to hide the checklist.
+ * When all 8 steps complete, awards the onboarding_complete badge.
+ */
+export async function POST(req: NextRequest) {
+  const user = await getAuthUser(req);
+  if (!user) {
+    return NextResponse.json({ error: "Unauthorized" }, { status: 401 });
+  }
+
+  const body = await req.json();
+  const { step_id, dismiss } = body;
+
+  if (dismiss === true) {
+    // Upsert and set dismissed = true
+    await db.query(
+      `INSERT INTO onboarding_progress (user_id, dismissed, updated_at)
+       VALUES ($1, true, now())
+       ON CONFLICT (user_id) DO UPDATE SET dismissed = true, updated_at = now()`,
+      [user.id]
+    );
+    return NextResponse.json({ success: true, dismissed: true });
+  }
+
+  if (!step_id || !VALID_STEPS.includes(step_id)) {
+    return NextResponse.json(
+      { error: `Invalid step_id. Must be one of: ${VALID_STEPS.join(", ")}` },
+      { status: 400 }
+    );
+  }
+
+  // Upsert progress row and append step_id to completed array (idempotent)
+  await db.query(
+    `INSERT INTO onboarding_progress (user_id, completed, updated_at)
+     VALUES ($1, ARRAY[$2::TEXT], now())
+     ON CONFLICT (user_id) DO UPDATE
+       SET completed   = array_append(
+                           CASE WHEN $2 = ANY(onboarding_progress.completed)
+                                THEN onboarding_progress.completed
+                                ELSE onboarding_progress.completed
+                           END, $2),
+           updated_at  = now()`,
+    [user.id, step_id]
+  );
+
+  // Check if all steps are now complete
+  const { rows } = await db.query(
+    `SELECT completed FROM onboarding_progress WHERE user_id = $1`,
+    [user.id]
+  );
+
+  const completedSteps: string[] = rows[0]?.completed ?? [];
+  const allDone = VALID_STEPS.every((s) => completedSteps.includes(s));
+
+  if (allDone) {
+    // Mark completed_at if not already set
+    await db.query(
+      `UPDATE onboarding_progress
+       SET completed_at = COALESCE(completed_at, now())
+       WHERE user_id = $1 AND completed_at IS NULL`,
+      [user.id]
+    );
+
+    // Award onboarding_complete badge (fire-and-forget; badge API handles idempotency)
+    try {
+      await fetch(
+        `${process.env.NEXT_PUBLIC_APP_URL}/api/routes-f/badges/award`,
+        {
+          method: "POST",
+          headers: { "Content-Type": "application/json" },
+          body: JSON.stringify({ user_id: user.id, badge_slug: "onboarding_complete" }),
+        }
+      );
+    } catch {
+      // Non-critical: badge award failure should not block the response
+    }
+  }
+
+  return NextResponse.json({
+    success: true,
+    step_id,
+    all_complete: allDone,
+  });
+}
diff --git a/app/api/routes-f/onboarding/route.ts b/app/api/routes-f/onboarding/route.ts
new file mode 100644
index 00000000..c61e2aa8
--- /dev/null
+++ b/app/api/routes-f/onboarding/route.ts
@@ -0,0 +1,123 @@
+// @ts-nocheck
+import { NextRequest, NextResponse } from "next/server";
+
+// ---------------------------------------------------------------------------
+// DB schema (apply via migration):
+//
+// CREATE TABLE onboarding_progress (
+//   user_id      UUID REFERENCES users(id) ON DELETE CASCADE PRIMARY KEY,
+//   completed    TEXT[] DEFAULT '{}',
+//   dismissed    BOOLEAN DEFAULT false,
+//   completed_at TIMESTAMPTZ,
+//   updated_at   TIMESTAMPTZ DEFAULT now()
+// );
+// ---------------------------------------------------------------------------
+
+import { db } from "@/lib/db";
+import { getAuthUser } from "@/lib/auth";
+
+const STEPS = [
+  { id: "set_avatar",      title: "Upload a profile photo" },
+  { id: "set_bio",         title: "Write a bio" },
+  { id: "set_stream_title",title: "Set a stream title" },
+  { id: "add_category",    title: "Pick a stream category" },
+  { id: "first_stream",    title: "Go live for the first time" },
+  { id: "connect_wallet",  title: "Connect Stellar wallet" },
+  { id: "first_follower",  title: "Get your first follower" },
+  { id: "first_tip",       title: "Receive a tip" },
+];
+
+/**
+ * Auto-detect which steps are complete by querying user data.
+ */
+async function detectCompletedSteps(userId: string): Promise<string[]> {
+  const { rows } = await db.query(
+    `SELECT
+       u.avatar                                   AS avatar,
+       u.bio                                      AS bio,
+       u.wallet                                   AS wallet,
+       c.stream_title                             AS stream_title,
+       c.category                                 AS category,
+       (SELECT COUNT(*) FROM streams WHERE creator_id = u.id)         AS total_streams,
+       (SELECT COUNT(*) FROM follows  WHERE followed_id = u.id)       AS follower_count,
+       (SELECT COUNT(*) FROM tips     WHERE recipient_id = u.id)      AS total_tips_count,
+       op.completed                               AS manually_completed
+     FROM users u
+     LEFT JOIN creators c ON c.user_id = u.id
+     LEFT JOIN onboarding_progress op ON op.user_id = u.id
+     WHERE u.id = $1`,
+    [userId]
+  );
+
+  if (rows.length === 0) {
+    return [];
+  }
+  const row = rows[0];
+  const manual: string[] = row.manually_completed ?? [];
+
+  const auto: string[] = [];
+  if (row.avatar) {
+    auto.push("set_avatar");
+  }
+  if (row.bio) {
+    auto.push("set_bio");
+  }
+  if (row.stream_title) {
+    auto.push("set_stream_title");
+  }
+  if (row.category) {
+    auto.push("add_category");
+  }
+  if (Number(row.total_streams) > 0) {
+    auto.push("first_stream");
+  }
+  if (row.wallet) {
+    auto.push("connect_wallet");
+  }
+  if (Number(row.follower_count) >= 1) {
+    auto.push("first_follower");
+  }
+  if (Number(row.total_tips_count) >= 1) {
+    auto.push("first_tip");
+  }
+
+  // Merge auto-detected with manually marked (deduplicate)
+  return [...new Set([...auto, ...manual])];
+}
+
+/**
+ * GET /api/routes-f/onboarding
+ * Returns the checklist progress for the authenticated user.
+ */
+export async function GET(req: NextRequest) {
+  const user = await getAuthUser(req);
+  if (!user) {
+    return NextResponse.json({ error: "Unauthorized" }, { status: 401 });
+  }
+
+  const completed = await detectCompletedSteps(user.id);
+
+  // Fetch dismissed state
+  const { rows: progressRows } = await db.query(
+    `SELECT dismissed, completed_at FROM onboarding_progress WHERE user_id = $1`,
+    [user.id]
+  );
+  const dismissed = progressRows[0]?.dismissed ?? false;
+  const completed_count = completed.length;
+  const total_count = STEPS.length;
+  const percentage = Math.round((completed_count / total_count) * 100);
+
+  const steps = STEPS.map((s) => ({
+    id: s.id,
+    title: s.title,
+    completed: completed.includes(s.id),
+  }));
+
+  return NextResponse.json({
+    steps,
+    completed_count,
+    total_count,
+    percentage,
+    dismissed,
+  });
+}
diff --git a/app/api/routes-f/overlay/route.ts b/app/api/routes-f/overlay/route.ts
new file mode 100644
index 00000000..5b38653d
--- /dev/null
+++ b/app/api/routes-f/overlay/route.ts
@@ -0,0 +1,113 @@
+import { NextRequest, NextResponse } from "next/server";
+import { sql } from "@vercel/postgres";
+import { verifySession } from "@/lib/auth/verify-session";
+import { verifyToken } from "@/lib/auth/sign-token";
+import { z } from "zod";
+
+export const runtime = "nodejs";
+export const dynamic = "force-dynamic";
+
+const overlaySettingsSchema = z.object({
+    theme: z.string().optional(),
+    position: z.string().optional(),
+    font_size: z.number().int().positive().optional(),
+    opacity: z.number().min(0).max(1).optional(),
+});
+
+/**
+ * GET /api/routes-f/overlay
+ * Public endpoint (token-auth) to fetch overlay config for a creator.
+ */
+export async function GET(req: NextRequest) {
+    const { searchParams } = req.nextUrl;
+    const token = searchParams.get("token");
+
+    if (!token) {
+        return NextResponse.json({ error: "Token required" }, { status: 400 });
+    }
+
+    const secret = process.env.SESSION_SECRET;
+    if (!secret) {
+        return NextResponse.json({ error: "Server misconfiguration" }, { status: 500 });
+    }
+
+    // Verify token
+    const payload = verifyToken<{ userId: string; type: string }>(token, secret);
+    if (!payload || payload.type !== "overlay") {
+        return NextResponse.json({ error: "Invalid or expired token" }, { status: 401 });
+    }
+
+    try {
+        const { rows } = await sql`
+      SELECT theme, position, font_size as "fontSize", opacity
+      FROM user_overlay_config
+      WHERE user_id = ${payload.userId}
+      LIMIT 1
+    `;
+
+        if (rows.length === 0) {
+            // Return default settings if none exist yet
+            return NextResponse.json({
+                theme: "default",
+                position: "bottom-right",
+                fontSize: 16,
+                opacity: 1.0,
+                primary_color: "#ac39f2"
+            });
+        }
+
+        return NextResponse.json({
+            ...rows[0],
+            primary_color: "#ac39f2"
+        });
+    } catch (error) {
+        console.error("[Overlay API] Error fetching config:", error);
+        return NextResponse.json({ error: "Internal server error" }, { status: 500 });
+    }
+}
+
+/**
+ * PATCH /api/routes-f/overlay
+ * Update overlay settings for authenticated creator.
+ */
+export async function PATCH(req: NextRequest) {
+    const session = await verifySession(req);
+    if (!session.ok) {
+        return session.response;
+    }
+
+    try {
+        const body = await req.json();
+        const result = overlaySettingsSchema.safeParse(body);
+        if (!result.success) {
+            return NextResponse.json({ error: "Invalid request body", details: result.error.format() }, { status: 400 });
+        }
+
+        const { theme, position, font_size, opacity } = result.data;
+
+        // Use upsert to handle new or existing config
+        await sql`
+      INSERT INTO user_overlay_config (user_id, theme, position, font_size, opacity, updated_at)
+      VALUES (
+        ${session.userId}, 
+        ${theme ?? 'default'}, 
+        ${position ?? 'bottom-right'}, 
+        ${font_size ?? 16}, 
+        ${opacity ?? 1.0},
+        CURRENT_TIMESTAMP
+      )
+      ON CONFLICT (user_id) 
+      DO UPDATE SET
+        theme = COALESCE(EXCLUDED.theme, user_overlay_config.theme),
+        position = COALESCE(EXCLUDED.position, user_overlay_config.position),
+        font_size = COALESCE(EXCLUDED.font_size, user_overlay_config.font_size),
+        opacity = COALESCE(EXCLUDED.opacity, user_overlay_config.opacity),
+        updated_at = CURRENT_TIMESTAMP
+    `;
+
+        return NextResponse.json({ message: "Settings updated" });
+    } catch (error) {
+        console.error("[Overlay API] Error updating settings:", error);
+        return NextResponse.json({ error: "Internal server error" }, { status: 500 });
+    }
+}
diff --git a/app/api/routes-f/overlay/token/route.ts b/app/api/routes-f/overlay/token/route.ts
new file mode 100644
index 00000000..52cfa3a8
--- /dev/null
+++ b/app/api/routes-f/overlay/token/route.ts
@@ -0,0 +1,41 @@
+import { NextRequest, NextResponse } from "next/server";
+import { sql } from "@vercel/postgres";
+import { verifySession } from "@/lib/auth/verify-session";
+import { signToken } from "@/lib/auth/sign-token";
+
+export const runtime = "nodejs";
+export const dynamic = "force-dynamic";
+
+/**
+ * GET /api/routes-f/overlay/token
+ * Authenticated creator generates or rotates their overlay token.
+ */
+export async function GET(req: NextRequest) {
+    const session = await verifySession(req);
+    if (!session.ok) {
+        return session.response;
+    }
+
+    const secret = process.env.SESSION_SECRET;
+    if (!secret) {
+        return NextResponse.json({ error: "Server misconfiguration" }, { status: 500 });
+    }
+
+    try {
+        // Generate new token (no exp)
+        const token = signToken({ userId: session.userId, type: "overlay" }, secret);
+
+        // Save to DB (overwrite existing)
+        await sql`
+      INSERT INTO user_overlay_config (user_id, token, updated_at)
+      VALUES (${session.userId}, ${token}, CURRENT_TIMESTAMP)
+      ON CONFLICT (user_id) 
+      DO UPDATE SET token = EXCLUDED.token, updated_at = CURRENT_TIMESTAMP
+    `;
+
+        return NextResponse.json({ token });
+    } catch (error) {
+        console.error("[Overlay Token API] Error generating token:", error);
+        return NextResponse.json({ error: "Internal server error" }, { status: 500 });
+    }
+}
diff --git a/app/api/routes-f/pace/route.ts b/app/api/routes-f/pace/route.ts
new file mode 100644
index 00000000..8ad06eed
--- /dev/null
+++ b/app/api/routes-f/pace/route.ts
@@ -0,0 +1,128 @@
+import { type NextRequest, NextResponse } from "next/server";
+
+const RACE_DISTANCES_KM: Record<string, number> = {
+  "1K": 1,
+  "5K": 5,
+  "10K": 10,
+  "Half Marathon": 21.0975,
+  Marathon: 42.195,
+};
+
+const RACE_DISTANCES_MI: Record<string, number> = {
+  "1 mile": 1,
+  "5K": 3.10686,
+  "10K": 6.21371,
+  "Half Marathon": 13.1094,
+  Marathon: 26.2188,
+};
+
+function parseTime(t: string): number | null {
+  const parts = t.split(":").map(Number);
+  if (parts.some(isNaN)) return null;
+  if (parts.length === 3) return parts[0] * 3600 + parts[1] * 60 + parts[2];
+  if (parts.length === 2) return parts[0] * 60 + parts[1];
+  return null;
+}
+
+function parsePace(p: string): number | null {
+  const parts = p.split(":").map(Number);
+  if (parts.length !== 2 || parts.some(isNaN)) return null;
+  return parts[0] * 60 + parts[1];
+}
+
+function formatTime(secs: number): string {
+  const h = Math.floor(secs / 3600);
+  const m = Math.floor((secs % 3600) / 60);
+  const s = Math.round(secs % 60);
+  return [h, m, s].map((v) => String(v).padStart(2, "0")).join(":");
+}
+
+function formatPace(secsPerUnit: number, unit: string): string {
+  const m = Math.floor(secsPerUnit / 60);
+  const s = Math.round(secsPerUnit % 60);
+  return `${m}:${String(s).padStart(2, "0")} per ${unit}`;
+}
+
+function isRecord(v: unknown): v is Record<string, unknown> {
+  return typeof v === "object" && v !== null && !Array.isArray(v);
+}
+
+export async function POST(req: NextRequest) {
+  let body: unknown;
+  try {
+    body = await req.json();
+  } catch {
+    return NextResponse.json({ error: "Invalid JSON body." }, { status: 400 });
+  }
+
+  if (!isRecord(body)) {
+    return NextResponse.json({ error: "Request body must be an object." }, { status: 400 });
+  }
+
+  const { mode, distance, time, pace, unit = "km" } = body as Record<string, unknown>;
+
+  if (unit !== "km" && unit !== "mi") {
+    return NextResponse.json({ error: "unit must be 'km' or 'mi'." }, { status: 400 });
+  }
+  if (mode !== "pace" && mode !== "time" && mode !== "distance") {
+    return NextResponse.json({ error: "mode must be 'pace', 'time', or 'distance'." }, { status: 400 });
+  }
+
+  const unitLabel = unit as string;
+
+  if (mode === "pace") {
+    if (typeof distance !== "number" || distance <= 0) {
+      return NextResponse.json({ error: "distance must be a positive number for mode 'pace'." }, { status: 400 });
+    }
+    if (typeof time !== "string") {
+      return NextResponse.json({ error: "time must be a string in HH:MM:SS format." }, { status: 400 });
+    }
+    const totalSecs = parseTime(time as string);
+    if (totalSecs === null) {
+      return NextResponse.json({ error: "Invalid time format. Use HH:MM:SS." }, { status: 400 });
+    }
+    const secsPerUnit = totalSecs / (distance as number);
+    const paceStr = formatPace(secsPerUnit, unitLabel);
+
+    const raceDists = unitLabel === "mi" ? RACE_DISTANCES_MI : RACE_DISTANCES_KM;
+    const race_splits: Record<string, string> = {};
+    for (const [name, d] of Object.entries(raceDists)) {
+      race_splits[name] = formatTime(secsPerUnit * d);
+    }
+
+    return NextResponse.json({ pace: paceStr, race_splits });
+  }
+
+  if (mode === "time") {
+    if (typeof distance !== "number" || distance <= 0) {
+      return NextResponse.json({ error: "distance must be a positive number for mode 'time'." }, { status: 400 });
+    }
+    if (typeof pace !== "string") {
+      return NextResponse.json({ error: "pace must be a string in M:SS format." }, { status: 400 });
+    }
+    const paceSecs = parsePace(pace as string);
+    if (paceSecs === null) {
+      return NextResponse.json({ error: "Invalid pace format. Use M:SS." }, { status: 400 });
+    }
+    const totalSecs = paceSecs * (distance as number);
+    return NextResponse.json({ time: formatTime(totalSecs) });
+  }
+
+  // mode === "distance"
+  if (typeof time !== "string") {
+    return NextResponse.json({ error: "time must be a string in HH:MM:SS format." }, { status: 400 });
+  }
+  if (typeof pace !== "string") {
+    return NextResponse.json({ error: "pace must be a string in M:SS format." }, { status: 400 });
+  }
+  const totalSecs = parseTime(time as string);
+  if (totalSecs === null) {
+    return NextResponse.json({ error: "Invalid time format. Use HH:MM:SS." }, { status: 400 });
+  }
+  const paceSecs = parsePace(pace as string);
+  if (paceSecs === null) {
+    return NextResponse.json({ error: "Invalid pace format. Use M:SS." }, { status: 400 });
+  }
+  const dist = Math.round((totalSecs / paceSecs) * 100) / 100;
+  return NextResponse.json({ distance: dist });
+}
diff --git a/app/api/routes-f/password-entropy/__tests__/route.test.ts b/app/api/routes-f/password-entropy/__tests__/route.test.ts
new file mode 100644
index 00000000..4c548150
--- /dev/null
+++ b/app/api/routes-f/password-entropy/__tests__/route.test.ts
@@ -0,0 +1,27 @@
+import { NextRequest } from "next/server";
+import { POST } from "../route";
+
+function makeReq(password: string) {
+  return new NextRequest("http://localhost/api/routes-f/password-entropy", {
+    method: "POST",
+    body: JSON.stringify({ password }),
+    headers: { "Content-Type": "application/json" },
+  });
+}
+
+describe("POST /api/routes-f/password-entropy", () => {
+  it("flags simple passwords as weak", async () => {
+    const res = await POST(makeReq("password123"));
+    const body = await res.json();
+    expect(body.strength === "very_weak" || body.strength === "weak").toBe(
+      true
+    );
+  });
+
+  it("rates complex passwords higher", async () => {
+    const res = await POST(makeReq("V3ry$Tr0ng!Passw0rd#2026"));
+    const body = await res.json();
+    expect(body.entropy_bits).toBeGreaterThan(60);
+    expect(["strong", "very_strong"]).toContain(body.strength);
+  });
+});
diff --git a/app/api/routes-f/password-entropy/route.ts b/app/api/routes-f/password-entropy/route.ts
new file mode 100644
index 00000000..5f65bad2
--- /dev/null
+++ b/app/api/routes-f/password-entropy/route.ts
@@ -0,0 +1,63 @@
+import { NextRequest, NextResponse } from "next/server";
+
+const COMMON_WORDS = ["password", "qwerty", "admin", "letmein", "welcome"];
+const SEQUENCES = ["abcdefghijklmnopqrstuvwxyz", "0123456789"];
+
+function detectCharsetSize(password: string) {
+  let size = 0;
+  if (/[a-z]/.test(password)) size += 26;
+  if (/[A-Z]/.test(password)) size += 26;
+  if (/[0-9]/.test(password)) size += 10;
+  if (/[^A-Za-z0-9]/.test(password)) size += 33;
+  return size;
+}
+
+function hasSequencePattern(password: string) {
+  const lower = password.toLowerCase();
+  return SEQUENCES.some(seq => seq.includes(lower));
+}
+
+function estimateEntropyBits(password: string) {
+  const charsetSize = detectCharsetSize(password);
+  if (charsetSize === 0) return { entropyBits: 0, charsetSize: 0 };
+
+  let entropyBits = password.length * Math.log2(charsetSize);
+
+  const lower = password.toLowerCase();
+  if (COMMON_WORDS.some(word => lower.includes(word))) entropyBits *= 0.55;
+  if (hasSequencePattern(password)) entropyBits *= 0.65;
+  if (/^(.)\1+$/.test(password)) entropyBits *= 0.4;
+
+  return { entropyBits: Number(entropyBits.toFixed(2)), charsetSize };
+}
+
+function toStrength(bits: number) {
+  if (bits < 28) return "very_weak";
+  if (bits < 36) return "weak";
+  if (bits < 60) return "medium";
+  if (bits < 80) return "strong";
+  return "very_strong";
+}
+
+export async function POST(request: NextRequest) {
+  let body: { password?: string };
+  try {
+    body = await request.json();
+  } catch {
+    return NextResponse.json({ error: "Invalid JSON body" }, { status: 400 });
+  }
+
+  if (typeof body.password !== "string") {
+    return NextResponse.json(
+      { error: "password must be a string" },
+      { status: 400 }
+    );
+  }
+
+  const { entropyBits, charsetSize } = estimateEntropyBits(body.password);
+  return NextResponse.json({
+    entropy_bits: entropyBits,
+    charset_size: charsetSize,
+    strength: toStrength(entropyBits),
+  });
+}
diff --git a/app/api/routes-f/percentage-change/__tests__/route.test.ts b/app/api/routes-f/percentage-change/__tests__/route.test.ts
new file mode 100644
index 00000000..d33efe67
--- /dev/null
+++ b/app/api/routes-f/percentage-change/__tests__/route.test.ts
@@ -0,0 +1,43 @@
+import { computePercentageChange } from "../route";
+
+describe("computePercentageChange", () => {
+  it("reports an increase", () => {
+    expect(computePercentageChange(100, 150)).toEqual({
+      percent_change: 50,
+      absolute_change: 50,
+      direction: "up",
+    });
+  });
+
+  it("reports a decrease", () => {
+    expect(computePercentageChange(200, 150)).toEqual({
+      percent_change: -25,
+      absolute_change: -50,
+      direction: "down",
+    });
+  });
+
+  it("reports no change", () => {
+    expect(computePercentageChange(42, 42)).toEqual({
+      percent_change: 0,
+      absolute_change: 0,
+      direction: "none",
+    });
+  });
+
+  it("handles a zero base explicitly (null percent, still directional)", () => {
+    expect(computePercentageChange(0, 10)).toEqual({
+      percent_change: null,
+      absolute_change: 10,
+      direction: "up",
+    });
+  });
+
+  it("treats 0 -> 0 as no change", () => {
+    expect(computePercentageChange(0, 0)).toEqual({
+      percent_change: 0,
+      absolute_change: 0,
+      direction: "none",
+    });
+  });
+});
diff --git a/app/api/routes-f/percentage-change/route.ts b/app/api/routes-f/percentage-change/route.ts
new file mode 100644
index 00000000..7b4779b3
--- /dev/null
+++ b/app/api/routes-f/percentage-change/route.ts
@@ -0,0 +1,46 @@
+import { NextResponse } from "next/server";
+import { z } from "zod";
+import { validateBody } from "@/app/api/routes-f/_lib/validate";
+
+export type ChangeDirection = "up" | "down" | "none";
+
+export interface PercentageChangeResult {
+  percent_change: number | null;
+  absolute_change: number;
+  direction: ChangeDirection;
+}
+
+/**
+ * Compute percentage change, absolute change, and direction between two numbers.
+ * When `from` is 0 the percentage is undefined (returned as null), except when
+ * `to` is also 0 (no change → 0%).
+ */
+export function computePercentageChange(
+  from: number,
+  to: number,
+): PercentageChangeResult {
+  const absolute_change = to - from;
+  const direction: ChangeDirection =
+    absolute_change > 0 ? "up" : absolute_change < 0 ? "down" : "none";
+
+  let percent_change: number | null;
+  if (from === 0) {
+    percent_change = to === 0 ? 0 : null;
+  } else {
+    percent_change = (absolute_change / Math.abs(from)) * 100;
+  }
+
+  return { percent_change, absolute_change, direction };
+}
+
+const schema = z.object({
+  from: z.number().finite(),
+  to: z.number().finite(),
+});
+
+export async function POST(request: Request): Promise<NextResponse> {
+  const result = await validateBody(request, schema);
+  if (result instanceof NextResponse) return result;
+  const { from, to } = result.data;
+  return NextResponse.json(computePercentageChange(from, to));
+}
diff --git a/app/api/routes-f/percentile-rank/__tests__/route.test.ts b/app/api/routes-f/percentile-rank/__tests__/route.test.ts
new file mode 100644
index 00000000..297426cf
--- /dev/null
+++ b/app/api/routes-f/percentile-rank/__tests__/route.test.ts
@@ -0,0 +1,67 @@
+jest.mock("next/server", () => ({
+  NextResponse: {
+    json: (body: unknown, init?: ResponseInit) =>
+      new Response(JSON.stringify(body), {
+        ...init,
+        headers: { "Content-Type": "application/json" },
+      }),
+  },
+}));
+
+import { POST } from "../route";
+
+function makeRequest(body: object) {
+  return new Request("http://localhost/api/routes-f/percentile-rank", {
+    method: "POST",
+    headers: { "Content-Type": "application/json" },
+    body: JSON.stringify(body),
+  }) as unknown as import("next/server").NextRequest;
+}
+
+describe("routes-f percentile-rank", () => {
+  const sample = [10, 20, 30, 40, 50];
+
+  it("computes percentile rank for the minimum value", async () => {
+    const res = await POST(makeRequest({ data: sample, value: 10 }));
+    const json = await res.json();
+
+    expect(res.status).toBe(200);
+    expect(json).toEqual({
+      percentile_rank: 10,
+      count_below: 0,
+      count_equal: 1,
+    });
+  });
+
+  it("computes percentile rank for the median value", async () => {
+    const res = await POST(makeRequest({ data: sample, value: 30 }));
+    const json = await res.json();
+
+    expect(json).toEqual({
+      percentile_rank: 50,
+      count_below: 2,
+      count_equal: 1,
+    });
+  });
+
+  it("computes percentile rank for the maximum value", async () => {
+    const res = await POST(makeRequest({ data: sample, value: 50 }));
+    const json = await res.json();
+
+    expect(json).toEqual({
+      percentile_rank: 90,
+      count_below: 4,
+      count_equal: 1,
+    });
+  });
+
+  it("handles out-of-range values", async () => {
+    const belowRes = await POST(makeRequest({ data: sample, value: 1 }));
+    const aboveRes = await POST(makeRequest({ data: sample, value: 99 }));
+    const below = await belowRes.json();
+    const above = await aboveRes.json();
+
+    expect(below.percentile_rank).toBe(0);
+    expect(above.percentile_rank).toBe(100);
+  });
+});
diff --git a/app/api/routes-f/percentile-rank/route.ts b/app/api/routes-f/percentile-rank/route.ts
new file mode 100644
index 00000000..f25d9a9f
--- /dev/null
+++ b/app/api/routes-f/percentile-rank/route.ts
@@ -0,0 +1,67 @@
+import { NextRequest, NextResponse } from "next/server";
+import { z } from "zod";
+
+const schema = z.object({
+  data: z.array(z.number()).min(1, "data must contain at least one number"),
+  value: z.number(),
+});
+
+function getPercentileRank(data: number[], value: number) {
+  const countBelow = data.filter(entry => entry < value).length;
+  const countEqual = data.filter(entry => entry === value).length;
+
+  if (countEqual === 0 && value > Math.max(...data)) {
+    return {
+      percentileRank: 100,
+      countBelow: data.length,
+      countEqual: 0,
+    };
+  }
+
+  if (countEqual === 0 && value < Math.min(...data)) {
+    return {
+      percentileRank: 0,
+      countBelow: 0,
+      countEqual: 0,
+    };
+  }
+
+  return {
+    percentileRank: ((countBelow + 0.5 * countEqual) / data.length) * 100,
+    countBelow,
+    countEqual,
+  };
+}
+
+export async function POST(req: NextRequest) {
+  let rawBody: unknown;
+
+  try {
+    rawBody = await req.json();
+  } catch {
+    return NextResponse.json({ error: "Invalid JSON body" }, { status: 400 });
+  }
+
+  const parsed = schema.safeParse(rawBody);
+  if (!parsed.success) {
+    return NextResponse.json(
+      {
+        error: "Validation failed",
+        issues: parsed.error.issues.map(issue => ({
+          field: issue.path.join(".") || "body",
+          message: issue.message,
+        })),
+      },
+      { status: 400 }
+    );
+  }
+
+  const { data, value } = parsed.data;
+  const result = getPercentileRank(data, value);
+
+  return NextResponse.json({
+    percentile_rank: Number(result.percentileRank.toFixed(2)),
+    count_below: result.countBelow,
+    count_equal: result.countEqual,
+  });
+}
diff --git a/app/api/routes-f/percentile/route.ts b/app/api/routes-f/percentile/route.ts
new file mode 100644
index 00000000..5e0aaf2b
--- /dev/null
+++ b/app/api/routes-f/percentile/route.ts
@@ -0,0 +1,58 @@
+import { type NextRequest, NextResponse } from "next/server";
+
+function isRecord(v: unknown): v is Record<string, unknown> {
+  return typeof v === "object" && v !== null && !Array.isArray(v);
+}
+
+function linearInterpolate(sorted: number[], p: number): number {
+  if (p === 0) return sorted[0];
+  if (p === 100) return sorted[sorted.length - 1];
+
+  const rank = (p / 100) * (sorted.length - 1);
+  const lower = Math.floor(rank);
+  const upper = Math.ceil(rank);
+  const frac = rank - lower;
+  return sorted[lower] + frac * (sorted[upper] - sorted[lower]);
+}
+
+export async function POST(req: NextRequest) {
+  let body: unknown;
+  try {
+    body = await req.json();
+  } catch {
+    return NextResponse.json({ error: "Invalid JSON body." }, { status: 400 });
+  }
+
+  if (!isRecord(body)) {
+    return NextResponse.json({ error: "Request body must be an object." }, { status: 400 });
+  }
+
+  const { data, percentiles } = body as Record<string, unknown>;
+
+  if (!Array.isArray(data) || data.length === 0) {
+    return NextResponse.json({ error: "data must be a non-empty array." }, { status: 400 });
+  }
+  if (!Array.isArray(percentiles) || percentiles.length === 0) {
+    return NextResponse.json({ error: "percentiles must be a non-empty array." }, { status: 400 });
+  }
+
+  for (const val of data) {
+    if (typeof val !== "number") {
+      return NextResponse.json({ error: "All data values must be numbers." }, { status: 400 });
+    }
+  }
+
+  for (const p of percentiles) {
+    if (typeof p !== "number" || p < 0 || p > 100) {
+      return NextResponse.json({ error: "All percentiles must be numbers between 0 and 100." }, { status: 400 });
+    }
+  }
+
+  const sorted = [...(data as number[])].sort((a, b) => a - b);
+  const results = (percentiles as number[]).map((p) => ({
+    percentile: p,
+    value: linearInterpolate(sorted, p),
+  }));
+
+  return NextResponse.json({ results });
+}
diff --git a/app/api/routes-f/polynomial-eval/route.test.ts b/app/api/routes-f/polynomial-eval/route.test.ts
new file mode 100644
index 00000000..be33cb4c
--- /dev/null
+++ b/app/api/routes-f/polynomial-eval/route.test.ts
@@ -0,0 +1,112 @@
+import { POST } from "./route";
+
+describe("Polynomial Evaluator API", () => {
+  it("should return 400 for invalid JSON", async () => {
+    const req = new Request("http://localhost/api/routes-f/polynomial-eval", {
+      method: "POST",
+      body: "not-json",
+    });
+    const res = await POST(req as any);
+    expect(res.status).toBe(400);
+    const data = await res.json();
+    expect(data.error).toBeDefined();
+  });
+
+  it("should return 400 when coefficients is missing", async () => {
+    const req = new Request("http://localhost/api/routes-f/polynomial-eval", {
+      method: "POST",
+      body: JSON.stringify({ x: 2 }),
+    });
+    const res = await POST(req as any);
+    expect(res.status).toBe(400);
+  });
+
+  it("should return 400 when coefficients is empty", async () => {
+    const req = new Request("http://localhost/api/routes-f/polynomial-eval", {
+      method: "POST",
+      body: JSON.stringify({ coefficients: [], x: 2 }),
+    });
+    const res = await POST(req as any);
+    expect(res.status).toBe(400);
+  });
+
+  it("should return 400 when x is not a number or array", async () => {
+    const req = new Request("http://localhost/api/routes-f/polynomial-eval", {
+      method: "POST",
+      body: JSON.stringify({ coefficients: [1, 2, 3], x: "hello" }),
+    });
+    const res = await POST(req as any);
+    expect(res.status).toBe(400);
+  });
+
+  it("evaluates a constant polynomial f(x) = 5", async () => {
+    const req = new Request("http://localhost/api/routes-f/polynomial-eval", {
+      method: "POST",
+      body: JSON.stringify({ coefficients: [5], x: 10 }),
+    });
+    const res = await POST(req as any);
+    expect(res.status).toBe(200);
+    const data = await res.json();
+    expect(data.results).toEqual([5]);
+  });
+
+  it("evaluates f(x) = 2x + 1 at x=3 via Horner's method", async () => {
+    // Horner: coefficients = [2, 1], x=3 → 2*3+1 = 7
+    const req = new Request("http://localhost/api/routes-f/polynomial-eval", {
+      method: "POST",
+      body: JSON.stringify({ coefficients: [2, 1], x: 3 }),
+    });
+    const res = await POST(req as any);
+    const data = await res.json();
+    expect(data.results).toEqual([7]);
+  });
+
+  it("evaluates f(x) = 3x² + 2x + 1 at x=2 via Horner (matches expanded form)", async () => {
+    // Expanded: 3*4 + 2*2 + 1 = 17. Horner: [3,2,1], x=2 → ((3*2)+2)*2+1=17
+    const req = new Request("http://localhost/api/routes-f/polynomial-eval", {
+      method: "POST",
+      body: JSON.stringify({ coefficients: [3, 2, 1], x: 2 }),
+    });
+    const res = await POST(req as any);
+    const data = await res.json();
+    expect(data.results).toEqual([17]);
+  });
+
+  it("evaluates a polynomial at multiple x values", async () => {
+    // f(x) = x^2 = [1, 0, 0], x=[0,2,3] → [0,4,9]
+    const req = new Request("http://localhost/api/routes-f/polynomial-eval", {
+      method: "POST",
+      body: JSON.stringify({ coefficients: [1, 0, 0], x: [0, 2, 3] }),
+    });
+    const res = await POST(req as any);
+    const data = await res.json();
+    expect(data.results).toEqual([0, 4, 9]);
+  });
+
+  it("Horner result matches expanded form for degree-3 polynomial", async () => {
+    // f(x) = 2x^3 - 3x^2 + x - 5 at x=4
+    // Expanded: 2*64 - 3*16 + 4 - 5 = 128 - 48 + 4 - 5 = 79
+    const x = 4;
+    const coefficients = [2, -3, 1, -5];
+    const expanded = 2 * x ** 3 - 3 * x ** 2 + 1 * x - 5;
+
+    const req = new Request("http://localhost/api/routes-f/polynomial-eval", {
+      method: "POST",
+      body: JSON.stringify({ coefficients, x }),
+    });
+    const res = await POST(req as any);
+    const data = await res.json();
+    expect(data.results[0]).toBeCloseTo(expanded);
+  });
+
+  it("handles x=0", async () => {
+    // f(0) = constant term (last coef)
+    const req = new Request("http://localhost/api/routes-f/polynomial-eval", {
+      method: "POST",
+      body: JSON.stringify({ coefficients: [5, 3, 7], x: 0 }),
+    });
+    const res = await POST(req as any);
+    const data = await res.json();
+    expect(data.results).toEqual([7]);
+  });
+});
diff --git a/app/api/routes-f/polynomial-eval/route.ts b/app/api/routes-f/polynomial-eval/route.ts
new file mode 100644
index 00000000..6a06e226
--- /dev/null
+++ b/app/api/routes-f/polynomial-eval/route.ts
@@ -0,0 +1,50 @@
+import { type NextRequest, NextResponse } from "next/server";
+
+/**
+ * Evaluates a polynomial at a given x value using Horner's method.
+ * Coefficients are ordered highest-degree first.
+ * e.g. [3, 2, 1] represents 3x² + 2x + 1
+ */
+function horner(coefficients: number[], x: number): number {
+  return coefficients.reduce((acc, coef) => acc * x + coef, 0);
+}
+
+export async function POST(req: NextRequest) {
+  let body: unknown;
+  try {
+    body = await req.json();
+  } catch {
+    return NextResponse.json({ error: "Invalid JSON body." }, { status: 400 });
+  }
+
+  if (typeof body !== "object" || body === null || Array.isArray(body)) {
+    return NextResponse.json({ error: "Request body must be an object." }, { status: 400 });
+  }
+
+  const { coefficients, x } = body as Record<string, unknown>;
+
+  if (
+    !Array.isArray(coefficients) ||
+    coefficients.length === 0 ||
+    coefficients.some((c) => typeof c !== "number")
+  ) {
+    return NextResponse.json(
+      { error: "coefficients must be a non-empty array of numbers." },
+      { status: 400 }
+    );
+  }
+
+  const isArrayOfX = Array.isArray(x);
+  const xValues: unknown[] = isArrayOfX ? x : [x];
+
+  if (xValues.some((v) => typeof v !== "number")) {
+    return NextResponse.json(
+      { error: "x must be a number or an array of numbers." },
+      { status: 400 }
+    );
+  }
+
+  const results = (xValues as number[]).map((xVal) => horner(coefficients as number[], xVal));
+
+  return NextResponse.json({ results });
+}
diff --git a/app/api/routes-f/presence/[streamId]/heartbeat/route.ts b/app/api/routes-f/presence/[streamId]/heartbeat/route.ts
new file mode 100644
index 00000000..774a01d8
--- /dev/null
+++ b/app/api/routes-f/presence/[streamId]/heartbeat/route.ts
@@ -0,0 +1,79 @@
+import { NextRequest, NextResponse } from "next/server";
+
+// Re-use the same stores defined in the parent route module via a shared singleton.
+// For a full-stack implementation these would be Redis sorted set operations.
+
+declare global {
+  // eslint-disable-next-line no-var
+  var __streamfi_presence: Map<string, Map<string, { lastSeen: number }>>;
+  // eslint-disable-next-line no-var
+  var __streamfi_peak: Map<string, number>;
+}
+
+globalThis.__streamfi_presence ??= new Map();
+globalThis.__streamfi_peak ??= new Map();
+
+const STALE_THRESHOLD_MS = 60_000;
+
+function getOrCreate(streamId: string) {
+  if (!globalThis.__streamfi_presence.has(streamId)) {
+    globalThis.__streamfi_presence.set(streamId, new Map());
+  }
+  return globalThis.__streamfi_presence.get(streamId)!;
+}
+
+// ---------------------------------------------------------------------------
+// POST /api/routes-f/presence/[streamId]/heartbeat
+// Body: { viewer_id: string }   (anonymous viewers pass a session-scoped ID)
+// ---------------------------------------------------------------------------
+export async function POST(
+  request: NextRequest,
+  context: { params: Promise<{ streamId: string }> }
+) {
+  const { streamId } = await context.params;
+
+  let body: { viewer_id?: string };
+  try {
+    body = await request.json();
+  } catch {
+    return NextResponse.json({ error: "Invalid JSON body." }, { status: 400 });
+  }
+
+  const viewerId = body.viewer_id;
+  if (!viewerId || typeof viewerId !== "string") {
+    return NextResponse.json(
+      { error: "viewer_id is required." },
+      { status: 400 }
+    );
+  }
+
+  const now = Date.now();
+  const viewers = getOrCreate(streamId);
+
+  // ZADD presence:{streamId} {now} {viewerId}  — update heartbeat
+  viewers.set(viewerId, { lastSeen: now });
+
+  // ZREMRANGEBYSCORE presence:{streamId} -inf {now - 60s}  — prune stale
+  const cutoff = now - STALE_THRESHOLD_MS;
+  for (const [id, entry] of viewers.entries()) {
+    if (entry.lastSeen < cutoff) {
+      viewers.delete(id);
+    }
+  }
+
+  // ZCOUNT  — count active
+  let count = 0;
+  for (const entry of viewers.values()) {
+    if (entry.lastSeen >= now - STALE_THRESHOLD_MS) {
+      count++;
+    }
+  }
+
+  // Update peak (mirrors Postgres ALTER TABLE stream_recordings peak_viewers)
+  const existingPeak = globalThis.__streamfi_peak.get(streamId) ?? 0;
+  if (count > existingPeak) {
+    globalThis.__streamfi_peak.set(streamId, count);
+  }
+
+  return NextResponse.json({ count }, { status: 200 });
+}
diff --git a/app/api/routes-f/presence/[streamId]/leave/route.ts b/app/api/routes-f/presence/[streamId]/leave/route.ts
new file mode 100644
index 00000000..10be0226
--- /dev/null
+++ b/app/api/routes-f/presence/[streamId]/leave/route.ts
@@ -0,0 +1,36 @@
+import { NextRequest, NextResponse } from "next/server";
+
+// ---------------------------------------------------------------------------
+// POST /api/routes-f/presence/[streamId]/leave
+// Explicit viewer leave — removes them from the sorted set immediately.
+// ---------------------------------------------------------------------------
+export async function POST(
+  request: NextRequest,
+  context: { params: Promise<{ streamId: string }> }
+) {
+  const { streamId } = await context.params;
+
+  let body: { viewer_id?: string };
+  try {
+    body = await request.json();
+  } catch {
+    return NextResponse.json({ error: "Invalid JSON body." }, { status: 400 });
+  }
+
+  const viewerId = body.viewer_id;
+  if (!viewerId) {
+    return NextResponse.json(
+      { error: "viewer_id is required." },
+      { status: 400 }
+    );
+  }
+
+  const viewers: Map<string, { lastSeen: number }> | undefined =
+    (globalThis as any).__streamfi_presence?.get(streamId);
+
+  if (viewers) {
+    viewers.delete(viewerId);
+  }
+
+  return NextResponse.json({ success: true }, { status: 200 });
+}
diff --git a/app/api/routes-f/presence/[streamId]/route.ts b/app/api/routes-f/presence/[streamId]/route.ts
new file mode 100644
index 00000000..ea59c005
--- /dev/null
+++ b/app/api/routes-f/presence/[streamId]/route.ts
@@ -0,0 +1,118 @@
+// @ts-nocheck
+import { NextRequest, NextResponse } from "next/server";
+
+// ---------------------------------------------------------------------------
+// DB schema (apply via migration):
+//
+// ALTER TABLE stream_recordings ADD COLUMN IF NOT EXISTS peak_viewers INT DEFAULT 0;
+// ---------------------------------------------------------------------------
+//
+// Redis storage model:
+//   Key:   presence:{streamId}     — Sorted Set
+//   Score: Unix timestamp (last heartbeat)
+//   Member: viewerId or anonymousId
+//
+// Heartbeat flow:
+//   ZADD presence:{streamId} {now} {viewerId}
+//   ZREMRANGEBYSCORE presence:{streamId} -inf {now - 60}   (expire stale > 60s)
+//   ZCOUNT presence:{streamId} {now - 60} +inf             (current count)
+// ---------------------------------------------------------------------------
+
+import { redis } from "@/lib/redis";
+import { db } from "@/lib/db";
+import { getAuthUser } from "@/lib/auth";
+
+function presenceKey(streamId: string) {
+  return `presence:${streamId}`;
+}
+
+/**
+ * GET /api/routes-f/presence/[streamId]
+ * Returns current live viewer count and all-time peak for this stream.
+ */
+export async function GET(
+  _req: NextRequest,
+  context: { params: Promise<{ streamId: string }> }
+) {
+  const { streamId } = await context.params;
+  const now = Math.floor(Date.now() / 1000);
+  const staleThreshold = now - 60;
+
+  const key = presenceKey(streamId);
+
+  // Count viewers whose last heartbeat was within the last 60 seconds
+  const count = await redis.zcount(key, staleThreshold, "+inf");
+
+  // Fetch peak from Postgres
+  const { rows } = await db.query(
+    `SELECT peak_viewers FROM stream_recordings WHERE stream_id = $1 ORDER BY created_at DESC LIMIT 1`,
+    [streamId]
+  );
+  const peak = rows[0]?.peak_viewers ?? count;
+
+  return NextResponse.json({ count, peak });
+}
+
+/**
+ * POST /api/routes-f/presence/[streamId]
+ * Body must include { viewer_id: string } — UUID for authed users, session ID for anon.
+ * Also used for explicit leave when action=leave is in the query string.
+ */
+export async function POST(
+  req: NextRequest,
+  context: { params: Promise<{ streamId: string }> }
+) {
+  const { streamId } = await context.params;
+  const { searchParams } = new URL(req.url);
+  const action = searchParams.get("action"); // 'heartbeat' | 'leave'
+
+  const body = await req.json().catch(() => ({}));
+  const user = await getAuthUser(req);
+
+  // Use authenticated user ID if available, otherwise fall back to provided anonymous ID
+  const viewerId: string | undefined =
+    user?.id ?? body.viewer_id ?? body.anonymous_id;
+
+  if (!viewerId) {
+    return NextResponse.json(
+      { error: "viewer_id or anonymous_id is required" },
+      { status: 400 }
+    );
+  }
+
+  const key = presenceKey(streamId);
+  const now = Math.floor(Date.now() / 1000);
+  const staleThreshold = now - 60;
+
+  // --- Explicit leave ---
+  if (action === "leave") {
+    await redis.zrem(key, viewerId);
+    return NextResponse.json({ success: true });
+  }
+
+  // --- Heartbeat (default) ---
+  // 1. Upsert viewer with current timestamp
+  await redis.zadd(key, now, viewerId);
+
+  // 2. Expire stale viewers (> 60s without a heartbeat)
+  await redis.zremrangebyscore(key, "-inf", staleThreshold);
+
+  // 3. Current live count
+  const count = await redis.zcount(key, staleThreshold, "+inf");
+
+  // 4. Update peak in Postgres if current count exceeds stored peak
+  const { rows } = await db.query(
+    `SELECT peak_viewers FROM stream_recordings WHERE stream_id = $1 ORDER BY created_at DESC LIMIT 1`,
+    [streamId]
+  );
+
+  const currentPeak = rows[0]?.peak_viewers ?? 0;
+  if (count > currentPeak) {
+    await db.query(
+      `UPDATE stream_recordings SET peak_viewers = $1 WHERE stream_id = $2`,
+      [count, streamId]
+    );
+  }
+
+  return NextResponse.json({ count });
+}
diff --git a/app/api/routes-f/presence/route.ts b/app/api/routes-f/presence/route.ts
new file mode 100644
index 00000000..729f0510
--- /dev/null
+++ b/app/api/routes-f/presence/route.ts
@@ -0,0 +1,12 @@
+import { NextResponse } from "next/server";
+
+/**
+ * Base /api/routes-f/presence
+ * Redirects to stream-specific endpoints.
+ * All viewer presence operations are stream-scoped at /presence/[streamId].
+ */
+export async function GET() {
+  return NextResponse.json({
+    message: "Use /api/routes-f/presence/[streamId] for stream-specific viewer counts.",
+  });
+}
diff --git a/app/api/routes-f/preview/_lib/store.ts b/app/api/routes-f/preview/_lib/store.ts
new file mode 100644
index 00000000..15790daf
--- /dev/null
+++ b/app/api/routes-f/preview/_lib/store.ts
@@ -0,0 +1,40 @@
+type SnapshotCacheEntry = {
+  url: string;
+  generatedAt: string;
+  expiresAt: number;
+};
+
+const snapshotCache = new Map<string, SnapshotCacheEntry>();
+const snapshotRateLimit = new Map<string, number>();
+
+export function getSnapshot(playbackId: string): SnapshotCacheEntry | null {
+  const entry = snapshotCache.get(playbackId);
+  if (!entry) return null;
+  if (Date.now() > entry.expiresAt) {
+    snapshotCache.delete(playbackId);
+    return null;
+  }
+  return entry;
+}
+
+export function setSnapshot(playbackId: string, url: string, ttlMs: number) {
+  const generatedAt = new Date().toISOString();
+  snapshotCache.set(playbackId, {
+    url,
+    generatedAt,
+    expiresAt: Date.now() + ttlMs,
+  });
+  return { url, generatedAt };
+}
+
+export function canRequestSnapshot(key: string, windowMs: number) {
+  const lastRequestAt = snapshotRateLimit.get(key) ?? 0;
+  const remainingMs = windowMs - (Date.now() - lastRequestAt);
+
+  if (remainingMs > 0) {
+    return { allowed: false, retryAfterSeconds: Math.ceil(remainingMs / 1000) };
+  }
+
+  snapshotRateLimit.set(key, Date.now());
+  return { allowed: true, retryAfterSeconds: 0 };
+}
diff --git a/app/api/routes-f/preview/custom/route.ts b/app/api/routes-f/preview/custom/route.ts
new file mode 100644
index 00000000..475571ac
--- /dev/null
+++ b/app/api/routes-f/preview/custom/route.ts
@@ -0,0 +1,168 @@
+import { NextRequest, NextResponse } from "next/server";
+import { sql } from "@vercel/postgres";
+import { verifySession } from "@/lib/auth/verify-session";
+import sharp from "sharp";
+
+const MAX_THUMBNAIL_BYTES = 10 * 1024 * 1024;
+const ALLOWED_MIME_TYPES = new Set(["image/jpeg", "image/png", "image/webp"]);
+const MIN_WIDTH = 1280;
+const MIN_HEIGHT = 720;
+
+async function validateRemoteImage(publicUrl: string) {
+  const headResponse = await fetch(publicUrl, {
+    method: "HEAD",
+    cache: "no-store",
+  });
+
+  if (!headResponse.ok) {
+    return { ok: false, error: "public_url is not reachable" };
+  }
+
+  const contentType = headResponse.headers.get("content-type") ?? "";
+  const mime = contentType.split(";")[0].trim().toLowerCase();
+  if (!ALLOWED_MIME_TYPES.has(mime)) {
+    return { ok: false, error: "Image type must be JPEG, PNG, or WebP" };
+  }
+
+  const contentLengthRaw = headResponse.headers.get("content-length") ?? "0";
+  const contentLength = Number.parseInt(contentLengthRaw, 10);
+  if (Number.isFinite(contentLength) && contentLength > MAX_THUMBNAIL_BYTES) {
+    return { ok: false, error: "Image exceeds 10MB limit" };
+  }
+
+  const probeResponse = await fetch(publicUrl, { cache: "no-store" });
+  if (!probeResponse.ok) {
+    return { ok: false, error: "public_url could not be fetched" };
+  }
+
+  const contentTypeFromGet = probeResponse.headers.get("content-type") ?? "";
+  const mimeFromGet = contentTypeFromGet.split(";")[0].trim().toLowerCase();
+  if (!ALLOWED_MIME_TYPES.has(mimeFromGet)) {
+    return { ok: false, error: "Image type must be JPEG, PNG, or WebP" };
+  }
+
+  const arrayBuffer = await probeResponse.arrayBuffer();
+  const buffer = Buffer.from(arrayBuffer);
+  if (buffer.byteLength > MAX_THUMBNAIL_BYTES) {
+    return { ok: false, error: "Image exceeds 10MB limit" };
+  }
+
+  const metadata = await sharp(buffer).metadata();
+  const width = metadata.width ?? 0;
+  const height = metadata.height ?? 0;
+  if (width < MIN_WIDTH || height < MIN_HEIGHT) {
+    return { ok: false, error: "Image must be at least 1280x720" };
+  }
+
+  return { ok: true };
+}
+
+export const runtime = "nodejs";
+
+export async function POST(req: NextRequest) {
+  const session = await verifySession(req);
+  if (!session.ok) return session.response;
+
+  let body: { public_url?: string };
+  try {
+    body = (await req.json()) as { public_url?: string };
+  } catch {
+    return NextResponse.json({ error: "Invalid JSON body" }, { status: 400 });
+  }
+
+  const publicUrl = body.public_url?.trim();
+  if (!publicUrl) {
+    return NextResponse.json(
+      { error: "public_url is required" },
+      { status: 400 }
+    );
+  }
+
+  let parsed: URL;
+  try {
+    parsed = new URL(publicUrl);
+  } catch {
+    return NextResponse.json(
+      { error: "public_url must be a valid URL" },
+      { status: 400 }
+    );
+  }
+  if (!["http:", "https:"].includes(parsed.protocol)) {
+    return NextResponse.json(
+      { error: "public_url must be HTTP or HTTPS" },
+      { status: 400 }
+    );
+  }
+
+  const validation = await validateRemoteImage(publicUrl);
+  if (!validation.ok) {
+    return NextResponse.json({ error: validation.error }, { status: 400 });
+  }
+
+  const generatedAt = new Date().toISOString();
+
+  try {
+    await sql`
+      UPDATE users
+      SET creator = jsonb_set(
+        jsonb_set(COALESCE(creator, '{}'::jsonb), '{customThumbnailUrl}', to_jsonb(${publicUrl}::text), true),
+        '{customThumbnailUpdatedAt}',
+        to_jsonb(${generatedAt}::text),
+        true
+      ),
+      updated_at = NOW()
+      WHERE id = ${session.userId}
+    `;
+
+    return NextResponse.json({
+      type: "custom",
+      url: publicUrl,
+      generated_at: generatedAt,
+      is_live: true,
+    });
+  } catch (error) {
+    console.error("[routes-f/preview/custom] POST error:", error);
+    return NextResponse.json(
+      { error: "Failed to save custom thumbnail" },
+      { status: 500 }
+    );
+  }
+}
+
+export async function DELETE(req: NextRequest) {
+  const session = await verifySession(req);
+  if (!session.ok) return session.response;
+
+  try {
+    const { rows } = await sql`
+      UPDATE users
+      SET creator = (COALESCE(creator, '{}'::jsonb) - 'customThumbnailUrl' - 'customThumbnailUpdatedAt'),
+          updated_at = NOW()
+      WHERE id = ${session.userId}
+      RETURNING mux_playback_id, is_live
+    `;
+
+    const user = rows[0];
+    const playbackId =
+      user && typeof user.mux_playback_id === "string"
+        ? user.mux_playback_id
+        : "";
+    const fallbackUrl = playbackId
+      ? `https://image.mux.com/${playbackId}/thumbnail.jpg?time=5`
+      : null;
+
+    return NextResponse.json({
+      ok: true,
+      type: fallbackUrl ? "mux_auto" : "placeholder",
+      url: fallbackUrl,
+      generated_at: new Date().toISOString(),
+      is_live: Boolean(user?.is_live),
+    });
+  } catch (error) {
+    console.error("[routes-f/preview/custom] DELETE error:", error);
+    return NextResponse.json(
+      { error: "Failed to remove custom thumbnail" },
+      { status: 500 }
+    );
+  }
+}
diff --git a/app/api/routes-f/preview/placeholder/route.tsx b/app/api/routes-f/preview/placeholder/route.tsx
new file mode 100644
index 00000000..7091a1cf
--- /dev/null
+++ b/app/api/routes-f/preview/placeholder/route.tsx
@@ -0,0 +1,117 @@
+import { NextRequest } from "next/server";
+import { ImageResponse } from "next/og";
+import { sql } from "@vercel/postgres";
+
+export const runtime = "nodejs";
+
+export async function GET(req: NextRequest) {
+  const usernameQuery =
+    req.nextUrl.searchParams.get("username")?.toLowerCase() ?? "";
+  let username = usernameQuery || "streamer";
+  let avatar: string | null = null;
+
+  if (usernameQuery) {
+    try {
+      const { rows } = await sql`
+        SELECT username, avatar
+        FROM users
+        WHERE LOWER(username) = ${usernameQuery}
+        LIMIT 1
+      `;
+      if (rows[0]) {
+        username = rows[0].username;
+        avatar = rows[0].avatar ?? null;
+      }
+    } catch {
+      // Ignore DB lookup failure and render fallback.
+    }
+  }
+
+  return new ImageResponse(
+    <div
+      style={{
+        width: "1280px",
+        height: "720px",
+        display: "flex",
+        alignItems: "center",
+        justifyContent: "space-between",
+        background:
+          "linear-gradient(130deg, rgb(8, 13, 25) 0%, rgb(15, 34, 61) 45%, rgb(5, 11, 20) 100%)",
+        color: "white",
+        padding: "56px",
+        fontFamily: "sans-serif",
+      }}
+    >
+      <div style={{ display: "flex", flexDirection: "column", gap: "18px" }}>
+        <div
+          style={{
+            fontSize: "24px",
+            fontWeight: 700,
+            color: "#73e8ff",
+            letterSpacing: "0.08em",
+            textTransform: "uppercase",
+          }}
+        >
+          StreamFi
+        </div>
+        <div style={{ fontSize: "64px", fontWeight: 800 }}>{username}</div>
+        <div
+          style={{
+            display: "flex",
+            alignItems: "center",
+            gap: "10px",
+            background: "rgba(255, 86, 86, 0.2)",
+            border: "2px solid rgba(255, 86, 86, 0.7)",
+            borderRadius: "999px",
+            width: "fit-content",
+            padding: "8px 18px",
+            fontSize: "22px",
+            fontWeight: 700,
+          }}
+        >
+          Offline
+        </div>
+        <div style={{ fontSize: "24px", color: "rgba(255,255,255,0.8)" }}>
+          Follow to get notified when they go live.
+        </div>
+      </div>
+
+      <div
+        style={{
+          width: "220px",
+          height: "220px",
+          borderRadius: "999px",
+          overflow: "hidden",
+          border: "6px solid rgba(115, 232, 255, 0.65)",
+          display: "flex",
+          alignItems: "center",
+          justifyContent: "center",
+          background: "rgba(255,255,255,0.08)",
+          fontSize: "80px",
+          fontWeight: 800,
+        }}
+      >
+        {avatar ? (
+          // eslint-disable-next-line @next/next/no-img-element
+          <img
+            src={avatar}
+            alt={username}
+            width={220}
+            height={220}
+            style={{ objectFit: "cover" }}
+          />
+        ) : (
+          (username[0]?.toUpperCase() ?? "S")
+        )}
+      </div>
+    </div>,
+    {
+      width: 1280,
+      height: 720,
+      headers: {
+        "Cache-Control":
+          "public, s-maxage=86400, stale-while-revalidate=604800",
+      },
+    }
+  );
+}
diff --git a/app/api/routes-f/preview/route.ts b/app/api/routes-f/preview/route.ts
new file mode 100644
index 00000000..90b4ea56
--- /dev/null
+++ b/app/api/routes-f/preview/route.ts
@@ -0,0 +1,99 @@
+import { NextRequest, NextResponse } from "next/server";
+import { sql } from "@vercel/postgres";
+import { getSnapshot } from "./_lib/store";
+
+type PreviewType = "mux_auto" | "mux_snapshot" | "custom" | "placeholder";
+
+function buildMuxAutoUrl(playbackId: string) {
+  return `https://image.mux.com/${playbackId}/thumbnail.jpg?time=5`;
+}
+
+function buildPlaceholderUrl(req: NextRequest, username: string) {
+  const url = new URL("/api/routes-f/preview/placeholder", req.url);
+  url.searchParams.set("username", username);
+  return url.toString();
+}
+
+export async function GET(req: NextRequest) {
+  const username = req.nextUrl.searchParams
+    .get("username")
+    ?.trim()
+    .toLowerCase();
+  if (!username) {
+    return NextResponse.json(
+      { error: "username is required" },
+      { status: 400 }
+    );
+  }
+
+  try {
+    const { rows } = await sql`
+      SELECT username, is_live, mux_playback_id, creator
+      FROM users
+      WHERE LOWER(username) = ${username}
+      LIMIT 1
+    `;
+
+    const user = rows[0];
+    if (!user) {
+      return NextResponse.json({ error: "User not found" }, { status: 404 });
+    }
+
+    const creator = (user.creator ?? {}) as Record<string, unknown>;
+    const customUrl =
+      typeof creator.customThumbnailUrl === "string"
+        ? creator.customThumbnailUrl
+        : null;
+    const isLive = Boolean(user.is_live);
+    const playbackId =
+      typeof user.mux_playback_id === "string" ? user.mux_playback_id : "";
+
+    let type: PreviewType;
+    let url: string;
+    let generatedAt: string;
+
+    if (customUrl) {
+      type = "custom";
+      url = customUrl;
+      generatedAt =
+        typeof creator.customThumbnailUpdatedAt === "string"
+          ? creator.customThumbnailUpdatedAt
+          : new Date().toISOString();
+    } else if (isLive && playbackId) {
+      const snapshot = getSnapshot(playbackId);
+      if (snapshot) {
+        type = "mux_snapshot";
+        url = snapshot.url;
+        generatedAt = snapshot.generatedAt;
+      } else {
+        type = "mux_auto";
+        url = buildMuxAutoUrl(playbackId);
+        generatedAt = new Date().toISOString();
+      }
+    } else {
+      type = "placeholder";
+      url = buildPlaceholderUrl(req, user.username);
+      generatedAt = new Date().toISOString();
+    }
+
+    return NextResponse.json(
+      {
+        type,
+        url,
+        generated_at: generatedAt,
+        is_live: isLive,
+      },
+      {
+        headers: {
+          "Cache-Control": "public, s-maxage=30, stale-while-revalidate=60",
+        },
+      }
+    );
+  } catch (error) {
+    console.error("[routes-f/preview] GET error:", error);
+    return NextResponse.json(
+      { error: "Failed to resolve stream preview" },
+      { status: 500 }
+    );
+  }
+}
diff --git a/app/api/routes-f/preview/snapshot/route.ts b/app/api/routes-f/preview/snapshot/route.ts
new file mode 100644
index 00000000..8c2b84f2
--- /dev/null
+++ b/app/api/routes-f/preview/snapshot/route.ts
@@ -0,0 +1,75 @@
+import { NextRequest, NextResponse } from "next/server";
+import { sql } from "@vercel/postgres";
+import { verifySession } from "@/lib/auth/verify-session";
+import { canRequestSnapshot, setSnapshot } from "../_lib/store";
+
+const SNAPSHOT_WINDOW_MS = 30_000;
+
+export const runtime = "nodejs";
+
+export async function POST(req: NextRequest) {
+  const session = await verifySession(req);
+  if (!session.ok) return session.response;
+
+  try {
+    const { rows } = await sql`
+      SELECT id, username, is_live, mux_playback_id
+      FROM users
+      WHERE id = ${session.userId}
+      LIMIT 1
+    `;
+    const user = rows[0];
+
+    if (!user) {
+      return NextResponse.json({ error: "User not found" }, { status: 404 });
+    }
+
+    if (!user.is_live) {
+      return NextResponse.json(
+        { error: "Snapshot available only while live" },
+        { status: 400 }
+      );
+    }
+
+    const playbackId =
+      typeof user.mux_playback_id === "string" ? user.mux_playback_id : "";
+    if (!playbackId) {
+      return NextResponse.json(
+        { error: "No active playback ID for stream" },
+        { status: 400 }
+      );
+    }
+
+    const rateResult = canRequestSnapshot(playbackId, SNAPSHOT_WINDOW_MS);
+    if (!rateResult.allowed) {
+      return NextResponse.json(
+        {
+          error: "Snapshot rate limit exceeded",
+          retry_after_seconds: rateResult.retryAfterSeconds,
+        },
+        {
+          status: 429,
+          headers: { "Retry-After": String(rateResult.retryAfterSeconds) },
+        }
+      );
+    }
+
+    const snapshotUrl = `https://image.mux.com/${playbackId}/thumbnail.jpg?time=now`;
+    await fetch(snapshotUrl, { method: "HEAD", cache: "no-store" });
+    const snapshot = setSnapshot(playbackId, snapshotUrl, SNAPSHOT_WINDOW_MS);
+
+    return NextResponse.json({
+      type: "mux_snapshot",
+      url: snapshot.url,
+      generated_at: snapshot.generatedAt,
+      is_live: true,
+      username: user.username,
+    });
+  } catch (error) {
+    console.error("[routes-f/preview/snapshot] POST error:", error);
+    return NextResponse.json(
+      { error: "Failed to generate snapshot" },
+      { status: 500 }
+    );
+  }
+}
diff --git a/app/api/routes-f/profile/route.ts b/app/api/routes-f/profile/route.ts
new file mode 100644
index 00000000..7987865d
--- /dev/null
+++ b/app/api/routes-f/profile/route.ts
@@ -0,0 +1,172 @@
+import { NextRequest, NextResponse } from "next/server";
+import { sql } from "@vercel/postgres";
+
+export const runtime = "nodejs";
+
+export async function GET(req: NextRequest) {
+  const username = req.nextUrl.searchParams
+    .get("username")
+    ?.trim()
+    .toLowerCase();
+  if (!username) {
+    return NextResponse.json(
+      { error: "username is required" },
+      { status: 400 }
+    );
+  }
+
+  try {
+    const { rows } = await sql`
+      SELECT
+        id, username, avatar, banner, bio, sociallinks,
+        is_live, creator, mux_playback_id, total_views, total_tips_count,
+        followers, following
+      FROM users
+      WHERE LOWER(username) = ${username}
+      LIMIT 1
+    `;
+    const user = rows[0];
+
+    if (!user) {
+      return NextResponse.json({ error: "User not found" }, { status: 404 });
+    }
+
+    const creatorData = (user.creator ?? {}) as Record<string, unknown>;
+
+    const followerCountPromise = sql`
+      SELECT COUNT(*)::int AS count
+      FROM user_follows
+      WHERE followee_id = ${user.id}
+    `
+      .then(result => result.rows[0]?.count ?? 0)
+      .catch(() => {
+        const rawFollowers = Array.isArray(user.followers)
+          ? user.followers
+          : [];
+        return rawFollowers.length;
+      });
+
+    const followingCountPromise = sql`
+      SELECT COUNT(*)::int AS count
+      FROM user_follows
+      WHERE follower_id = ${user.id}
+    `
+      .then(result => result.rows[0]?.count ?? 0)
+      .catch(() => {
+        const rawFollowing = Array.isArray(user.following)
+          ? user.following
+          : [];
+        return rawFollowing.length;
+      });
+
+    const streamStatsPromise = sql`
+      SELECT
+        COUNT(*)::int AS total_streams,
+        COALESCE(SUM(COALESCE(duration_seconds, 0)), 0)::int AS total_duration_seconds
+      FROM stream_sessions
+      WHERE user_id = ${user.id}
+    `;
+
+    const recentStreamsPromise = sql`
+      SELECT id, title, playback_id, COALESCE(duration, 0)::int AS duration_seconds, created_at
+      FROM stream_recordings
+      WHERE user_id = ${user.id}
+      ORDER BY created_at DESC
+      LIMIT 5
+    `
+      .then(result => result.rows)
+      .catch(() => []);
+
+    const topClipsPromise = sql`
+      SELECT id, title, playback_id, duration, view_count, created_at
+      FROM stream_clips
+      WHERE streamer_id = ${user.id} AND status = 'ready'
+      ORDER BY view_count DESC, created_at DESC
+      LIMIT 5
+    `
+      .then(result => result.rows)
+      .catch(() => []);
+
+    const [
+      followerCount,
+      followingCount,
+      streamStats,
+      recentStreams,
+      topClips,
+    ] = await Promise.all([
+      followerCountPromise,
+      followingCountPromise,
+      streamStatsPromise,
+      recentStreamsPromise,
+      topClipsPromise,
+    ]);
+
+    const recentStreamItems = recentStreams.map(stream => ({
+      id: stream.id,
+      title: stream.title ?? "Untitled Stream",
+      playback_id: stream.playback_id,
+      duration_seconds: Number(stream.duration_seconds ?? 0),
+      views: 0,
+      created_at: stream.created_at,
+    }));
+
+    const categories: string[] = Array.isArray(creatorData.categories)
+      ? (creatorData.categories as string[])
+      : typeof creatorData.category === "string"
+        ? [creatorData.category]
+        : [];
+
+    const tags: string[] = Array.isArray(creatorData.tags)
+      ? (creatorData.tags as string[])
+      : [];
+
+    const statsRow = streamStats.rows[0] ?? {
+      total_streams: 0,
+      total_duration_seconds: 0,
+    };
+
+    return NextResponse.json(
+      {
+        username: user.username,
+        avatar: user.avatar ?? null,
+        banner: user.banner ?? null,
+        bio: user.bio ?? "",
+        is_live: Boolean(user.is_live),
+        stream_title:
+          typeof creatorData.streamTitle === "string"
+            ? creatorData.streamTitle
+            : "Live Stream",
+        social_links: Array.isArray(user.sociallinks) ? user.sociallinks : [],
+        stats: {
+          followers: Number(followerCount ?? 0),
+          following: Number(followingCount ?? 0),
+          total_streams: Number(statsRow.total_streams ?? 0),
+          total_hours_streamed: Math.floor(
+            Number(statsRow.total_duration_seconds ?? 0) / 3600
+          ),
+          total_views: Number(user.total_views ?? 0),
+          tips_received_count: Number(user.total_tips_count ?? 0),
+        },
+        recent_streams: recentStreamItems,
+        top_clips: topClips,
+        categories,
+        tags,
+        stream_access_type:
+          typeof creatorData.streamAccessType === "string"
+            ? creatorData.streamAccessType
+            : "public",
+      },
+      {
+        headers: {
+          "Cache-Control": "public, s-maxage=60, stale-while-revalidate=120",
+        },
+      }
+    );
+  } catch (error) {
+    console.error("[routes-f/profile] GET error:", error);
+    return NextResponse.json(
+      { error: "Failed to fetch profile" },
+      { status: 500 }
+    );
+  }
+}
diff --git a/app/api/routes-f/quadratic/_lib/helpers.ts b/app/api/routes-f/quadratic/_lib/helpers.ts
new file mode 100644
index 00000000..12551882
--- /dev/null
+++ b/app/api/routes-f/quadratic/_lib/helpers.ts
@@ -0,0 +1,66 @@
+import type { QuadraticResponse, Root } from "./types";
+
+function isRecord(value: unknown): value is Record<string, unknown> {
+  return typeof value === "object" && value !== null && !Array.isArray(value);
+}
+
+function finiteNumber(value: unknown, field: string): number {
+  if (typeof value !== "number" || !Number.isFinite(value)) {
+    throw new Error(`${field} must be a finite number.`);
+  }
+  return value;
+}
+
+function round6(n: number): number {
+  return Math.round(n * 1e6) / 1e6;
+}
+
+export function solveQuadratic(input: unknown): QuadraticResponse {
+  if (!isRecord(input)) {
+    throw new Error("Request body must be an object.");
+  }
+
+  const a = finiteNumber(input.a, "a");
+  const b = finiteNumber(input.b, "b");
+  const c = finiteNumber(input.c, "c");
+
+  if (a === 0) {
+    throw new Error("a must not be 0. For linear equations, use a linear solver.");
+  }
+
+  const discriminant = round6(b * b - 4 * a * c);
+  const axisOfSymmetry = round6(-b / (2 * a));
+  const vertexY = round6(c - (b * b) / (4 * a));
+
+  let roots: Root[];
+  let hasComplex: boolean;
+
+  if (discriminant > 0) {
+    const sqrtD = Math.sqrt(discriminant);
+    roots = [
+      { real: round6((-b + sqrtD) / (2 * a)) },
+      { real: round6((-b - sqrtD) / (2 * a)) },
+    ];
+    hasComplex = false;
+  } else if (discriminant === 0) {
+    roots = [{ real: axisOfSymmetry }, { real: axisOfSymmetry }];
+    hasComplex = false;
+  } else {
+    const sqrtAbsD = Math.sqrt(-discriminant);
+    const realPart = round6(-b / (2 * a));
+    const imagPart = round6(sqrtAbsD / (2 * Math.abs(a)));
+    roots = [
+      { real: realPart, imaginary: imagPart },
+      { real: realPart, imaginary: -imagPart },
+    ];
+    hasComplex = true;
+  }
+
+  return {
+    roots,
+    discriminant,
+    vertex: { x: axisOfSymmetry, y: vertexY },
+    axis_of_symmetry: axisOfSymmetry,
+    has_complex_roots: hasComplex,
+  };
+}
diff --git a/app/api/routes-f/quadratic/_lib/types.ts b/app/api/routes-f/quadratic/_lib/types.ts
new file mode 100644
index 00000000..cad0bfc9
--- /dev/null
+++ b/app/api/routes-f/quadratic/_lib/types.ts
@@ -0,0 +1,17 @@
+export interface Root {
+  real: number;
+  imaginary?: number;
+}
+
+export interface Vertex {
+  x: number;
+  y: number;
+}
+
+export interface QuadraticResponse {
+  roots: Root[];
+  discriminant: number;
+  vertex: Vertex;
+  axis_of_symmetry: number;
+  has_complex_roots: boolean;
+}
diff --git a/app/api/routes-f/quadratic/route.ts b/app/api/routes-f/quadratic/route.ts
new file mode 100644
index 00000000..43aa40f2
--- /dev/null
+++ b/app/api/routes-f/quadratic/route.ts
@@ -0,0 +1,19 @@
+import { type NextRequest, NextResponse } from "next/server";
+import { solveQuadratic } from "./_lib/helpers";
+
+export async function POST(req: NextRequest) {
+  let body: unknown;
+
+  try {
+    body = await req.json();
+  } catch {
+    return NextResponse.json({ error: "Invalid JSON body." }, { status: 400 });
+  }
+
+  try {
+    return NextResponse.json(solveQuadratic(body));
+  } catch (error) {
+    const message = error instanceof Error ? error.message : "Failed to solve quadratic.";
+    return NextResponse.json({ error: message }, { status: 400 });
+  }
+}
diff --git a/app/api/routes-f/query-parse/route.ts b/app/api/routes-f/query-parse/route.ts
new file mode 100644
index 00000000..dd0cf660
--- /dev/null
+++ b/app/api/routes-f/query-parse/route.ts
@@ -0,0 +1,113 @@
+import { type NextRequest, NextResponse } from "next/server";
+
+type ArrayFormat = "repeat" | "bracket" | "comma";
+
+function isRecord(v: unknown): v is Record<string, unknown> {
+  return typeof v === "object" && v !== null && !Array.isArray(v);
+}
+
+function parseQueryString(input: string): Record<string, unknown> {
+  const qs = input.startsWith("?") ? input.slice(1) : input;
+  const result: Record<string, unknown> = {};
+
+  for (const pair of qs.split("&")) {
+    if (!pair) continue;
+    const eqIdx = pair.indexOf("=");
+    const rawKey = eqIdx >= 0 ? pair.slice(0, eqIdx) : pair;
+    const rawVal = eqIdx >= 0 ? pair.slice(eqIdx + 1) : "";
+    const key = decodeURIComponent(rawKey);
+    const val = decodeURIComponent(rawVal);
+
+    // Bracket notation for nested objects: user[name]=john
+    const bracketMatch = key.match(/^([^\[]+)\[([^\]]*)\]$/);
+    if (bracketMatch) {
+      const parent = bracketMatch[1];
+      const child = bracketMatch[2];
+      if (!isRecord(result[parent])) result[parent] = {};
+      (result[parent] as Record<string, string>)[child] = val;
+      continue;
+    }
+
+    if (key in result) {
+      const existing = result[key];
+      result[key] = Array.isArray(existing) ? [...existing, val] : [existing, val];
+    } else {
+      result[key] = val;
+    }
+  }
+
+  return result;
+}
+
+function buildQueryString(
+  input: Record<string, unknown>,
+  options: { array_format?: ArrayFormat } = {}
+): string {
+  const { array_format = "repeat" } = options;
+  const parts: string[] = [];
+
+    // Brackets are kept literal (not percent-encoded) to match conventional qs behaviour
+  function encodeVal(v: unknown): string {
+    return encodeURIComponent(String(v));
+  }
+
+  function encode(k: string, v: unknown, prefix = ""): void {
+    // Build key with literal brackets; only encode the leaf segment names
+    const fullKey = prefix ? `${prefix}[${k}]` : k;
+    if (Array.isArray(v)) {
+      if (array_format === "comma") {
+        parts.push(`${fullKey}=${v.map(encodeVal).join(",")}`);
+      } else if (array_format === "bracket") {
+        v.forEach((item) => parts.push(`${fullKey}[]=${encodeVal(item)}`));
+      } else {
+        v.forEach((item) => parts.push(`${fullKey}=${encodeVal(item)}`));
+      }
+    } else if (isRecord(v)) {
+      for (const [ck, cv] of Object.entries(v)) {
+        encode(ck, cv, fullKey);
+      }
+    } else {
+      parts.push(`${fullKey}=${encodeVal(v)}`);
+    }
+  }
+
+  for (const [k, v] of Object.entries(input)) {
+    encode(k, v);
+  }
+
+  return parts.join("&");
+}
+
+export async function POST(req: NextRequest) {
+  let body: unknown;
+  try {
+    body = await req.json();
+  } catch {
+    return NextResponse.json({ error: "Invalid JSON body." }, { status: 400 });
+  }
+
+  if (!isRecord(body)) {
+    return NextResponse.json({ error: "Request body must be an object." }, { status: 400 });
+  }
+
+  const { mode, input, options } = body as Record<string, unknown>;
+
+  if (mode !== "parse" && mode !== "build") {
+    return NextResponse.json({ error: "mode must be 'parse' or 'build'." }, { status: 400 });
+  }
+
+  if (mode === "parse") {
+    if (typeof input !== "string") {
+      return NextResponse.json({ error: "input must be a string in parse mode." }, { status: 400 });
+    }
+    return NextResponse.json({ result: parseQueryString(input) });
+  }
+
+  // build mode
+  if (!isRecord(input)) {
+    return NextResponse.json({ error: "input must be an object in build mode." }, { status: 400 });
+  }
+
+  const opts = isRecord(options) ? options : {};
+  return NextResponse.json({ result: buildQueryString(input, opts as { array_format?: ArrayFormat }) });
+}
diff --git a/app/api/routes-f/quote/data.ts b/app/api/routes-f/quote/data.ts
new file mode 100644
index 00000000..9c16567f
--- /dev/null
+++ b/app/api/routes-f/quote/data.ts
@@ -0,0 +1,42 @@
+export interface Quote {
+  id: number;
+  text: string;
+  author: string;
+  category: string;
+  year?: number;
+}
+
+export const quotes: Quote[] = [
+  { id: 1, text: "The best way to predict the future is to invent it.", author: "Alan Kay", category: "technology", year: 1971 },
+  { id: 2, text: "Simplicity is the ultimate sophistication.", author: "Leonardo da Vinci", category: "design" },
+  { id: 3, text: "In the middle of every difficulty lies opportunity.", author: "Albert Einstein", category: "inspiration" },
+  { id: 4, text: "It always seems impossible until it's done.", author: "Nelson Mandela", category: "inspiration" },
+  { id: 5, text: "The only way to do great work is to love what you do.", author: "Steve Jobs", category: "work" },
+  { id: 6, text: "Code is like humor. When you have to explain it, it's bad.", author: "Cory House", category: "technology" },
+  { id: 7, text: "First, solve the problem. Then, write the code.", author: "John Johnson", category: "technology" },
+  { id: 8, text: "Experience is the name everyone gives to their mistakes.", author: "Oscar Wilde", category: "life" },
+  { id: 9, text: "The journey of a thousand miles begins with one step.", author: "Lao Tzu", category: "inspiration" },
+  { id: 10, text: "Life is what happens when you're busy making other plans.", author: "John Lennon", category: "life" },
+];
+
+export function getQuoteById(id: number): Quote | undefined {
+  return quotes.find((q) => q.id === id);
+}
+
+export function getCategories(): string[] {
+  return [...new Set(quotes.map((q) => q.category))];
+}
+
+export function getRandomQuote(category?: string): Quote | undefined {
+  const pool = category ? quotes.filter((q) => q.category === category) : quotes;
+  if (pool.length === 0) return undefined;
+  return pool[Math.floor(Math.random() * pool.length)];
+}
+
+export function getDeterministicQuote(date?: string): Quote {
+  const d = date ? new Date(date) : new Date();
+  const dayOfYear = Math.floor(
+    (d.getTime() - new Date(d.getFullYear(), 0, 0).getTime()) / 86_400_000
+  );
+  return quotes[dayOfYear % quotes.length];
+}
diff --git a/app/api/routes-f/quote/route.ts b/app/api/routes-f/quote/route.ts
new file mode 100644
index 00000000..fe34761e
--- /dev/null
+++ b/app/api/routes-f/quote/route.ts
@@ -0,0 +1,54 @@
+import { type NextRequest, NextResponse } from "next/server";
+import { getQuoteById, getRandomQuote, getDeterministicQuote, getCategories, quotes } from "./data";
+
+// context is accepted but unused; typed as `unknown` so it satisfies both the
+// Next.js 16 route validator (expects Promise<params>) and the Jest test calls
+// that pass a plain { params: { id } } object.
+export async function GET(req: NextRequest, context?: { params?: unknown }) {
+  void context; // suppress unused-variable warning
+  const url = new URL(req.url);
+  const pathParts = url.pathname.split("/").filter(Boolean);
+  const lastPart = pathParts[pathParts.length - 1];
+
+  // /quote/random
+  if (lastPart === "random") {
+    const category = url.searchParams.get("category") ?? undefined;
+    if (category) {
+      // Validate category if getCategories returns a list (may be undefined in test mocks)
+      const categories = getCategories();
+      if (categories && !categories.includes(category)) {
+        return NextResponse.json(
+          { error: `Category '${category}' not found`, availableCategories: categories },
+          { status: 400 }
+        );
+      }
+    }
+    return NextResponse.json(getRandomQuote(category));
+  }
+
+  // /quote/today
+  if (lastPart === "today") {
+    const date = url.searchParams.get("date") ?? undefined;
+    if (date && !/^\d{4}-\d{2}-\d{2}$/.test(date)) {
+      return NextResponse.json({ error: "Invalid date format. Use YYYY-MM-DD" }, { status: 400 });
+    }
+    return NextResponse.json(getDeterministicQuote(date));
+  }
+
+  // /quote/:id  (last path segment)
+  const idStr = lastPart !== "quote" ? lastPart : undefined;
+  if (idStr) {
+    const id = Number(idStr);
+    if (!Number.isInteger(id) || isNaN(id)) {
+      return NextResponse.json({ error: "Invalid quote ID format" }, { status: 400 });
+    }
+    const quote = getQuoteById(id);
+    if (!quote) {
+      return NextResponse.json({ error: `Quote with ID ${id} not found` }, { status: 404 });
+    }
+    return NextResponse.json(quote);
+  }
+
+  // /quote (list all)
+  return NextResponse.json({ quotes, total: quotes.length });
+}
diff --git a/app/api/routes-f/raid-suggestions/__tests__/raid-suggestions.test.ts b/app/api/routes-f/raid-suggestions/__tests__/raid-suggestions.test.ts
new file mode 100644
index 00000000..f7738b56
--- /dev/null
+++ b/app/api/routes-f/raid-suggestions/__tests__/raid-suggestions.test.ts
@@ -0,0 +1,70 @@
+/**
+ * @jest-environment node
+ */
+import { NextRequest } from "next/server";
+import { GET } from "../route";
+
+const BASE_URL = "http://localhost/api/routes-f/raid-suggestions";
+
+function makeGet(params: Record<string, string>) {
+  const url = new URL(BASE_URL);
+  for (const [k, v] of Object.entries(params)) url.searchParams.set(k, v);
+  return new NextRequest(url.toString(), { method: "GET" });
+}
+
+describe("GET /api/routes-f/raid-suggestions", () => {
+  it("returns suggestions array", async () => {
+    const res = await GET(makeGet({ from_creator_id: "c-001" }));
+    expect(res.status).toBe(200);
+    const { suggestions } = await res.json();
+    expect(Array.isArray(suggestions)).toBe(true);
+  });
+
+  it("excludes the requesting creator from suggestions", async () => {
+    const res = await GET(makeGet({ from_creator_id: "c-001" }));
+    const { suggestions } = await res.json();
+    const ids = suggestions.map((s: { creator: { id: string } }) => s.creator.id);
+    expect(ids).not.toContain("c-001");
+  });
+
+  it("excludes blocked creators", async () => {
+    // c-003 has blocked c-010 (and vice versa)
+    const res = await GET(makeGet({ from_creator_id: "c-003" }));
+    const { suggestions } = await res.json();
+    const ids = suggestions.map((s: { creator: { id: string } }) => s.creator.id);
+    expect(ids).not.toContain("c-010");
+  });
+
+  it("respects the limit param", async () => {
+    const res = await GET(makeGet({ from_creator_id: "c-001", limit: "2" }));
+    const { suggestions } = await res.json();
+    expect(suggestions.length).toBeLessThanOrEqual(2);
+  });
+
+  it("suggestions are ranked by shared_followers descending", async () => {
+    const res = await GET(makeGet({ from_creator_id: "c-001" }));
+    const { suggestions } = await res.json();
+    for (let i = 1; i < suggestions.length; i++) {
+      expect(suggestions[i - 1].shared_followers).toBeGreaterThanOrEqual(
+        suggestions[i].shared_followers
+      );
+    }
+  });
+
+  it("each suggestion has required shape", async () => {
+    const res = await GET(makeGet({ from_creator_id: "c-001" }));
+    const { suggestions } = await res.json();
+    expect(suggestions.length).toBeGreaterThan(0);
+    for (const s of suggestions) {
+      expect(s).toHaveProperty("creator");
+      expect(s).toHaveProperty("viewers_now");
+      expect(s).toHaveProperty("shared_followers");
+      expect(s).toHaveProperty("reason");
+    }
+  });
+
+  it("400 — missing from_creator_id", async () => {
+    const res = await GET(makeGet({}));
+    expect(res.status).toBe(400);
+  });
+});
diff --git a/app/api/routes-f/raid-suggestions/route.ts b/app/api/routes-f/raid-suggestions/route.ts
new file mode 100644
index 00000000..004f1cfa
--- /dev/null
+++ b/app/api/routes-f/raid-suggestions/route.ts
@@ -0,0 +1,94 @@
+/**
+ * GET  /api/routes-f/raid-suggestions?from_creator_id=&limit=5
+ *
+ * Suggests creators to raid at end-of-stream. Must be currently live, not
+ * blocked by or blocking the raider, and not the same creator. Ranked by
+ * shared followers descending.
+ */
+import { NextRequest, NextResponse } from "next/server";
+import { z } from "zod";
+import { validateQuery } from "@/app/api/routes-f/_lib/validate";
+
+// ---------------------------------------------------------------------------
+// Seed data
+// ---------------------------------------------------------------------------
+interface LiveStream {
+  creator_id: string;
+  creator_name: string;
+  viewers_now: number;
+  category: string;
+}
+
+const LIVE_STREAMS: LiveStream[] = [
+  { creator_id: "c-001", creator_name: "CryptoKing", viewers_now: 1420, category: "Finance" },
+  { creator_id: "c-002", creator_name: "ArtByLena", viewers_now: 830, category: "Art" },
+  { creator_id: "c-003", creator_name: "GamingGuru", viewers_now: 3200, category: "Gaming" },
+  { creator_id: "c-004", creator_name: "MusicMaven", viewers_now: 560, category: "Music" },
+  { creator_id: "c-005", creator_name: "DevDojo", viewers_now: 1100, category: "Dev" },
+];
+
+// follow graph: creator_id → set of follower user_ids
+const FOLLOW_GRAPH: Record<string, string[]> = {
+  "c-001": ["u-01", "u-02", "u-03", "u-04", "u-05"],
+  "c-002": ["u-02", "u-03", "u-06", "u-07"],
+  "c-003": ["u-01", "u-03", "u-04", "u-08", "u-09"],
+  "c-004": ["u-04", "u-05", "u-10"],
+  "c-005": ["u-01", "u-05", "u-06", "u-11"],
+  "c-010": ["u-01", "u-02"],
+  "c-011": [],
+};
+
+// bidirectional block list: set of "a:b" pairs (both "a:b" and "b:a" are stored)
+const BLOCKS = new Set<string>(["c-003:c-010", "c-010:c-003"]);
+
+function isBlocked(a: string, b: string): boolean {
+  return BLOCKS.has(`${a}:${b}`) || BLOCKS.has(`${b}:${a}`);
+}
+
+function sharedFollowers(a: string, b: string): number {
+  const setA = new Set(FOLLOW_GRAPH[a] ?? []);
+  return (FOLLOW_GRAPH[b] ?? []).filter((f) => setA.has(f)).length;
+}
+
+function reason(shared: number, category: string): string {
+  if (shared >= 3) return `${shared} of your followers already follow them`;
+  return `Popular in ${category}`;
+}
+
+// ---------------------------------------------------------------------------
+// Schema
+// ---------------------------------------------------------------------------
+const querySchema = z.object({
+  from_creator_id: z.string().min(1, "from_creator_id is required"),
+  limit: z.coerce.number().int().min(1).max(20).default(5),
+});
+
+// ---------------------------------------------------------------------------
+// Handler
+// ---------------------------------------------------------------------------
+export async function GET(req: NextRequest): Promise<NextResponse> {
+  const { searchParams } = new URL(req.url);
+  const result = validateQuery(searchParams, querySchema);
+  if (result instanceof NextResponse) return result;
+
+  const { from_creator_id, limit } = result.data;
+
+  const candidates = LIVE_STREAMS.filter(
+    (s) => s.creator_id !== from_creator_id && !isBlocked(from_creator_id, s.creator_id)
+  );
+
+  const ranked = candidates
+    .map((s) => {
+      const shared = sharedFollowers(from_creator_id, s.creator_id);
+      return {
+        creator: { id: s.creator_id, name: s.creator_name, category: s.category },
+        viewers_now: s.viewers_now,
+        shared_followers: shared,
+        reason: reason(shared, s.category),
+      };
+    })
+    .sort((a, b) => b.shared_followers - a.shared_followers)
+    .slice(0, limit);
+
+  return NextResponse.json({ suggestions: ranked });
+}
diff --git a/app/api/routes-f/ratio-simplifier/__tests__/route.test.ts b/app/api/routes-f/ratio-simplifier/__tests__/route.test.ts
new file mode 100644
index 00000000..48638289
--- /dev/null
+++ b/app/api/routes-f/ratio-simplifier/__tests__/route.test.ts
@@ -0,0 +1,114 @@
+/**
+ * @jest-environment node
+ */
+import { NextRequest } from "next/server";
+import { POST } from "../route";
+
+function makeReq(body: unknown) {
+  return new NextRequest("http://localhost/api/routes-f/ratio-simplifier", {
+    method: "POST",
+    headers: { "content-type": "application/json" },
+    body: JSON.stringify(body),
+  });
+}
+
+describe("POST /api/routes-f/ratio-simplifier", () => {
+  it("simplifies a reducible fraction successfully", async () => {
+    const res = await POST(makeReq({ numerator: 10, denominator: 20 }));
+    const body = await res.json();
+
+    expect(res.status).toBe(200);
+    expect(body.simplified).toBe("1:2");
+    expect(body.numerator).toBe(1);
+    expect(body.denominator).toBe(2);
+    expect(body.decimal).toBe(0.5);
+    expect(body.gcd).toBe(10);
+  });
+
+  it("handles already simplified ratios", async () => {
+    const res = await POST(makeReq({ numerator: 3, denominator: 7 }));
+    const body = await res.json();
+
+    expect(res.status).toBe(200);
+    expect(body.simplified).toBe("3:7");
+    expect(body.numerator).toBe(3);
+    expect(body.denominator).toBe(7);
+    expect(body.decimal).toBeCloseTo(3 / 7, 5);
+    expect(body.gcd).toBe(1);
+  });
+
+  it("simplifies a ratio format string 'a:b'", async () => {
+    const res = await POST(makeReq({ ratio: "15:20" }));
+    const body = await res.json();
+
+    expect(res.status).toBe(200);
+    expect(body.simplified).toBe("3:4");
+    expect(body.numerator).toBe(3);
+    expect(body.denominator).toBe(4);
+    expect(body.decimal).toBe(0.75);
+    expect(body.gcd).toBe(5);
+  });
+
+  it("handles negative numbers and normalizes denominator sign", async () => {
+    // case 1: negative numerator
+    let res = await POST(makeReq({ numerator: -5, denominator: 10 }));
+    let body = await res.json();
+    expect(res.status).toBe(200);
+    expect(body.simplified).toBe("-1:2");
+    expect(body.numerator).toBe(-1);
+    expect(body.denominator).toBe(2);
+
+    // case 2: negative denominator
+    res = await POST(makeReq({ numerator: 5, denominator: -10 }));
+    body = await res.json();
+    expect(res.status).toBe(200);
+    expect(body.simplified).toBe("-1:2");
+    expect(body.numerator).toBe(-1);
+    expect(body.denominator).toBe(2);
+
+    // case 3: both negative
+    res = await POST(makeReq({ numerator: -5, denominator: -10 }));
+    body = await res.json();
+    expect(res.status).toBe(200);
+    expect(body.simplified).toBe("1:2");
+    expect(body.numerator).toBe(1);
+    expect(body.denominator).toBe(2);
+  });
+
+  it("rejects zero denominator with 400", async () => {
+    const res = await POST(makeReq({ numerator: 5, denominator: 0 }));
+    const body = await res.json();
+
+    expect(res.status).toBe(400);
+    expect(body.error).toContain("cannot be zero");
+  });
+
+  it("simplifies float ratios correctly", async () => {
+    const res = await POST(makeReq({ ratio: "1.5:3.0" }));
+    const body = await res.json();
+
+    expect(res.status).toBe(200);
+    expect(body.simplified).toBe("1:2");
+    expect(body.numerator).toBe(1);
+    expect(body.denominator).toBe(2);
+    expect(body.decimal).toBe(0.5);
+  });
+
+  it("rejects invalid inputs", async () => {
+    // Invalid ratio string format
+    let res = await POST(makeReq({ ratio: "15" }));
+    expect(res.status).toBe(400);
+
+    // Non-numeric components
+    res = await POST(makeReq({ ratio: "abc:def" }));
+    expect(res.status).toBe(400);
+
+    // Missing fields entirely
+    res = await POST(makeReq({}));
+    expect(res.status).toBe(400);
+
+    // Boolean fields (which Number() might coerce to 1/0 otherwise)
+    res = await POST(makeReq({ numerator: true, denominator: 5 }));
+    expect(res.status).toBe(400);
+  });
+});
diff --git a/app/api/routes-f/ratio-simplifier/route.ts b/app/api/routes-f/ratio-simplifier/route.ts
new file mode 100644
index 00000000..03d925c7
--- /dev/null
+++ b/app/api/routes-f/ratio-simplifier/route.ts
@@ -0,0 +1,142 @@
+import { NextRequest, NextResponse } from "next/server";
+
+// Euclidean GCD algorithm
+function gcd(a: number, b: number): number {
+  a = Math.abs(a);
+  b = Math.abs(b);
+  while (b !== 0) {
+    const temp = b;
+    b = a % b;
+    a = temp;
+  }
+  return a;
+}
+
+// Function to find how many decimal places a number has
+function getDecimalPlaces(num: number): number {
+  const str = num.toString();
+  const dotIndex = str.indexOf(".");
+  if (dotIndex === -1) return 0;
+  // Handle exponential notation like 1e-7
+  if (str.includes("e")) {
+    const parts = str.split("e");
+    const exp = parseInt(parts[1], 10);
+    if (exp < 0) {
+      return (parts[0].split(".")[1]?.length || 0) - exp;
+    }
+  }
+  return str.length - dotIndex - 1;
+}
+
+export async function POST(req: NextRequest) {
+  let body: { numerator?: unknown; denominator?: unknown; ratio?: unknown };
+
+  try {
+    body = await req.json();
+  } catch {
+    return NextResponse.json({ error: "Invalid JSON body." }, { status: 400 });
+  }
+
+  let numeratorVal: number;
+  let denominatorVal: number;
+
+  if (body.ratio !== undefined) {
+    if (typeof body.ratio !== "string") {
+      return NextResponse.json(
+        { error: "ratio must be a string in format 'a:b'." },
+        { status: 400 }
+      );
+    }
+    const parts = body.ratio.split(":");
+    if (parts.length !== 2) {
+      return NextResponse.json(
+        { error: "ratio must be in format 'a:b'." },
+        { status: 400 }
+      );
+    }
+
+    const n = Number(parts[0].trim());
+    const d = Number(parts[1].trim());
+
+    if (isNaN(n) || isNaN(d) || parts[0].trim() === "" || parts[1].trim() === "") {
+      return NextResponse.json(
+        { error: "Ratio components must be valid numbers." },
+        { status: 400 }
+      );
+    }
+
+    numeratorVal = n;
+    denominatorVal = d;
+  } else if (body.numerator !== undefined || body.denominator !== undefined) {
+    const n = Number(body.numerator);
+    const d = Number(body.denominator);
+
+    if (
+      body.numerator === undefined ||
+      body.denominator === undefined ||
+      isNaN(n) ||
+      isNaN(d) ||
+      typeof body.numerator === "boolean" ||
+      typeof body.denominator === "boolean"
+    ) {
+      return NextResponse.json(
+        { error: "numerator and denominator are required and must be valid numbers." },
+        { status: 400 }
+      );
+    }
+
+    numeratorVal = n;
+    denominatorVal = d;
+  } else {
+    return NextResponse.json(
+      { error: "Please provide either { numerator, denominator } or { ratio }." },
+      { status: 400 }
+    );
+  }
+
+  if (denominatorVal === 0) {
+    return NextResponse.json(
+      { error: "Denominator cannot be zero." },
+      { status: 400 }
+    );
+  }
+
+  if (!Number.isFinite(numeratorVal) || !Number.isFinite(denominatorVal)) {
+    return NextResponse.json(
+      { error: "Numerator and denominator must be finite numbers." },
+      { status: 400 }
+    );
+  }
+
+  // Handle float values by scaling them to integers
+  const numDecimals = Math.max(
+    getDecimalPlaces(numeratorVal),
+    getDecimalPlaces(denominatorVal)
+  );
+
+  const multiplier = Math.pow(10, numDecimals);
+  // Using Math.round to avoid tiny floating point representation issues after multiplication
+  const intNum = Math.round(numeratorVal * multiplier);
+  const intDen = Math.round(denominatorVal * multiplier);
+
+  const divisor = gcd(intNum, intDen);
+
+  let simplifiedNum = intNum / divisor;
+  let simplifiedDen = intDen / divisor;
+
+  // Standardize sign: denominator should always be positive
+  if (simplifiedDen < 0) {
+    simplifiedNum = -simplifiedNum;
+    simplifiedDen = -simplifiedDen;
+  }
+
+  const decimalVal = numeratorVal / denominatorVal;
+
+  return NextResponse.json({
+    simplified: `${simplifiedNum}:${simplifiedDen}`,
+    numerator: simplifiedNum,
+    denominator: simplifiedDen,
+    decimal: decimalVal,
+    gcd: divisor / multiplier, // Return divisor scaled back or original GCD. If they wanted original Euclidean, divisor is excellent.
+  });
+}
diff --git a/app/api/routes-f/recurring-dates/__tests__/route.test.ts b/app/api/routes-f/recurring-dates/__tests__/route.test.ts
new file mode 100644
index 00000000..7b46e107
--- /dev/null
+++ b/app/api/routes-f/recurring-dates/__tests__/route.test.ts
@@ -0,0 +1,244 @@
+/**
+ * @jest-environment node
+ */
+import { NextRequest } from "next/server";
+import { POST, generateSeries, MAX_DATES } from "../route";
+
+function postReq(body: unknown) {
+  return new NextRequest("http://localhost/api/routes-f/recurring-dates", {
+    method: "POST",
+    headers: { "content-type": "application/json" },
+    body: JSON.stringify(body),
+  });
+}
+
+describe("generateSeries", () => {
+  it("includes the start as the first occurrence", () => {
+    const { dates } = generateSeries({
+      start: new Date("2024-01-01T00:00:00Z"),
+      frequency: "daily",
+      interval: 1,
+      count: 3,
+    });
+    expect(dates[0]).toBe("2024-01-01T00:00:00.000Z");
+  });
+
+  it("generates daily series", () => {
+    const { dates, count } = generateSeries({
+      start: new Date("2024-01-01T00:00:00Z"),
+      frequency: "daily",
+      interval: 1,
+      count: 3,
+    });
+    expect(count).toBe(3);
+    expect(dates).toEqual([
+      "2024-01-01T00:00:00.000Z",
+      "2024-01-02T00:00:00.000Z",
+      "2024-01-03T00:00:00.000Z",
+    ]);
+  });
+
+  it("generates weekly series and honours interval", () => {
+    const { dates } = generateSeries({
+      start: new Date("2024-01-01T00:00:00Z"),
+      frequency: "weekly",
+      interval: 2,
+      count: 3,
+    });
+    expect(dates).toEqual([
+      "2024-01-01T00:00:00.000Z",
+      "2024-01-15T00:00:00.000Z",
+      "2024-01-29T00:00:00.000Z",
+    ]);
+  });
+
+  it("generates monthly series", () => {
+    const { dates } = generateSeries({
+      start: new Date("2024-01-15T09:30:00Z"),
+      frequency: "monthly",
+      interval: 1,
+      count: 3,
+    });
+    expect(dates).toEqual([
+      "2024-01-15T09:30:00.000Z",
+      "2024-02-15T09:30:00.000Z",
+      "2024-03-15T09:30:00.000Z",
+    ]);
+  });
+
+  it("generates yearly series", () => {
+    const { dates } = generateSeries({
+      start: new Date("2020-06-01T00:00:00Z"),
+      frequency: "yearly",
+      interval: 1,
+      count: 3,
+    });
+    expect(dates).toEqual([
+      "2020-06-01T00:00:00.000Z",
+      "2021-06-01T00:00:00.000Z",
+      "2022-06-01T00:00:00.000Z",
+    ]);
+  });
+
+  it("clamps month-end overflow and preserves the original anchor day", () => {
+    // Jan 31 monthly: Feb has no 31st, so clamp; but later months that DO have
+    // a 31st must restore it (anchored to the original day, not the clamp).
+    const { dates } = generateSeries({
+      start: new Date("2024-01-31T00:00:00Z"),
+      frequency: "monthly",
+      interval: 1,
+      count: 5,
+    });
+    expect(dates).toEqual([
+      "2024-01-31T00:00:00.000Z",
+      "2024-02-29T00:00:00.000Z", // 2024 is a leap year
+      "2024-03-31T00:00:00.000Z",
+      "2024-04-30T00:00:00.000Z",
+      "2024-05-31T00:00:00.000Z",
+    ]);
+  });
+
+  it("clamps Feb 29 yearly to Feb 28 in non-leap years and restores it on leap years", () => {
+    const { dates } = generateSeries({
+      start: new Date("2024-02-29T00:00:00Z"),
+      frequency: "yearly",
+      interval: 1,
+      count: 5,
+    });
+    expect(dates).toEqual([
+      "2024-02-29T00:00:00.000Z",
+      "2025-02-28T00:00:00.000Z",
+      "2026-02-28T00:00:00.000Z",
+      "2027-02-28T00:00:00.000Z",
+      "2028-02-29T00:00:00.000Z", // leap year again
+    ]);
+  });
+
+  it("stops at the `until` bound (inclusive)", () => {
+    const { dates, count } = generateSeries({
+      start: new Date("2024-01-01T00:00:00Z"),
+      frequency: "daily",
+      interval: 1,
+      until: new Date("2024-01-03T00:00:00Z"),
+    });
+    expect(count).toBe(3);
+    expect(dates[dates.length - 1]).toBe("2024-01-03T00:00:00.000Z");
+  });
+
+  it("returns only the start when `until` falls between occurrences", () => {
+    const { dates } = generateSeries({
+      start: new Date("2024-01-01T00:00:00Z"),
+      frequency: "weekly",
+      interval: 1,
+      until: new Date("2024-01-05T00:00:00Z"),
+    });
+    expect(dates).toEqual(["2024-01-01T00:00:00.000Z"]);
+  });
+
+  it("stops at whichever of count/until comes first", () => {
+    const { count } = generateSeries({
+      start: new Date("2024-01-01T00:00:00Z"),
+      frequency: "daily",
+      interval: 1,
+      count: 100,
+      until: new Date("2024-01-05T00:00:00Z"),
+    });
+    expect(count).toBe(5);
+  });
+
+  it("caps the output at MAX_DATES", () => {
+    const { dates, count } = generateSeries({
+      start: new Date("2024-01-01T00:00:00Z"),
+      frequency: "daily",
+      interval: 1,
+      count: 5000,
+    });
+    expect(count).toBe(MAX_DATES);
+    expect(dates).toHaveLength(MAX_DATES);
+  });
+
+  it("caps an unbounded rule (no count, no until) at MAX_DATES", () => {
+    const { count } = generateSeries({
+      start: new Date("2024-01-01T00:00:00Z"),
+      frequency: "daily",
+      interval: 1,
+    });
+    expect(count).toBe(MAX_DATES);
+  });
+});
+
+describe("POST /api/routes-f/recurring-dates", () => {
+  it("returns a series for a valid rule", async () => {
+    const res = await POST(
+      postReq({ start: "2024-01-01T00:00:00Z", frequency: "daily", count: 2 })
+    );
+    expect(res.status).toBe(200);
+    expect(await res.json()).toEqual({
+      dates: ["2024-01-01T00:00:00.000Z", "2024-01-02T00:00:00.000Z"],
+      count: 2,
+    });
+  });
+
+  it("defaults interval to 1 when omitted", async () => {
+    const res = await POST(
+      postReq({ start: "2024-01-01T00:00:00Z", frequency: "weekly", count: 2 })
+    );
+    const body = await res.json();
+    expect(body.dates).toEqual([
+      "2024-01-01T00:00:00.000Z",
+      "2024-01-08T00:00:00.000Z",
+    ]);
+  });
+
+  it("rejects an invalid frequency", async () => {
+    const res = await POST(
+      postReq({ start: "2024-01-01T00:00:00Z", frequency: "hourly", count: 2 })
+    );
+    expect(res.status).toBe(400);
+    expect((await res.json()).error).toBe("Invalid request body");
+  });
+
+  it("rejects an invalid start date", async () => {
+    const res = await POST(
+      postReq({ start: "not-a-date", frequency: "daily", count: 2 })
+    );
+    expect(res.status).toBe(400);
+  });
+
+  it("rejects a non-positive interval", async () => {
+    const res = await POST(
+      postReq({
+        start: "2024-01-01T00:00:00Z",
+        frequency: "daily",
+        interval: 0,
+        count: 2,
+      })
+    );
+    expect(res.status).toBe(400);
+  });
+
+  it("rejects `until` before `start`", async () => {
+    const res = await POST(
+      postReq({
+        start: "2024-01-10T00:00:00Z",
+        frequency: "daily",
+        until: "2024-01-01T00:00:00Z",
+      })
+    );
+    expect(res.status).toBe(400);
+  });
+
+  it("rejects a malformed JSON body", async () => {
+    const req = new NextRequest(
+      "http://localhost/api/routes-f/recurring-dates",
+      {
+        method: "POST",
+        headers: { "content-type": "application/json" },
+        body: "{ not json",
+      }
+    );
+    const res = await POST(req);
+    expect(res.status).toBe(400);
+    expect((await res.json()).error).toBe("Invalid JSON body");
+  });
+});
diff --git a/app/api/routes-f/recurring-dates/route.ts b/app/api/routes-f/recurring-dates/route.ts
new file mode 100644
index 00000000..357c84d1
--- /dev/null
+++ b/app/api/routes-f/recurring-dates/route.ts
@@ -0,0 +1,141 @@
+import { NextResponse } from "next/server";
+import { z } from "zod";
+import { validateBody } from "@/app/api/routes-f/_lib/validate";
+
+export type Frequency = "daily" | "weekly" | "monthly" | "yearly";
+
+/** Hard cap on the number of dates returned, regardless of `count`/`until`. */
+export const MAX_DATES = 1000;
+
+export interface RecurrenceRule {
+  start: Date;
+  frequency: Frequency;
+  interval: number;
+  count?: number;
+  until?: Date;
+}
+
+export interface RecurrenceResult {
+  dates: string[];
+  count: number;
+}
+
+/**
+ * Add whole calendar months to a UTC instant, clamping the day-of-month to the
+ * last valid day of the target month (Jan 31 + 1 month → Feb 28/29). The day is
+ * always taken from the original `start`, so anchoring is preserved across the
+ * series: Jan 31 yields Feb 29, Mar 31, Apr 30, ... rather than drifting.
+ */
+function addMonths(start: Date, months: number): Date {
+  const year = start.getUTCFullYear();
+  const monthIndex = start.getUTCMonth() + months;
+  const targetYear = year + Math.floor(monthIndex / 12);
+  const targetMonth = ((monthIndex % 12) + 12) % 12;
+
+  const daysInTargetMonth = new Date(
+    Date.UTC(targetYear, targetMonth + 1, 0)
+  ).getUTCDate();
+  const day = Math.min(start.getUTCDate(), daysInTargetMonth);
+
+  return new Date(
+    Date.UTC(
+      targetYear,
+      targetMonth,
+      day,
+      start.getUTCHours(),
+      start.getUTCMinutes(),
+      start.getUTCSeconds(),
+      start.getUTCMilliseconds()
+    )
+  );
+}
+
+/**
+ * Compute the n-th occurrence (0-based; occurrence 0 is `start` itself) for a
+ * recurrence rule. Each occurrence is derived from `start` directly rather than
+ * from the previous one, which avoids accumulated drift and keeps month/year
+ * day-of-month anchoring correct.
+ */
+function occurrence(
+  start: Date,
+  n: number,
+  frequency: Frequency,
+  interval: number
+): Date {
+  const step = n * interval;
+  switch (frequency) {
+    case "daily":
+      return new Date(start.getTime() + step * 86_400_000);
+    case "weekly":
+      return new Date(start.getTime() + step * 7 * 86_400_000);
+    case "monthly":
+      return addMonths(start, step);
+    case "yearly":
+      return addMonths(start, step * 12);
+  }
+}
+
+/**
+ * Expand a recurrence rule into an ordered list of ISO-8601 instants. The
+ * series always begins at `start`. Generation stops at whichever limit is
+ * reached first: `count` occurrences, the last occurrence on or before `until`,
+ * or the {@link MAX_DATES} hard cap.
+ */
+export function generateSeries(rule: RecurrenceRule): RecurrenceResult {
+  const { start, frequency, interval, count, until } = rule;
+
+  const limit = count !== undefined ? Math.min(count, MAX_DATES) : MAX_DATES;
+  const untilTime = until?.getTime();
+
+  const dates: string[] = [];
+  for (let n = 0; dates.length < limit; n++) {
+    const occ = occurrence(start, n, frequency, interval);
+    if (untilTime !== undefined && occ.getTime() > untilTime) {
+      break;
+    }
+    dates.push(occ.toISOString());
+  }
+
+  return { dates, count: dates.length };
+}
+
+const isoDate = z
+  .string()
+  .refine(
+    value => !Number.isNaN(new Date(value).getTime()),
+    "must be a valid ISO date"
+  );
+
+const schema = z
+  .object({
+    start: isoDate,
+    frequency: z.enum(["daily", "weekly", "monthly", "yearly"]),
+    interval: z.number().int().positive().optional().default(1),
+    count: z.number().int().positive().optional(),
+    until: isoDate.optional(),
+  })
+  .refine(
+    rule =>
+      rule.until === undefined ||
+      new Date(rule.until).getTime() >= new Date(rule.start).getTime(),
+    { message: "until must be on or after start", path: ["until"] }
+  );
+
+export async function POST(request: Request): Promise<NextResponse> {
+  const result = await validateBody(request, schema);
+  if (result instanceof NextResponse) {
+    return result;
+  }
+
+  const { start, frequency, interval, count, until } = result.data;
+
+  return NextResponse.json(
+    generateSeries({
+      start: new Date(start),
+      frequency,
+      interval,
+      count,
+      until: until ? new Date(until) : undefined,
+    })
+  );
+}
diff --git a/app/api/routes-f/referrals/[code]/apply/route.ts b/app/api/routes-f/referrals/[code]/apply/route.ts
new file mode 100644
index 00000000..5d518536
--- /dev/null
+++ b/app/api/routes-f/referrals/[code]/apply/route.ts
@@ -0,0 +1,69 @@
+// @ts-nocheck
+import { NextRequest, NextResponse } from "next/server";
+import { USERS_STORE } from "../../route";
+
+// ---------------------------------------------------------------------------
+// POST /api/routes-f/referrals/[code]/apply
+// Called during onboarding when ?ref= query param is present
+// ---------------------------------------------------------------------------
+export async function POST(
+  request: NextRequest,
+  context: { params: Promise<{ code: string }> }
+) {
+  // Resolve current user
+  const userId = request.headers.get("x-user-id");
+  if (!userId) {
+    return NextResponse.json({ error: "Unauthorised." }, { status: 401 });
+  }
+
+  const user = USERS_STORE.get(userId);
+  if (!user) {
+    return NextResponse.json({ error: "User not found." }, { status: 404 });
+  }
+
+  // Can only be applied once
+  if (user.referred_by) {
+    return NextResponse.json(
+      { error: "Referral code already applied." },
+      { status: 409 }
+    );
+  }
+
+  // Must be within 24h of signup
+  const hoursSinceSignup =
+    (Date.now() - user.created_at) / (1000 * 60 * 60);
+  if (hoursSinceSignup > 24) {
+    return NextResponse.json(
+      { error: "Referral window expired. Must be applied within 24h of signup." },
+      { status: 400 }
+    );
+  }
+
+  // Resolve referrer
+  const { code } = await context.params;
+  const referrer = Array.from(USERS_STORE.values()).find(
+    (u) => u.referral_code === code
+  );
+
+  if (!referrer) {
+    return NextResponse.json(
+      { error: "Invalid referral code." },
+      { status: 404 }
+    );
+  }
+
+  if (referrer.id === userId) {
+    return NextResponse.json(
+      { error: "Cannot apply your own referral code." },
+      { status: 400 }
+    );
+  }
+
+  // Apply referral
+  user.referred_by = referrer.id;
+
+  return NextResponse.json(
+    { success: true, message: `Referral code '${code}' applied.` },
+    { status: 200 }
+  );
+}
diff --git a/app/api/routes-f/referrals/[code]/route.ts b/app/api/routes-f/referrals/[code]/route.ts
new file mode 100644
index 00000000..ab05b316
--- /dev/null
+++ b/app/api/routes-f/referrals/[code]/route.ts
@@ -0,0 +1,97 @@
+// @ts-nocheck
+import { NextRequest, NextResponse } from "next/server";
+import { db } from "@/lib/db";
+import { getAuthUser } from "@/lib/auth";
+
+/**
+ * GET /api/routes-f/referrals/[code]
+ * Public endpoint: validates whether a referral code exists.
+ * Used by the onboarding page to verify a ?ref= param.
+ */
+export async function GET(
+  _req: NextRequest,
+  context: { params: Promise<{ code: string }> }
+) {
+  const { code } = await context.params;
+
+  const { rows } = await db.query(
+    `SELECT id, username FROM users WHERE referral_code = $1`,
+    [code]
+  );
+
+  if (rows.length === 0) {
+    return NextResponse.json({ valid: false, error: "Invalid referral code" }, { status: 404 });
+  }
+
+  return NextResponse.json({
+    valid: true,
+    referrer: rows[0].username,
+  });
+}
+
+/**
+ * POST /api/routes-f/referrals/[code]/apply
+ * Apply a referral code for the authenticated user.
+ * Can only be applied once and within 24h of signup.
+ */
+export async function POST(
+  req: NextRequest,
+  context: { params: Promise<{ code: string }> }
+) {
+  const user = await getAuthUser(req);
+  if (!user) {
+    return NextResponse.json({ error: "Unauthorized" }, { status: 401 });
+  }
+
+  const { code } = await context.params;
+
+  // Ensure the current user hasn't already been referred
+  const { rows: currentUser } = await db.query(
+    `SELECT id, referred_by, created_at FROM users WHERE id = $1`,
+    [user.id]
+  );
+
+  if (currentUser.length === 0) {
+    return NextResponse.json({ error: "User not found" }, { status: 404 });
+  }
+
+  if (currentUser[0].referred_by) {
+    return NextResponse.json(
+      { error: "Referral code has already been applied" },
+      { status: 409 }
+    );
+  }
+
+  // Enforce 24h signup window
+  const signedUpAt = new Date(currentUser[0].created_at);
+  const hoursSinceSignup =
+    (Date.now() - signedUpAt.getTime()) / (1000 * 60 * 60);
+  if (hoursSinceSignup > 24) {
+    return NextResponse.json(
+      { error: "Referral code can only be applied within 24 hours of signup" },
+      { status: 403 }
+    );
+  }
+
+  // Resolve referral code to a referrer
+  const { rows: referrer } = await db.query(
+    `SELECT id FROM users WHERE referral_code = $1`,
+    [code]
+  );
+
+  if (referrer.length === 0) {
+    return NextResponse.json({ error: "Invalid referral code" }, { status: 404 });
+  }
+
+  // Prevent self-referral
+  if (referrer[0].id === user.id) {
+    return NextResponse.json({ error: "Cannot refer yourself" }, { status: 400 });
+  }
+
+  await db.query(`UPDATE users SET referred_by = $1 WHERE id = $2`, [
+    referrer[0].id,
+    user.id,
+  ]);
+
+  return NextResponse.json({ success: true, message: "Referral code applied" });
+}
diff --git a/app/api/routes-f/referrals/route.ts b/app/api/routes-f/referrals/route.ts
new file mode 100644
index 00000000..054a3f08
--- /dev/null
+++ b/app/api/routes-f/referrals/route.ts
@@ -0,0 +1,114 @@
+// @ts-nocheck
+import { NextRequest, NextResponse } from "next/server";
+
+// ---------------------------------------------------------------------------
+// DB schema (apply via migration):
+//
+// ALTER TABLE users ADD COLUMN IF NOT EXISTS referral_code TEXT UNIQUE;
+// ALTER TABLE users ADD COLUMN IF NOT EXISTS referred_by   UUID REFERENCES users(id);
+//
+// CREATE TABLE referral_rewards (
+//   id            UUID PRIMARY KEY DEFAULT gen_random_uuid(),
+//   referrer_id   UUID REFERENCES users(id),
+//   referred_id   UUID REFERENCES users(id),
+//   trigger       TEXT NOT NULL,  -- 'signup' | 'first_earnings' | 'milestone_100usd'
+//   reward_usdc   NUMERIC(10,2),
+//   tx_hash       TEXT,
+//   created_at    TIMESTAMPTZ DEFAULT now()
+// );
+// ---------------------------------------------------------------------------
+
+import { db } from "@/lib/db";
+import { getAuthUser } from "@/lib/auth";
+
+/**
+ * Generates a referral code: first 6 chars of username + 4 random alphanumeric chars.
+ * e.g. 'alice-X7K2'
+ */
+export function generateReferralCode(username: string): string {
+  const base = username.slice(0, 6).toLowerCase();
+  const chars = "ABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789";
+  const suffix = Array.from({ length: 4 }, () =>
+    chars.charAt(Math.floor(Math.random() * chars.length))
+  ).join("");
+  return `${base}-${suffix}`;
+}
+
+/**
+ * GET /api/routes-f/referrals
+ * Returns the authenticated user's referral code, share URL, and stats.
+ */
+export async function GET(req: NextRequest) {
+  const user = await getAuthUser(req);
+  if (!user) {
+    return NextResponse.json({ error: "Unauthorized" }, { status: 401 });
+  }
+
+  // Fetch or lazily create a referral code
+  const { rows: userRows } = await db.query(
+    `SELECT id, username, referral_code FROM users WHERE id = $1`,
+    [user.id]
+  );
+
+  if (userRows.length === 0) {
+    return NextResponse.json({ error: "User not found" }, { status: 404 });
+  }
+
+  let { referral_code } = userRows[0];
+
+  if (!referral_code) {
+    referral_code = generateReferralCode(userRows[0].username);
+    await db.query(`UPDATE users SET referral_code = $1 WHERE id = $2`, [
+      referral_code,
+      user.id,
+    ]);
+  }
+
+  // Aggregate stats
+  const { rows: statsRows } = await db.query(
+    `SELECT
+       COUNT(DISTINCT u.id)                                           AS total_referred,
+       COUNT(DISTINCT CASE WHEN u.created_at > NOW() - INTERVAL '30 days' THEN u.id END) AS active_referrals,
+       COALESCE(SUM(rr.reward_usdc), 0)                              AS total_earned_usdc,
+       COALESCE(SUM(CASE WHEN rr.tx_hash IS NULL THEN rr.reward_usdc END), 0) AS pending_usdc
+     FROM users u
+     LEFT JOIN referral_rewards rr ON rr.referrer_id = $1 AND rr.referred_id = u.id
+     WHERE u.referred_by = $1`,
+    [user.id]
+  );
+
+  // Individual referrals list
+  const { rows: referrals } = await db.query(
+    `SELECT u.username, u.created_at AS joined_at,
+            CASE WHEN u.created_at > NOW() - INTERVAL '30 days' THEN 'active' ELSE 'inactive' END AS status,
+            COALESCE(SUM(rr.reward_usdc), 0) AS earned_usdc
+     FROM users u
+     LEFT JOIN referral_rewards rr ON rr.referrer_id = $1 AND rr.referred_id = u.id
+     WHERE u.referred_by = $1
+     GROUP BY u.id, u.username, u.created_at
+     ORDER BY u.created_at DESC`,
+    [user.id]
+  );
+
+  const stats = statsRows[0];
+
+  return NextResponse.json({
+    code: referral_code,
+    share_url: `https://www.streamfi.media/join?ref=${referral_code}`,
+    stats: {
+      total_referred: Number(stats.total_referred),
+      active_referrals: Number(stats.active_referrals),
+      total_earned_usdc: String(Number(stats.total_earned_usdc).toFixed(2)),
+      pending_usdc: String(Number(stats.pending_usdc).toFixed(2)),
+    },
+    referrals: referrals.map((r) => ({
+      username: r.username,
+      joined_at: r.joined_at,
+      status: r.status,
+      earned_usdc: String(Number(r.earned_usdc).toFixed(2)),
+    })),
+  });
+}
+
+// Stub in-memory store for apply route compatibility
+export const USERS_STORE = new Map<string, Record<string, unknown>>();
diff --git a/app/api/routes-f/register/check/route.ts b/app/api/routes-f/register/check/route.ts
new file mode 100644
index 00000000..ef6f92d0
--- /dev/null
+++ b/app/api/routes-f/register/check/route.ts
@@ -0,0 +1,48 @@
+import { type NextRequest, NextResponse } from "next/server";
+import { sql } from "@vercel/postgres";
+
+const RESERVED = [
+  "admin", "api", "dashboard", "settings", "explore",
+  "browse", "onboarding", "streamfi", "support", "help",
+];
+
+const USERNAME_RE = /^[a-zA-Z0-9_]{3,30}$/;
+
+function buildSuggestions(base: string): string[] {
+  const clean = base.toLowerCase().replace(/[^a-z0-9_]/g, "");
+  const suffix = String(Math.floor(1000 + Math.random() * 9000));
+  return [`${clean}_streams`, `${clean}_live`, `${clean}${suffix}`];
+}
+
+export async function GET(request: NextRequest) {
+  const username = request.nextUrl.searchParams.get("username") ?? "";
+
+  if (!USERNAME_RE.test(username)) {
+    return NextResponse.json(
+      { error: "Username must be 3–30 characters: letters, numbers, underscores only" },
+      { status: 400 }
+    );
+  }
+
+  if (RESERVED.includes(username.toLowerCase())) {
+    return NextResponse.json(
+      { available: false, suggestions: buildSuggestions(username), reason: "reserved" },
+      { status: 200 }
+    );
+  }
+
+  try {
+    const { rows } = await sql`
+      SELECT 1 FROM users WHERE lower(username) = lower(${username}) LIMIT 1
+    `;
+
+    const available = rows.length === 0;
+    return NextResponse.json({
+      available,
+      suggestions: available ? [] : buildSuggestions(username),
+    });
+  } catch (error) {
+    console.error("[routes-f register/check GET]", error);
+    return NextResponse.json({ error: "Failed to check username" }, { status: 500 });
+  }
+}
diff --git a/app/api/routes-f/register/complete/route.ts b/app/api/routes-f/register/complete/route.ts
new file mode 100644
index 00000000..e9a9e465
--- /dev/null
+++ b/app/api/routes-f/register/complete/route.ts
@@ -0,0 +1,90 @@
+import { type NextRequest, NextResponse } from "next/server";
+import { z } from "zod";
+import { sql } from "@vercel/postgres";
+import { verifySession } from "@/lib/auth/verify-session";
+
+const completeSchema = z.object({
+  display_name: z.string().min(1).max(50).optional(),
+  bio: z.string().max(300).optional(),
+  avatar_url: z.string().url().optional().or(z.literal("")),
+});
+
+export async function POST(request: NextRequest) {
+  const session = await verifySession(request);
+  if (!session.ok) {
+    return session.response;
+  }
+
+  let body: z.infer<typeof completeSchema>;
+  try {
+    const raw = await request.json();
+    const parsed = completeSchema.safeParse(raw);
+    if (!parsed.success) {
+      return NextResponse.json(
+        { error: "Invalid request", details: parsed.error.flatten() },
+        { status: 400 }
+      );
+    }
+    body = parsed.data;
+  } catch {
+    return NextResponse.json({ error: "Invalid JSON body" }, { status: 400 });
+  }
+
+  try {
+    // Verify user has completed /register first
+    const { rows: userRows } = await sql`
+      SELECT id, username FROM users WHERE id = ${session.userId} AND username IS NOT NULL LIMIT 1
+    `;
+    if (userRows.length === 0) {
+      return NextResponse.json(
+        { error: "Complete /api/routes-f/register before calling /complete" },
+        { status: 400 }
+      );
+    }
+
+    const { display_name, bio, avatar_url } = body;
+
+    await sql`
+      UPDATE users
+      SET display_name = COALESCE(${display_name ?? null}, display_name),
+          bio          = COALESCE(${bio ?? null}, bio),
+          avatar_url   = COALESCE(${avatar_url || null}, avatar_url),
+          updated_at   = NOW()
+      WHERE id = ${session.userId}
+    `;
+
+    // Mark onboarding as completed
+    await sql`
+      UPDATE onboarding_progress
+      SET current_step = 'done',
+          completed    = true,
+          updated_at   = NOW()
+      WHERE user_id = ${session.userId}
+    `;
+
+    // Seed welcome badge (idempotent)
+    await sql`
+      INSERT INTO user_badges (user_id, badge_slug, earned_at)
+      VALUES (${session.userId}, 'early-adopter', NOW())
+      ON CONFLICT (user_id, badge_slug) DO NOTHING
+    `;
+
+    // Welcome notification
+    await sql`
+      INSERT INTO notifications (user_id, type, title, body, is_read, created_at)
+      VALUES (
+        ${session.userId},
+        'system',
+        'Welcome to StreamFi!',
+        'Your account is ready. Start streaming or explore live channels.',
+        false,
+        NOW()
+      )
+    `;
+
+    return NextResponse.json({ completed: true, next_step: "/dashboard" });
+  } catch (error) {
+    console.error("[routes-f register/complete POST]", error);
+    return NextResponse.json({ error: "Failed to complete registration" }, { status: 500 });
+  }
+}
diff --git a/app/api/routes-f/register/route.ts b/app/api/routes-f/register/route.ts
new file mode 100644
index 00000000..6ee93ccf
--- /dev/null
+++ b/app/api/routes-f/register/route.ts
@@ -0,0 +1,130 @@
+import { type NextRequest, NextResponse } from "next/server";
+import { z } from "zod";
+import { sql } from "@vercel/postgres";
+import { verifySession } from "@/lib/auth/verify-session";
+import { createRateLimiter } from "@/lib/rate-limit";
+
+const isRateLimited = createRateLimiter(60 * 60 * 1000, 3); // 3 attempts per IP per hour
+
+const RESERVED = [
+  "admin", "api", "dashboard", "settings", "explore",
+  "browse", "onboarding", "streamfi", "support", "help",
+];
+
+const USERNAME_RE = /^[a-zA-Z0-9_]{3,30}$/;
+
+const registerSchema = z.object({
+  username: z
+    .string()
+    .regex(USERNAME_RE, "Username must be 3–30 characters: letters, numbers, underscores only"),
+  ref_code: z.string().min(1).optional(),
+});
+
+export async function POST(request: NextRequest) {
+  const ip =
+    request.headers.get("x-real-ip") ??
+    request.headers.get("x-forwarded-for")?.split(",")[0].trim() ??
+    "unknown";
+
+  if (await isRateLimited(ip)) {
+    return NextResponse.json(
+      { error: "Too many registration attempts. Try again later." },
+      { status: 429 }
+    );
+  }
+
+  const session = await verifySession(request);
+  if (!session.ok) {
+    return session.response;
+  }
+
+  let body: z.infer<typeof registerSchema>;
+  try {
+    const raw = await request.json();
+    const parsed = registerSchema.safeParse(raw);
+    if (!parsed.success) {
+      return NextResponse.json(
+        { error: "Invalid request", details: parsed.error.flatten() },
+        { status: 400 }
+      );
+    }
+    body = parsed.data;
+  } catch {
+    return NextResponse.json({ error: "Invalid JSON body" }, { status: 400 });
+  }
+
+  const { username, ref_code } = body;
+
+  if (RESERVED.includes(username.toLowerCase())) {
+    return NextResponse.json(
+      { error: "Username is reserved and cannot be used" },
+      { status: 400 }
+    );
+  }
+
+  try {
+    // Check uniqueness
+    const { rows: existing } = await sql`
+      SELECT id FROM users WHERE lower(username) = lower(${username}) AND id != ${session.userId} LIMIT 1
+    `;
+    if (existing.length > 0) {
+      return NextResponse.json({ error: "Username is already taken" }, { status: 409 });
+    }
+
+    // Apply referral code if provided
+    let referredBy: string | null = null;
+    if (ref_code) {
+      const { rows: refRows } = await sql`
+        SELECT id FROM users WHERE referral_code = ${ref_code} LIMIT 1
+      `;
+      if (refRows.length > 0) {
+        referredBy = refRows[0].id;
+      }
+    }
+
+    // Upsert user row
+    const { rows: userRows } = await sql`
+      INSERT INTO users (id, username, referred_by, updated_at)
+      VALUES (${session.userId}, ${username}, ${referredBy}, NOW())
+      ON CONFLICT (id) DO UPDATE SET
+        username    = EXCLUDED.username,
+        referred_by = COALESCE(users.referred_by, EXCLUDED.referred_by),
+        updated_at  = NOW()
+      RETURNING id, username
+    `;
+
+    const user = userRows[0];
+
+    // Initialise onboarding progress (idempotent)
+    await sql`
+      INSERT INTO onboarding_progress (user_id, current_step, completed, created_at)
+      VALUES (${session.userId}, 'profile', false, NOW())
+      ON CONFLICT (user_id) DO NOTHING
+    `;
+
+    // Apply referral reward if this is a new referral
+    if (referredBy) {
+      await sql`
+        INSERT INTO referral_rewards (referrer_id, referred_id, created_at)
+        VALUES (${referredBy}, ${session.userId}, NOW())
+        ON CONFLICT DO NOTHING
+      `;
+    }
+
+    // Trigger welcome email (fire-and-forget, non-blocking)
+    const baseUrl = process.env.NEXT_PUBLIC_APP_URL ?? "";
+    fetch(`${baseUrl}/api/request-email-verification`, {
+      method: "POST",
+      headers: { "Content-Type": "application/json", cookie: request.headers.get("cookie") ?? "" },
+      body: JSON.stringify({ type: "welcome" }),
+    }).catch(() => {/* non-critical */});
+
+    return NextResponse.json(
+      { user_id: user.id, username: user.username, next_step: "/onboarding" },
+      { status: 200 }
+    );
+  } catch (error) {
+    console.error("[routes-f register POST]", error);
+    return NextResponse.json({ error: "Registration failed" }, { status: 500 });
+  }
+}
diff --git a/app/api/routes-f/relative-date/route.ts b/app/api/routes-f/relative-date/route.ts
new file mode 100644
index 00000000..537a3356
--- /dev/null
+++ b/app/api/routes-f/relative-date/route.ts
@@ -0,0 +1,106 @@
+import { NextRequest, NextResponse } from "next/server";
+
+export async function POST(req: NextRequest) {
+  let body: { text?: unknown; now?: unknown };
+  try {
+    body = await req.json();
+  } catch {
+    return NextResponse.json({ error: "Invalid JSON" }, { status: 400 });
+  }
+
+  const textInput = body.text;
+  const nowInput = body.now;
+
+  if (typeof textInput !== "string") {
+    return NextResponse.json(
+      { error: "text must be a string" },
+      { status: 400 }
+    );
+  }
+
+  const text = textInput.trim().toLowerCase();
+  if (!text) {
+    return NextResponse.json(
+      { error: "text cannot be empty" },
+      { status: 400 }
+    );
+  }
+
+  let baseDate = new Date();
+  if (nowInput !== undefined && nowInput !== null) {
+    if (typeof nowInput !== "string") {
+      return NextResponse.json(
+        { error: "now must be a valid ISO string" },
+        { status: 400 }
+      );
+    }
+    baseDate = new Date(nowInput);
+    if (isNaN(baseDate.getTime())) {
+      return NextResponse.json(
+        { error: "now is not a valid date string" },
+        { status: 400 }
+      );
+    }
+  }
+
+  let resolvedDate: Date | null = null;
+  let matchedRule: string | null = null;
+
+  if (text === "tomorrow") {
+    resolvedDate = new Date(baseDate);
+    resolvedDate.setDate(resolvedDate.getDate() + 1);
+    matchedRule = "tomorrow";
+  } else if (text === "yesterday") {
+    resolvedDate = new Date(baseDate);
+    resolvedDate.setDate(resolvedDate.getDate() - 1);
+    matchedRule = "yesterday";
+  } else if (text === "next monday") {
+    resolvedDate = new Date(baseDate);
+    const day = resolvedDate.getDay();
+    const daysToAdd = (1 - day + 7) % 7 || 7;
+    resolvedDate.setDate(resolvedDate.getDate() + daysToAdd);
+    matchedRule = "next monday";
+  } else {
+    // Check for "in X days" or "in X weeks"
+    const inRegex = /^in\s+(\d+)\s+(day|week)s?$/i;
+    const inMatch = text.match(inRegex);
+    if (inMatch) {
+      const amount = parseInt(inMatch[1], 10);
+      const unit = inMatch[2].toLowerCase();
+      resolvedDate = new Date(baseDate);
+      if (unit === "day") {
+        resolvedDate.setDate(resolvedDate.getDate() + amount);
+      } else if (unit === "week") {
+        resolvedDate.setDate(resolvedDate.getDate() + amount * 7);
+      }
+      matchedRule = textInput;
+    }
+
+    // Check for "X weeks ago" or "X days ago"
+    const agoRegex = /^(\d+)\s+(day|week)s?\s+ago$/i;
+    const agoMatch = text.match(agoRegex);
+    if (agoMatch) {
+      const amount = parseInt(agoMatch[1], 10);
+      const unit = agoMatch[2].toLowerCase();
+      resolvedDate = new Date(baseDate);
+      if (unit === "day") {
+        resolvedDate.setDate(resolvedDate.getDate() - amount);
+      } else if (unit === "week") {
+        resolvedDate.setDate(resolvedDate.getDate() - amount * 7);
+      }
+      matchedRule = textInput;
+    }
+  }
+
+  if (!resolvedDate || !matchedRule) {
+    return NextResponse.json(
+      { error: `Unable to parse relative date: "${textInput}"` },
+      { status: 400 }
+    );
+  }
+
+  return NextResponse.json({
+    resolved: resolvedDate.toISOString(),
+    matched: matchedRule,
+  });
+}
diff --git a/app/api/routes-f/retry-after/parse.ts b/app/api/routes-f/retry-after/parse.ts
new file mode 100644
index 00000000..7e13c402
--- /dev/null
+++ b/app/api/routes-f/retry-after/parse.ts
@@ -0,0 +1,44 @@
+import type { RetryAfterResponse } from './types';
+
+const INTEGER_SECONDS_PATTERN = /^\d+$/;
+
+export function parseRetryAfterValue(
+  header: string,
+  nowIso?: string
+): RetryAfterResponse | null {
+  const now = nowIso ? new Date(nowIso) : new Date();
+  if (nowIso && Number.isNaN(now.valueOf())) {
+    return null;
+  }
+
+  const trimmed = header.trim();
+  if (trimmed.length === 0) {
+    return null;
+  }
+
+  if (INTEGER_SECONDS_PATTERN.test(trimmed)) {
+    const delay = Number(trimmed);
+    if (!Number.isFinite(delay) || delay < 0) {
+      return null;
+    }
+
+    const retryAt = new Date(now.getTime() + delay * 1000);
+    return {
+      delay_seconds: delay,
+      retry_at: retryAt.toISOString(),
+    };
+  }
+
+  const parsed = Date.parse(trimmed);
+  if (Number.isNaN(parsed)) {
+    return null;
+  }
+
+  const retryAt = new Date(parsed);
+  const delaySeconds = Math.max(0, Math.ceil((retryAt.getTime() - now.getTime()) / 1000));
+
+  return {
+    delay_seconds: delaySeconds,
+    retry_at: retryAt.toISOString(),
+  };
+}
diff --git a/app/api/routes-f/retry-after/route.ts b/app/api/routes-f/retry-after/route.ts
new file mode 100644
index 00000000..23b0d471
--- /dev/null
+++ b/app/api/routes-f/retry-after/route.ts
@@ -0,0 +1,29 @@
+import { NextResponse } from "next/server";
+import { z } from "zod";
+import { validateBody } from "@/app/api/routes-f/_lib/validate";
+import { parseRetryAfterValue } from "./parse";
+import type { RetryAfterRequest } from "./types";
+
+const schema = z.object({
+  header: z.string().min(1),
+  now: z.string().optional(),
+});
+
+export async function POST(request: Request): Promise<NextResponse> {
+  const result = await validateBody(request, schema);
+  if (result instanceof NextResponse) {
+    return result;
+  }
+
+  const { header, now } = result.data;
+  const parsed = parseRetryAfterValue(header, now);
+
+  if (!parsed) {
+    return NextResponse.json(
+      { error: "Invalid Retry-After header or now timestamp" },
+      { status: 400 }
+    );
+  }
+
+  return NextResponse.json(parsed);
+}
diff --git a/app/api/routes-f/retry-after/types.ts b/app/api/routes-f/retry-after/types.ts
new file mode 100644
index 00000000..6611b633
--- /dev/null
+++ b/app/api/routes-f/retry-after/types.ts
@@ -0,0 +1,9 @@
+export interface RetryAfterRequest {
+  header: string;
+  now?: string;
+}
+
+export interface RetryAfterResponse {
+  delay_seconds: number;
+  retry_at: string;
+}
diff --git a/app/api/routes-f/robots-txt/_lib/helpers.ts b/app/api/routes-f/robots-txt/_lib/helpers.ts
new file mode 100644
index 00000000..886b3a09
--- /dev/null
+++ b/app/api/routes-f/robots-txt/_lib/helpers.ts
@@ -0,0 +1,73 @@
+import type { RobotsRule } from "./types";
+
+function isRecord(value: unknown): value is Record<string, unknown> {
+  return typeof value === "object" && value !== null && !Array.isArray(value);
+}
+
+function normalizeString(value: unknown, field: string): string {
+  if (typeof value !== "string") {
+    throw new Error(`${field} must be a string.`);
+  }
+
+  const trimmed = value.trim();
+  if (!trimmed) {
+    throw new Error(`${field} must not be empty.`);
+  }
+
+  return trimmed;
+}
+
+function normalizePathList(value: unknown, field: string): string[] | undefined {
+  if (value === undefined) {
+    return undefined;
+  }
+
+  if (!Array.isArray(value)) {
+    throw new Error(`${field} must be an array of strings.`);
+  }
+
+  return value.map((item, index) => normalizeString(item, `${field}[${index}]`));
+}
+
+function normalizeRule(value: unknown, index: number): RobotsRule {
+  if (!isRecord(value)) {
+    throw new Error(`rules[${index}] must be an object.`);
+  }
+
+  return {
+    user_agent: normalizeString(value.user_agent, `rules[${index}].user_agent`),
+    allow: normalizePathList(value.allow, `rules[${index}].allow`),
+    disallow: normalizePathList(value.disallow, `rules[${index}].disallow`),
+  };
+}
+
+export function buildRobotsTxt(input: unknown): string {
+  if (!isRecord(input)) {
+    throw new Error("Request body must be an object.");
+  }
+
+  if (!Array.isArray(input.rules) || input.rules.length === 0) {
+    throw new Error("rules must contain at least one rule.");
+  }
+
+  const rules = input.rules.map(normalizeRule);
+  const sections = rules.map((rule) => {
+    const lines = [`User-agent: ${rule.user_agent}`];
+
+    for (const path of rule.allow ?? []) {
+      lines.push(`Allow: ${path}`);
+    }
+
+    for (const path of rule.disallow ?? []) {
+      lines.push(`Disallow: ${path}`);
+    }
+
+    return lines.join("\n");
+  });
+
+  if (input.sitemap !== undefined) {
+    sections.push(`Sitemap: ${normalizeString(input.sitemap, "sitemap")}`);
+  }
+
+  return `${sections.join("\n\n")}\n`;
+}
diff --git a/app/api/routes-f/robots-txt/_lib/types.ts b/app/api/routes-f/robots-txt/_lib/types.ts
new file mode 100644
index 00000000..de06dae4
--- /dev/null
+++ b/app/api/routes-f/robots-txt/_lib/types.ts
@@ -0,0 +1,9 @@
+export interface RobotsRule {
+  user_agent: string;
+  allow?: string[];
+  disallow?: string[];
+}
+
+export interface RobotsResponse {
+  robots_txt: string;
+}
diff --git a/app/api/routes-f/robots-txt/route.ts b/app/api/routes-f/robots-txt/route.ts
new file mode 100644
index 00000000..5165e64b
--- /dev/null
+++ b/app/api/routes-f/robots-txt/route.ts
@@ -0,0 +1,21 @@
+import { type NextRequest, NextResponse } from "next/server";
+import { buildRobotsTxt } from "./_lib/helpers";
+import type { RobotsResponse } from "./_lib/types";
+
+export async function POST(req: NextRequest) {
+  let body: unknown;
+
+  try {
+    body = await req.json();
+  } catch {
+    return NextResponse.json({ error: "Invalid JSON body." }, { status: 400 });
+  }
+
+  try {
+    const robotsTxt = buildRobotsTxt(body);
+    return NextResponse.json({ robots_txt: robotsTxt } satisfies RobotsResponse);
+  } catch (error) {
+    const message = error instanceof Error ? error.message : "Failed to build robots.txt.";
+    return NextResponse.json({ error: message }, { status: 400 });
+  }
+}
diff --git a/app/api/routes-f/rounding/__tests__/route.test.ts b/app/api/routes-f/rounding/__tests__/route.test.ts
new file mode 100644
index 00000000..d80f189d
--- /dev/null
+++ b/app/api/routes-f/rounding/__tests__/route.test.ts
@@ -0,0 +1,29 @@
+import { roundValue } from "../route";
+
+describe("roundValue", () => {
+  it("half_up rounds .5 away from zero", () => {
+    expect(roundValue(2.5, "half_up")).toBe(3);
+    expect(roundValue(3.5, "half_up")).toBe(4);
+    expect(roundValue(-2.5, "half_up")).toBe(-3);
+  });
+
+  it("half_even uses banker's rounding on .5", () => {
+    expect(roundValue(2.5, "half_even")).toBe(2);
+    expect(roundValue(3.5, "half_even")).toBe(4);
+    expect(roundValue(0.5, "half_even")).toBe(0);
+    expect(roundValue(1.5, "half_even")).toBe(2);
+    expect(roundValue(-2.5, "half_even")).toBe(-2);
+  });
+
+  it("ceil / floor / trunc", () => {
+    expect(roundValue(2.1, "ceil")).toBe(3);
+    expect(roundValue(2.9, "floor")).toBe(2);
+    expect(roundValue(-2.9, "trunc")).toBe(-2);
+    expect(roundValue(2.9, "trunc")).toBe(2);
+  });
+
+  it("respects decimals", () => {
+    expect(roundValue(2.345, "floor", 2)).toBe(2.34);
+    expect(roundValue(2.5, "ceil", 0)).toBe(3);
+  });
+});
diff --git a/app/api/routes-f/rounding/route.ts b/app/api/routes-f/rounding/route.ts
new file mode 100644
index 00000000..10336344
--- /dev/null
+++ b/app/api/routes-f/rounding/route.ts
@@ -0,0 +1,54 @@
+import { NextResponse } from "next/server";
+import { z } from "zod";
+import { validateBody } from "@/app/api/routes-f/_lib/validate";
+
+export type RoundingMode = "half_up" | "half_even" | "ceil" | "floor" | "trunc";
+
+/** Banker's rounding (round half to even). */
+function roundHalfEven(x: number): number {
+  const floor = Math.floor(x);
+  const diff = x - floor;
+  if (diff < 0.5) return floor;
+  if (diff > 0.5) return floor + 1;
+  // exactly .5 → round to the even neighbour
+  return floor % 2 === 0 ? floor : floor + 1;
+}
+
+/** Round `value` to `decimals` places using the given strategy. */
+export function roundValue(value: number, mode: RoundingMode, decimals = 0): number {
+  const factor = 10 ** decimals;
+  const scaled = value * factor;
+  let r: number;
+  switch (mode) {
+    case "ceil":
+      r = Math.ceil(scaled);
+      break;
+    case "floor":
+      r = Math.floor(scaled);
+      break;
+    case "trunc":
+      r = Math.trunc(scaled);
+      break;
+    case "half_up":
+      // round half away from zero
+      r = Math.sign(scaled) * Math.round(Math.abs(scaled));
+      break;
+    case "half_even":
+      r = roundHalfEven(scaled);
+      break;
+  }
+  return r / factor;
+}
+
+const schema = z.object({
+  value: z.number().finite(),
+  mode: z.enum(["half_up", "half_even", "ceil", "floor", "trunc"]),
+  decimals: z.number().int().min(0).max(15).optional().default(0),
+});
+
+export async function POST(request: Request): Promise<NextResponse> {
+  const result = await validateBody(request, schema);
+  if (result instanceof NextResponse) return result;
+  const { value, mode, decimals } = result.data;
+  return NextResponse.json({ result: roundValue(value, mode, decimals), mode });
+}
diff --git a/app/api/routes-f/savings-goal/__tests__/route.test.ts b/app/api/routes-f/savings-goal/__tests__/route.test.ts
new file mode 100644
index 00000000..42920233
--- /dev/null
+++ b/app/api/routes-f/savings-goal/__tests__/route.test.ts
@@ -0,0 +1,121 @@
+/**
+ * @jest-environment node
+ */
+import { NextRequest } from "next/server";
+import { POST } from "../route";
+
+function makeReq(body: unknown) {
+  return new NextRequest("http://localhost/api/routes-f/savings-goal", {
+    method: "POST",
+    headers: { "content-type": "application/json" },
+    body: JSON.stringify(body),
+  });
+}
+
+describe("POST /api/routes-f/savings-goal", () => {
+  it("returns 0 months if goal is already met", async () => {
+    const res = await POST(
+      makeReq({ goal: 1000, initial: 1200, monthly_contribution: 100 })
+    );
+    const body = await res.json();
+
+    expect(res.status).toBe(200);
+    expect(body.months_to_goal).toBe(0);
+    expect(body.total_contributed).toBe(0);
+    expect(body.total_interest).toBe(0);
+    expect(body.final_balance).toBe(1200);
+  });
+
+  it("calculates timeline correctly without interest", async () => {
+    const res = await POST(
+      makeReq({
+        goal: 1000,
+        initial: 100,
+        monthly_contribution: 100,
+        annual_rate: 0,
+      })
+    );
+    const body = await res.json();
+
+    expect(res.status).toBe(200);
+    expect(body.months_to_goal).toBe(9);
+    expect(body.total_contributed).toBe(900);
+    expect(body.total_interest).toBe(0);
+    expect(body.final_balance).toBe(1000);
+  });
+
+  it("calculates timeline correctly with monthly compounded interest", async () => {
+    // Goal: 1000, Initial: 500, Monthly Contribution: 100, Annual Rate: 12% (1% monthly rate)
+    // Month 1: balance = 500 * 1.01 + 100 = 605
+    // Month 2: balance = 605 * 1.01 + 100 = 711.05
+    // Month 3: balance = 711.05 * 1.01 + 100 = 818.1605
+    // Month 4: balance = 818.1605 * 1.01 + 100 = 926.3421
+    // Month 5: balance = 926.3421 * 1.01 + 100 = 1035.6055 (reaches goal!)
+    const res = await POST(
+      makeReq({
+        goal: 1000,
+        initial: 500,
+        monthly_contribution: 100,
+        annual_rate: 12,
+      })
+    );
+    const body = await res.json();
+
+    expect(res.status).toBe(200);
+    expect(body.months_to_goal).toBe(5);
+    expect(body.total_contributed).toBe(500); // 5 * 100
+    expect(body.total_interest).toBeCloseTo(35.61, 2);
+    expect(body.final_balance).toBeCloseTo(1035.61, 2);
+  });
+
+  it("rejects impossible goals with 400", async () => {
+    // No contribution and no interest
+    let res = await POST(
+      makeReq({
+        goal: 1000,
+        initial: 100,
+        monthly_contribution: 0,
+        annual_rate: 0,
+      })
+    );
+    expect(res.status).toBe(400);
+
+    // Initial is zero, monthly contribution is zero
+    res = await POST(
+      makeReq({
+        goal: 1000,
+        initial: 0,
+        monthly_contribution: 0,
+        annual_rate: 10,
+      })
+    );
+    expect(res.status).toBe(400);
+
+    // Negative contribution
+    res = await POST(
+      makeReq({
+        goal: 1000,
+        initial: 100,
+        monthly_contribution: -10,
+        annual_rate: 0,
+      })
+    );
+    expect(res.status).toBe(400);
+  });
+
+  it("rejects invalid inputs", async () => {
+    // Missing required fields
+    let res = await POST(makeReq({ goal: 1000, initial: 100 }));
+    expect(res.status).toBe(400);
+
+    // Non-numeric types
+    res = await POST(
+      makeReq({
+        goal: "abc",
+        initial: 100,
+        monthly_contribution: 10,
+      })
+    );
+    expect(res.status).toBe(400);
+  });
+});
diff --git a/app/api/routes-f/savings-goal/route.ts b/app/api/routes-f/savings-goal/route.ts
new file mode 100644
index 00000000..8f9368f3
--- /dev/null
+++ b/app/api/routes-f/savings-goal/route.ts
@@ -0,0 +1,93 @@
+import { NextRequest, NextResponse } from "next/server";
+
+export async function POST(req: NextRequest) {
+  let body: {
+    goal?: unknown;
+    initial?: unknown;
+    monthly_contribution?: unknown;
+    annual_rate?: unknown;
+  };
+
+  try {
+    body = await req.json();
+  } catch {
+    return NextResponse.json({ error: "Invalid JSON body." }, { status: 400 });
+  }
+
+  const goal = Number(body.goal);
+  const initial = Number(body.initial);
+  const monthlyContribution = Number(body.monthly_contribution);
+  const annualRate = body.annual_rate !== undefined ? Number(body.annual_rate) : 0;
+
+  if (
+    body.goal === undefined ||
+    body.initial === undefined ||
+    body.monthly_contribution === undefined ||
+    isNaN(goal) ||
+    isNaN(initial) ||
+    isNaN(monthlyContribution) ||
+    isNaN(annualRate) ||
+    typeof body.goal === "boolean" ||
+    typeof body.initial === "boolean" ||
+    typeof body.monthly_contribution === "boolean"
+  ) {
+    return NextResponse.json(
+      { error: "goal, initial, and monthly_contribution are required and must be numbers." },
+      { status: 400 }
+    );
+  }
+
+  if (goal <= 0 || initial < 0 || annualRate < 0) {
+    return NextResponse.json(
+      { error: "goal must be positive. initial and annual_rate must be non-negative." },
+      { status: 400 }
+    );
+  }
+
+  // Reject impossible goals initially
+  if (initial < goal) {
+    if (monthlyContribution <= 0 && annualRate <= 0) {
+      return NextResponse.json(
+        { error: "Goal is impossible to reach (no contribution and no interest)." },
+        { status: 400 }
+      );
+    }
+    if (initial <= 0 && monthlyContribution <= 0) {
+      return NextResponse.json(
+        { error: "Goal is impossible to reach (initial balance and monthly contribution are both zero)." },
+        { status: 400 }
+      );
+    }
+  }
+
+  let balance = initial;
+  let months = 0;
+  let totalInterest = 0;
+  let totalContributed = 0;
+  const monthlyRate = (annualRate / 100) / 12;
+
+  // Let's protect against infinite/extremely long runtimes
+  const maxMonths = 12000; // 1000 years limit
+
+  while (balance < goal && months < maxMonths) {
+    months++;
+    const interest = balance * monthlyRate;
+    totalInterest += interest;
+    totalContributed += monthlyContribution;
+    balance = balance + interest + monthlyContribution;
+  }
+
+  if (months >= maxMonths && balance < goal) {
+    return NextResponse.json(
+      { error: "Goal is impossible or takes too long (> 1000 years) to reach with current parameters." },
+      { status: 400 }
+    );
+  }
+
+  return NextResponse.json({
+    months_to_goal: months,
+    total_contributed: Math.round(totalContributed * 100) / 100,
+    total_interest: Math.round(totalInterest * 100) / 100,
+    final_balance: Math.round(balance * 100) / 100,
+  });
+}
diff --git a/app/api/routes-f/scientific-notation/_lib/helpers.ts b/app/api/routes-f/scientific-notation/_lib/helpers.ts
new file mode 100644
index 00000000..3adcac43
--- /dev/null
+++ b/app/api/routes-f/scientific-notation/_lib/helpers.ts
@@ -0,0 +1,190 @@
+import type { NotationResponse, NotationStyle } from "./types";
+
+const SI_PREFIXES = new Map<number, string>([
+  [-24, "y"],
+  [-21, "z"],
+  [-18, "a"],
+  [-15, "f"],
+  [-12, "p"],
+  [-9, "n"],
+  [-6, "u"],
+  [-3, "m"],
+  [0, ""],
+  [3, "k"],
+  [6, "M"],
+  [9, "G"],
+  [12, "T"],
+  [15, "P"],
+  [18, "E"],
+  [21, "Z"],
+  [24, "Y"],
+]);
+
+const SI_EXPONENTS = new Map<string, number>([
+  ["", 0],
+  ["y", -24],
+  ["z", -21],
+  ["a", -18],
+  ["f", -15],
+  ["p", -12],
+  ["n", -9],
+  ["u", -6],
+  ["\u00b5", -6],
+  ["\u03bc", -6],
+  ["m", -3],
+  ["k", 3],
+  ["K", 3],
+  ["M", 6],
+  ["G", 9],
+  ["T", 12],
+  ["P", 15],
+  ["E", 18],
+  ["Z", 21],
+  ["Y", 24],
+]);
+
+function isRecord(value: unknown): value is Record<string, unknown> {
+  return typeof value === "object" && value !== null && !Array.isArray(value);
+}
+
+function normalizeStyle(value: unknown): NotationStyle {
+  if (value === undefined) {
+    return "scientific";
+  }
+
+  if (value === "scientific" || value === "engineering") {
+    return value;
+  }
+
+  throw new Error("style must be scientific or engineering.");
+}
+
+function normalizeSigFigs(value: unknown): number {
+  if (value === undefined) {
+    return 3;
+  }
+
+  if (typeof value !== "number" || !Number.isInteger(value) || value < 1 || value > 15) {
+    throw new Error("sig_figs must be an integer from 1 to 15.");
+  }
+
+  return value;
+}
+
+function finiteNumber(value: unknown, field: string): number {
+  if (typeof value !== "number" || !Number.isFinite(value)) {
+    throw new Error(`${field} must be a finite number.`);
+  }
+
+  return value;
+}
+
+function normalizeExponent(exponentPart: string): number {
+  return Number.parseInt(exponentPart.replace("+", ""), 10);
+}
+
+export function formatScientific(value: number, sigFigs = 3): string {
+  if (Object.is(value, 0) || value === 0) {
+    return "0e0";
+  }
+
+  const [coefficient, exponentPart] = value.toExponential(sigFigs - 1).split("e");
+  return `${coefficient}e${normalizeExponent(exponentPart)}`;
+}
+
+export function formatEngineering(value: number, sigFigs = 3): string {
+  if (Object.is(value, 0) || value === 0) {
+    return "0";
+  }
+
+  let exponent = Math.floor(Math.log10(Math.abs(value)) / 3) * 3;
+  let coefficient = value / 10 ** exponent;
+  let coefficientText = coefficient.toPrecision(sigFigs);
+
+  if (Math.abs(Number(coefficientText)) >= 1000) {
+    exponent += 3;
+    coefficient = value / 10 ** exponent;
+    coefficientText = coefficient.toPrecision(sigFigs);
+  }
+
+  const suffix = SI_PREFIXES.get(exponent);
+  if (suffix === undefined) {
+    return `${coefficientText}e${exponent}`;
+  }
+
+  return suffix ? `${coefficientText} ${suffix}` : coefficientText;
+}
+
+export function parseScientific(value: unknown): number {
+  if (typeof value === "number") {
+    return finiteNumber(value, "value");
+  }
+
+  if (typeof value !== "string") {
+    throw new Error("value must be a string or finite number.");
+  }
+
+  const parsed = Number(value.trim());
+  if (!Number.isFinite(parsed)) {
+    throw new Error("value must be valid scientific notation.");
+  }
+
+  return parsed;
+}
+
+export function parseEngineering(value: unknown): number {
+  if (typeof value === "number") {
+    return finiteNumber(value, "value");
+  }
+
+  if (typeof value !== "string") {
+    throw new Error("value must be a string or finite number.");
+  }
+
+  const match = value
+    .trim()
+    .match(
+      /^([+-]?(?:\d+\.?\d*|\.\d+)(?:e[+-]?\d+)?)\s*([A-Za-z]|\u00b5|\u03bc)?$/
+    );
+
+  if (!match) {
+    throw new Error("value must be valid engineering notation.");
+  }
+
+  const numberPart = Number(match[1]);
+  const suffix = match[2] ?? "";
+  const exponent = SI_EXPONENTS.get(suffix);
+
+  if (!Number.isFinite(numberPart) || exponent === undefined) {
+    throw new Error("value must be valid engineering notation.");
+  }
+
+  return numberPart * 10 ** exponent;
+}
+
+export function processNotation(input: unknown): NotationResponse {
+  if (!isRecord(input)) {
+    throw new Error("Request body must be an object.");
+  }
+
+  const style = normalizeStyle(input.style);
+
+  if (input.mode === "format") {
+    const value = finiteNumber(input.value, "value");
+    const sigFigs = normalizeSigFigs(input.sig_figs);
+    const result =
+      style === "engineering"
+        ? formatEngineering(value, sigFigs)
+        : formatScientific(value, sigFigs);
+
+    return { result };
+  }
+
+  if (input.mode === "parse") {
+    const result =
+      style === "engineering" ? parseEngineering(input.value) : parseScientific(input.value);
+    return { result };
+  }
+
+  throw new Error("mode must be format or parse.");
+}
diff --git a/app/api/routes-f/scientific-notation/_lib/types.ts b/app/api/routes-f/scientific-notation/_lib/types.ts
new file mode 100644
index 00000000..9611f341
--- /dev/null
+++ b/app/api/routes-f/scientific-notation/_lib/types.ts
@@ -0,0 +1,6 @@
+export type NotationMode = "format" | "parse";
+export type NotationStyle = "scientific" | "engineering";
+
+export interface NotationResponse {
+  result: number | string;
+}
diff --git a/app/api/routes-f/scientific-notation/route.ts b/app/api/routes-f/scientific-notation/route.ts
new file mode 100644
index 00000000..9597e585
--- /dev/null
+++ b/app/api/routes-f/scientific-notation/route.ts
@@ -0,0 +1,19 @@
+import { type NextRequest, NextResponse } from "next/server";
+import { processNotation } from "./_lib/helpers";
+
+export async function POST(req: NextRequest) {
+  let body: unknown;
+
+  try {
+    body = await req.json();
+  } catch {
+    return NextResponse.json({ error: "Invalid JSON body." }, { status: 400 });
+  }
+
+  try {
+    return NextResponse.json(processNotation(body));
+  } catch (error) {
+    const message = error instanceof Error ? error.message : "Failed to process notation.";
+    return NextResponse.json({ error: message }, { status: 400 });
+  }
+}
diff --git a/app/api/routes-f/session/[id]/route.ts b/app/api/routes-f/session/[id]/route.ts
new file mode 100644
index 00000000..6a72382c
--- /dev/null
+++ b/app/api/routes-f/session/[id]/route.ts
@@ -0,0 +1,74 @@
+/**
+ * DELETE /api/routes-f/session/[id]
+ *
+ * Revokes a specific session by its UUID.
+ * The authenticated user can only revoke their own sessions.
+ *
+ * - Revoking the current session is allowed (effectively a logout from this device).
+ * - Revocation takes effect immediately — the next request with that token will be
+ *   rejected by verifySession.
+ */
+
+import { NextRequest, NextResponse } from "next/server";
+import { verifySession } from "@/lib/auth/verify-session";
+import { revokeSession } from "@/lib/sessions/user-sessions";
+import { createRateLimiter } from "@/lib/rate-limit";
+
+// 20 revocations per minute per IP
+const isRateLimited = createRateLimiter(60_000, 20);
+
+export async function DELETE(
+  req: NextRequest,
+  { params }: { params: Promise<{ id: string }> }
+) {
+  // 1. Rate limit
+  const ip =
+    req.headers.get("x-forwarded-for")?.split(",")[0]?.trim() ??
+    req.headers.get("x-real-ip") ??
+    "unknown";
+
+  if (await isRateLimited(ip)) {
+    return NextResponse.json(
+      { error: "Too many requests" },
+      { status: 429, headers: { "Retry-After": "60" } }
+    );
+  }
+
+  // 2. Verify session
+  const session = await verifySession(req);
+  if (!session.ok) {
+    return session.response;
+  }
+
+  // 3. Validate the target session ID
+  const { id } = await params;
+  const UUID_RE =
+    /^[0-9a-f]{8}-[0-9a-f]{4}-[0-9a-f]{4}-[0-9a-f]{4}-[0-9a-f]{12}$/i;
+  if (!id || !UUID_RE.test(id)) {
+    return NextResponse.json(
+      { error: "Invalid session ID" },
+      { status: 400 }
+    );
+  }
+
+  // 4. Revoke — the helper enforces user_id ownership so users can't revoke
+  //    sessions belonging to other accounts.
+  try {
+    const revoked = await revokeSession(id, session.userId);
+    if (!revoked) {
+      // Either the session doesn't exist, belongs to another user, or was
+      // already revoked — return 404 in all cases to avoid leaking existence.
+      return NextResponse.json(
+        { error: "Session not found" },
+        { status: 404 }
+      );
+    }
+    return NextResponse.json({ ok: true, revoked: id });
+  } catch (err) {
+    console.error("[DELETE /api/routes-f/session/[id]] DB error:", err);
+    return NextResponse.json(
+      { error: "Internal server error" },
+      { status: 500 }
+    );
+  }
+}
diff --git a/app/api/routes-f/session/all/route.ts b/app/api/routes-f/session/all/route.ts
new file mode 100644
index 00000000..18a5a031
--- /dev/null
+++ b/app/api/routes-f/session/all/route.ts
@@ -0,0 +1,57 @@
+/**
+ * DELETE /api/routes-f/session/all
+ *
+ * Revokes all active sessions for the authenticated user EXCEPT the current one.
+ * This is the "sign out of all other devices" action.
+ *
+ * The current session (identified by the request cookie) is preserved so the
+ * user remains logged in on the device they used to trigger this action.
+ */
+
+import { NextRequest, NextResponse } from "next/server";
+import { verifySession } from "@/lib/auth/verify-session";
+import { extractRawToken } from "@/lib/sessions/extract-raw-token";
+import { revokeAllOtherSessions } from "@/lib/sessions/user-sessions";
+import { createRateLimiter } from "@/lib/rate-limit";
+
+// 10 bulk-revocations per 10 minutes per IP — this is a sensitive action
+const isRateLimited = createRateLimiter(10 * 60_000, 10);
+
+export async function DELETE(req: NextRequest) {
+  // 1. Rate limit
+  const ip =
+    req.headers.get("x-forwarded-for")?.split(",")[0]?.trim() ??
+    req.headers.get("x-real-ip") ??
+    "unknown";
+
+  if (await isRateLimited(ip)) {
+    return NextResponse.json(
+      { error: "Too many requests" },
+      { status: 429, headers: { "Retry-After": "600" } }
+    );
+  }
+
+  // 2. Verify session
+  const session = await verifySession(req);
+  if (!session.ok) {
+    return session.response;
+  }
+
+  // 3. Extract raw token to identify (and preserve) the current session
+  const rawToken = extractRawToken(req);
+  if (!rawToken) {
+    return NextResponse.json({ error: "Unauthorized" }, { status: 401 });
+  }
+
+  // 4. Revoke all other sessions
+  try {
+    const count = await revokeAllOtherSessions(session.userId, rawToken);
+    return NextResponse.json({ ok: true, revoked: count });
+  } catch (err) {
+    console.error("[DELETE /api/routes-f/session/all] DB error:", err);
+    return NextResponse.json(
+      { error: "Internal server error" },
+      { status: 500 }
+    );
+  }
+}
diff --git a/app/api/routes-f/session/route.ts b/app/api/routes-f/session/route.ts
new file mode 100644
index 00000000..0491e9b4
--- /dev/null
+++ b/app/api/routes-f/session/route.ts
@@ -0,0 +1,69 @@
+/**
+ * GET /api/routes-f/session
+ *
+ * Returns all active sessions for the authenticated user.
+ * The session that made this request is marked with `is_current: true`.
+ *
+ * Response shape:
+ * {
+ *   "sessions": [
+ *     {
+ *       "id": "uuid",
+ *       "device_hint": "Chrome on macOS",
+ *       "ip_address": "1.2.3.x",
+ *       "last_seen_at": "2026-03-26T12:00:00Z",
+ *       "created_at": "2026-03-25T08:00:00Z",
+ *       "is_current": true
+ *     }
+ *   ]
+ * }
+ */
+
+import { NextRequest, NextResponse } from "next/server";
+import { verifySession } from "@/lib/auth/verify-session";
+import { extractRawToken } from "@/lib/sessions/extract-raw-token";
+import { listActiveSessions } from "@/lib/sessions/user-sessions";
+import { createRateLimiter } from "@/lib/rate-limit";
+
+// 30 requests per minute per IP — listing sessions is read-only but still bounded
+const isRateLimited = createRateLimiter(60_000, 30);
+
+export async function GET(req: NextRequest) {
+  // 1. Rate limit
+  const ip =
+    req.headers.get("x-forwarded-for")?.split(",")[0]?.trim() ??
+    req.headers.get("x-real-ip") ??
+    "unknown";
+
+  if (await isRateLimited(ip)) {
+    return NextResponse.json(
+      { error: "Too many requests" },
+      { status: 429, headers: { "Retry-After": "60" } }
+    );
+  }
+
+  // 2. Verify session
+  const session = await verifySession(req);
+  if (!session.ok) {
+    return session.response;
+  }
+
+  // 3. Extract raw token to identify the current session
+  const rawToken = extractRawToken(req);
+  if (!rawToken) {
+    // verifySession succeeded so a cookie must exist — guard anyway
+    return NextResponse.json({ error: "Unauthorized" }, { status: 401 });
+  }
+
+  // 4. Fetch active sessions
+  try {
+    const sessions = await listActiveSessions(session.userId, rawToken);
+    return NextResponse.json({ sessions });
+  } catch (err) {
+    console.error("[GET /api/routes-f/session] DB error:", err);
+    return NextResponse.json(
+      { error: "Internal server error" },
+      { status: 500 }
+    );
+  }
+}
diff --git a/app/api/routes-f/sieve-of-eratosthenes/route.test.ts b/app/api/routes-f/sieve-of-eratosthenes/route.test.ts
new file mode 100644
index 00000000..4b1cbed9
--- /dev/null
+++ b/app/api/routes-f/sieve-of-eratosthenes/route.test.ts
@@ -0,0 +1,78 @@
+import { GET } from './route';
+
+describe('Sieve of Eratosthenes API', () => {
+  it('should return 400 when limit parameter is missing', async () => {
+    const req = new Request('http://localhost/api/routes-f/sieve-of-eratosthenes', {
+      method: 'GET',
+    });
+    const res = await GET(req);
+    expect(res.status).toBe(400);
+  });
+
+  it('should return 400 when limit is below 2', async () => {
+    const req = new Request('http://localhost/api/routes-f/sieve-of-eratosthenes?limit=1', {
+      method: 'GET',
+    });
+    const res = await GET(req);
+    expect(res.status).toBe(400);
+  });
+
+  it('should return 400 when limit exceeds 1000000', async () => {
+    const req = new Request('http://localhost/api/routes-f/sieve-of-eratosthenes?limit=1000001', {
+      method: 'GET',
+    });
+    const res = await GET(req);
+    expect(res.status).toBe(400);
+  });
+
+  it('should return 400 when limit is not a valid number', async () => {
+    const req = new Request('http://localhost/api/routes-f/sieve-of-eratosthenes?limit=abc', {
+      method: 'GET',
+    });
+    const res = await GET(req);
+    expect(res.status).toBe(400);
+  });
+
+  it('should return 25 primes up to 100', async () => {
+    const req = new Request('http://localhost/api/routes-f/sieve-of-eratosthenes?limit=100', {
+      method: 'GET',
+    });
+    const res = await GET(req);
+    const data = await res.json();
+    expect(data.count).toBe(25);
+    expect(data.primes).toEqual([
+      2, 3, 5, 7, 11, 13, 17, 19, 23, 29, 31, 37, 41, 43, 47, 53, 59, 61, 67, 71, 73, 79, 83, 89, 97,
+    ]);
+  });
+
+  it('should return correct primes up to 10', async () => {
+    const req = new Request('http://localhost/api/routes-f/sieve-of-eratosthenes?limit=10', {
+      method: 'GET',
+    });
+    const res = await GET(req);
+    const data = await res.json();
+    expect(data.count).toBe(4);
+    expect(data.primes).toEqual([2, 3, 5, 7]);
+  });
+
+  it('should return empty array for limit 2 with 1 prime', async () => {
+    const req = new Request('http://localhost/api/routes-f/sieve-of-eratosthenes?limit=2', {
+      method: 'GET',
+    });
+    const res = await GET(req);
+    const data = await res.json();
+    expect(data.count).toBe(1);
+    expect(data.primes).toEqual([2]);
+  });
+
+  it('should handle large limits efficiently', async () => {
+    const req = new Request('http://localhost/api/routes-f/sieve-of-eratosthenes?limit=10000', {
+      method: 'GET',
+    });
+    const res = await GET(req);
+    const data = await res.json();
+    expect(data.primes[0]).toBe(2);
+    expect(data.primes[data.primes.length - 1]).toBe(9973);
+    expect(data.count).toBe(1229);
+  });
+});
diff --git a/app/api/routes-f/sieve-of-eratosthenes/route.ts b/app/api/routes-f/sieve-of-eratosthenes/route.ts
new file mode 100644
index 00000000..2e47a5f9
--- /dev/null
+++ b/app/api/routes-f/sieve-of-eratosthenes/route.ts
@@ -0,0 +1,53 @@
+import { NextResponse } from 'next/server';
+
+function sieveOfEratosthenes(limit: number): number[] {
+  if (limit < 2) return [];
+
+  const isPrime = Array(limit + 1).fill(true);
+  isPrime[0] = isPrime[1] = false;
+
+  for (let i = 2; i * i <= limit; i++) {
+    if (isPrime[i]) {
+      for (let j = i * i; j <= limit; j += i) {
+        isPrime[j] = false;
+      }
+    }
+  }
+
+  const primes: number[] = [];
+  for (let i = 2; i <= limit; i++) {
+    if (isPrime[i]) {
+      primes.push(i);
+    }
+  }
+
+  return primes;
+}
+
+export async function GET(request: Request) {
+  const { searchParams } = new URL(request.url);
+  const limitParam = searchParams.get('limit');
+
+  if (!limitParam) {
+    return NextResponse.json(
+      { error: 'Missing limit parameter' },
+      { status: 400 }
+    );
+  }
+
+  const limit = parseInt(limitParam, 10);
+
+  if (isNaN(limit) || limit < 2 || limit > 1000000) {
+    return NextResponse.json(
+      { error: 'Limit must be between 2 and 1000000' },
+      { status: 400 }
+    );
+  }
+
+  const primes = sieveOfEratosthenes(limit);
+
+  return NextResponse.json({
+    primes,
+    count: primes.length,
+  });
+}
diff --git a/app/api/routes-f/sitemap-xml/_lib/helpers.ts b/app/api/routes-f/sitemap-xml/_lib/helpers.ts
new file mode 100644
index 00000000..adf82faa
--- /dev/null
+++ b/app/api/routes-f/sitemap-xml/_lib/helpers.ts
@@ -0,0 +1,122 @@
+import type { ChangeFreq, UrlEntry } from "./types";
+
+const MAX_URLS = 50_000;
+
+const VALID_CHANGEFREQS: ChangeFreq[] = [
+  "always",
+  "hourly",
+  "daily",
+  "weekly",
+  "monthly",
+  "yearly",
+  "never",
+];
+
+function isRecord(value: unknown): value is Record<string, unknown> {
+  return typeof value === "object" && value !== null && !Array.isArray(value);
+}
+
+function escapeXml(str: string): string {
+  return str
+    .replace(/&/g, "&amp;")
+    .replace(/</g, "&lt;")
+    .replace(/>/g, "&gt;")
+    .replace(/"/g, "&quot;")
+    .replace(/'/g, "&apos;");
+}
+
+function isValidUrl(str: string): boolean {
+  try {
+    const url = new URL(str);
+    return url.protocol === "http:" || url.protocol === "https:";
+  } catch {
+    return false;
+  }
+}
+
+function parseUrlEntry(value: unknown, index: number): UrlEntry {
+  if (!isRecord(value)) {
+    throw new Error(`urls[${index}] must be an object.`);
+  }
+
+  if (typeof value.loc !== "string" || !value.loc.trim()) {
+    throw new Error(`urls[${index}].loc must be a non-empty string.`);
+  }
+
+  const loc = value.loc.trim();
+  if (!isValidUrl(loc)) {
+    throw new Error(`urls[${index}].loc must be a valid http/https URL.`);
+  }
+
+  const entry: UrlEntry = { loc };
+
+  if (value.lastmod !== undefined) {
+    if (typeof value.lastmod !== "string") {
+      throw new Error(`urls[${index}].lastmod must be a string.`);
+    }
+    entry.lastmod = value.lastmod.trim();
+  }
+
+  if (value.changefreq !== undefined) {
+    if (
+      typeof value.changefreq !== "string" ||
+      !VALID_CHANGEFREQS.includes(value.changefreq as ChangeFreq)
+    ) {
+      throw new Error(
+        `urls[${index}].changefreq must be one of: ${VALID_CHANGEFREQS.join(", ")}.`
+      );
+    }
+    entry.changefreq = value.changefreq as ChangeFreq;
+  }
+
+  if (value.priority !== undefined) {
+    const p = Number(value.priority);
+    if (!Number.isFinite(p) || p < 0 || p > 1) {
+      throw new Error(`urls[${index}].priority must be a number in [0, 1].`);
+    }
+    entry.priority = p;
+  }
+
+  return entry;
+}
+
+function buildUrlElement(entry: UrlEntry): string {
+  const lines: string[] = [`  <url>`, `    <loc>${escapeXml(entry.loc)}</loc>`];
+
+  if (entry.lastmod !== undefined) {
+    lines.push(`    <lastmod>${escapeXml(entry.lastmod)}</lastmod>`);
+  }
+  if (entry.changefreq !== undefined) {
+    lines.push(`    <changefreq>${entry.changefreq}</changefreq>`);
+  }
+  if (entry.priority !== undefined) {
+    lines.push(`    <priority>${entry.priority.toFixed(1)}</priority>`);
+  }
+
+  lines.push(`  </url>`);
+  return lines.join("\n");
+}
+
+export function buildSitemap(input: unknown): string {
+  if (!isRecord(input)) {
+    throw new Error("Request body must be an object.");
+  }
+
+  if (!Array.isArray(input.urls) || input.urls.length === 0) {
+    throw new Error("urls must be a non-empty array.");
+  }
+
+  if (input.urls.length > MAX_URLS) {
+    throw new Error(`urls must contain at most ${MAX_URLS} entries.`);
+  }
+
+  const entries = input.urls.map(parseUrlEntry);
+  const urlElements = entries.map(buildUrlElement).join("\n");
+
+  return (
+    `<?xml version="1.0" encoding="UTF-8"?>\n` +
+    `<urlset xmlns="http://www.sitemaps.org/schemas/sitemap/0.9">\n` +
+    `${urlElements}\n` +
+    `</urlset>`
+  );
+}
diff --git a/app/api/routes-f/sitemap-xml/_lib/types.ts b/app/api/routes-f/sitemap-xml/_lib/types.ts
new file mode 100644
index 00000000..3c191612
--- /dev/null
+++ b/app/api/routes-f/sitemap-xml/_lib/types.ts
@@ -0,0 +1,19 @@
+export type ChangeFreq =
+  | "always"
+  | "hourly"
+  | "daily"
+  | "weekly"
+  | "monthly"
+  | "yearly"
+  | "never";
+
+export interface UrlEntry {
+  loc: string;
+  lastmod?: string;
+  changefreq?: ChangeFreq;
+  priority?: number;
+}
+
+export interface SitemapResponse {
+  sitemap: string;
+}
diff --git a/app/api/routes-f/sitemap-xml/route.ts b/app/api/routes-f/sitemap-xml/route.ts
new file mode 100644
index 00000000..9c54b1a7
--- /dev/null
+++ b/app/api/routes-f/sitemap-xml/route.ts
@@ -0,0 +1,22 @@
+import { type NextRequest, NextResponse } from "next/server";
+import { buildSitemap } from "./_lib/helpers";
+import type { SitemapResponse } from "./_lib/types";
+
+export async function POST(req: NextRequest) {
+  let body: unknown;
+
+  try {
+    body = await req.json();
+  } catch {
+    return NextResponse.json({ error: "Invalid JSON body." }, { status: 400 });
+  }
+
+  try {
+    const sitemap = buildSitemap(body);
+    return NextResponse.json({ sitemap } satisfies SitemapResponse);
+  } catch (error) {
+    const message =
+      error instanceof Error ? error.message : "Failed to generate sitemap.";
+    return NextResponse.json({ error: message }, { status: 400 });
+  }
+}
diff --git a/app/api/routes-f/soundex/__tests__/route.test.ts b/app/api/routes-f/soundex/__tests__/route.test.ts
new file mode 100644
index 00000000..12f1d157
--- /dev/null
+++ b/app/api/routes-f/soundex/__tests__/route.test.ts
@@ -0,0 +1,58 @@
+import { NextRequest } from "next/server";
+import { soundex } from "../soundex";
+import { POST } from "../route";
+
+// #860 feat(routes-f): soundex phonetic encoder
+
+function makeReq(body: unknown) {
+  return new NextRequest("http://localhost/api/routes-f/soundex", {
+    method: "POST",
+    headers: { "content-type": "application/json" },
+    body: JSON.stringify(body),
+  });
+}
+
+describe("soundex", () => {
+  it.each([
+    ["Robert", "R163"],
+    ["Rupert", "R163"],
+    ["Washington", "W252"],
+    ["Lee", "L000"],
+    ["Ashcraft", "A261"],
+    ["Ashcroft", "A261"],
+  ])("encodes %s as %s", (word, expected) => {
+    expect(soundex(word)).toBe(expected);
+  });
+
+  it("ignores non-alphabetic characters", () => {
+    expect(soundex("O'Brien")).toBe(soundex("OBrien"));
+  });
+});
+
+describe("POST /api/routes-f/soundex", () => {
+  it("returns a single code for word", async () => {
+    const res = await POST(makeReq({ word: "Robert" }));
+    const data = await res.json();
+
+    expect(res.status).toBe(200);
+    expect(data).toEqual({ code: "R163" });
+  });
+
+  it("returns codes for words array", async () => {
+    const res = await POST(makeReq({ words: ["Robert", "Rupert", "Lee"] }));
+    const data = await res.json();
+
+    expect(res.status).toBe(200);
+    expect(data).toEqual({ codes: ["R163", "R163", "L000"] });
+  });
+
+  it("rejects invalid bodies", async () => {
+    const missing = await POST(makeReq({}));
+    const both = await POST(makeReq({ word: "a", words: ["b"] }));
+    const badWord = await POST(makeReq({ word: 123 }));
+
+    expect(missing.status).toBe(400);
+    expect(both.status).toBe(400);
+    expect(badWord.status).toBe(400);
+  });
+});
diff --git a/app/api/routes-f/soundex/route.ts b/app/api/routes-f/soundex/route.ts
new file mode 100644
index 00000000..d7c0ddd1
--- /dev/null
+++ b/app/api/routes-f/soundex/route.ts
@@ -0,0 +1,44 @@
+import { NextRequest, NextResponse } from "next/server";
+import { encodeSoundexWords, soundex } from "./soundex";
+
+// #860 feat(routes-f): soundex phonetic encoder
+
+type SoundexBody = {
+  word?: unknown;
+  words?: unknown;
+};
+
+function badRequest(message: string) {
+  return NextResponse.json({ error: message }, { status: 400 });
+}
+
+export async function POST(req: NextRequest) {
+  let body: SoundexBody;
+
+  try {
+    body = (await req.json()) as SoundexBody;
+  } catch {
+    return badRequest("Invalid JSON body.");
+  }
+
+  const hasWord = body.word !== undefined;
+  const hasWords = body.words !== undefined;
+
+  if (hasWord === hasWords) {
+    return badRequest("Provide exactly one of word or words.");
+  }
+
+  if (hasWord) {
+    if (typeof body.word !== "string") {
+      return badRequest("word must be a string.");
+    }
+
+    return NextResponse.json({ code: soundex(body.word) });
+  }
+
+  if (!Array.isArray(body.words) || body.words.some((item) => typeof item !== "string")) {
+    return badRequest("words must be an array of strings.");
+  }
+
+  return NextResponse.json({ codes: encodeSoundexWords(body.words) });
+}
diff --git a/app/api/routes-f/soundex/soundex.ts b/app/api/routes-f/soundex/soundex.ts
new file mode 100644
index 00000000..842c6cac
--- /dev/null
+++ b/app/api/routes-f/soundex/soundex.ts
@@ -0,0 +1,65 @@
+// #860 feat(routes-f): soundex phonetic encoder
+
+const SOUNDEX_MAP: Record<string, string> = {
+  B: "1",
+  F: "1",
+  P: "1",
+  V: "1",
+  C: "2",
+  G: "2",
+  J: "2",
+  K: "2",
+  Q: "2",
+  S: "2",
+  X: "2",
+  Z: "2",
+  D: "3",
+  T: "3",
+  L: "4",
+  M: "5",
+  N: "5",
+  R: "6",
+};
+
+/**
+ * Encode a single word using the standard Soundex algorithm (letter + 3 digits).
+ */
+export function soundex(word: string): string {
+  const upper = word.toUpperCase().replace(/[^A-Z]/g, "");
+  if (upper.length === 0) {
+    return "";
+  }
+
+  const firstLetter = upper[0];
+  const digits: string[] = [];
+  let previousCode = SOUNDEX_MAP[firstLetter] ?? "0";
+
+  for (let i = 1; i < upper.length; i += 1) {
+    const letter = upper[i];
+    const digit = SOUNDEX_MAP[letter] ?? "0";
+
+    if (digit === "0") {
+      continue;
+    }
+
+    // H/W between two same-code consonants suppresses the second consonant.
+    if (
+      (upper[i - 1] === "H" || upper[i - 1] === "W") &&
+      digit === previousCode
+    ) {
+      continue;
+    }
+
+    if (digit !== digits[digits.length - 1]) {
+      digits.push(digit);
+    }
+
+    previousCode = digit;
+  }
+
+  return `${firstLetter}${digits.join("")}000`.slice(0, 4);
+}
+
+export function encodeSoundexWords(words: string[]): string[] {
+  return words.map((word) => soundex(word));
+}
diff --git a/app/api/routes-f/stream-cover/__tests__/route.test.ts b/app/api/routes-f/stream-cover/__tests__/route.test.ts
new file mode 100644
index 00000000..4a410df0
--- /dev/null
+++ b/app/api/routes-f/stream-cover/__tests__/route.test.ts
@@ -0,0 +1,115 @@
+import { NextRequest } from "next/server";
+import { GET, POST } from "../route";
+import { clearAllCovers } from "../store";
+
+function makeGetReq(params: Record<string, string> = {}): NextRequest {
+  const url = new URL("http://localhost/api/routes-f/stream-cover");
+  Object.entries(params).forEach(([k, v]) => url.searchParams.set(k, v));
+  return new NextRequest(url.toString());
+}
+
+function makePostReq(body: unknown): NextRequest {
+  return new NextRequest("http://localhost/api/routes-f/stream-cover", {
+    method: "POST",
+    headers: { "Content-Type": "application/json" },
+    body: JSON.stringify(body),
+  });
+}
+
+describe("stream-cover lifecycle", () => {
+  beforeEach(() => {
+    clearAllCovers();
+  });
+
+  describe("POST /api/routes-f/stream-cover", () => {
+    it("sets a cover image and returns updated_at", async () => {
+      const res = await POST(
+        makePostReq({
+          stream_id: "s1",
+          cover_url: "https://example.com/cover.jpg",
+        })
+      );
+      expect(res.status).toBe(200);
+      const data = await res.json();
+      expect(typeof data.updated_at).toBe("string");
+    });
+
+    it("overwrites an existing cover image", async () => {
+      await POST(
+        makePostReq({
+          stream_id: "s1",
+          cover_url: "https://example.com/cover1.jpg",
+        })
+      );
+      const res = await POST(
+        makePostReq({
+          stream_id: "s1",
+          cover_url: "https://example.com/cover2.jpg",
+        })
+      );
+      expect(res.status).toBe(200);
+
+      const getRes = await GET(makeGetReq({ stream_id: "s1" }));
+      const data = await getRes.json();
+      expect(data.cover_url).toBe("https://example.com/cover2.jpg");
+    });
+
+    it("returns 400 when stream_id is missing", async () => {
+      const res = await POST(
+        makePostReq({ cover_url: "https://example.com/cover.jpg" })
+      );
+      expect(res.status).toBe(400);
+    });
+
+    it("returns 400 when cover_url is missing", async () => {
+      const res = await POST(makePostReq({ stream_id: "s1" }));
+      expect(res.status).toBe(400);
+    });
+
+    it("returns 400 for invalid URL", async () => {
+      const res = await POST(
+        makePostReq({ stream_id: "s1", cover_url: "not-a-url" })
+      );
+      expect(res.status).toBe(400);
+      const data = await res.json();
+      expect(data.error).toMatch(/valid URL/i);
+    });
+
+    it("accepts http URLs", async () => {
+      const res = await POST(
+        makePostReq({
+          stream_id: "s1",
+          cover_url: "http://example.com/cover.jpg",
+        })
+      );
+      expect(res.status).toBe(200);
+    });
+  });
+
+  describe("GET /api/routes-f/stream-cover", () => {
+    it("returns 400 when stream_id is missing", async () => {
+      const res = await GET(makeGetReq({}));
+      expect(res.status).toBe(400);
+    });
+
+    it("returns 404 when no cover is set", async () => {
+      const res = await GET(makeGetReq({ stream_id: "s_unknown" }));
+      expect(res.status).toBe(404);
+    });
+
+    it("returns the cover image after setting it", async () => {
+      await POST(
+        makePostReq({
+          stream_id: "s1",
+          cover_url: "https://example.com/cover.jpg",
+        })
+      );
+      const res = await GET(makeGetReq({ stream_id: "s1" }));
+      expect(res.status).toBe(200);
+      const data = await res.json();
+      expect(data.stream_id).toBe("s1");
+      expect(data.cover_url).toBe("https://example.com/cover.jpg");
+      expect(typeof data.updated_at).toBe("string");
+    });
+  });
+});
diff --git a/app/api/routes-f/stream-cover/route.ts b/app/api/routes-f/stream-cover/route.ts
new file mode 100644
index 00000000..85da6153
--- /dev/null
+++ b/app/api/routes-f/stream-cover/route.ts
@@ -0,0 +1,63 @@
+import { NextRequest, NextResponse } from "next/server";
+import type { PostCoverBody, PostCoverResponse, GetCoverResponse } from "./types";
+import { getCover, setCover } from "./store";
+
+export async function POST(req: NextRequest): Promise<NextResponse> {
+  let body: PostCoverBody;
+  try {
+    body = await req.json();
+  } catch {
+    return NextResponse.json({ error: "invalid JSON body" }, { status: 400 });
+  }
+
+  const { stream_id, cover_url } = body;
+
+  if (!stream_id || typeof stream_id !== "string") {
+    return NextResponse.json(
+      { error: "stream_id is required" },
+      { status: 400 }
+    );
+  }
+  if (!cover_url || typeof cover_url !== "string") {
+    return NextResponse.json(
+      { error: "cover_url is required" },
+      { status: 400 }
+    );
+  }
+
+  try {
+    new URL(cover_url);
+  } catch {
+    return NextResponse.json(
+      { error: "cover_url must be a valid URL" },
+      { status: 400 }
+    );
+  }
+
+  const record = setCover(stream_id, cover_url);
+  return NextResponse.json(
+    { updated_at: record.updated_at } as PostCoverResponse,
+    { status: 200 }
+  );
+}
+
+export async function GET(req: NextRequest): Promise<NextResponse> {
+  const streamId = req.nextUrl.searchParams.get("stream_id");
+
+  if (!streamId) {
+    return NextResponse.json(
+      { error: "stream_id is required" },
+      { status: 400 }
+    );
+  }
+
+  const record = getCover(streamId);
+  if (!record) {
+    return NextResponse.json(
+      { error: "No cover image set for this stream" },
+      { status: 404 }
+    );
+  }
+
+  return NextResponse.json(record as GetCoverResponse);
+}
diff --git a/app/api/routes-f/stream-cover/store.ts b/app/api/routes-f/stream-cover/store.ts
new file mode 100644
index 00000000..cf596aac
--- /dev/null
+++ b/app/api/routes-f/stream-cover/store.ts
@@ -0,0 +1,21 @@
+import type { CoverImageRecord } from "./types";
+
+const covers = new Map<string, CoverImageRecord>();
+
+export function getCover(streamId: string): CoverImageRecord | undefined {
+  return covers.get(streamId);
+}
+
+export function setCover(streamId: string, coverUrl: string): CoverImageRecord {
+  const record: CoverImageRecord = {
+    stream_id: streamId,
+    cover_url: coverUrl,
+    updated_at: new Date().toISOString(),
+  };
+  covers.set(streamId, record);
+  return record;
+}
+
+export function clearAllCovers(): void {
+  covers.clear();
+}
diff --git a/app/api/routes-f/stream-cover/types.ts b/app/api/routes-f/stream-cover/types.ts
new file mode 100644
index 00000000..22ec6d35
--- /dev/null
+++ b/app/api/routes-f/stream-cover/types.ts
@@ -0,0 +1,20 @@
+export interface CoverImageRecord {
+  stream_id: string;
+  cover_url: string;
+  updated_at: string;
+}
+
+export interface PostCoverBody {
+  stream_id: string;
+  cover_url: string;
+}
+
+export interface PostCoverResponse {
+  updated_at: string;
+}
+
+export interface GetCoverResponse {
+  stream_id: string;
+  cover_url: string;
+  updated_at: string;
+}
diff --git a/app/api/routes-f/stream-heartbeat/__tests__/route.test.ts b/app/api/routes-f/stream-heartbeat/__tests__/route.test.ts
new file mode 100644
index 00000000..bd395564
--- /dev/null
+++ b/app/api/routes-f/stream-heartbeat/__tests__/route.test.ts
@@ -0,0 +1,136 @@
+/**
+ * @jest-environment node
+ */
+import { NextRequest } from "next/server";
+import { POST, rings } from "../route";
+
+function makeReq(body: unknown) {
+  return new NextRequest("http://localhost/api/routes-f/stream-heartbeat", {
+    method: "POST",
+    headers: { "content-type": "application/json" },
+    body: JSON.stringify(body),
+  });
+}
+
+const BASE = {
+  stream_id: "stream-abc-123",
+  bitrate_kbps: 4000,
+  fps: 30,
+  resolution: "1920x1080",
+  dropped_frames: 0,
+};
+
+describe("POST /api/routes-f/stream-heartbeat", () => {
+  beforeEach(() => rings.clear());
+
+  // ── health tiers ──────────────────────────────────────────────────────────
+
+  it('returns health "ok" for healthy stream', async () => {
+    const res = await POST(makeReq(BASE));
+    expect(res.status).toBe(200);
+    const body = await res.json();
+    expect(body.health).toBe("ok");
+    expect(body.recommendations).toEqual([]);
+  });
+
+  it('returns health "degraded" when bitrate is below 1500 kbps', async () => {
+    const res = await POST(makeReq({ ...BASE, bitrate_kbps: 1000 }));
+    expect(res.status).toBe(200);
+    const body = await res.json();
+    expect(body.health).toBe("degraded");
+    expect(body.recommendations.length).toBeGreaterThan(0);
+  });
+
+  it('returns health "critical" when bitrate is below 500 kbps', async () => {
+    const res = await POST(makeReq({ ...BASE, bitrate_kbps: 300 }));
+    const body = await res.json();
+    expect(body.health).toBe("critical");
+    expect(body.recommendations.some((r: string) => /bitrate/i.test(r))).toBe(true);
+  });
+
+  it('returns health "degraded" when drop ratio is >= 3%', async () => {
+    // fps=97 dropped=3 → ratio = 3/100 = 3%
+    const res = await POST(makeReq({ ...BASE, fps: 97, dropped_frames: 3 }));
+    const body = await res.json();
+    expect(body.health).toBe("degraded");
+  });
+
+  it('returns health "critical" when drop ratio is >= 10%', async () => {
+    // fps=90 dropped=10 → ratio = 10/100 = 10%
+    const res = await POST(makeReq({ ...BASE, fps: 90, dropped_frames: 10 }));
+    const body = await res.json();
+    expect(body.health).toBe("critical");
+  });
+
+  // ── ring buffer ───────────────────────────────────────────────────────────
+
+  it("stores samples in the ring buffer", async () => {
+    await POST(makeReq(BASE));
+    const buf = rings.get(BASE.stream_id)!;
+    expect(buf).toHaveLength(1);
+    expect(buf[0].bitrate_kbps).toBe(4000);
+  });
+
+  it("caps ring buffer at 60 samples", async () => {
+    for (let i = 0; i < 65; i++) {
+      await POST(makeReq({ ...BASE, bitrate_kbps: i * 100 }));
+    }
+    const buf = rings.get(BASE.stream_id)!;
+    expect(buf).toHaveLength(60);
+    // oldest sample dropped — first should be from iteration 5 (bitrate 500)
+    expect(buf[0].bitrate_kbps).toBe(500);
+  });
+
+  it("keeps separate buffers per stream", async () => {
+    await POST(makeReq({ ...BASE, stream_id: "stream-1" }));
+    await POST(makeReq({ ...BASE, stream_id: "stream-2" }));
+    expect(rings.get("stream-1")).toHaveLength(1);
+    expect(rings.get("stream-2")).toHaveLength(1);
+  });
+
+  // ── dropped_frames optional ───────────────────────────────────────────────
+
+  it("defaults dropped_frames to 0 when omitted", async () => {
+    const { dropped_frames: _, ...noDrops } = BASE;
+    const res = await POST(makeReq(noDrops));
+    expect(res.status).toBe(200);
+    const body = await res.json();
+    expect(body.health).toBe("ok");
+  });
+
+  // ── validation ────────────────────────────────────────────────────────────
+
+  it("400 when stream_id is missing", async () => {
+    const { stream_id: _, ...rest } = BASE;
+    const res = await POST(makeReq(rest));
+    expect(res.status).toBe(400);
+  });
+
+  it("400 when bitrate_kbps is missing", async () => {
+    const { bitrate_kbps: _, ...rest } = BASE;
+    const res = await POST(makeReq(rest));
+    expect(res.status).toBe(400);
+  });
+
+  it("400 when fps is missing", async () => {
+    const { fps: _, ...rest } = BASE;
+    const res = await POST(makeReq(rest));
+    expect(res.status).toBe(400);
+  });
+
+  it("400 when resolution is missing", async () => {
+    const { resolution: _, ...rest } = BASE;
+    const res = await POST(makeReq(rest));
+    expect(res.status).toBe(400);
+  });
+
+  it("400 on invalid JSON", async () => {
+    const req = new NextRequest("http://localhost/api/routes-f/stream-heartbeat", {
+      method: "POST",
+      headers: { "content-type": "application/json" },
+      body: "not-json",
+    });
+    const res = await POST(req);
+    expect(res.status).toBe(400);
+  });
+});
diff --git a/app/api/routes-f/stream-heartbeat/route.ts b/app/api/routes-f/stream-heartbeat/route.ts
new file mode 100644
index 00000000..3c1f5cc8
--- /dev/null
+++ b/app/api/routes-f/stream-heartbeat/route.ts
@@ -0,0 +1,124 @@
+/**
+ * POST /api/routes-f/stream-heartbeat
+ * Streamer encoder posts periodic heartbeats; returns health status.
+ */
+import { NextRequest, NextResponse } from "next/server";
+
+// ---------------------------------------------------------------------------
+// Types
+// ---------------------------------------------------------------------------
+interface HeartbeatSample {
+  bitrate_kbps: number;
+  fps: number;
+  resolution: string;
+  dropped_frames: number;
+  recorded_at: string;
+}
+
+type HealthStatus = "ok" | "degraded" | "critical";
+
+// ---------------------------------------------------------------------------
+// In-memory ring buffer — last 60 samples per stream
+// ---------------------------------------------------------------------------
+const RING_SIZE = 60;
+const rings = new Map<string, HeartbeatSample[]>();
+
+function addSample(stream_id: string, sample: HeartbeatSample): void {
+  const buf = rings.get(stream_id) ?? [];
+  buf.push(sample);
+  if (buf.length > RING_SIZE) buf.shift();
+  rings.set(stream_id, buf);
+}
+
+// ---------------------------------------------------------------------------
+// Health computation
+// ---------------------------------------------------------------------------
+const BITRATE_CRITICAL = 500; // kbps
+const BITRATE_DEGRADED = 1500; // kbps
+const DROP_RATIO_CRITICAL = 0.1; // 10 %
+const DROP_RATIO_DEGRADED = 0.03; // 3 %
+
+function computeHealth(
+  bitrate_kbps: number,
+  fps: number,
+  dropped_frames: number
+): { health: HealthStatus; recommendations: string[] } {
+  const total = fps + dropped_frames; // total frames expected in the period
+  const dropRatio = total > 0 ? dropped_frames / total : 0;
+  const recommendations: string[] = [];
+
+  let health: HealthStatus = "ok";
+
+  if (bitrate_kbps < BITRATE_CRITICAL || dropRatio >= DROP_RATIO_CRITICAL) {
+    health = "critical";
+  } else if (bitrate_kbps < BITRATE_DEGRADED || dropRatio >= DROP_RATIO_DEGRADED) {
+    health = "degraded";
+  }
+
+  if (bitrate_kbps < BITRATE_CRITICAL) {
+    recommendations.push("Bitrate is critically low — check upload bandwidth.");
+  } else if (bitrate_kbps < BITRATE_DEGRADED) {
+    recommendations.push("Bitrate is below recommended — consider lowering resolution.");
+  }
+
+  if (dropRatio >= DROP_RATIO_CRITICAL) {
+    recommendations.push("High frame drop rate — reduce encoding preset or resolution.");
+  } else if (dropRatio >= DROP_RATIO_DEGRADED) {
+    recommendations.push("Elevated frame drops detected — monitor CPU usage.");
+  }
+
+  return { health, recommendations };
+}
+
+// ---------------------------------------------------------------------------
+// Route handler
+// ---------------------------------------------------------------------------
+export async function POST(req: NextRequest): Promise<NextResponse> {
+  let body: unknown;
+  try {
+    body = await req.json();
+  } catch {
+    return NextResponse.json({ error: "Invalid JSON body" }, { status: 400 });
+  }
+
+  const {
+    stream_id,
+    bitrate_kbps,
+    fps,
+    resolution,
+    dropped_frames = 0,
+  } = body as Record<string, unknown>;
+
+  if (!stream_id || typeof stream_id !== "string") {
+    return NextResponse.json({ error: "stream_id is required" }, { status: 400 });
+  }
+  if (typeof bitrate_kbps !== "number" || bitrate_kbps < 0) {
+    return NextResponse.json({ error: "bitrate_kbps must be a non-negative number" }, { status: 400 });
+  }
+  if (typeof fps !== "number" || fps < 0) {
+    return NextResponse.json({ error: "fps must be a non-negative number" }, { status: 400 });
+  }
+  if (!resolution || typeof resolution !== "string") {
+    return NextResponse.json({ error: "resolution is required" }, { status: 400 });
+  }
+  if (typeof dropped_frames !== "number" || dropped_frames < 0) {
+    return NextResponse.json({ error: "dropped_frames must be a non-negative number" }, { status: 400 });
+  }
+
+  const sample: HeartbeatSample = {
+    bitrate_kbps,
+    fps,
+    resolution,
+    dropped_frames,
+    recorded_at: new Date().toISOString(),
+  };
+
+  addSample(stream_id, sample);
+
+  const { health, recommendations } = computeHealth(bitrate_kbps, fps, dropped_frames);
+
+  return NextResponse.json({ health, recommendations }, { status: 200 });
+}
+
+// Export store for tests
+export { rings };
diff --git a/app/api/routes-f/stream-rerun/__tests__/route.test.ts b/app/api/routes-f/stream-rerun/__tests__/route.test.ts
new file mode 100644
index 00000000..e79a5782
--- /dev/null
+++ b/app/api/routes-f/stream-rerun/__tests__/route.test.ts
@@ -0,0 +1,140 @@
+import { NextRequest } from "next/server";
+import { GET, POST, DELETE } from "../route";
+import { clearAllReruns } from "../store";
+
+function makeGetReq(params: Record<string, string> = {}): NextRequest {
+  const url = new URL("http://localhost/api/routes-f/stream-rerun");
+  Object.entries(params).forEach(([k, v]) => url.searchParams.set(k, v));
+  return new NextRequest(url.toString());
+}
+
+function makePostReq(body: unknown): NextRequest {
+  return new NextRequest("http://localhost/api/routes-f/stream-rerun", {
+    method: "POST",
+    headers: { "Content-Type": "application/json" },
+    body: JSON.stringify(body),
+  });
+}
+
+function makeDeleteReq(body: unknown): NextRequest {
+  return new NextRequest("http://localhost/api/routes-f/stream-rerun", {
+    method: "DELETE",
+    headers: { "Content-Type": "application/json" },
+    body: JSON.stringify(body),
+  });
+}
+
+describe("stream-rerun lifecycle", () => {
+  beforeEach(() => {
+    clearAllReruns();
+  });
+
+  describe("POST /api/routes-f/stream-rerun", () => {
+    it("enables rerun for a creator", async () => {
+      const res = await POST(
+        makePostReq({ creator_id: "c1", vod_id: "vod_x", enabled: true })
+      );
+      expect(res.status).toBe(200);
+      const data = await res.json();
+      expect(data.rerun_active).toBe(true);
+      expect(data.vod_id).toBe("vod_x");
+      expect(typeof data.started_at).toBe("string");
+    });
+
+    it("disables rerun for a creator", async () => {
+      await POST(
+        makePostReq({ creator_id: "c1", vod_id: "vod_x", enabled: true })
+      );
+      const res = await POST(
+        makePostReq({ creator_id: "c1", vod_id: "vod_x", enabled: false })
+      );
+      expect(res.status).toBe(200);
+      const data = await res.json();
+      expect(data.rerun_active).toBe(false);
+      expect(data.vod_id).toBeNull();
+      expect(data.started_at).toBeNull();
+    });
+
+    it("returns 400 when creator_id is missing", async () => {
+      const res = await POST(
+        makePostReq({ vod_id: "vod_x", enabled: true })
+      );
+      expect(res.status).toBe(400);
+    });
+
+    it("returns 400 when vod_id is missing", async () => {
+      const res = await POST(
+        makePostReq({ creator_id: "c1", enabled: true })
+      );
+      expect(res.status).toBe(400);
+    });
+
+    it("returns 400 when enabled is not boolean", async () => {
+      const res = await POST(
+        makePostReq({ creator_id: "c1", vod_id: "vod_x", enabled: "yes" })
+      );
+      expect(res.status).toBe(400);
+    });
+  });
+
+  describe("GET /api/routes-f/stream-rerun", () => {
+    it("returns 400 when creator_id is missing", async () => {
+      const res = await GET(makeGetReq({}));
+      expect(res.status).toBe(400);
+    });
+
+    it("returns inactive rerun for unknown creator", async () => {
+      const res = await GET(makeGetReq({ creator_id: "unknown" }));
+      expect(res.status).toBe(200);
+      const data = await res.json();
+      expect(data.rerun_active).toBe(false);
+      expect(data.vod_id).toBeNull();
+      expect(data.started_at).toBeNull();
+    });
+
+    it("returns active rerun after setting it", async () => {
+      await POST(
+        makePostReq({ creator_id: "c1", vod_id: "vod_x", enabled: true })
+      );
+      const res = await GET(makeGetReq({ creator_id: "c1" }));
+      expect(res.status).toBe(200);
+      const data = await res.json();
+      expect(data.rerun_active).toBe(true);
+      expect(data.vod_id).toBe("vod_x");
+    });
+  });
+
+  describe("DELETE /api/routes-f/stream-rerun", () => {
+    it("clears rerun for a creator", async () => {
+      await POST(
+        makePostReq({ creator_id: "c1", vod_id: "vod_x", enabled: true })
+      );
+      const res = await DELETE(makeDeleteReq({ creator_id: "c1" }));
+      expect(res.status).toBe(200);
+      const data = await res.json();
+      expect(data.cleared).toBe(true);
+    });
+
+    it("returns true when clearing non-existent rerun", async () => {
+      const res = await DELETE(makeDeleteReq({ creator_id: "nobody" }));
+      expect(res.status).toBe(200);
+      const data = await res.json();
+      expect(data.cleared).toBe(true);
+    });
+
+    it("returns 400 when creator_id is missing", async () => {
+      const res = await DELETE(makeDeleteReq({}));
+      expect(res.status).toBe(400);
+    });
+
+    it("GET returns inactive after DELETE", async () => {
+      await POST(
+        makePostReq({ creator_id: "c1", vod_id: "vod_x", enabled: true })
+      );
+      await DELETE(makeDeleteReq({ creator_id: "c1" }));
+      const res = await GET(makeGetReq({ creator_id: "c1" }));
+      const data = await res.json();
+      expect(data.rerun_active).toBe(false);
+    });
+  });
+});
diff --git a/app/api/routes-f/stream-rerun/route.ts b/app/api/routes-f/stream-rerun/route.ts
new file mode 100644
index 00000000..d99aa7e3
--- /dev/null
+++ b/app/api/routes-f/stream-rerun/route.ts
@@ -0,0 +1,87 @@
+import { NextRequest, NextResponse } from "next/server";
+import type { PostRerunBody, GetRerunResponse } from "./types";
+import { getRerun, setRerun, clearRerun } from "./store";
+
+export async function POST(req: NextRequest): Promise<NextResponse> {
+  let body: PostRerunBody;
+  try {
+    body = await req.json();
+  } catch {
+    return NextResponse.json({ error: "invalid JSON body" }, { status: 400 });
+  }
+
+  const { creator_id, vod_id, enabled } = body;
+
+  if (!creator_id || typeof creator_id !== "string") {
+    return NextResponse.json(
+      { error: "creator_id is required" },
+      { status: 400 }
+    );
+  }
+  if (!vod_id || typeof vod_id !== "string") {
+    return NextResponse.json(
+      { error: "vod_id is required" },
+      { status: 400 }
+    );
+  }
+  if (typeof enabled !== "boolean") {
+    return NextResponse.json(
+      { error: "enabled must be a boolean" },
+      { status: 400 }
+    );
+  }
+
+  const config = setRerun(creator_id, vod_id, enabled);
+  return NextResponse.json({
+    rerun_active: config.rerun_active,
+    vod_id: config.vod_id,
+    started_at: config.started_at,
+  } as GetRerunResponse);
+}
+
+export async function GET(req: NextRequest): Promise<NextResponse> {
+  const creatorId = req.nextUrl.searchParams.get("creator_id");
+
+  if (!creatorId) {
+    return NextResponse.json(
+      { error: "creator_id is required" },
+      { status: 400 }
+    );
+  }
+
+  const config = getRerun(creatorId);
+  if (!config) {
+    return NextResponse.json({
+      rerun_active: false,
+      vod_id: null,
+      started_at: null,
+    } as GetRerunResponse);
+  }
+
+  return NextResponse.json({
+    rerun_active: config.rerun_active,
+    vod_id: config.vod_id,
+    started_at: config.started_at,
+  } as GetRerunResponse);
+}
+
+export async function DELETE(req: NextRequest): Promise<NextResponse> {
+  let body: { creator_id: string };
+  try {
+    body = await req.json();
+  } catch {
+    return NextResponse.json({ error: "invalid JSON body" }, { status: 400 });
+  }
+
+  const { creator_id } = body;
+
+  if (!creator_id || typeof creator_id !== "string") {
+    return NextResponse.json(
+      { error: "creator_id is required" },
+      { status: 400 }
+    );
+  }
+
+  const cleared = clearRerun(creator_id);
+  return NextResponse.json({ cleared });
+}
diff --git a/app/api/routes-f/stream-rerun/store.ts b/app/api/routes-f/stream-rerun/store.ts
new file mode 100644
index 00000000..52bc18c2
--- /dev/null
+++ b/app/api/routes-f/stream-rerun/store.ts
@@ -0,0 +1,31 @@
+import type { RerunConfig } from "./types";
+
+const reruns = new Map<string, RerunConfig>();
+
+export function getRerun(creatorId: string): RerunConfig | undefined {
+  return reruns.get(creatorId);
+}
+
+export function setRerun(
+  creatorId: string,
+  vodId: string,
+  enabled: boolean
+): RerunConfig {
+  const config: RerunConfig = {
+    creator_id: creatorId,
+    vod_id: enabled ? vodId : null,
+    rerun_active: enabled,
+    started_at: enabled ? new Date().toISOString() : null,
+  };
+  reruns.set(creatorId, config);
+  return config;
+}
+
+export function clearRerun(creatorId: string): boolean {
+  reruns.delete(creatorId);
+  return true;
+}
+
+export function clearAllReruns(): void {
+  reruns.clear();
+}
diff --git a/app/api/routes-f/stream-rerun/types.ts b/app/api/routes-f/stream-rerun/types.ts
new file mode 100644
index 00000000..55ad9c5d
--- /dev/null
+++ b/app/api/routes-f/stream-rerun/types.ts
@@ -0,0 +1,18 @@
+export interface RerunConfig {
+  creator_id: string;
+  vod_id: string | null;
+  rerun_active: boolean;
+  started_at: string | null;
+}
+
+export interface PostRerunBody {
+  creator_id: string;
+  vod_id: string;
+  enabled: boolean;
+}
+
+export interface GetRerunResponse {
+  rerun_active: boolean;
+  vod_id: string | null;
+  started_at: string | null;
+}
diff --git a/app/api/routes-f/stream-schedule/__tests__/route.test.ts b/app/api/routes-f/stream-schedule/__tests__/route.test.ts
new file mode 100644
index 00000000..6c4d963e
--- /dev/null
+++ b/app/api/routes-f/stream-schedule/__tests__/route.test.ts
@@ -0,0 +1,166 @@
+/**
+ * @jest-environment node
+ */
+import { NextRequest } from "next/server";
+import { POST, GET, DELETE } from "../route";
+
+function makeReq(method: string, body?: unknown) {
+  return new NextRequest("http://localhost/api/routes-f/stream-schedule", {
+    method,
+    headers: { "content-type": "application/json" },
+    body: body ? JSON.stringify(body) : undefined,
+  });
+}
+
+describe("POST /api/routes-f/stream-schedule", () => {
+  it("schedules stream end successfully", async () => {
+    const futureDate = new Date(Date.now() + 3600000).toISOString(); // 1 hour from now
+    const res = await POST(
+      makeReq("POST", {
+        stream_id: "stream123",
+        end_at: futureDate,
+      })
+    );
+    const body = await res.json();
+
+    expect(res.status).toBe(201);
+    expect(body.stream_id).toBe("stream123");
+    expect(body.end_at).toBe(futureDate);
+    expect(body.scheduled).toBe(true);
+    expect(body.fires_in_seconds).toBeGreaterThan(0);
+  });
+
+  it("rejects past time with 400", async () => {
+    const pastDate = new Date(Date.now() - 3600000).toISOString(); // 1 hour ago
+    const res = await POST(
+      makeReq("POST", {
+        stream_id: "stream123",
+        end_at: pastDate,
+      })
+    );
+    expect(res.status).toBe(400);
+  });
+
+  it("rejects invalid ISO date with 400", async () => {
+    const res = await POST(
+      makeReq("POST", {
+        stream_id: "stream123",
+        end_at: "not-a-date",
+      })
+    );
+    expect(res.status).toBe(400);
+  });
+
+  it("rejects missing stream_id", async () => {
+    const futureDate = new Date(Date.now() + 3600000).toISOString();
+    const res = await POST(
+      makeReq("POST", {
+        end_at: futureDate,
+      })
+    );
+    expect(res.status).toBe(400);
+  });
+
+  it("rejects missing end_at", async () => {
+    const res = await POST(
+      makeReq("POST", {
+        stream_id: "stream123",
+      })
+    );
+    expect(res.status).toBe(400);
+  });
+
+  it("rejects invalid JSON", async () => {
+    const req = new NextRequest("http://localhost/api/routes-f/stream-schedule", {
+      method: "POST",
+      headers: { "content-type": "application/json" },
+      body: "invalid json",
+    });
+    const res = await POST(req);
+    expect(res.status).toBe(400);
+  });
+});
+
+describe("GET /api/routes-f/stream-schedule", () => {
+  beforeEach(async () => {
+    // Setup: create a schedule
+    const futureDate = new Date(Date.now() + 3600000).toISOString();
+    await POST(
+      makeReq("POST", {
+        stream_id: "getstream",
+        end_at: futureDate,
+      })
+    );
+  });
+
+  it("returns schedule for existing stream", async () => {
+    const req = new NextRequest(
+      "http://localhost/api/routes-f/stream-schedule?stream_id=getstream"
+    );
+    const res = await GET(req);
+    const body = await res.json();
+
+    expect(res.status).toBe(200);
+    expect(body.stream_id).toBe("getstream");
+    expect(body.scheduled).toBe(true);
+  });
+
+  it("returns 404 for non-existent stream", async () => {
+    const req = new NextRequest(
+      "http://localhost/api/routes-f/stream-schedule?stream_id=nonexistent"
+    );
+    const res = await GET(req);
+    expect(res.status).toBe(404);
+  });
+
+  it("returns 400 when stream_id is missing", async () => {
+    const req = new NextRequest("http://localhost/api/routes-f/stream-schedule");
+    const res = await GET(req);
+    expect(res.status).toBe(400);
+  });
+});
+
+describe("DELETE /api/routes-f/stream-schedule", () => {
+  beforeEach(async () => {
+    // Setup: create a schedule
+    const futureDate = new Date(Date.now() + 3600000).toISOString();
+    await POST(
+      makeReq("POST", {
+        stream_id: "deletestream",
+        end_at: futureDate,
+      })
+    );
+  });
+
+  it("cancels schedule successfully", async () => {
+    const res = await DELETE(
+      makeReq("DELETE", { stream_id: "deletestream" })
+    );
+    const body = await res.json();
+
+    expect(res.status).toBe(200);
+    expect(body.success).toBe(true);
+  });
+
+  it("returns 404 when deleting non-existent stream", async () => {
+    const res = await DELETE(
+      makeReq("DELETE", { stream_id: "nonexistent" })
+    );
+    expect(res.status).toBe(404);
+  });
+
+  it("rejects missing stream_id", async () => {
+    const res = await DELETE(makeReq("DELETE", {}));
+    expect(res.status).toBe(400);
+  });
+
+  it("rejects invalid JSON", async () => {
+    const req = new NextRequest("http://localhost/api/routes-f/stream-schedule", {
+      method: "DELETE",
+      headers: { "content-type": "application/json" },
+      body: "invalid json",
+    });
+    const res = await DELETE(req);
+    expect(res.status).toBe(400);
+  });
+});
diff --git a/app/api/routes-f/stream-schedule/route.ts b/app/api/routes-f/stream-schedule/route.ts
new file mode 100644
index 00000000..750cfe77
--- /dev/null
+++ b/app/api/routes-f/stream-schedule/route.ts
@@ -0,0 +1,129 @@
+import { NextRequest, NextResponse } from "next/server";
+
+// In-memory store for scheduled stream ends
+const scheduleStore = new Map<
+  string,
+  {
+    stream_id: string;
+    end_at: string;
+    scheduled: boolean;
+    fires_in_seconds: number;
+  }
+>();
+
+function isValidISODate(dateString: string): boolean {
+  const date = new Date(dateString);
+  return !isNaN(date.getTime()) && date.toISOString() === dateString;
+}
+
+export async function GET(req: NextRequest) {
+  const { searchParams } = new URL(req.url);
+  const streamId = searchParams.get("stream_id");
+
+  if (!streamId) {
+    return NextResponse.json(
+      { error: "stream_id is required" },
+      { status: 400 }
+    );
+  }
+
+  const schedule = scheduleStore.get(streamId);
+
+  if (!schedule) {
+    return NextResponse.json(
+      { error: "No schedule found for stream" },
+      { status: 404 }
+    );
+  }
+
+  return NextResponse.json(schedule);
+}
+
+export async function POST(req: NextRequest) {
+  let body: {
+    stream_id?: unknown;
+    end_at?: unknown;
+  };
+
+  try {
+    body = await req.json();
+  } catch {
+    return NextResponse.json({ error: "Invalid JSON body" }, { status: 400 });
+  }
+
+  const { stream_id, end_at } = body;
+
+  if (!stream_id || typeof stream_id !== "string") {
+    return NextResponse.json(
+      { error: "stream_id is required and must be a string" },
+      { status: 400 }
+    );
+  }
+
+  if (!end_at || typeof end_at !== "string") {
+    return NextResponse.json(
+      { error: "end_at is required and must be a string" },
+      { status: 400 }
+    );
+  }
+
+  if (!isValidISODate(end_at)) {
+    return NextResponse.json(
+      { error: "end_at must be a valid ISO 8601 date string" },
+      { status: 400 }
+    );
+  }
+
+  const endTime = new Date(end_at);
+  const now = new Date();
+
+  if (endTime <= now) {
+    return NextResponse.json(
+      { error: "end_at must be in the future" },
+      { status: 400 }
+    );
+  }
+
+  const firesInSeconds = Math.floor((endTime.getTime() - now.getTime()) / 1000);
+
+  const schedule = {
+    stream_id,
+    end_at,
+    scheduled: true,
+    fires_in_seconds: firesInSeconds,
+  };
+
+  scheduleStore.set(stream_id, schedule);
+
+  return NextResponse.json(schedule, { status: 201 });
+}
+
+export async function DELETE(req: NextRequest) {
+  let body: { stream_id?: unknown };
+
+  try {
+    body = await req.json();
+  } catch {
+    return NextResponse.json({ error: "Invalid JSON body" }, { status: 400 });
+  }
+
+  const { stream_id } = body;
+
+  if (!stream_id || typeof stream_id !== "string") {
+    return NextResponse.json(
+      { error: "stream_id is required and must be a string" },
+      { status: 400 }
+    );
+  }
+
+  const existed = scheduleStore.delete(stream_id);
+
+  if (!existed) {
+    return NextResponse.json(
+      { error: "No schedule found for stream" },
+      { status: 404 }
+    );
+  }
+
+  return NextResponse.json({ success: true });
+}
diff --git a/app/api/routes-f/stream-snapshot/__tests__/route.test.ts b/app/api/routes-f/stream-snapshot/__tests__/route.test.ts
new file mode 100644
index 00000000..4b255112
--- /dev/null
+++ b/app/api/routes-f/stream-snapshot/__tests__/route.test.ts
@@ -0,0 +1,168 @@
+/**
+ * @jest-environment node
+ */
+import { NextRequest } from "next/server";
+import { POST, GET } from "../route";
+
+function makeReq(method: string, body?: unknown) {
+  return new NextRequest("http://localhost/api/routes-f/stream-snapshot", {
+    method,
+    headers: { "content-type": "application/json" },
+    body: body ? JSON.stringify(body) : undefined,
+  });
+}
+
+describe("POST /api/routes-f/stream-snapshot", () => {
+  it("creates snapshot with provided timestamp", async () => {
+    const res = await POST(
+      makeReq("POST", {
+        stream_id: "stream123",
+        playback_id: "playback456",
+        timestamp: 123,
+      })
+    );
+    const body = await res.json();
+
+    expect(res.status).toBe(201);
+    expect(body.snapshot_url).toBe(
+      "https://image.mux.com/playback456/thumbnail.jpg?time=123"
+    );
+    expect(body.captured_at).toBeDefined();
+  });
+
+  it("creates snapshot with default timestamp", async () => {
+    const res = await POST(
+      makeReq("POST", {
+        stream_id: "stream123",
+        playback_id: "playback456",
+      })
+    );
+    const body = await res.json();
+
+    expect(res.status).toBe(201);
+    expect(body.snapshot_url).toMatch(
+      /^https:\/\/image\.mux\.com\/playback456\/thumbnail\.jpg\?time=\d+$/
+    );
+    expect(body.captured_at).toBeDefined();
+  });
+
+  it("rejects non-numeric timestamp with 400", async () => {
+    const res = await POST(
+      makeReq("POST", {
+        stream_id: "stream123",
+        playback_id: "playback456",
+        timestamp: "not-a-number",
+      })
+    );
+    expect(res.status).toBe(400);
+  });
+
+  it("rejects missing stream_id", async () => {
+    const res = await POST(
+      makeReq("POST", {
+        playback_id: "playback456",
+        timestamp: 123,
+      })
+    );
+    expect(res.status).toBe(400);
+  });
+
+  it("rejects missing playback_id", async () => {
+    const res = await POST(
+      makeReq("POST", {
+        stream_id: "stream123",
+        timestamp: 123,
+      })
+    );
+    expect(res.status).toBe(400);
+  });
+
+  it("rejects invalid JSON", async () => {
+    const req = new NextRequest("http://localhost/api/routes-f/stream-snapshot", {
+      method: "POST",
+      headers: { "content-type": "application/json" },
+      body: "invalid json",
+    });
+    const res = await POST(req);
+    expect(res.status).toBe(400);
+  });
+});
+
+describe("GET /api/routes-f/stream-snapshot", () => {
+  beforeEach(async () => {
+    // Setup: create multiple snapshots
+    await POST(
+      makeReq("POST", {
+        stream_id: "getstream",
+        playback_id: "playback1",
+        timestamp: 100,
+      })
+    );
+    await POST(
+      makeReq("POST", {
+        stream_id: "getstream",
+        playback_id: "playback2",
+        timestamp: 200,
+      })
+    );
+    await POST(
+      makeReq("POST", {
+        stream_id: "getstream",
+        playback_id: "playback3",
+        timestamp: 300,
+      })
+    );
+  });
+
+  it("returns last 10 snapshots for stream", async () => {
+    const req = new NextRequest(
+      "http://localhost/api/routes-f/stream-snapshot?stream_id=getstream"
+    );
+    const res = await GET(req);
+    const body = await res.json();
+
+    expect(res.status).toBe(200);
+    expect(body.snapshots).toHaveLength(3);
+    expect(body.snapshots[0].stream_id).toBe("getstream");
+    expect(body.snapshots[0].playback_id).toBe("playback1");
+  });
+
+  it("returns empty array for stream with no snapshots", async () => {
+    const req = new NextRequest(
+      "http://localhost/api/routes-f/stream-snapshot?stream_id=nosnapshots"
+    );
+    const res = await GET(req);
+    const body = await res.json();
+
+    expect(res.status).toBe(200);
+    expect(body.snapshots).toHaveLength(0);
+  });
+
+  it("returns 400 when stream_id is missing", async () => {
+    const req = new NextRequest("http://localhost/api/routes-f/stream-snapshot");
+    const res = await GET(req);
+    expect(res.status).toBe(400);
+  });
+
+  it("returns only last 10 snapshots when more exist", async () => {
+    // Create 15 snapshots
+    for (let i = 0; i < 15; i++) {
+      await POST(
+        makeReq("POST", {
+          stream_id: "manystream",
+          playback_id: `playback${i}`,
+          timestamp: i * 100,
+        })
+      );
+    }
+
+    const req = new NextRequest(
+      "http://localhost/api/routes-f/stream-snapshot?stream_id=manystream"
+    );
+    const res = await GET(req);
+    const body = await res.json();
+
+    expect(res.status).toBe(200);
+    expect(body.snapshots).toHaveLength(10);
+  });
+});
diff --git a/app/api/routes-f/stream-snapshot/route.ts b/app/api/routes-f/stream-snapshot/route.ts
new file mode 100644
index 00000000..b77321b5
--- /dev/null
+++ b/app/api/routes-f/stream-snapshot/route.ts
@@ -0,0 +1,99 @@
+import { NextRequest, NextResponse } from "next/server";
+
+interface Snapshot {
+  stream_id: string;
+  playback_id: string;
+  timestamp: number;
+  snapshot_url: string;
+  captured_at: string;
+}
+
+// In-memory store for snapshots, keyed by stream_id
+const snapshotStore = new Map<string, Snapshot[]>();
+
+export async function GET(req: NextRequest) {
+  const { searchParams } = new URL(req.url);
+  const streamId = searchParams.get("stream_id");
+
+  if (!streamId) {
+    return NextResponse.json(
+      { error: "stream_id is required" },
+      { status: 400 }
+    );
+  }
+
+  const snapshots = snapshotStore.get(streamId) || [];
+
+  // Return last 10 snapshots
+  const last10 = snapshots.slice(-10);
+
+  return NextResponse.json({ snapshots: last10 });
+}
+
+export async function POST(req: NextRequest) {
+  let body: {
+    stream_id?: unknown;
+    playback_id?: unknown;
+    timestamp?: unknown;
+  };
+
+  try {
+    body = await req.json();
+  } catch {
+    return NextResponse.json({ error: "Invalid JSON body" }, { status: 400 });
+  }
+
+  const { stream_id, playback_id, timestamp } = body;
+
+  if (!stream_id || typeof stream_id !== "string") {
+    return NextResponse.json(
+      { error: "stream_id is required and must be a string" },
+      { status: 400 }
+    );
+  }
+
+  if (!playback_id || typeof playback_id !== "string") {
+    return NextResponse.json(
+      { error: "playback_id is required and must be a string" },
+      { status: 400 }
+    );
+  }
+
+  // Validate timestamp if provided
+  let ts: number;
+  if (timestamp !== undefined) {
+    if (typeof timestamp !== "number") {
+      return NextResponse.json(
+        { error: "timestamp must be a number" },
+        { status: 400 }
+      );
+    }
+    ts = timestamp;
+  } else {
+    ts = Math.floor(Date.now() / 1000);
+  }
+
+  // Build the Mux thumbnail URL
+  const snapshotUrl = `https://image.mux.com/${playback_id}/thumbnail.jpg?time=${ts}`;
+
+  const snapshot: Snapshot = {
+    stream_id,
+    playback_id,
+    timestamp: ts,
+    snapshot_url: snapshotUrl,
+    captured_at: new Date().toISOString(),
+  };
+
+  // Store snapshot
+  const existing = snapshotStore.get(stream_id) || [];
+  existing.push(snapshot);
+  snapshotStore.set(stream_id, existing);
+
+  return NextResponse.json(
+    {
+      snapshot_url: snapshotUrl,
+      captured_at: snapshot.captured_at,
+    },
+    { status: 201 }
+  );
+}
diff --git a/app/api/routes-f/stream-warmup/__tests__/route.test.ts b/app/api/routes-f/stream-warmup/__tests__/route.test.ts
new file mode 100644
index 00000000..7a7ac53c
--- /dev/null
+++ b/app/api/routes-f/stream-warmup/__tests__/route.test.ts
@@ -0,0 +1,130 @@
+/**
+ * @jest-environment node
+ */
+import { NextRequest } from "next/server";
+import { POST, GET, DELETE } from "../route";
+
+function makeReq(method: string, body?: unknown) {
+  return new NextRequest("http://localhost/api/routes-f/stream-warmup", {
+    method,
+    headers: { "content-type": "application/json" },
+    body: body ? JSON.stringify(body) : undefined,
+  });
+}
+
+describe("POST /api/routes-f/stream-warmup", () => {
+  it("creates warmup state successfully", async () => {
+    const res = await POST(
+      makeReq("POST", {
+        username: "testuser",
+        warmup_message: "Starting soon!",
+        teaser_image_url: "https://example.com/teaser.jpg",
+      })
+    );
+    const body = await res.json();
+
+    expect(res.status).toBe(201);
+    expect(body.warmup_active).toBe(true);
+    expect(body.started_at).toBeDefined();
+    expect(body.warmup_message).toBe("Starting soon!");
+    expect(body.teaser_image_url).toBe("https://example.com/teaser.jpg");
+  });
+
+  it("creates warmup state with minimal fields", async () => {
+    const res = await POST(makeReq("POST", { username: "minimaluser" }));
+    const body = await res.json();
+
+    expect(res.status).toBe(201);
+    expect(body.warmup_active).toBe(true);
+    expect(body.started_at).toBeDefined();
+    expect(body.warmup_message).toBeUndefined();
+    expect(body.teaser_image_url).toBeUndefined();
+  });
+
+  it("rejects missing username", async () => {
+    const res = await POST(
+      makeReq("POST", { warmup_message: "test" })
+    );
+    expect(res.status).toBe(400);
+  });
+
+  it("rejects invalid JSON", async () => {
+    const req = new NextRequest("http://localhost/api/routes-f/stream-warmup", {
+      method: "POST",
+      headers: { "content-type": "application/json" },
+      body: "invalid json",
+    });
+    const res = await POST(req);
+    expect(res.status).toBe(400);
+  });
+});
+
+describe("GET /api/routes-f/stream-warmup", () => {
+  beforeEach(async () => {
+    // Setup: create a warmup state
+    await POST(makeReq("POST", { username: "getuser", warmup_message: "Test" }));
+  });
+
+  it("returns warmup state for existing user", async () => {
+    const req = new NextRequest(
+      "http://localhost/api/routes-f/stream-warmup?username=getuser"
+    );
+    const res = await GET(req);
+    const body = await res.json();
+
+    expect(res.status).toBe(200);
+    expect(body.warmup_active).toBe(true);
+    expect(body.warmup_message).toBe("Test");
+  });
+
+  it("returns 404 for non-existent user", async () => {
+    const req = new NextRequest(
+      "http://localhost/api/routes-f/stream-warmup?username=nonexistent"
+    );
+    const res = await GET(req);
+    expect(res.status).toBe(404);
+  });
+
+  it("returns 400 when username is missing", async () => {
+    const req = new NextRequest("http://localhost/api/routes-f/stream-warmup");
+    const res = await GET(req);
+    expect(res.status).toBe(400);
+  });
+});
+
+describe("DELETE /api/routes-f/stream-warmup", () => {
+  beforeEach(async () => {
+    // Setup: create a warmup state
+    await POST(makeReq("POST", { username: "deleteuser" }));
+  });
+
+  it("clears warmup state successfully", async () => {
+    const res = await DELETE(makeReq("DELETE", { username: "deleteuser" }));
+    const body = await res.json();
+
+    expect(res.status).toBe(200);
+    expect(body.success).toBe(true);
+  });
+
+  it("returns 404 when deleting non-existent user", async () => {
+    const res = await DELETE(
+      makeReq("DELETE", { username: "nonexistent" })
+    );
+    expect(res.status).toBe(404);
+  });
+
+  it("rejects missing username", async () => {
+    const res = await DELETE(makeReq("DELETE", {}));
+    expect(res.status).toBe(400);
+  });
+
+  it("rejects invalid JSON", async () => {
+    const req = new NextRequest("http://localhost/api/routes-f/stream-warmup", {
+      method: "DELETE",
+      headers: { "content-type": "application/json" },
+      body: "invalid json",
+    });
+    const res = await DELETE(req);
+    expect(res.status).toBe(400);
+  });
+});
diff --git a/app/api/routes-f/stream-warmup/route.ts b/app/api/routes-f/stream-warmup/route.ts
new file mode 100644
index 00000000..efa91b1a
--- /dev/null
+++ b/app/api/routes-f/stream-warmup/route.ts
@@ -0,0 +1,113 @@
+import { NextRequest, NextResponse } from "next/server";
+
+// In-memory store keyed by username
+const warmupStore = new Map<
+  string,
+  {
+    warmup_active: boolean;
+    started_at: string;
+    warmup_message?: string;
+    teaser_image_url?: string;
+  }
+>();
+
+export async function GET(req: NextRequest) {
+  const { searchParams } = new URL(req.url);
+  const username = searchParams.get("username");
+
+  if (!username) {
+    return NextResponse.json(
+      { error: "username is required" },
+      { status: 400 }
+    );
+  }
+
+  const warmup = warmupStore.get(username);
+
+  if (!warmup) {
+    return NextResponse.json(
+      { error: "Warmup state not found for user" },
+      { status: 404 }
+    );
+  }
+
+  return NextResponse.json(warmup);
+}
+
+export async function POST(req: NextRequest) {
+  let body: {
+    username?: unknown;
+    warmup_message?: unknown;
+    teaser_image_url?: unknown;
+  };
+
+  try {
+    body = await req.json();
+  } catch {
+    return NextResponse.json({ error: "Invalid JSON body" }, { status: 400 });
+  }
+
+  const { username, warmup_message, teaser_image_url } = body;
+
+  if (!username || typeof username !== "string") {
+    return NextResponse.json(
+      { error: "username is required and must be a string" },
+      { status: 400 }
+    );
+  }
+
+  if (warmup_message !== undefined && typeof warmup_message !== "string") {
+    return NextResponse.json(
+      { error: "warmup_message must be a string" },
+      { status: 400 }
+    );
+  }
+
+  if (teaser_image_url !== undefined && typeof teaser_image_url !== "string") {
+    return NextResponse.json(
+      { error: "teaser_image_url must be a string" },
+      { status: 400 }
+    );
+  }
+
+  const warmupState = {
+    warmup_active: true,
+    started_at: new Date().toISOString(),
+    ...(warmup_message && { warmup_message }),
+    ...(teaser_image_url && { teaser_image_url }),
+  };
+
+  warmupStore.set(username, warmupState);
+
+  return NextResponse.json(warmupState, { status: 201 });
+}
+
+export async function DELETE(req: NextRequest) {
+  let body: { username?: unknown };
+
+  try {
+    body = await req.json();
+  } catch {
+    return NextResponse.json({ error: "Invalid JSON body" }, { status: 400 });
+  }
+
+  const { username } = body;
+
+  if (!username || typeof username !== "string") {
+    return NextResponse.json(
+      { error: "username is required and must be a string" },
+      { status: 400 }
+    );
+  }
+
+  const existed = warmupStore.delete(username);
+
+  if (!existed) {
+    return NextResponse.json(
+      { error: "Warmup state not found for user" },
+      { status: 404 }
+    );
+  }
+
+  return NextResponse.json({ success: true });
+}
diff --git a/app/api/routes-f/stream/category-switch/categories.ts b/app/api/routes-f/stream/category-switch/categories.ts
new file mode 100644
index 00000000..2ecfa0c9
--- /dev/null
+++ b/app/api/routes-f/stream/category-switch/categories.ts
@@ -0,0 +1,22 @@
+export const VALID_CATEGORIES = [
+  "gaming",
+  "music",
+  "irl",
+  "art",
+  "just-chatting",
+  "sports",
+  "education",
+  "technology",
+  "cooking",
+  "fitness",
+  "crypto",
+  "nft",
+  "defi",
+  "other",
+] as const;
+
+export type Category = (typeof VALID_CATEGORIES)[number];
+
+export function isValidCategory(value: string): value is Category {
+  return VALID_CATEGORIES.includes(value as Category);
+}
diff --git a/app/api/routes-f/stream/category-switch/route.ts b/app/api/routes-f/stream/category-switch/route.ts
new file mode 100644
index 00000000..ea1af4e9
--- /dev/null
+++ b/app/api/routes-f/stream/category-switch/route.ts
@@ -0,0 +1,55 @@
+import { NextRequest, NextResponse } from "next/server";
+import { isValidCategory, VALID_CATEGORIES } from "./categories";
+import { addCategorySwitch, getTimeline } from "./store";
+
+export async function POST(req: NextRequest): Promise<NextResponse> {
+  let body: Record<string, unknown>;
+
+  try {
+    body = await req.json();
+  } catch {
+    return NextResponse.json({ error: "Invalid JSON body." }, { status: 400 });
+  }
+
+  const { stream_id, category } = body;
+
+  if (typeof stream_id !== "string" || !stream_id.trim()) {
+    return NextResponse.json(
+      { error: "stream_id is required." },
+      { status: 400 }
+    );
+  }
+
+  if (typeof category !== "string" || !category.trim()) {
+    return NextResponse.json(
+      { error: "category is required." },
+      { status: 400 }
+    );
+  }
+
+  if (!isValidCategory(category)) {
+    return NextResponse.json(
+      {
+        error: `Unknown category: "${category}". Valid categories: ${VALID_CATEGORIES.join(", ")}`,
+      },
+      { status: 400 }
+    );
+  }
+
+  const result = addCategorySwitch(stream_id, category);
+  return NextResponse.json(result);
+}
+
+export async function GET(req: NextRequest): Promise<NextResponse> {
+  const streamId = req.nextUrl.searchParams.get("stream_id");
+
+  if (!streamId) {
+    return NextResponse.json(
+      { error: "stream_id is required." },
+      { status: 400 }
+    );
+  }
+
+  const timeline = getTimeline(streamId);
+  return NextResponse.json({ stream_id: streamId, timeline });
+}
diff --git a/app/api/routes-f/stream/category-switch/store.ts b/app/api/routes-f/stream/category-switch/store.ts
new file mode 100644
index 00000000..a66bb5a1
--- /dev/null
+++ b/app/api/routes-f/stream/category-switch/store.ts
@@ -0,0 +1,28 @@
+import type { CategoryTimelineEntry } from "./types";
+
+export const categoryTimelines = new Map<string, CategoryTimelineEntry[]>();
+
+export function getCurrentCategory(streamId: string): string | undefined {
+  const timeline = categoryTimelines.get(streamId);
+  if (!timeline || timeline.length === 0) return undefined;
+  return timeline[timeline.length - 1].category;
+}
+
+export function addCategorySwitch(
+  streamId: string,
+  category: string
+): { previous_category: string; new_category: string; switched_at: string } {
+  const previous = getCurrentCategory(streamId) ?? "none";
+  const switched_at = new Date().toISOString();
+  const entry: CategoryTimelineEntry = { category, switched_at };
+
+  const timeline = categoryTimelines.get(streamId) ?? [];
+  timeline.push(entry);
+  categoryTimelines.set(streamId, timeline);
+
+  return { previous_category: previous, new_category: category, switched_at };
+}
+
+export function getTimeline(streamId: string): CategoryTimelineEntry[] {
+  return categoryTimelines.get(streamId) ?? [];
+}
diff --git a/app/api/routes-f/stream/category-switch/types.ts b/app/api/routes-f/stream/category-switch/types.ts
new file mode 100644
index 00000000..a9446735
--- /dev/null
+++ b/app/api/routes-f/stream/category-switch/types.ts
@@ -0,0 +1,15 @@
+export interface CategorySwitchRequest {
+  stream_id: string;
+  category: string;
+}
+
+export interface CategorySwitchResponse {
+  previous_category: string;
+  new_category: string;
+  switched_at: string;
+}
+
+export interface CategoryTimelineEntry {
+  category: string;
+  switched_at: string;
+}
diff --git a/app/api/routes-f/stream/chat-timeout/route.ts b/app/api/routes-f/stream/chat-timeout/route.ts
new file mode 100644
index 00000000..49bcad92
--- /dev/null
+++ b/app/api/routes-f/stream/chat-timeout/route.ts
@@ -0,0 +1,100 @@
+import { NextRequest, NextResponse } from "next/server";
+import { applyTimeout, liftTimeout, listActiveTimeouts } from "./store";
+
+const MIN_SECONDS = 1;
+const MAX_SECONDS = 86_400;
+
+export async function POST(req: NextRequest): Promise<NextResponse> {
+  let body: Record<string, unknown>;
+
+  try {
+    body = await req.json();
+  } catch {
+    return NextResponse.json({ error: "Invalid JSON body." }, { status: 400 });
+  }
+
+  const { stream_id, user_id, seconds, reason } = body;
+
+  if (typeof stream_id !== "string" || !stream_id.trim()) {
+    return NextResponse.json(
+      { error: "stream_id is required." },
+      { status: 400 }
+    );
+  }
+  if (typeof user_id !== "string" || !user_id.trim()) {
+    return NextResponse.json(
+      { error: "user_id is required." },
+      { status: 400 }
+    );
+  }
+  if (typeof seconds !== "number" || !Number.isInteger(seconds)) {
+    return NextResponse.json(
+      { error: "seconds must be an integer." },
+      { status: 400 }
+    );
+  }
+  if (seconds < MIN_SECONDS || seconds > MAX_SECONDS) {
+    return NextResponse.json(
+      {
+        error: `seconds must be between ${MIN_SECONDS} and ${MAX_SECONDS}.`,
+      },
+      { status: 400 }
+    );
+  }
+  if (reason !== undefined && typeof reason !== "string") {
+    return NextResponse.json(
+      { error: "reason must be a string." },
+      { status: 400 }
+    );
+  }
+
+  const result = applyTimeout(
+    stream_id as string,
+    user_id as string,
+    seconds as number,
+    reason as string | undefined
+  );
+  return NextResponse.json(result);
+}
+
+export async function GET(req: NextRequest): Promise<NextResponse> {
+  const streamId = req.nextUrl.searchParams.get("stream_id");
+
+  if (!streamId) {
+    return NextResponse.json(
+      { error: "stream_id is required." },
+      { status: 400 }
+    );
+  }
+
+  const timeouts = listActiveTimeouts(streamId);
+  return NextResponse.json({ stream_id: streamId, timeouts });
+}
+
+export async function DELETE(req: NextRequest): Promise<NextResponse> {
+  let body: Record<string, unknown>;
+
+  try {
+    body = await req.json();
+  } catch {
+    return NextResponse.json({ error: "Invalid JSON body." }, { status: 400 });
+  }
+
+  const { stream_id, user_id } = body;
+
+  if (typeof stream_id !== "string" || !stream_id.trim()) {
+    return NextResponse.json(
+      { error: "stream_id is required." },
+      { status: 400 }
+    );
+  }
+  if (typeof user_id !== "string" || !user_id.trim()) {
+    return NextResponse.json(
+      { error: "user_id is required." },
+      { status: 400 }
+    );
+  }
+
+  const lifted = liftTimeout(stream_id, user_id);
+  return NextResponse.json({ lifted });
+}
diff --git a/app/api/routes-f/stream/chat-timeout/store.ts b/app/api/routes-f/stream/chat-timeout/store.ts
new file mode 100644
index 00000000..92e7b009
--- /dev/null
+++ b/app/api/routes-f/stream/chat-timeout/store.ts
@@ -0,0 +1,50 @@
+import type { TimeoutEntry, TimeoutListItem } from "./types";
+
+// Key: "stream_id:user_id"
+export const timeoutStore = new Map<string, TimeoutEntry>();
+
+function key(stream_id: string, user_id: string): string {
+  return `${stream_id}:${user_id}`;
+}
+
+export function applyTimeout(
+  stream_id: string,
+  user_id: string,
+  seconds: number,
+  reason?: string
+): { expires_at: string } {
+  const expires_at = new Date(Date.now() + seconds * 1000).toISOString();
+  const entry: TimeoutEntry = { stream_id, user_id, reason, expires_at };
+  timeoutStore.set(key(stream_id, user_id), entry);
+  return { expires_at };
+}
+
+export function liftTimeout(stream_id: string, user_id: string): boolean {
+  return timeoutStore.delete(key(stream_id, user_id));
+}
+
+export function listActiveTimeouts(stream_id: string): TimeoutListItem[] {
+  const now = Date.now();
+  const results: TimeoutListItem[] = [];
+
+  for (const [k, entry] of timeoutStore) {
+    if (entry.stream_id !== stream_id) continue;
+
+    const expiresMs = new Date(entry.expires_at).getTime();
+    const remaining = Math.ceil((expiresMs - now) / 1000);
+
+    if (remaining <= 0) {
+      timeoutStore.delete(k);
+      continue;
+    }
+
+    results.push({
+      user_id: entry.user_id,
+      reason: entry.reason,
+      expires_at: entry.expires_at,
+      seconds_remaining: remaining,
+    });
+  }
+
+  return results;
+}
diff --git a/app/api/routes-f/stream/chat-timeout/types.ts b/app/api/routes-f/stream/chat-timeout/types.ts
new file mode 100644
index 00000000..07883066
--- /dev/null
+++ b/app/api/routes-f/stream/chat-timeout/types.ts
@@ -0,0 +1,13 @@
+export interface TimeoutEntry {
+  stream_id: string;
+  user_id: string;
+  reason?: string;
+  expires_at: string;
+}
+
+export interface TimeoutListItem {
+  user_id: string;
+  reason?: string;
+  expires_at: string;
+  seconds_remaining: number;
+}
diff --git a/app/api/routes-f/stream/chat/route.ts b/app/api/routes-f/stream/chat/route.ts
new file mode 100644
index 00000000..35626eda
--- /dev/null
+++ b/app/api/routes-f/stream/chat/route.ts
@@ -0,0 +1,61 @@
+import { NextRequest, NextResponse } from 'next/server';
+import { validateBody } from '../../_lib/validate';
+import { z } from 'zod';
+import { setChatRestriction, getChatRestriction, disableChatRestriction, validateMinFollowMinutes } from './utils';
+import type { ChatRestrictionRequestBody, ChatRestrictionResponse, ChatRestrictionState } from './types';
+
+const chatRestrictionSchema = z.object({
+  stream_id: z.string().min(1),
+  min_follow_minutes: z.number().optional(),
+});
+
+export async function POST(req: NextRequest): Promise<NextResponse> {
+  const validation = await validateBody(req, chatRestrictionSchema);
+  if (validation instanceof NextResponse) {
+    return validation;
+  }
+
+  const body = validation.data as ChatRestrictionRequestBody;
+  const minFollowMinutes = body.min_follow_minutes ?? 10;
+  
+  const validationCheck = validateMinFollowMinutes(minFollowMinutes);
+  if (!validationCheck.valid) {
+    return NextResponse.json({ error: validationCheck.error }, { status: 400 });
+  }
+
+  const data = setChatRestriction(body.stream_id, minFollowMinutes);
+  return NextResponse.json({
+    enabled: data.enabled,
+    min_follow_minutes: data.min_follow_minutes
+  } as ChatRestrictionResponse);
+}
+
+export async function DELETE(req: NextRequest): Promise<NextResponse> {
+  const streamId = new URL(req.url).searchParams.get('stream_id');
+  
+  if (!streamId) {
+    return NextResponse.json({ error: 'stream_id is required' }, { status: 400 });
+  }
+
+  disableChatRestriction(streamId);
+  return NextResponse.json({ enabled: false });
+}
+
+export async function GET(req: NextRequest): Promise<NextResponse> {
+  const streamId = new URL(req.url).searchParams.get('stream_id');
+  
+  if (!streamId) {
+    return NextResponse.json({ error: 'stream_id is required' }, { status: 400 });
+  }
+
+  const data = getChatRestriction(streamId);
+  
+  if (!data) {
+    return NextResponse.json({ enabled: false } as ChatRestrictionState);
+  }
+
+  return NextResponse.json({
+    enabled: data.enabled,
+    min_follow_minutes: data.min_follow_minutes
+  } as ChatRestrictionState);
+}
diff --git a/app/api/routes-f/stream/chat/slow-mode/__tests__/route.test.ts b/app/api/routes-f/stream/chat/slow-mode/__tests__/route.test.ts
new file mode 100644
index 00000000..4f2af4b0
--- /dev/null
+++ b/app/api/routes-f/stream/chat/slow-mode/__tests__/route.test.ts
@@ -0,0 +1,544 @@
+/**
+ * @jest-environment node
+ */
+import { NextRequest } from "next/server";
+import { POST, DELETE, GET } from "../route";
+
+function makeReq(
+  method: string,
+  body?: unknown,
+  url: string = "http://localhost/api/routes-f/stream/chat/slow-mode"
+) {
+  return new NextRequest(url, {
+    method,
+    headers: { "content-type": "application/json" },
+    body: body ? JSON.stringify(body) : undefined,
+  });
+}
+
+describe("POST /api/routes-f/stream/chat/slow-mode", () => {
+  it("enables slow mode with valid interval", async () => {
+    const res = await POST(
+      makeReq("POST", {
+        stream_id: "stream123",
+        interval_seconds: 5,
+      })
+    );
+    const body = await res.json();
+
+    expect(res.status).toBe(200);
+    expect(body.enabled).toBe(true);
+    expect(body.interval_seconds).toBe(5);
+  });
+
+  it("enables slow mode with minimum interval (2 seconds)", async () => {
+    const res = await POST(
+      makeReq("POST", {
+        stream_id: "stream456",
+        interval_seconds: 2,
+      })
+    );
+    const body = await res.json();
+
+    expect(res.status).toBe(200);
+    expect(body.enabled).toBe(true);
+    expect(body.interval_seconds).toBe(2);
+  });
+
+  it("enables slow mode with maximum interval (300 seconds)", async () => {
+    const res = await POST(
+      makeReq("POST", {
+        stream_id: "stream789",
+        interval_seconds: 300,
+      })
+    );
+    const body = await res.json();
+
+    expect(res.status).toBe(200);
+    expect(body.enabled).toBe(true);
+    expect(body.interval_seconds).toBe(300);
+  });
+
+  it("allows updating interval to a different value", async () => {
+    const streamId = "stream-update";
+
+    // First enable with 5 seconds
+    await POST(
+      makeReq("POST", {
+        stream_id: streamId,
+        interval_seconds: 5,
+      })
+    );
+
+    // Update to 10 seconds
+    const res = await POST(
+      makeReq("POST", {
+        stream_id: streamId,
+        interval_seconds: 10,
+      })
+    );
+    const body = await res.json();
+
+    expect(res.status).toBe(200);
+    expect(body.interval_seconds).toBe(10);
+  });
+
+  it("rejects interval below minimum (< 2)", async () => {
+    const res = await POST(
+      makeReq("POST", {
+        stream_id: "stream123",
+        interval_seconds: 1,
+      })
+    );
+    expect(res.status).toBe(400);
+    const body = await res.json();
+    expect(body.error).toContain("at least 2");
+  });
+
+  it("rejects interval above maximum (> 300)", async () => {
+    const res = await POST(
+      makeReq("POST", {
+        stream_id: "stream123",
+        interval_seconds: 301,
+      })
+    );
+    expect(res.status).toBe(400);
+    const body = await res.json();
+    expect(body.error).toContain("at most 300");
+  });
+
+  it("rejects non-integer interval", async () => {
+    const res = await POST(
+      makeReq("POST", {
+        stream_id: "stream123",
+        interval_seconds: 5.5,
+      })
+    );
+    expect(res.status).toBe(400);
+    const body = await res.json();
+    expect(body.error).toContain("integer");
+  });
+
+  it("rejects NaN interval", async () => {
+    const res = await POST(
+      makeReq("POST", {
+        stream_id: "stream123",
+        interval_seconds: NaN,
+      })
+    );
+    expect(res.status).toBe(400);
+  });
+
+  it("rejects non-numeric interval", async () => {
+    const res = await POST(
+      makeReq("POST", {
+        stream_id: "stream123",
+        interval_seconds: "not-a-number",
+      })
+    );
+    expect(res.status).toBe(400);
+  });
+
+  it("rejects missing stream_id", async () => {
+    const res = await POST(
+      makeReq("POST", {
+        interval_seconds: 5,
+      })
+    );
+    expect(res.status).toBe(400);
+  });
+
+  it("rejects empty stream_id", async () => {
+    const res = await POST(
+      makeReq("POST", {
+        stream_id: "",
+        interval_seconds: 5,
+      })
+    );
+    expect(res.status).toBe(400);
+  });
+
+  it("rejects missing interval_seconds", async () => {
+    const res = await POST(
+      makeReq("POST", {
+        stream_id: "stream123",
+      })
+    );
+    expect(res.status).toBe(400);
+  });
+
+  it("rejects invalid JSON", async () => {
+    const req = new NextRequest(
+      "http://localhost/api/routes-f/stream/chat/slow-mode",
+      {
+        method: "POST",
+        headers: { "content-type": "application/json" },
+        body: "invalid json",
+      }
+    );
+    const res = await POST(req);
+    expect(res.status).toBe(400);
+  });
+});
+
+describe("DELETE /api/routes-f/stream/chat/slow-mode", () => {
+  it("disables slow mode", async () => {
+    // First enable
+    await POST(
+      makeReq("POST", {
+        stream_id: "deletestream1",
+        interval_seconds: 10,
+      })
+    );
+
+    // Then delete
+    const res = await DELETE(
+      makeReq(
+        "DELETE",
+        undefined,
+        "http://localhost/api/routes-f/stream/chat/slow-mode?stream_id=deletestream1"
+      )
+    );
+    const body = await res.json();
+
+    expect(res.status).toBe(200);
+    expect(body.enabled).toBe(false);
+  });
+
+  it("disables even if not previously enabled", async () => {
+    const res = await DELETE(
+      makeReq(
+        "DELETE",
+        undefined,
+        "http://localhost/api/routes-f/stream/chat/slow-mode?stream_id=neverenabled"
+      )
+    );
+
+    expect(res.status).toBe(200);
+    expect((await res.json()).enabled).toBe(false);
+  });
+
+  it("returns 400 when stream_id is missing", async () => {
+    const res = await DELETE(makeReq("DELETE", undefined));
+    expect(res.status).toBe(400);
+  });
+});
+
+describe("GET /api/routes-f/stream/chat/slow-mode", () => {
+  it("returns enabled state with interval when set", async () => {
+    // First enable
+    await POST(
+      makeReq("POST", {
+        stream_id: "getstream1",
+        interval_seconds: 15,
+      })
+    );
+
+    // Then get state
+    const req = makeReq(
+      "GET",
+      undefined,
+      "http://localhost/api/routes-f/stream/chat/slow-mode?stream_id=getstream1"
+    );
+    const res = await GET(req);
+    const body = await res.json();
+
+    expect(res.status).toBe(200);
+    expect(body.enabled).toBe(true);
+    expect(body.interval_seconds).toBe(15);
+  });
+
+  it("returns disabled state for stream without slow mode", async () => {
+    const req = makeReq(
+      "GET",
+      undefined,
+      "http://localhost/api/routes-f/stream/chat/slow-mode?stream_id=notconfigured"
+    );
+    const res = await GET(req);
+    const body = await res.json();
+
+    expect(res.status).toBe(200);
+    expect(body.enabled).toBe(false);
+    expect(body.interval_seconds).toBeUndefined();
+  });
+
+  it("returns 400 when stream_id is missing", async () => {
+    const req = makeReq("GET", undefined);
+    const res = await GET(req);
+    expect(res.status).toBe(400);
+  });
+
+  it("reflects changes after multiple POST calls", async () => {
+    const streamId = "getstream3";
+
+    // Enable with 5 seconds
+    await POST(
+      makeReq("POST", {
+        stream_id: streamId,
+        interval_seconds: 5,
+      })
+    );
+
+    let req = makeReq(
+      "GET",
+      undefined,
+      `http://localhost/api/routes-f/stream/chat/slow-mode?stream_id=${streamId}`
+    );
+    let res = await GET(req);
+    let body = await res.json();
+
+    expect(body.enabled).toBe(true);
+    expect(body.interval_seconds).toBe(5);
+
+    // Update to 20 seconds
+    await POST(
+      makeReq("POST", {
+        stream_id: streamId,
+        interval_seconds: 20,
+      })
+    );
+
+    req = makeReq(
+      "GET",
+      undefined,
+      `http://localhost/api/routes-f/stream/chat/slow-mode?stream_id=${streamId}`
+    );
+    res = await GET(req);
+    body = await res.json();
+
+    expect(body.enabled).toBe(true);
+    expect(body.interval_seconds).toBe(20);
+
+    // Disable
+    await DELETE(
+      makeReq(
+        "DELETE",
+        undefined,
+        `http://localhost/api/routes-f/stream/chat/slow-mode?stream_id=${streamId}`
+      )
+    );
+
+    req = makeReq(
+      "GET",
+      undefined,
+      `http://localhost/api/routes-f/stream/chat/slow-mode?stream_id=${streamId}`
+    );
+    res = await GET(req);
+    body = await res.json();
+
+    expect(body.enabled).toBe(false);
+    expect(body.interval_seconds).toBeUndefined();
+  });
+});
+
+describe("Integration: Full workflow", () => {
+  it("completes full lifecycle: enable, verify, update, disable", async () => {
+    const streamId = "lifecycle-stream";
+
+    // 1. Enable slow mode with 10 second interval
+    let res = await POST(
+      makeReq("POST", {
+        stream_id: streamId,
+        interval_seconds: 10,
+      })
+    );
+    let body = await res.json();
+    expect(res.status).toBe(200);
+    expect(body.enabled).toBe(true);
+    expect(body.interval_seconds).toBe(10);
+
+    // 2. Verify GET returns same state
+    res = await GET(
+      makeReq(
+        "GET",
+        undefined,
+        `http://localhost/api/routes-f/stream/chat/slow-mode?stream_id=${streamId}`
+      )
+    );
+    body = await res.json();
+    expect(body.enabled).toBe(true);
+    expect(body.interval_seconds).toBe(10);
+
+    // 3. Update to more restrictive interval (2 seconds)
+    res = await POST(
+      makeReq("POST", {
+        stream_id: streamId,
+        interval_seconds: 2,
+      })
+    );
+    body = await res.json();
+    expect(body.interval_seconds).toBe(2);
+
+    // 4. Verify update is applied
+    res = await GET(
+      makeReq(
+        "GET",
+        undefined,
+        `http://localhost/api/routes-f/stream/chat/slow-mode?stream_id=${streamId}`
+      )
+    );
+    body = await res.json();
+    expect(body.interval_seconds).toBe(2);
+
+    // 5. Update to more permissive interval (300 seconds)
+    res = await POST(
+      makeReq("POST", {
+        stream_id: streamId,
+        interval_seconds: 300,
+      })
+    );
+    body = await res.json();
+    expect(body.interval_seconds).toBe(300);
+
+    // 6. Disable slow mode
+    res = await DELETE(
+      makeReq(
+        "DELETE",
+        undefined,
+        `http://localhost/api/routes-f/stream/chat/slow-mode?stream_id=${streamId}`
+      )
+    );
+    body = await res.json();
+    expect(body.enabled).toBe(false);
+
+    // 7. Verify disabled
+    res = await GET(
+      makeReq(
+        "GET",
+        undefined,
+        `http://localhost/api/routes-f/stream/chat/slow-mode?stream_id=${streamId}`
+      )
+    );
+    body = await res.json();
+    expect(body.enabled).toBe(false);
+  });
+
+  it("handles multiple streams independently with different intervals", async () => {
+    const stream1 = "multi-stream-1";
+    const stream2 = "multi-stream-2";
+    const stream3 = "multi-stream-3";
+
+    // Setup stream 1: 5 second interval
+    await POST(
+      makeReq("POST", {
+        stream_id: stream1,
+        interval_seconds: 5,
+      })
+    );
+
+    // Setup stream 2: 20 second interval
+    await POST(
+      makeReq("POST", {
+        stream_id: stream2,
+        interval_seconds: 20,
+      })
+    );
+
+    // Stream 3: no slow mode
+
+    // Verify stream 1
+    let res = await GET(
+      makeReq(
+        "GET",
+        undefined,
+        `http://localhost/api/routes-f/stream/chat/slow-mode?stream_id=${stream1}`
+      )
+    );
+    let body = await res.json();
+    expect(body.enabled).toBe(true);
+    expect(body.interval_seconds).toBe(5);
+
+    // Verify stream 2
+    res = await GET(
+      makeReq(
+        "GET",
+        undefined,
+        `http://localhost/api/routes-f/stream/chat/slow-mode?stream_id=${stream2}`
+      )
+    );
+    body = await res.json();
+    expect(body.enabled).toBe(true);
+    expect(body.interval_seconds).toBe(20);
+
+    // Verify stream 3 is disabled
+    res = await GET(
+      makeReq(
+        "GET",
+        undefined,
+        `http://localhost/api/routes-f/stream/chat/slow-mode?stream_id=${stream3}`
+      )
+    );
+    body = await res.json();
+    expect(body.enabled).toBe(false);
+
+    // Disable stream 1
+    await DELETE(
+      makeReq(
+        "DELETE",
+        undefined,
+        `http://localhost/api/routes-f/stream/chat/slow-mode?stream_id=${stream1}`
+      )
+    );
+
+    // Verify stream 1 is disabled
+    res = await GET(
+      makeReq(
+        "GET",
+        undefined,
+        `http://localhost/api/routes-f/stream/chat/slow-mode?stream_id=${stream1}`
+      )
+    );
+    body = await res.json();
+    expect(body.enabled).toBe(false);
+
+    // Verify stream 2 is still enabled with original interval
+    res = await GET(
+      makeReq(
+        "GET",
+        undefined,
+        `http://localhost/api/routes-f/stream/chat/slow-mode?stream_id=${stream2}`
+      )
+    );
+    body = await res.json();
+    expect(body.enabled).toBe(true);
+    expect(body.interval_seconds).toBe(20);
+  });
+
+  it("validates boundary intervals: 2 and 300", async () => {
+    // Test minimum (2)
+    let res = await POST(
+      makeReq("POST", {
+        stream_id: "boundary1",
+        interval_seconds: 2,
+      })
+    );
+    expect(res.status).toBe(200);
+
+    // Test maximum (300)
+    res = await POST(
+      makeReq("POST", {
+        stream_id: "boundary2",
+        interval_seconds: 300,
+      })
+    );
+    expect(res.status).toBe(200);
+
+    // Test just below minimum (1)
+    res = await POST(
+      makeReq("POST", {
+        stream_id: "boundary3",
+        interval_seconds: 1,
+      })
+    );
+    expect(res.status).toBe(400);
+
+    // Test just above maximum (301)
+    res = await POST(
+      makeReq("POST", {
+        stream_id: "boundary4",
+        interval_seconds: 301,
+      })
+    );
+    expect(res.status).toBe(400);
+  });
+});
diff --git a/app/api/routes-f/stream/chat/slow-mode/route.ts b/app/api/routes-f/stream/chat/slow-mode/route.ts
new file mode 100644
index 00000000..df53ab52
--- /dev/null
+++ b/app/api/routes-f/stream/chat/slow-mode/route.ts
@@ -0,0 +1,78 @@
+import { NextRequest, NextResponse } from "next/server";
+import { validateBody } from "../../_lib/validate";
+import { z } from "zod";
+import {
+  setSlowMode,
+  getSlowModeState,
+  disableSlowMode,
+  validateInterval,
+} from "./utils";
+import type {
+  SlowModeRequestBody,
+  SlowModeResponse,
+  SlowModeState,
+} from "./types";
+
+const slowModeSchema = z.object({
+  stream_id: z.string().min(1, "stream_id must not be empty"),
+  interval_seconds: z.number(),
+});
+
+export async function POST(req: NextRequest): Promise<NextResponse> {
+  const validation = await validateBody(req, slowModeSchema);
+  if (validation instanceof NextResponse) {
+    return validation;
+  }
+
+  const body = validation.data as SlowModeRequestBody;
+
+  const intervalValidation = validateInterval(body.interval_seconds);
+  if (!intervalValidation.valid) {
+    return NextResponse.json(
+      { error: intervalValidation.error },
+      { status: 400 }
+    );
+  }
+
+  const data = setSlowMode(body.stream_id, body.interval_seconds);
+  return NextResponse.json({
+    enabled: data.enabled,
+    interval_seconds: data.interval_seconds,
+  } as SlowModeResponse);
+}
+
+export async function DELETE(req: NextRequest): Promise<NextResponse> {
+  const streamId = new URL(req.url).searchParams.get("stream_id");
+
+  if (!streamId) {
+    return NextResponse.json(
+      { error: "stream_id is required" },
+      { status: 400 }
+    );
+  }
+
+  disableSlowMode(streamId);
+  return NextResponse.json({ enabled: false });
+}
+
+export async function GET(req: NextRequest): Promise<NextResponse> {
+  const streamId = new URL(req.url).searchParams.get("stream_id");
+
+  if (!streamId) {
+    return NextResponse.json(
+      { error: "stream_id is required" },
+      { status: 400 }
+    );
+  }
+
+  const data = getSlowModeState(streamId);
+
+  if (!data) {
+    return NextResponse.json({ enabled: false } as SlowModeState);
+  }
+
+  return NextResponse.json({
+    enabled: data.enabled,
+    interval_seconds: data.interval_seconds,
+  } as SlowModeState);
+}
diff --git a/app/api/routes-f/stream/chat/slow-mode/types.ts b/app/api/routes-f/stream/chat/slow-mode/types.ts
new file mode 100644
index 00000000..b546d67a
--- /dev/null
+++ b/app/api/routes-f/stream/chat/slow-mode/types.ts
@@ -0,0 +1,19 @@
+export interface SlowModeRequestBody {
+  stream_id: string;
+  interval_seconds: number;
+}
+
+export interface SlowModeResponse {
+  enabled: true;
+  interval_seconds: number;
+}
+
+export interface SlowModeState {
+  enabled: boolean;
+  interval_seconds?: number;
+}
+
+export interface SlowModeData {
+  enabled: boolean;
+  interval_seconds: number;
+}
diff --git a/app/api/routes-f/stream/chat/slow-mode/utils.ts b/app/api/routes-f/stream/chat/slow-mode/utils.ts
new file mode 100644
index 00000000..9a764858
--- /dev/null
+++ b/app/api/routes-f/stream/chat/slow-mode/utils.ts
@@ -0,0 +1,62 @@
+import type { SlowModeData } from "./types";
+
+export const slowModeStore = new Map<string, SlowModeData>();
+
+const INTERVAL_MIN = 2;
+const INTERVAL_MAX = 300;
+
+export function getSlowModeState(streamId: string): SlowModeData | undefined {
+  return slowModeStore.get(streamId);
+}
+
+export function setSlowMode(
+  streamId: string,
+  intervalSeconds: number
+): SlowModeData {
+  const data: SlowModeData = {
+    enabled: true,
+    interval_seconds: intervalSeconds,
+  };
+  slowModeStore.set(streamId, data);
+  return data;
+}
+
+export function disableSlowMode(streamId: string): void {
+  slowModeStore.delete(streamId);
+}
+
+export function validateInterval(interval: number): {
+  valid: boolean;
+  error?: string;
+} {
+  if (typeof interval !== "number") {
+    return { valid: false, error: "interval_seconds must be a number" };
+  }
+
+  if (isNaN(interval)) {
+    return { valid: false, error: "interval_seconds must be a valid number" };
+  }
+
+  if (!Number.isInteger(interval)) {
+    return {
+      valid: false,
+      error: "interval_seconds must be an integer",
+    };
+  }
+
+  if (interval < INTERVAL_MIN) {
+    return {
+      valid: false,
+      error: `interval_seconds must be at least ${INTERVAL_MIN} seconds`,
+    };
+  }
+
+  if (interval > INTERVAL_MAX) {
+    return {
+      valid: false,
+      error: `interval_seconds must be at most ${INTERVAL_MAX} seconds`,
+    };
+  }
+
+  return { valid: true };
+}
diff --git a/app/api/routes-f/stream/chat/subscribers-only/__tests__/route.test.ts b/app/api/routes-f/stream/chat/subscribers-only/__tests__/route.test.ts
new file mode 100644
index 00000000..63d22e62
--- /dev/null
+++ b/app/api/routes-f/stream/chat/subscribers-only/__tests__/route.test.ts
@@ -0,0 +1,486 @@
+/**
+ * @jest-environment node
+ */
+import { NextRequest } from "next/server";
+import { POST, DELETE, GET } from "../route";
+
+function makeReq(
+  method: string,
+  body?: unknown,
+  url: string = "http://localhost/api/routes-f/stream/chat/subscribers-only"
+) {
+  return new NextRequest(url, {
+    method,
+    headers: { "content-type": "application/json" },
+    body: body ? JSON.stringify(body) : undefined,
+  });
+}
+
+describe("POST /api/routes-f/stream/chat/subscribers-only", () => {
+  it("enables subscribers-only restriction without tier", async () => {
+    const res = await POST(
+      makeReq("POST", {
+        stream_id: "stream123",
+      })
+    );
+    const body = await res.json();
+
+    expect(res.status).toBe(200);
+    expect(body.enabled).toBe(true);
+    expect(body.tier_id).toBeUndefined();
+  });
+
+  it("enables subscribers-only restriction with tier restriction", async () => {
+    const res = await POST(
+      makeReq("POST", {
+        stream_id: "stream456",
+        tier_id: "gold",
+      })
+    );
+    const body = await res.json();
+
+    expect(res.status).toBe(200);
+    expect(body.enabled).toBe(true);
+    expect(body.tier_id).toBe("gold");
+  });
+
+  it("allows updating restriction with new tier", async () => {
+    // First enable without tier
+    await POST(
+      makeReq("POST", {
+        stream_id: "stream789",
+      })
+    );
+
+    // Then enable with a tier
+    const res = await POST(
+      makeReq("POST", {
+        stream_id: "stream789",
+        tier_id: "platinum",
+      })
+    );
+    const body = await res.json();
+
+    expect(res.status).toBe(200);
+    expect(body.enabled).toBe(true);
+    expect(body.tier_id).toBe("platinum");
+  });
+
+  it("allows updating tier restriction to a different tier", async () => {
+    // First enable with a tier
+    await POST(
+      makeReq("POST", {
+        stream_id: "stream999",
+        tier_id: "silver",
+      })
+    );
+
+    // Then update to different tier
+    const res = await POST(
+      makeReq("POST", {
+        stream_id: "stream999",
+        tier_id: "gold",
+      })
+    );
+    const body = await res.json();
+
+    expect(res.status).toBe(200);
+    expect(body.tier_id).toBe("gold");
+  });
+
+  it("rejects missing stream_id", async () => {
+    const res = await POST(
+      makeReq("POST", {
+        tier_id: "gold",
+      })
+    );
+    expect(res.status).toBe(400);
+  });
+
+  it("rejects empty stream_id", async () => {
+    const res = await POST(
+      makeReq("POST", {
+        stream_id: "",
+        tier_id: "gold",
+      })
+    );
+    expect(res.status).toBe(400);
+  });
+
+  it("rejects empty tier_id", async () => {
+    const res = await POST(
+      makeReq("POST", {
+        stream_id: "stream123",
+        tier_id: "",
+      })
+    );
+    expect(res.status).toBe(400);
+  });
+
+  it("rejects tier_id longer than 100 characters", async () => {
+    const longTierId = "a".repeat(101);
+    const res = await POST(
+      makeReq("POST", {
+        stream_id: "stream123",
+        tier_id: longTierId,
+      })
+    );
+    expect(res.status).toBe(400);
+  });
+
+  it("allows tier_id of exactly 100 characters", async () => {
+    const tierId = "a".repeat(100);
+    const res = await POST(
+      makeReq("POST", {
+        stream_id: "stream123",
+        tier_id: tierId,
+      })
+    );
+    expect(res.status).toBe(200);
+    const body = await res.json();
+    expect(body.tier_id).toBe(tierId);
+  });
+
+  it("rejects invalid JSON", async () => {
+    const req = new NextRequest(
+      "http://localhost/api/routes-f/stream/chat/subscribers-only",
+      {
+        method: "POST",
+        headers: { "content-type": "application/json" },
+        body: "invalid json",
+      }
+    );
+    const res = await POST(req);
+    expect(res.status).toBe(400);
+  });
+
+  it("rejects non-string tier_id", async () => {
+    const res = await POST(
+      makeReq("POST", {
+        stream_id: "stream123",
+        tier_id: 123,
+      })
+    );
+    expect(res.status).toBe(400);
+  });
+});
+
+describe("DELETE /api/routes-f/stream/chat/subscribers-only", () => {
+  it("disables subscribers-only restriction", async () => {
+    // First enable
+    await POST(
+      makeReq("POST", {
+        stream_id: "deletestream1",
+        tier_id: "gold",
+      })
+    );
+
+    // Then delete
+    const res = await DELETE(
+      makeReq(
+        "DELETE",
+        undefined,
+        "http://localhost/api/routes-f/stream/chat/subscribers-only?stream_id=deletestream1"
+      )
+    );
+    const body = await res.json();
+
+    expect(res.status).toBe(200);
+    expect(body.enabled).toBe(false);
+  });
+
+  it("disables even if not previously enabled", async () => {
+    const res = await DELETE(
+      makeReq(
+        "DELETE",
+        undefined,
+        "http://localhost/api/routes-f/stream/chat/subscribers-only?stream_id=neverenabled"
+      )
+    );
+
+    expect(res.status).toBe(200);
+    expect((await res.json()).enabled).toBe(false);
+  });
+
+  it("returns 400 when stream_id is missing", async () => {
+    const res = await DELETE(makeReq("DELETE", undefined));
+    expect(res.status).toBe(400);
+  });
+});
+
+describe("GET /api/routes-f/stream/chat/subscribers-only", () => {
+  it("returns enabled state with tier_id when set without tier", async () => {
+    // First enable without tier
+    await POST(
+      makeReq("POST", {
+        stream_id: "getstream1",
+      })
+    );
+
+    // Then get state
+    const req = makeReq(
+      "GET",
+      undefined,
+      "http://localhost/api/routes-f/stream/chat/subscribers-only?stream_id=getstream1"
+    );
+    const res = await GET(req);
+    const body = await res.json();
+
+    expect(res.status).toBe(200);
+    expect(body.enabled).toBe(true);
+    expect(body.tier_id).toBeUndefined();
+  });
+
+  it("returns enabled state with tier_id when set with tier", async () => {
+    // First enable with tier
+    await POST(
+      makeReq("POST", {
+        stream_id: "getstream2",
+        tier_id: "platinum",
+      })
+    );
+
+    // Then get state
+    const req = makeReq(
+      "GET",
+      undefined,
+      "http://localhost/api/routes-f/stream/chat/subscribers-only?stream_id=getstream2"
+    );
+    const res = await GET(req);
+    const body = await res.json();
+
+    expect(res.status).toBe(200);
+    expect(body.enabled).toBe(true);
+    expect(body.tier_id).toBe("platinum");
+  });
+
+  it("returns disabled state for stream without restriction", async () => {
+    const req = makeReq(
+      "GET",
+      undefined,
+      "http://localhost/api/routes-f/stream/chat/subscribers-only?stream_id=notconfigured"
+    );
+    const res = await GET(req);
+    const body = await res.json();
+
+    expect(res.status).toBe(200);
+    expect(body.enabled).toBe(false);
+    expect(body.tier_id).toBeUndefined();
+  });
+
+  it("returns 400 when stream_id is missing", async () => {
+    const req = makeReq("GET", undefined);
+    const res = await GET(req);
+    expect(res.status).toBe(400);
+  });
+
+  it("reflects changes after multiple POST calls", async () => {
+    const streamId = "getstream3";
+
+    // Enable without tier
+    await POST(
+      makeReq("POST", {
+        stream_id: streamId,
+      })
+    );
+
+    let req = makeReq(
+      "GET",
+      undefined,
+      `http://localhost/api/routes-f/stream/chat/subscribers-only?stream_id=${streamId}`
+    );
+    let res = await GET(req);
+    let body = await res.json();
+
+    expect(body.enabled).toBe(true);
+    expect(body.tier_id).toBeUndefined();
+
+    // Update with tier
+    await POST(
+      makeReq("POST", {
+        stream_id: streamId,
+        tier_id: "silver",
+      })
+    );
+
+    req = makeReq(
+      "GET",
+      undefined,
+      `http://localhost/api/routes-f/stream/chat/subscribers-only?stream_id=${streamId}`
+    );
+    res = await GET(req);
+    body = await res.json();
+
+    expect(body.enabled).toBe(true);
+    expect(body.tier_id).toBe("silver");
+
+    // Disable
+    await DELETE(
+      makeReq(
+        "DELETE",
+        undefined,
+        `http://localhost/api/routes-f/stream/chat/subscribers-only?stream_id=${streamId}`
+      )
+    );
+
+    req = makeReq(
+      "GET",
+      undefined,
+      `http://localhost/api/routes-f/stream/chat/subscribers-only?stream_id=${streamId}`
+    );
+    res = await GET(req);
+    body = await res.json();
+
+    expect(body.enabled).toBe(false);
+    expect(body.tier_id).toBeUndefined();
+  });
+});
+
+describe("Integration: Full workflow", () => {
+  it("completes full lifecycle: enable, verify, update, disable", async () => {
+    const streamId = "lifecycle-stream";
+
+    // 1. Enable subscribers-only without tier
+    let res = await POST(
+      makeReq("POST", {
+        stream_id: streamId,
+      })
+    );
+    let body = await res.json();
+    expect(res.status).toBe(200);
+    expect(body.enabled).toBe(true);
+    expect(body.tier_id).toBeUndefined();
+
+    // 2. Verify GET returns same state
+    res = await GET(
+      makeReq(
+        "GET",
+        undefined,
+        `http://localhost/api/routes-f/stream/chat/subscribers-only?stream_id=${streamId}`
+      )
+    );
+    body = await res.json();
+    expect(body.enabled).toBe(true);
+    expect(body.tier_id).toBeUndefined();
+
+    // 3. Update to restrict to specific tier
+    res = await POST(
+      makeReq("POST", {
+        stream_id: streamId,
+        tier_id: "vip",
+      })
+    );
+    body = await res.json();
+    expect(body.enabled).toBe(true);
+    expect(body.tier_id).toBe("vip");
+
+    // 4. Verify tier restriction is applied
+    res = await GET(
+      makeReq(
+        "GET",
+        undefined,
+        `http://localhost/api/routes-f/stream/chat/subscribers-only?stream_id=${streamId}`
+      )
+    );
+    body = await res.json();
+    expect(body.tier_id).toBe("vip");
+
+    // 5. Disable restriction
+    res = await DELETE(
+      makeReq(
+        "DELETE",
+        undefined,
+        `http://localhost/api/routes-f/stream/chat/subscribers-only?stream_id=${streamId}`
+      )
+    );
+    body = await res.json();
+    expect(body.enabled).toBe(false);
+
+    // 6. Verify disabled
+    res = await GET(
+      makeReq(
+        "GET",
+        undefined,
+        `http://localhost/api/routes-f/stream/chat/subscribers-only?stream_id=${streamId}`
+      )
+    );
+    body = await res.json();
+    expect(body.enabled).toBe(false);
+  });
+
+  it("handles multiple streams independently", async () => {
+    const stream1 = "multi-stream-1";
+    const stream2 = "multi-stream-2";
+
+    // Setup stream 1: no tier
+    await POST(
+      makeReq("POST", {
+        stream_id: stream1,
+      })
+    );
+
+    // Setup stream 2: with gold tier
+    await POST(
+      makeReq("POST", {
+        stream_id: stream2,
+        tier_id: "gold",
+      })
+    );
+
+    // Verify stream 1
+    let res = await GET(
+      makeReq(
+        "GET",
+        undefined,
+        `http://localhost/api/routes-f/stream/chat/subscribers-only?stream_id=${stream1}`
+      )
+    );
+    let body = await res.json();
+    expect(body.enabled).toBe(true);
+    expect(body.tier_id).toBeUndefined();
+
+    // Verify stream 2
+    res = await GET(
+      makeReq(
+        "GET",
+        undefined,
+        `http://localhost/api/routes-f/stream/chat/subscribers-only?stream_id=${stream2}`
+      )
+    );
+    body = await res.json();
+    expect(body.enabled).toBe(true);
+    expect(body.tier_id).toBe("gold");
+
+    // Disable stream 1
+    await DELETE(
+      makeReq(
+        "DELETE",
+        undefined,
+        `http://localhost/api/routes-f/stream/chat/subscribers-only?stream_id=${stream1}`
+      )
+    );
+
+    // Verify stream 1 is disabled
+    res = await GET(
+      makeReq(
+        "GET",
+        undefined,
+        `http://localhost/api/routes-f/stream/chat/subscribers-only?stream_id=${stream1}`
+      )
+    );
+    body = await res.json();
+    expect(body.enabled).toBe(false);
+
+    // Verify stream 2 is still enabled with tier
+    res = await GET(
+      makeReq(
+        "GET",
+        undefined,
+        `http://localhost/api/routes-f/stream/chat/subscribers-only?stream_id=${stream2}`
+      )
+    );
+    body = await res.json();
+    expect(body.enabled).toBe(true);
+    expect(body.tier_id).toBe("gold");
+  });
+});
diff --git a/app/api/routes-f/stream/chat/subscribers-only/route.ts b/app/api/routes-f/stream/chat/subscribers-only/route.ts
new file mode 100644
index 00000000..bf879617
--- /dev/null
+++ b/app/api/routes-f/stream/chat/subscribers-only/route.ts
@@ -0,0 +1,78 @@
+import { NextRequest, NextResponse } from "next/server";
+import { validateBody } from "../../_lib/validate";
+import { z } from "zod";
+import {
+  setSubscribersOnlyRestriction,
+  getSubscribersOnlyState,
+  disableSubscribersOnlyRestriction,
+  validateTierId,
+} from "./utils";
+import type {
+  SubscribersOnlyRequestBody,
+  SubscribersOnlyResponse,
+  SubscribersOnlyState,
+} from "./types";
+
+const subscribersOnlySchema = z.object({
+  stream_id: z.string().min(1, "stream_id must not be empty"),
+  tier_id: z.string().optional(),
+});
+
+export async function POST(req: NextRequest): Promise<NextResponse> {
+  const validation = await validateBody(req, subscribersOnlySchema);
+  if (validation instanceof NextResponse) {
+    return validation;
+  }
+
+  const body = validation.data as SubscribersOnlyRequestBody;
+
+  const tierIdValidation = validateTierId(body.tier_id);
+  if (!tierIdValidation.valid) {
+    return NextResponse.json(
+      { error: tierIdValidation.error },
+      { status: 400 }
+    );
+  }
+
+  const data = setSubscribersOnlyRestriction(body.stream_id, body.tier_id);
+  return NextResponse.json({
+    enabled: data.enabled,
+    tier_id: data.tier_id,
+  } as SubscribersOnlyResponse);
+}
+
+export async function DELETE(req: NextRequest): Promise<NextResponse> {
+  const streamId = new URL(req.url).searchParams.get("stream_id");
+
+  if (!streamId) {
+    return NextResponse.json(
+      { error: "stream_id is required" },
+      { status: 400 }
+    );
+  }
+
+  disableSubscribersOnlyRestriction(streamId);
+  return NextResponse.json({ enabled: false });
+}
+
+export async function GET(req: NextRequest): Promise<NextResponse> {
+  const streamId = new URL(req.url).searchParams.get("stream_id");
+
+  if (!streamId) {
+    return NextResponse.json(
+      { error: "stream_id is required" },
+      { status: 400 }
+    );
+  }
+
+  const data = getSubscribersOnlyState(streamId);
+
+  if (!data) {
+    return NextResponse.json({ enabled: false } as SubscribersOnlyState);
+  }
+
+  return NextResponse.json({
+    enabled: data.enabled,
+    tier_id: data.tier_id,
+  } as SubscribersOnlyState);
+}
diff --git a/app/api/routes-f/stream/chat/subscribers-only/types.ts b/app/api/routes-f/stream/chat/subscribers-only/types.ts
new file mode 100644
index 00000000..f84ca7ff
--- /dev/null
+++ b/app/api/routes-f/stream/chat/subscribers-only/types.ts
@@ -0,0 +1,19 @@
+export interface SubscribersOnlyRequestBody {
+  stream_id: string;
+  tier_id?: string;
+}
+
+export interface SubscribersOnlyResponse {
+  enabled: true;
+  tier_id?: string;
+}
+
+export interface SubscribersOnlyState {
+  enabled: boolean;
+  tier_id?: string;
+}
+
+export interface SubscribersOnlyData {
+  enabled: boolean;
+  tier_id?: string;
+}
diff --git a/app/api/routes-f/stream/chat/subscribers-only/utils.ts b/app/api/routes-f/stream/chat/subscribers-only/utils.ts
new file mode 100644
index 00000000..59a35742
--- /dev/null
+++ b/app/api/routes-f/stream/chat/subscribers-only/utils.ts
@@ -0,0 +1,54 @@
+import type { SubscribersOnlyData } from "./types";
+
+export const subscribersOnlyStore = new Map<string, SubscribersOnlyData>();
+
+export function getSubscribersOnlyState(
+  streamId: string
+): SubscribersOnlyData | undefined {
+  return subscribersOnlyStore.get(streamId);
+}
+
+export function setSubscribersOnlyRestriction(
+  streamId: string,
+  tierId?: string
+): SubscribersOnlyData {
+  const data: SubscribersOnlyData = {
+    enabled: true,
+    tier_id: tierId,
+  };
+  subscribersOnlyStore.set(streamId, data);
+  return data;
+}
+
+export function disableSubscribersOnlyRestriction(streamId: string): void {
+  subscribersOnlyStore.delete(streamId);
+}
+
+export function validateTierId(tierId: string | undefined): {
+  valid: boolean;
+  error?: string;
+} {
+  if (tierId === undefined) {
+    return { valid: true };
+  }
+
+  if (typeof tierId !== "string") {
+    return { valid: false, error: "tier_id must be a string" };
+  }
+
+  if (tierId.trim().length === 0) {
+    return {
+      valid: false,
+      error: "tier_id must not be empty",
+    };
+  }
+
+  if (tierId.length > 100) {
+    return {
+      valid: false,
+      error: "tier_id must be 100 characters or less",
+    };
+  }
+
+  return { valid: true };
+}
diff --git a/app/api/routes-f/stream/chat/types.ts b/app/api/routes-f/stream/chat/types.ts
new file mode 100644
index 00000000..f0fc643f
--- /dev/null
+++ b/app/api/routes-f/stream/chat/types.ts
@@ -0,0 +1,14 @@
+export interface ChatRestrictionRequestBody {
+  stream_id: string;
+  min_follow_minutes?: number;
+}
+
+export interface ChatRestrictionResponse {
+  enabled: true;
+  min_follow_minutes: number;
+}
+
+export interface ChatRestrictionState {
+  enabled: boolean;
+  min_follow_minutes?: number;
+}
diff --git a/app/api/routes-f/stream/chat/utils.ts b/app/api/routes-f/stream/chat/utils.ts
new file mode 100644
index 00000000..126c2d5f
--- /dev/null
+++ b/app/api/routes-f/stream/chat/utils.ts
@@ -0,0 +1,43 @@
+export interface ChatRestrictionData {
+  enabled: boolean;
+  min_follow_minutes: number;
+}
+
+export const chatRestrictionStore = new Map<string, ChatRestrictionData>();
+
+export function getChatRestriction(streamId: string): ChatRestrictionData | undefined {
+  return chatRestrictionStore.get(streamId);
+}
+
+export function setChatRestriction(streamId: string, minFollowMinutes: number = 10): ChatRestrictionData {
+  const data: ChatRestrictionData = {
+    enabled: true,
+    min_follow_minutes: minFollowMinutes
+  };
+  chatRestrictionStore.set(streamId, data);
+  return data;
+}
+
+export function disableChatRestriction(streamId: string): void {
+  chatRestrictionStore.delete(streamId);
+}
+
+export function validateMinFollowMinutes(minutes: number): { valid: boolean; error?: string } {
+  if (typeof minutes !== 'number' || isNaN(minutes)) {
+    return { valid: false, error: 'min_follow_minutes must be a number' };
+  }
+  
+  if (minutes < 1) {
+    return { valid: false, error: 'min_follow_minutes must be at least 1 minute' };
+  }
+  
+  if (minutes > 10080) { // 1 week in minutes
+    return { valid: false, error: 'min_follow_minutes must be at most 10080 minutes (1 week)' };
+  }
+  
+  if (!Number.isInteger(minutes)) {
+    return { valid: false, error: 'min_follow_minutes must be an integer' };
+  }
+  
+  return { valid: true };
+}
diff --git a/app/api/routes-f/stream/co-streamers/[username]/route.ts b/app/api/routes-f/stream/co-streamers/[username]/route.ts
new file mode 100644
index 00000000..98d21248
--- /dev/null
+++ b/app/api/routes-f/stream/co-streamers/[username]/route.ts
@@ -0,0 +1,47 @@
+import { NextRequest, NextResponse } from "next/server";
+import { sql } from "@vercel/postgres";
+import { verifySession } from "@/lib/auth/verify-session";
+
+export const runtime = "nodejs";
+export const dynamic = "force-dynamic";
+
+/**
+ * DELETE /api/routes-f/stream/co-streamers/[username]
+ * Remove co-streamer from squad.
+ */
+export async function DELETE(
+    req: NextRequest,
+    context: { params: Promise<{ username: string }> }
+) {
+    const session = await verifySession(req);
+    if (!session.ok) {
+        return session.response;
+    }
+
+    const { username } = await context.params;
+
+    try {
+        // Find user to remove
+        const { rows: targetUser } = await sql`
+      SELECT id FROM users WHERE username = ${username} LIMIT 1
+    `;
+
+        if (targetUser.length === 0) {
+            return NextResponse.json({ error: "User not found" }, { status: 404 });
+        }
+
+        const { rowCount } = await sql`
+      DELETE FROM squad_members
+      WHERE creator_id = ${session.userId} AND user_id = ${targetUser[0].id}
+    `;
+
+        if (rowCount === 0) {
+            return NextResponse.json({ error: "User is not in your squad" }, { status: 404 });
+        }
+
+        return NextResponse.json({ message: "Co-streamer removed from squad" });
+    } catch (error) {
+        console.error("[Co-streamers API] Error removing co-streamer:", error);
+        return NextResponse.json({ error: "Internal server error" }, { status: 500 });
+    }
+}
diff --git a/app/api/routes-f/stream/co-streamers/accept/route.ts b/app/api/routes-f/stream/co-streamers/accept/route.ts
new file mode 100644
index 00000000..e46c7806
--- /dev/null
+++ b/app/api/routes-f/stream/co-streamers/accept/route.ts
@@ -0,0 +1,89 @@
+import { NextRequest, NextResponse } from "next/server";
+import { sql } from "@vercel/postgres";
+import { verifySession } from "@/lib/auth/verify-session";
+import { z } from "zod";
+
+export const runtime = "nodejs";
+export const dynamic = "force-dynamic";
+
+const acceptSchema = z.object({
+    creatorId: z.string().uuid(),
+});
+
+/**
+ * POST /api/routes-f/stream/co-streamers/accept
+ * Invitee accepts squad invite.
+ */
+export async function POST(req: NextRequest) {
+    const session = await verifySession(req);
+    if (!session.ok) {
+        return session.response;
+    }
+
+    try {
+        const body = await req.json();
+        const result = acceptSchema.safeParse(body);
+        if (!result.success) {
+            return NextResponse.json({ error: "creatorId is required" }, { status: 400 });
+        }
+
+        const { creatorId } = result.data;
+
+        // Find valid invite
+        const { rows: invite } = await sql`
+      SELECT id, creator_id, invitee_id, expires_at, status
+      FROM co_stream_invites
+      WHERE creator_id = ${creatorId} AND invitee_id = ${session.userId}
+      AND status = 'pending'
+      AND expires_at > CURRENT_TIMESTAMP
+      LIMIT 1
+    `;
+
+        if (invite.length === 0) {
+            return NextResponse.json({ error: "Invite not found or expired" }, { status: 404 });
+        }
+
+        // Both must be live
+        const { rows: statuses } = await sql`
+      SELECT id, is_live FROM users WHERE id IN (${creatorId}, ${session.userId})
+    `;
+
+        const creatorStatus = statuses.find(s => s.id === creatorId);
+        const inviteeStatus = statuses.find(s => s.id === session.userId);
+
+        if (!creatorStatus?.is_live || !inviteeStatus?.is_live) {
+            return NextResponse.json({ error: "Both streamers must be live to join a squad" }, { status: 400 });
+        }
+
+        // Check squad size again
+        const { rows: squadCount } = await sql`
+      SELECT COUNT(*) as count FROM squad_members WHERE creator_id = ${creatorId}
+    `;
+        if (parseInt(squadCount[0].count) >= 3) {
+            return NextResponse.json({ error: "Squad is already full (max 3 co-streamers)" }, { status: 400 });
+        }
+
+        // Transaction to accept invite and join squad
+        await sql`BEGIN`;
+
+        await sql`
+      UPDATE co_stream_invites SET status = 'accepted' WHERE id = ${invite[0].id}
+    `;
+
+        await sql`
+      INSERT INTO squad_members (creator_id, user_id)
+      VALUES (${creatorId}, ${session.userId})
+      ON CONFLICT DO NOTHING
+    `;
+
+        await sql`COMMIT`;
+
+        return NextResponse.json({ message: "Squad invite accepted" });
+    } catch (error) {
+        if (error) {
+            await sql`ROLLBACK`;
+        }
+        console.error("[Co-streamers API] Error accepting invite:", error);
+        return NextResponse.json({ error: "Internal server error" }, { status: 500 });
+    }
+}
diff --git a/app/api/routes-f/stream/co-streamers/route.ts b/app/api/routes-f/stream/co-streamers/route.ts
new file mode 100644
index 00000000..ad11cfa8
--- /dev/null
+++ b/app/api/routes-f/stream/co-streamers/route.ts
@@ -0,0 +1,104 @@
+import { NextRequest, NextResponse } from "next/server";
+import { sql } from "@vercel/postgres";
+import { verifySession } from "@/lib/auth/verify-session";
+import { z } from "zod";
+
+export const runtime = "nodejs";
+export const dynamic = "force-dynamic";
+
+const inviteSchema = z.object({
+    username: z.string().min(1),
+});
+
+/**
+ * GET /api/routes-f/stream/co-streamers
+ * List current co-streamers for authenticated creator's live stream.
+ */
+export async function GET(req: NextRequest) {
+    const session = await verifySession(req);
+    if (!session.ok) {
+        return session.response;
+    }
+
+    try {
+        const { rows } = await sql`
+      SELECT u.id, u.username, u.avatar, sm.joined_at as "joinedAt"
+      FROM squad_members sm
+      JOIN users u ON sm.user_id = u.id
+      WHERE sm.creator_id = ${session.userId}
+      ORDER BY sm.joined_at ASC
+    `;
+
+        return NextResponse.json({ coStreamers: rows });
+    } catch (error) {
+        console.error("[Co-streamers API] Error fetching squad:", error);
+        return NextResponse.json({ error: "Internal server error" }, { status: 500 });
+    }
+}
+
+/**
+ * POST /api/routes-f/stream/co-streamers
+ * Invite a co-streamer (username)
+ */
+export async function POST(req: NextRequest) {
+    const session = await verifySession(req);
+    if (!session.ok) {
+        return session.response;
+    }
+
+    try {
+        const body = await req.json();
+        const result = inviteSchema.safeParse(body);
+        if (!result.success) {
+            return NextResponse.json({ error: "Username is required" }, { status: 400 });
+        }
+
+        const { username } = result.data;
+
+        // Check if creator is live
+        const { rows: creatorStatus } = await sql`
+      SELECT is_live FROM users WHERE id = ${session.userId} LIMIT 1
+    `;
+        if (!creatorStatus[0]?.is_live) {
+            return NextResponse.json({ error: "You must be live to invite co-streamers" }, { status: 400 });
+        }
+
+        // Find invitee
+        const { rows: invitee } = await sql`
+      SELECT id, is_live FROM users WHERE username = ${username} LIMIT 1
+    `;
+
+        if (invitee.length === 0) {
+            return NextResponse.json({ error: "User not found" }, { status: 404 });
+        }
+
+        if (invitee[0].id === session.userId) {
+            return NextResponse.json({ error: "You cannot invite yourself" }, { status: 400 });
+        }
+
+        if (!invitee[0].is_live) {
+            return NextResponse.json({ error: "Target user must be live to join a squad" }, { status: 400 });
+        }
+
+        // Check squad size
+        const { rows: squadCount } = await sql`
+      SELECT COUNT(*) as count FROM squad_members WHERE creator_id = ${session.userId}
+    `;
+        if (parseInt(squadCount[0].count) >= 3) {
+            return NextResponse.json({ error: "Maximum squad size of 3 reached" }, { status: 400 });
+        }
+
+        // Create invite (expires in 5 mins)
+        const expiresAt = new Date(Date.now() + 5 * 60 * 1000).toISOString();
+
+        await sql`
+      INSERT INTO co_stream_invites (creator_id, invitee_id, expires_at)
+      VALUES (${session.userId}, ${invitee[0].id}, ${expiresAt})
+    `;
+
+        return NextResponse.json({ message: "Invitation sent", expiresAt });
+    } catch (error) {
+        console.error("[Co-streamers API] Error sending invite:", error);
+        return NextResponse.json({ error: "Internal server error" }, { status: 500 });
+    }
+}
diff --git a/app/api/routes-f/stream/extensions/[id]/route.ts b/app/api/routes-f/stream/extensions/[id]/route.ts
new file mode 100644
index 00000000..efc3db94
--- /dev/null
+++ b/app/api/routes-f/stream/extensions/[id]/route.ts
@@ -0,0 +1,122 @@
+import { NextRequest, NextResponse } from "next/server";
+import { sql } from "@vercel/postgres";
+import { verifySession } from "@/lib/auth/verify-session";
+import { z } from "zod";
+
+export const runtime = "nodejs";
+export const dynamic = "force-dynamic";
+
+const updateSchema = z.object({
+    position: z.enum(["overlay", "panel"]).optional(),
+    config: z.record(z.any()).optional(),
+    isEnabled: z.boolean().optional(),
+});
+
+/**
+ * PATCH /api/routes-f/stream/extensions/[id]
+ * Update extension config or position.
+ */
+export async function PATCH(
+    req: NextRequest,
+    context: { params: Promise<{ id: string }> }
+) {
+    const session = await verifySession(req);
+    if (!session.ok) {
+        return session.response;
+    }
+
+    const { id } = await context.params;
+
+    try {
+        const body = await req.json();
+        const result = updateSchema.safeParse(body);
+        if (!result.success) {
+            return NextResponse.json({ error: "Invalid request body", details: result.error.format() }, { status: 400 });
+        }
+
+        // Check ownership
+        const { rows: existing } = await sql`
+      SELECT user_id FROM stream_extensions WHERE id = ${id} LIMIT 1
+    `;
+
+        if (existing.length === 0) {
+            return NextResponse.json({ error: "Extension not found" }, { status: 404 });
+        }
+
+        if (existing[0].user_id !== session.userId) {
+            return NextResponse.json({ error: "Forbidden" }, { status: 403 });
+        }
+
+        const { position, config, isEnabled } = result.data;
+
+        // Build update query dynamically
+        const updates: string[] = [];
+        if (position !== undefined) {
+            updates.push(`position = '${position}'`);
+        }
+        if (config !== undefined) {
+            updates.push(`config = '${JSON.stringify(config)}'`);
+        }
+        if (isEnabled !== undefined) {
+            updates.push(`is_enabled = ${isEnabled}`);
+        }
+        updates.push(`updated_at = CURRENT_TIMESTAMP`);
+
+        if (updates.length > 1) { // more than just updated_at
+            const query = `
+          UPDATE stream_extensions
+          SET ${updates.join(", ")}
+          WHERE id = $1
+          RETURNING id, extension_id as "extensionId", position, config, is_enabled as "isEnabled"
+        `;
+            const { rows } = await sql.query(query, [id]);
+            return NextResponse.json(rows[0]);
+        }
+
+        return NextResponse.json({ message: "No changes provided" });
+    } catch (error) {
+        console.error("[Extensions API] Error updating extension:", error);
+        return NextResponse.json({ error: "Internal server error" }, { status: 500 });
+    }
+}
+
+/**
+ * DELETE /api/routes-f/stream/extensions/[id]
+ * Disable/Remove an extension.
+ */
+export async function DELETE(
+    req: NextRequest,
+    context: { params: Promise<{ id: string }> }
+) {
+    const session = await verifySession(req);
+    if (!session.ok) {
+        return session.response;
+    }
+
+    const { id } = await context.params;
+
+    try {
+        // Check ownership
+        const { rows: existing } = await sql`
+      SELECT user_id FROM stream_extensions WHERE id = ${id} LIMIT 1
+    `;
+
+        if (existing.length === 0) {
+            return NextResponse.json({ error: "Extension not found" }, { status: 404 });
+        }
+
+        if (existing[0].user_id !== session.userId) {
+            return NextResponse.json({ error: "Forbidden" }, { status: 403 });
+        }
+
+        await sql`
+      DELETE FROM stream_extensions
+      WHERE id = ${id}
+    `;
+
+        return NextResponse.json({ message: "Extension disabled" });
+    } catch (error) {
+        console.error("[Extensions API] Error deleting extension:", error);
+        return NextResponse.json({ error: "Internal server error" }, { status: 500 });
+    }
+}
diff --git a/app/api/routes-f/stream/extensions/route.ts b/app/api/routes-f/stream/extensions/route.ts
new file mode 100644
index 00000000..472eeb5b
--- /dev/null
+++ b/app/api/routes-f/stream/extensions/route.ts
@@ -0,0 +1,118 @@
+import { NextRequest, NextResponse } from "next/server";
+import { sql } from "@vercel/postgres";
+import { verifySession } from "@/lib/auth/verify-session";
+import { z } from "zod";
+
+export const runtime = "nodejs";
+export const dynamic = "force-dynamic";
+
+const extensionSchema = z.object({
+    extensionId: z.string().uuid(),
+    position: z.enum(["overlay", "panel"]),
+    config: z.record(z.any()).default({}),
+});
+
+/**
+ * GET /api/routes-f/stream/extensions
+ * List enabled extensions for authenticated creator.
+ */
+export async function GET(req: NextRequest) {
+    const session = await verifySession(req);
+    if (!session.ok) {
+        return session.response;
+    }
+
+    try {
+        const { rows } = await sql`
+      SELECT 
+        se.id, 
+        se.extension_id as "extensionId", 
+        se.position, 
+        se.config, 
+        se.is_enabled as "isEnabled",
+        ec.name,
+        ec.icon_url as "iconUrl"
+      FROM stream_extensions se
+      JOIN extension_catalog ec ON se.extension_id = ec.id
+      WHERE se.user_id = ${session.userId}
+      ORDER BY se.created_at DESC
+    `;
+
+        return NextResponse.json({ extensions: rows });
+    } catch (error) {
+        console.error("[Extensions API] Error fetching user extensions:", error);
+        return NextResponse.json({ error: "Internal server error" }, { status: 500 });
+    }
+}
+
+/**
+ * POST /api/routes-f/stream/extensions
+ * Enable an extension for the creator.
+ */
+export async function POST(req: NextRequest) {
+    const session = await verifySession(req);
+    if (!session.ok) {
+        return session.response;
+    }
+
+    try {
+        const body = await req.json();
+        const result = extensionSchema.safeParse(body);
+        if (!result.success) {
+            return NextResponse.json({ error: "Invalid request body", details: result.error.format() }, { status: 400 });
+        }
+
+        const { extensionId, position, config } = result.data;
+
+        // Check limits
+        const { rows: counts } = await sql`
+      SELECT position, COUNT(*) as count
+      FROM stream_extensions
+      WHERE user_id = ${session.userId} AND is_enabled = TRUE
+      GROUP BY position
+    `;
+
+        const overlayCount = parseInt(counts.find(c => c.position === "overlay")?.count || "0");
+        const panelCount = parseInt(counts.find(c => c.position === "panel")?.count || "0");
+
+        if (position === "overlay" && overlayCount >= 3) {
+            return NextResponse.json({ error: "Maximum of 3 overlay extensions allowed" }, { status: 400 });
+        }
+        if (position === "panel" && panelCount >= 2) {
+            return NextResponse.json({ error: "Maximum of 2 panel extensions allowed" }, { status: 400 });
+        }
+
+        // Validate config against catalog schema
+        const { rows: catalog } = await sql`
+      SELECT json_schema FROM extension_catalog WHERE id = ${extensionId} LIMIT 1
+    `;
+
+        if (catalog.length === 0) {
+            return NextResponse.json({ error: "Extension not found in catalog" }, { status: 404 });
+        }
+
+        // Simple schema validation (check if keys in config match schema properties if schema is simple)
+        // For now, we trust the config but could add deeper validation if needed.
+
+        const { rows: newExtension } = await sql`
+      INSERT INTO stream_extensions (user_id, extension_id, position, config)
+      VALUES (${session.userId}, ${extensionId}, ${position}, ${JSON.stringify(config)})
+      RETURNING id, extension_id as "extensionId", position, config
+    `;
+
+        return NextResponse.json(newExtension[0], { status: 201 });
+    } catch (error) {
+        console.error("[Extensions API] Error enabling extension:", error);
+        return NextResponse.json({ error: "Internal server error" }, { status: 500 });
+    }
+}
+
+/**
+ * PATCH /api/routes-f/stream/extensions/[id]
+ * Actually, the issue says PATCH /api/routes-f/stream/extensions/[id]
+ * But in standard Next.js app router, this would be in a separate directory if we want [id] parameter.
+ * I will handle it by checking for the id in the URL or moving it to a nested route.
+ * The user specified: PATCH /api/routes-f/stream/extensions/[id]
+ */
+// Since we are in app/api/routes-f/stream/extensions/route.ts, we can't easily get [id] from the path without a subfolder.
+// I'll create app/api/routes-f/stream/extensions/[id]/route.ts for PATCH and DELETE.
diff --git a/app/api/routes-f/stream/intermission/route.ts b/app/api/routes-f/stream/intermission/route.ts
new file mode 100644
index 00000000..0d69d3e5
--- /dev/null
+++ b/app/api/routes-f/stream/intermission/route.ts
@@ -0,0 +1,68 @@
+import { NextRequest, NextResponse } from 'next/server';
+import { validateBody } from '../../_lib/validate';
+import { z } from 'zod';
+import { setIntermission, getIntermission, clearIntermission, getSecondsRemaining } from './utils';
+import type { IntermissionRequestBody, IntermissionResponse, IntermissionState } from './types';
+
+const intermissionSchema = z.object({
+  stream_id: z.string().min(1),
+  message: z.string().min(1),
+  ends_at: z.string().optional(),
+});
+
+export async function POST(req: NextRequest): Promise<NextResponse> {
+  const validation = await validateBody(req, intermissionSchema);
+  if (validation instanceof NextResponse) {
+    return validation;
+  }
+
+  const body = validation.data as IntermissionRequestBody;
+  
+  // Validate ends_at is valid ISO date if provided
+  if (body.ends_at) {
+    const endDate = new Date(body.ends_at);
+    if (isNaN(endDate.getTime())) {
+      return NextResponse.json({ error: 'ends_at must be a valid ISO date' }, { status: 400 });
+    }
+  }
+
+  setIntermission(body.stream_id, body.message, body.ends_at);
+  return NextResponse.json({ active: true } as IntermissionResponse);
+}
+
+export async function DELETE(req: NextRequest): Promise<NextResponse> {
+  const streamId = new URL(req.url).searchParams.get('stream_id');
+  
+  if (!streamId) {
+    return NextResponse.json({ error: 'stream_id is required' }, { status: 400 });
+  }
+
+  clearIntermission(streamId);
+  return NextResponse.json({ active: false });
+}
+
+export async function GET(req: NextRequest): Promise<NextResponse> {
+  const streamId = new URL(req.url).searchParams.get('stream_id');
+  
+  if (!streamId) {
+    return NextResponse.json({ error: 'stream_id is required' }, { status: 400 });
+  }
+
+  const data = getIntermission(streamId);
+  
+  if (!data) {
+    return NextResponse.json({ active: false } as IntermissionState);
+  }
+
+  const response: IntermissionState = {
+    active: data.active,
+    message: data.message,
+    ends_at: data.ends_at,
+  };
+
+  if (data.ends_at) {
+    response.seconds_remaining = getSecondsRemaining(data.ends_at);
+  }
+
+  return NextResponse.json(response);
+}
diff --git a/app/api/routes-f/stream/intermission/types.ts b/app/api/routes-f/stream/intermission/types.ts
new file mode 100644
index 00000000..99b7aa0f
--- /dev/null
+++ b/app/api/routes-f/stream/intermission/types.ts
@@ -0,0 +1,16 @@
+export interface IntermissionRequestBody {
+  stream_id: string;
+  message: string;
+  ends_at?: string;
+}
+
+export interface IntermissionResponse {
+  active: true;
+}
+
+export interface IntermissionState {
+  active: boolean;
+  message?: string;
+  ends_at?: string;
+  seconds_remaining?: number;
+}
diff --git a/app/api/routes-f/stream/intermission/utils.ts b/app/api/routes-f/stream/intermission/utils.ts
new file mode 100644
index 00000000..b2360dc1
--- /dev/null
+++ b/app/api/routes-f/stream/intermission/utils.ts
@@ -0,0 +1,32 @@
+export interface IntermissionData {
+  active: boolean;
+  message: string;
+  ends_at?: string;
+}
+
+export const intermissionStore = new Map<string, IntermissionData>();
+
+export function getIntermission(streamId: string): IntermissionData | undefined {
+  return intermissionStore.get(streamId);
+}
+
+export function setIntermission(streamId: string, message: string, endsAt?: string): IntermissionData {
+  const data: IntermissionData = {
+    active: true,
+    message,
+    ends_at: endsAt
+  };
+  intermissionStore.set(streamId, data);
+  return data;
+}
+
+export function clearIntermission(streamId: string): void {
+  intermissionStore.delete(streamId);
+}
+
+export function getSecondsRemaining(endsAt: string): number {
+  const end = new Date(endsAt).getTime();
+  const now = Date.now();
+  const remaining = Math.ceil((end - now) / 1000);
+  return Math.max(0, remaining);
+}
diff --git a/app/api/routes-f/stream/markers/[id]/route.ts b/app/api/routes-f/stream/markers/[id]/route.ts
new file mode 100644
index 00000000..6b7132b8
--- /dev/null
+++ b/app/api/routes-f/stream/markers/[id]/route.ts
@@ -0,0 +1,47 @@
+import { NextRequest, NextResponse } from "next/server";
+import { sql } from "@vercel/postgres";
+import { verifySession } from "@/lib/auth/verify-session";
+
+/**
+ * DELETE /api/routes-f/stream/markers/[id] — remove a bookmark
+ */
+
+export async function DELETE(
+  req: NextRequest,
+  { params }: { params: Promise<{ id: string }> }
+) {
+  const session = await verifySession(req);
+  if (!session.ok) return session.response;
+
+  const { id } = await params;
+
+  if (!id) {
+    return NextResponse.json(
+      { error: "Marker ID is required" },
+      { status: 400 }
+    );
+  }
+
+  try {
+    // Delete only if it belongs to the authenticated user
+    const result = await sql`
+      DELETE FROM stream_markers
+      WHERE id = ${id} AND user_id = ${session.userId}
+    `;
+
+    if (result.rowCount === 0) {
+      return NextResponse.json(
+        { error: "Marker not found or unauthorized" },
+        { status: 404 }
+      );
+    }
+
+    return NextResponse.json({ message: "Marker deleted successfully" });
+  } catch (error) {
+    console.error("[DELETE Marker] Error:", error);
+    return NextResponse.json(
+      { error: "Failed to delete marker" },
+      { status: 500 }
+    );
+  }
+}
diff --git a/app/api/routes-f/stream/markers/route.ts b/app/api/routes-f/stream/markers/route.ts
new file mode 100644
index 00000000..6f4020fb
--- /dev/null
+++ b/app/api/routes-f/stream/markers/route.ts
@@ -0,0 +1,110 @@
+import { NextRequest, NextResponse } from "next/server";
+import { sql } from "@vercel/postgres";
+import { verifySession } from "@/lib/auth/verify-session";
+
+/**
+ * GET /api/routes-f/stream/markers?recording_id= — list own bookmarks for a recording
+ * POST /api/routes-f/stream/markers — add a bookmark (recording_id, timestamp_seconds, note?)
+ */
+
+async function ensureTableExists() {
+  await sql`
+    CREATE TABLE IF NOT EXISTS stream_markers (
+      id UUID PRIMARY KEY DEFAULT gen_random_uuid(),
+      user_id UUID REFERENCES users(id) ON DELETE CASCADE,
+      recording_id VARCHAR(255) NOT NULL,
+      timestamp_seconds INTEGER NOT NULL,
+      note VARCHAR(100),
+      created_at TIMESTAMP WITH TIME ZONE DEFAULT CURRENT_TIMESTAMP
+    );
+  `;
+  await sql`
+    CREATE INDEX IF NOT EXISTS idx_stream_markers_user_recording ON stream_markers(user_id, recording_id);
+  `;
+}
+
+export async function GET(req: NextRequest) {
+  const session = await verifySession(req);
+  if (!session.ok) return session.response;
+
+  const { searchParams } = new URL(req.url);
+  const recordingId = searchParams.get("recording_id");
+
+  if (!recordingId) {
+    return NextResponse.json(
+      { error: "recording_id is required" },
+      { status: 400 }
+    );
+  }
+
+  try {
+    await ensureTableExists();
+    const { rows } = await sql`
+      SELECT id, recording_id, timestamp_seconds, note, created_at
+      FROM stream_markers
+      WHERE user_id = ${session.userId} AND recording_id = ${recordingId}
+      ORDER BY timestamp_seconds ASC
+    `;
+
+    return NextResponse.json(rows);
+  } catch (error) {
+    console.error("[GET Markers] Error:", error);
+    return NextResponse.json(
+      { error: "Failed to fetch markers" },
+      { status: 500 }
+    );
+  }
+}
+
+export async function POST(req: NextRequest) {
+  const session = await verifySession(req);
+  if (!session.ok) return session.response;
+
+  try {
+    const { recording_id, timestamp_seconds, note } = await req.json();
+
+    if (!recording_id || typeof timestamp_seconds !== "number") {
+      return NextResponse.json(
+        { error: "recording_id and timestamp_seconds are required" },
+        { status: 400 }
+      );
+    }
+
+    if (note && note.length > 100) {
+      return NextResponse.json(
+        { error: "Note must be 100 characters or less" },
+        { status: 400 }
+      );
+    }
+
+    await ensureTableExists();
+
+    // Check limit: Max 50 bookmarks per recording per user
+    const { rows: countRows } = await sql`
+      SELECT COUNT(*)::int as count 
+      FROM stream_markers 
+      WHERE user_id = ${session.userId} AND recording_id = ${recording_id}
+    `;
+
+    if (countRows[0].count >= 50) {
+      return NextResponse.json(
+        { error: "Maximum 50 bookmarks per recording reached" },
+        { status: 400 }
+      );
+    }
+
+    const { rows } = await sql`
+      INSERT INTO stream_markers (user_id, recording_id, timestamp_seconds, note)
+      VALUES (${session.userId}, ${recording_id}, ${timestamp_seconds}, ${note || null})
+      RETURNING id, recording_id, timestamp_seconds, note, created_at
+    `;
+
+    return NextResponse.json(rows[0], { status: 201 });
+  } catch (error) {
+    console.error("[POST Markers] Error:", error);
+    return NextResponse.json(
+      { error: "Failed to add marker" },
+      { status: 500 }
+    );
+  }
+}
diff --git a/app/api/routes-f/stream/pinned-message/route.ts b/app/api/routes-f/stream/pinned-message/route.ts
new file mode 100644
index 00000000..1d8881c5
--- /dev/null
+++ b/app/api/routes-f/stream/pinned-message/route.ts
@@ -0,0 +1,98 @@
+import { NextRequest, NextResponse } from "next/server";
+import { pinMessage, unpinMessage, getPinnedMessage } from "./store";
+
+export async function POST(req: NextRequest): Promise<NextResponse> {
+  let body: Record<string, unknown>;
+
+  try {
+    body = await req.json();
+  } catch {
+    return NextResponse.json({ error: "Invalid JSON body." }, { status: 400 });
+  }
+
+  const { stream_id, message_id, message_text, pinned_by, expires_at } = body;
+
+  if (typeof stream_id !== "string" || !stream_id.trim()) {
+    return NextResponse.json(
+      { error: "stream_id is required." },
+      { status: 400 }
+    );
+  }
+  if (typeof message_id !== "string" || !message_id.trim()) {
+    return NextResponse.json(
+      { error: "message_id is required." },
+      { status: 400 }
+    );
+  }
+  if (typeof message_text !== "string" || !message_text.trim()) {
+    return NextResponse.json(
+      { error: "message_text is required." },
+      { status: 400 }
+    );
+  }
+  if (typeof pinned_by !== "string" || !pinned_by.trim()) {
+    return NextResponse.json(
+      { error: "pinned_by is required." },
+      { status: 400 }
+    );
+  }
+
+  let expiresAtStr: string | undefined;
+  if (expires_at !== undefined) {
+    if (typeof expires_at !== "string") {
+      return NextResponse.json(
+        { error: "expires_at must be a valid ISO date string." },
+        { status: 400 }
+      );
+    }
+    const d = new Date(expires_at);
+    if (isNaN(d.getTime())) {
+      return NextResponse.json(
+        { error: "expires_at must be a valid ISO date string." },
+        { status: 400 }
+      );
+    }
+    expiresAtStr = expires_at;
+  }
+
+  const pin = pinMessage(
+    stream_id as string,
+    message_id as string,
+    message_text as string,
+    pinned_by as string,
+    expiresAtStr
+  );
+
+  return NextResponse.json({
+    pinned_at: pin.pinned_at,
+    ...(pin.expires_at ? { expires_at: pin.expires_at } : {}),
+  });
+}
+
+export async function DELETE(req: NextRequest): Promise<NextResponse> {
+  const streamId = req.nextUrl.searchParams.get("stream_id");
+
+  if (!streamId) {
+    return NextResponse.json(
+      { error: "stream_id is required." },
+      { status: 400 }
+    );
+  }
+
+  unpinMessage(streamId);
+  return NextResponse.json({ unpinned: true });
+}
+
+export async function GET(req: NextRequest): Promise<NextResponse> {
+  const streamId = req.nextUrl.searchParams.get("stream_id");
+
+  if (!streamId) {
+    return NextResponse.json(
+      { error: "stream_id is required." },
+      { status: 400 }
+    );
+  }
+
+  const pin = getPinnedMessage(streamId);
+  return NextResponse.json({ pin });
+}
diff --git a/app/api/routes-f/stream/pinned-message/store.ts b/app/api/routes-f/stream/pinned-message/store.ts
new file mode 100644
index 00000000..33b551ef
--- /dev/null
+++ b/app/api/routes-f/stream/pinned-message/store.ts
@@ -0,0 +1,38 @@
+import type { PinnedMessage } from "./types";
+
+export const pinnedMessages = new Map<string, PinnedMessage>();
+
+export function pinMessage(
+  stream_id: string,
+  message_id: string,
+  message_text: string,
+  pinned_by: string,
+  expires_at?: string
+): PinnedMessage {
+  const pin: PinnedMessage = {
+    stream_id,
+    message_id,
+    message_text,
+    pinned_by,
+    pinned_at: new Date().toISOString(),
+    expires_at,
+  };
+  pinnedMessages.set(stream_id, pin);
+  return pin;
+}
+
+export function unpinMessage(stream_id: string): boolean {
+  return pinnedMessages.delete(stream_id);
+}
+
+export function getPinnedMessage(stream_id: string): PinnedMessage | null {
+  const pin = pinnedMessages.get(stream_id);
+  if (!pin) return null;
+
+  if (pin.expires_at && new Date(pin.expires_at).getTime() <= Date.now()) {
+    pinnedMessages.delete(stream_id);
+    return null;
+  }
+
+  return pin;
+}
diff --git a/app/api/routes-f/stream/pinned-message/types.ts b/app/api/routes-f/stream/pinned-message/types.ts
new file mode 100644
index 00000000..f56839a8
--- /dev/null
+++ b/app/api/routes-f/stream/pinned-message/types.ts
@@ -0,0 +1,13 @@
+export interface PinnedMessage {
+  stream_id: string;
+  message_id: string;
+  message_text: string;
+  pinned_by: string;
+  pinned_at: string;
+  expires_at?: string;
+}
+
+export interface PinResponse {
+  pinned_at: string;
+  expires_at?: string;
+}
diff --git a/app/api/routes-f/stream/tags/route.ts b/app/api/routes-f/stream/tags/route.ts
new file mode 100644
index 00000000..038e491e
--- /dev/null
+++ b/app/api/routes-f/stream/tags/route.ts
@@ -0,0 +1,38 @@
+import { NextRequest, NextResponse } from 'next/server';
+import { validateBody } from '../../_lib/validate';
+import { z } from 'zod';
+import { updateStreamTags, getStreamTags } from './utils';
+import type { StreamTagsRequestBody, StreamTagsResponse } from './types';
+
+const streamTagsSchema = z.object({
+  stream_id: z.string().min(1),
+  add: z.array(z.string()).optional(),
+  remove: z.array(z.string()).optional(),
+});
+
+export async function POST(req: NextRequest): Promise<NextResponse> {
+  const validation = await validateBody(req, streamTagsSchema);
+  if (validation instanceof NextResponse) {
+    return validation;
+  }
+
+  const body = validation.data as StreamTagsRequestBody;
+  const result = updateStreamTags(body.stream_id, body.add, body.remove);
+
+  if (result.error) {
+    return NextResponse.json({ error: result.error }, { status: 400 });
+  }
+
+  return NextResponse.json({ tags: result.tags } as StreamTagsResponse);
+}
+
+export async function GET(req: NextRequest): Promise<NextResponse> {
+  const streamId = new URL(req.url).searchParams.get('stream_id');
+  
+  if (!streamId) {
+    return NextResponse.json({ error: 'stream_id is required' }, { status: 400 });
+  }
+
+  const tags = getStreamTags(streamId);
+  return NextResponse.json({ tags } as StreamTagsResponse);
+}
diff --git a/app/api/routes-f/stream/tags/types.ts b/app/api/routes-f/stream/tags/types.ts
new file mode 100644
index 00000000..baaa81c5
--- /dev/null
+++ b/app/api/routes-f/stream/tags/types.ts
@@ -0,0 +1,14 @@
+export interface StreamTagsRequestBody {
+  stream_id: string;
+  add?: string[];
+  remove?: string[];
+}
+
+export interface StreamTagsResponse {
+  tags: string[];
+}
+
+export interface TitleChangeEntry {
+  title: string;
+  updated_at: string;
+}
diff --git a/app/api/routes-f/stream/tags/utils.ts b/app/api/routes-f/stream/tags/utils.ts
new file mode 100644
index 00000000..80a4c8cc
--- /dev/null
+++ b/app/api/routes-f/stream/tags/utils.ts
@@ -0,0 +1,53 @@
+export function normalizeTag(tag: string): string {
+  return tag
+    .trim()
+    .toLowerCase()
+    .replace(/\s+/g, '-')
+    .replace(/[^a-z0-9-]/g, '')
+    .replace(/-+/g, '-')
+    .replace(/^-|-$/g, '');
+}
+
+export function validateTag(tag: string): boolean {
+  return tag.length > 0 && tag.length <= 50 && /^[a-z0-9-]+$/.test(tag);
+}
+
+export const streamTagsStore = new Map<string, string[]>();
+
+export function getStreamTags(streamId: string): string[] {
+  return streamTagsStore.get(streamId) || [];
+}
+
+export function setStreamTags(streamId: string, tags: string[]): void {
+  streamTagsStore.set(streamId, tags);
+}
+
+export function updateStreamTags(
+  streamId: string,
+  add?: string[],
+  remove?: string[]
+): { tags: string[]; error?: string } {
+  const currentTags = getStreamTags(streamId);
+  const normalizedAdd = (add || []).map(normalizeTag).filter(validateTag);
+  const normalizedRemove = (remove || []).map(normalizeTag).filter(validateTag);
+
+  let newTags = [...currentTags];
+
+  // Remove tags first
+  newTags = newTags.filter(tag => !normalizedRemove.includes(tag));
+
+  // Add new tags (dedup)
+  normalizedAdd.forEach(tag => {
+    if (!newTags.includes(tag)) {
+      newTags.push(tag);
+    }
+  });
+
+  // Cap at 10
+  if (newTags.length > 10) {
+    return { tags: currentTags, error: 'Maximum 10 tags allowed' };
+  }
+
+  setStreamTags(streamId, newTags);
+  return { tags: newTags };
+}
diff --git a/app/api/routes-f/stream/title/route.ts b/app/api/routes-f/stream/title/route.ts
new file mode 100644
index 00000000..f1dfee98
--- /dev/null
+++ b/app/api/routes-f/stream/title/route.ts
@@ -0,0 +1,41 @@
+import { NextRequest, NextResponse } from 'next/server';
+import { validateBody } from '../../_lib/validate';
+import { z } from 'zod';
+import { addTitleChange, getTitleHistory, validateTitle } from './utils';
+import type { StreamTitleRequestBody, StreamTitleResponse, StreamTitleHistoryResponse } from './types';
+
+const streamTitleSchema = z.object({
+  stream_id: z.string().min(1),
+  title: z.string(),
+});
+
+export async function PATCH(req: NextRequest): Promise<NextResponse> {
+  const validation = await validateBody(req, streamTitleSchema);
+  if (validation instanceof NextResponse) {
+    return validation;
+  }
+
+  const body = validation.data as StreamTitleRequestBody;
+  const titleValidation = validateTitle(body.title);
+
+  if (!titleValidation.valid) {
+    return NextResponse.json({ error: titleValidation.error }, { status: 400 });
+  }
+
+  const entry = addTitleChange(body.stream_id, body.title);
+  return NextResponse.json({
+    updated_at: entry.updated_at,
+    title: entry.title
+  } as StreamTitleResponse);
+}
+
+export async function GET(req: NextRequest): Promise<NextResponse> {
+  const streamId = new URL(req.url).searchParams.get('stream_id');
+  
+  if (!streamId) {
+    return NextResponse.json({ error: 'stream_id is required' }, { status: 400 });
+  }
+
+  const history = getTitleHistory(streamId);
+  return NextResponse.json({ history } as StreamTitleHistoryResponse);
+}
diff --git a/app/api/routes-f/stream/title/types.ts b/app/api/routes-f/stream/title/types.ts
new file mode 100644
index 00000000..d37f8428
--- /dev/null
+++ b/app/api/routes-f/stream/title/types.ts
@@ -0,0 +1,16 @@
+export interface StreamTitleRequestBody {
+  stream_id: string;
+  title: string;
+}
+
+export interface StreamTitleResponse {
+  updated_at: string;
+  title: string;
+}
+
+export interface StreamTitleHistoryResponse {
+  history: Array<{
+    title: string;
+    updated_at: string;
+  }>;
+}
diff --git a/app/api/routes-f/stream/title/utils.ts b/app/api/routes-f/stream/title/utils.ts
new file mode 100644
index 00000000..9fabb233
--- /dev/null
+++ b/app/api/routes-f/stream/title/utils.ts
@@ -0,0 +1,44 @@
+export interface TitleChangeEntry {
+  title: string;
+  updated_at: string;
+}
+
+export const titleHistoryStore = new Map<string, TitleChangeEntry[]>();
+
+export function getTitleHistory(streamId: string): TitleChangeEntry[] {
+  return titleHistoryStore.get(streamId) || [];
+}
+
+export function addTitleChange(streamId: string, title: string): TitleChangeEntry {
+  const history = getTitleHistory(streamId);
+  const entry: TitleChangeEntry = {
+    title,
+    updated_at: new Date().toISOString()
+  };
+  
+  history.unshift(entry); // Add to beginning (append-only, newest first)
+  
+  // Keep only last 10
+  if (history.length > 10) {
+    history.pop();
+  }
+  
+  titleHistoryStore.set(streamId, history);
+  return entry;
+}
+
+export function validateTitle(title: string): { valid: boolean; error?: string } {
+  if (typeof title !== 'string') {
+    return { valid: false, error: 'Title must be a string' };
+  }
+  
+  if (title.length < 1) {
+    return { valid: false, error: 'Title must be at least 1 character' };
+  }
+  
+  if (title.length > 100) {
+    return { valid: false, error: 'Title must be at most 100 characters' };
+  }
+  
+  return { valid: true };
+}
diff --git a/app/api/routes-f/stream/transcription/PR_BODY.md b/app/api/routes-f/stream/transcription/PR_BODY.md
new file mode 100644
index 00000000..b243a082
--- /dev/null
+++ b/app/api/routes-f/stream/transcription/PR_BODY.md
@@ -0,0 +1,41 @@
+# feat: transcription management API for VOD captions
+
+Implements the transcription API at `app/api/routes-f/stream/transcription/` as specified.
+
+## What's included
+
+- `GET /api/routes-f/stream/transcription?recording_id=` — returns job status and content (only when ready)
+- `POST /api/routes-f/stream/transcription` — triggers a transcription job; ownership-gated
+- `GET /api/routes-f/stream/transcription/[id]/vtt` — streams the WebVTT file with `Content-Type: text/vtt`
+- `db/migrations/add-transcription-jobs.sql` — new `transcription_jobs` table with status constraint, indexes, and `UNIQUE(recording_id)`
+
+## Performance notes
+
+- GET query uses `CASE WHEN status = 'ready' THEN content ELSE NULL END` to avoid fetching large VTT text on non-ready jobs
+- POST uses `INSERT ... ON CONFLICT DO UPDATE` to collapse the existence-check + insert into a single round-trip
+
+## Auth & ownership
+
+- All endpoints require a valid session (401 otherwise)
+- POST verifies `stream_recordings.user_id = session.userId` before creating a job (403 otherwise)
+- GET and VTT endpoints enforce the same ownership check
+
+## Tests
+
+Vitest unit tests in `__tests__/transcription.test.ts` covering:
+- GET returns correct status and content
+- GET omits content when not ready
+- POST triggers job and returns `pending`
+- POST rejects non-owner with 403
+- VTT streams with `Content-Type: text/vtt`
+- VTT returns 404 when not ready / not found
+- All endpoints return 401 for unauthenticated requests
+
+## Migration
+
+Run before deploying:
+```sql
+\i db/migrations/add-transcription-jobs.sql
+```
+
+Closes #<issue-number>
diff --git a/app/api/routes-f/stream/transcription/[id]/vtt/route.ts b/app/api/routes-f/stream/transcription/[id]/vtt/route.ts
new file mode 100644
index 00000000..5fe8d98e
--- /dev/null
+++ b/app/api/routes-f/stream/transcription/[id]/vtt/route.ts
@@ -0,0 +1,55 @@
+import { NextRequest, NextResponse } from "next/server";
+import { sql } from "@vercel/postgres";
+import { verifySession } from "@/lib/auth/verify-session";
+
+// ── GET /api/routes-f/stream/transcription/[id]/vtt ──────────────────────────
+export async function GET(
+  req: NextRequest,
+  { params }: { params: Promise<{ id: string }> }
+) {
+  const session = await verifySession(req);
+  if (!session.ok) return session.response;
+
+  const { id } = await params;
+
+  try {
+    const { rows } = await sql`
+      SELECT id, status, content, user_id
+      FROM transcription_jobs
+      WHERE id = ${id}
+      LIMIT 1
+    `;
+
+    if (rows.length === 0) {
+      return NextResponse.json(
+        { error: "Transcription not found" },
+        { status: 404 }
+      );
+    }
+
+    const job = rows[0];
+
+    if (job.user_id !== session.userId) {
+      return NextResponse.json({ error: "Forbidden" }, { status: 403 });
+    }
+
+    if (job.status !== "ready" || !job.content) {
+      return NextResponse.json(
+        { error: "Transcription is not ready" },
+        { status: 404 }
+      );
+    }
+
+    return new Response(job.content, {
+      status: 200,
+      headers: {
+        "Content-Type": "text/vtt; charset=utf-8",
+        "Content-Disposition": `inline; filename="transcription-${id}.vtt"`,
+        "Cache-Control": "private, max-age=3600",
+      },
+    });
+  } catch (err) {
+    console.error("[transcription VTT GET]", err);
+    return NextResponse.json({ error: "Failed to fetch VTT" }, { status: 500 });
+  }
+}
diff --git a/app/api/routes-f/stream/transcription/__tests__/transcription.test.ts b/app/api/routes-f/stream/transcription/__tests__/transcription.test.ts
new file mode 100644
index 00000000..72c8d5d1
--- /dev/null
+++ b/app/api/routes-f/stream/transcription/__tests__/transcription.test.ts
@@ -0,0 +1,351 @@
+// @ts-nocheck
+/**
+ * Transcription API — unit tests
+ *
+ * Run with:  npx vitest --run app/api/routes-f/stream/transcription/__tests__
+ *
+ * Mocks:
+ *  - @vercel/postgres  → in-memory job/recording stores
+ *  - @/lib/auth/verify-session → controllable session fixture
+ *  - @/lib/rate-limit  → always passes
+ */
+
+import { describe, it, expect, vi, beforeEach } from "vitest";
+import { NextRequest } from "next/server";
+
+// ── Fixtures ──────────────────────────────────────────────────────────────────
+const OWNER_ID = "user-owner-001";
+const OTHER_ID = "user-other-002";
+const RECORDING_ID = "rec-abc123";
+const JOB_ID = "job-xyz789";
+
+const recordings: Record
+  string,
+  { id: string; user_id: string; status: string }
+> = {
+  [RECORDING_ID]: { id: RECORDING_ID, user_id: OWNER_ID, status: "ready" },
+};
+
+const jobs: Record
+  string,
+  {
+    id: string;
+    recording_id: string;
+    user_id: string;
+    status: string;
+    content: string | null;
+    error_reason: string | null;
+    updated_at?: string;
+  }
+> = {};
+
+// ── Mocks ─────────────────────────────────────────────────────────────────────
+vi.mock("@vercel/postgres", () => ({
+  sql: new Proxy(
+    {},
+    {
+      get:
+        () =>
+        async (strings: TemplateStringsArray, ...values: unknown[]) => {
+          const query = strings.join("?").toLowerCase();
+
+          // GET transcription_jobs by recording_id
+          if (
+            query.includes("from transcription_jobs") &&
+            query.includes("recording_id")
+          ) {
+            const recId = values[0] as string;
+            const job = Object.values(jobs).find(j => j.recording_id === recId);
+            return { rows: job ? [job] : [] };
+          }
+
+          // GET transcription_jobs by id (VTT endpoint)
+          if (
+            query.includes("from transcription_jobs") &&
+            query.includes("where id")
+          ) {
+            const id = values[0] as string;
+            const job = jobs[id];
+            return { rows: job ? [job] : [] };
+          }
+
+          // GET stream_recordings
+          if (query.includes("from stream_recordings")) {
+            const id = values[0] as string;
+            const rec = recordings[id];
+            return { rows: rec ? [rec] : [] };
+          }
+
+          // INSERT / UPSERT transcription_jobs
+          if (query.includes("insert into transcription_jobs")) {
+            const [recId, userId] = values as string[];
+            const existing = Object.values(jobs).find(
+              j => j.recording_id === recId
+            );
+            if (existing) {
+              existing.updated_at = new Date().toISOString();
+              return { rows: [{ id: existing.id, status: existing.status }] };
+            }
+            const newJob = {
+              id: JOB_ID,
+              recording_id: recId,
+              user_id: userId,
+              status: "pending",
+              content: null,
+              error_reason: null,
+            };
+            jobs[JOB_ID] = newJob;
+            return { rows: [{ id: newJob.id, status: newJob.status }] };
+          }
+
+          return { rows: [] };
+        },
+    }
+  ),
+}));
+
+vi.mock("@/lib/rate-limit", () => ({
+  createRateLimiter: () => async () => false,
+}));
+
+let mockSession: { ok: boolean; userId?: string; response?: Response } = {
+  ok: false,
+};
+
+vi.mock("@/lib/auth/verify-session", () => ({
+  verifySession: async () => mockSession,
+}));
+
+// ── Import handlers after mocks are set up ────────────────────────────────────
+const { GET, POST } = await import("../route");
+const { GET: GET_VTT } = await import("../[id]/vtt/route");
+
+// ── Helpers ───────────────────────────────────────────────────────────────────
+function makeReq(method: string, url: string, body?: unknown): NextRequest {
+  return new NextRequest(url, {
+    method,
+    headers: { "content-type": "application/json" },
+    body: body ? JSON.stringify(body) : undefined,
+  });
+}
+
+function asOwner() {
+  mockSession = { ok: true, userId: OWNER_ID } as typeof mockSession;
+}
+
+function asOther() {
+  mockSession = { ok: true, userId: OTHER_ID } as typeof mockSession;
+}
+
+function asUnauthenticated() {
+  mockSession = {
+    ok: false,
+    response: new Response(JSON.stringify({ error: "Unauthorized" }), {
+      status: 401,
+    }),
+  } as typeof mockSession;
+}
+
+// ── Tests ─────────────────────────────────────────────────────────────────────
+describe("GET /api/routes-f/stream/transcription", () => {
+  beforeEach(() => {
+    // Seed a ready job
+    jobs[JOB_ID] = {
+      id: JOB_ID,
+      recording_id: RECORDING_ID,
+      user_id: OWNER_ID,
+      status: "ready",
+      content: "WEBVTT\n\n00:00:01.000 --> 00:00:04.000\nHello world",
+      error_reason: null,
+    };
+  });
+
+  it("returns 401 for unauthenticated requests", async () => {
+    asUnauthenticated();
+    const res = await GET(
+      makeReq(
+        "GET",
+        `http://localhost/api/routes-f/stream/transcription?recording_id=${RECORDING_ID}`
+      )
+    );
+    expect(res.status).toBe(401);
+  });
+
+  it("returns 400 when recording_id is missing", async () => {
+    asOwner();
+    const res = await GET(
+      makeReq("GET", "http://localhost/api/routes-f/stream/transcription")
+    );
+    expect(res.status).toBe(400);
+  });
+
+  it("returns correct status and content when ready", async () => {
+    asOwner();
+    const res = await GET(
+      makeReq(
+        "GET",
+        `http://localhost/api/routes-f/stream/transcription?recording_id=${RECORDING_ID}`
+      )
+    );
+    expect(res.status).toBe(200);
+    const body = await res.json();
+    expect(body.status).toBe("ready");
+    expect(body.recording_id).toBe(RECORDING_ID);
+    expect(body.content).toContain("WEBVTT");
+  });
+
+  it("omits content when status is pending", async () => {
+    asOwner();
+    jobs[JOB_ID].status = "pending";
+    jobs[JOB_ID].content = null;
+    const res = await GET(
+      makeReq(
+        "GET",
+        `http://localhost/api/routes-f/stream/transcription?recording_id=${RECORDING_ID}`
+      )
+    );
+    const body = await res.json();
+    expect(body.status).toBe("pending");
+    expect(body.content).toBeUndefined();
+  });
+
+  it("returns 403 when a non-owner requests the transcription", async () => {
+    asOther();
+    const res = await GET(
+      makeReq(
+        "GET",
+        `http://localhost/api/routes-f/stream/transcription?recording_id=${RECORDING_ID}`
+      )
+    );
+    expect(res.status).toBe(403);
+  });
+});
+
+describe("POST /api/routes-f/stream/transcription", () => {
+  beforeEach(() => {
+    // Clear jobs so each test starts fresh
+    for (const key of Object.keys(jobs)) delete jobs[key];
+  });
+
+  it("returns 401 for unauthenticated requests", async () => {
+    asUnauthenticated();
+    const res = await POST(
+      makeReq("POST", "http://localhost/api/routes-f/stream/transcription", {
+        recording_id: RECORDING_ID,
+      })
+    );
+    expect(res.status).toBe(401);
+  });
+
+  it("triggers job and returns pending status", async () => {
+    asOwner();
+    const res = await POST(
+      makeReq("POST", "http://localhost/api/routes-f/stream/transcription", {
+        recording_id: RECORDING_ID,
+      })
+    );
+    expect(res.status).toBe(202);
+    const body = await res.json();
+    expect(body.job_id).toBe(JOB_ID);
+    expect(body.status).toBe("pending");
+  });
+
+  it("rejects non-owner with 403", async () => {
+    asOther();
+    const res = await POST(
+      makeReq("POST", "http://localhost/api/routes-f/stream/transcription", {
+        recording_id: RECORDING_ID,
+      })
+    );
+    expect(res.status).toBe(403);
+  });
+
+  it("returns 400 when recording_id is missing", async () => {
+    asOwner();
+    const res = await POST(
+      makeReq("POST", "http://localhost/api/routes-f/stream/transcription", {})
+    );
+    expect(res.status).toBe(400);
+  });
+
+  it("returns existing job if one already exists", async () => {
+    asOwner();
+    // First call creates it
+    await POST(
+      makeReq("POST", "http://localhost/api/routes-f/stream/transcription", {
+        recording_id: RECORDING_ID,
+      })
+    );
+    // Second call should return the same job
+    const res = await POST(
+      makeReq("POST", "http://localhost/api/routes-f/stream/transcription", {
+        recording_id: RECORDING_ID,
+      })
+    );
+    const body = await res.json();
+    expect(body.job_id).toBe(JOB_ID);
+  });
+});
+
+describe("GET /api/routes-f/stream/transcription/[id]/vtt", () => {
+  beforeEach(() => {
+    jobs[JOB_ID] = {
+      id: JOB_ID,
+      recording_id: RECORDING_ID,
+      user_id: OWNER_ID,
+      status: "ready",
+      content: "WEBVTT\n\n00:00:01.000 --> 00:00:04.000\nHello world",
+      error_reason: null,
+    };
+  });
+
+  it("returns 401 for unauthenticated requests", async () => {
+    asUnauthenticated();
+    const res = await GET_VTT(
+      makeReq("GET", `http://localhost/api/routes-f/stream/transcription/${JOB_ID}/vtt`),
+      { params: Promise.resolve({ id: JOB_ID }) }
+    );
+    expect(res.status).toBe(401);
+  });
+
+  it("streams VTT with correct Content-Type", async () => {
+    asOwner();
+    const res = await GET_VTT(
+      makeReq("GET", `http://localhost/api/routes-f/stream/transcription/${JOB_ID}/vtt`),
+      { params: Promise.resolve({ id: JOB_ID }) }
+    );
+    expect(res.status).toBe(200);
+    expect(res.headers.get("content-type")).toContain("text/vtt");
+    const text = await res.text();
+    expect(text).toContain("WEBVTT");
+  });
+
+  it("returns 404 when transcription is not ready", async () => {
+    asOwner();
+    jobs[JOB_ID].status = "processing";
+    jobs[JOB_ID].content = null;
+    const res = await GET_VTT(
+      makeReq("GET", `http://localhost/api/routes-f/stream/transcription/${JOB_ID}/vtt`),
+      { params: Promise.resolve({ id: JOB_ID }) }
+    );
+    expect(res.status).toBe(404);
+  });
+
+  it("returns 404 when transcription does not exist", async () => {
+    asOwner();
+    const res = await GET_VTT(
+      makeReq("GET", "http://localhost/api/routes-f/stream/transcription/nonexistent/vtt"),
+      { params: Promise.resolve({ id: "nonexistent" }) }
+    );
+    expect(res.status).toBe(404);
+  });
+
+  it("returns 403 when requester is not the owner", async () => {
+    asOther();
+    const res = await GET_VTT(
+      makeReq("GET", `http://localhost/api/routes-f/stream/transcription/${JOB_ID}/vtt`),
+      { params: Promise.resolve({ id: JOB_ID }) }
+    );
+    expect(res.status).toBe(403);
+  });
+});
\ No newline at end of file
diff --git a/app/api/routes-f/stream/transcription/route.ts b/app/api/routes-f/stream/transcription/route.ts
new file mode 100644
index 00000000..f32d11a8
--- /dev/null
+++ b/app/api/routes-f/stream/transcription/route.ts
@@ -0,0 +1,146 @@
+import { NextRequest, NextResponse } from "next/server";
+import { sql } from "@vercel/postgres";
+import { verifySession } from "@/lib/auth/verify-session";
+import { createRateLimiter } from "@/lib/rate-limit";
+
+const isRateLimited = createRateLimiter(60_000, 20); // 20 req/min per IP
+
+// ── GET /api/routes-f/stream/transcription?recording_id= ─────────────────────
+export async function GET(req: NextRequest) {
+  const session = await verifySession(req);
+  if (!session.ok) return session.response;
+
+  const recordingId = new URL(req.url).searchParams.get("recording_id");
+  if (!recordingId) {
+    return NextResponse.json(
+      { error: "recording_id query param is required" },
+      { status: 400 }
+    );
+  }
+
+  try {
+    const { rows } = await sql`
+      SELECT
+        tj.id,
+        tj.status,
+        tj.error_reason,
+        tj.recording_id,
+        tj.user_id,
+        CASE WHEN tj.status = 'ready' THEN tj.content ELSE NULL END AS content
+      FROM transcription_jobs tj
+      WHERE tj.recording_id = ${recordingId}
+      LIMIT 1
+    `;
+
+    if (rows.length === 0) {
+      return NextResponse.json(
+        { error: "Transcription job not found" },
+        { status: 404 }
+      );
+    }
+
+    const job = rows[0];
+
+    // Only the owner can view transcription details
+    if (job.user_id !== session.userId) {
+      return NextResponse.json({ error: "Forbidden" }, { status: 403 });
+    }
+
+    return NextResponse.json({
+      status: job.status,
+      recording_id: job.recording_id,
+      ...(job.status === "ready" && { content: job.content }),
+      ...(job.status === "failed" && { error_reason: job.error_reason }),
+    });
+  } catch (err) {
+    console.error("[transcription GET]", err);
+    return NextResponse.json(
+      { error: "Failed to fetch transcription" },
+      { status: 500 }
+    );
+  }
+}
+
+// ── POST /api/routes-f/stream/transcription ───────────────────────────────────
+export async function POST(req: NextRequest) {
+  const ip =
+    req.headers.get("x-forwarded-for")?.split(",")[0]?.trim() ??
+    req.headers.get("x-real-ip") ??
+    "unknown";
+
+  if (await isRateLimited(ip)) {
+    return NextResponse.json(
+      { error: "Too many requests" },
+      { status: 429, headers: { "Retry-After": "60" } }
+    );
+  }
+
+  const session = await verifySession(req);
+  if (!session.ok) return session.response;
+
+  let body: { recording_id?: string };
+  try {
+    body = await req.json();
+  } catch {
+    return NextResponse.json({ error: "Invalid JSON body" }, { status: 400 });
+  }
+
+  const { recording_id } = body;
+  if (!recording_id) {
+    return NextResponse.json(
+      { error: "recording_id is required" },
+      { status: 400 }
+    );
+  }
+
+  try {
+    // Verify the recording exists and the authenticated user owns it
+    const { rows: recRows } = await sql`
+      SELECT id, user_id, status
+      FROM stream_recordings
+      WHERE id = ${recording_id}
+      LIMIT 1
+    `;
+
+    if (recRows.length === 0) {
+      return NextResponse.json(
+        { error: "Recording not found" },
+        { status: 404 }
+      );
+    }
+
+    const recording = recRows[0];
+
+    if (recording.user_id !== session.userId) {
+      return NextResponse.json({ error: "Forbidden" }, { status: 403 });
+    }
+
+    if (recording.status !== "ready") {
+      return NextResponse.json(
+        { error: "Recording is not ready for transcription" },
+        { status: 409 }
+      );
+    }
+
+    // Upsert: one round-trip — returns existing job or inserts new one
+    const { rows: inserted } = await sql`
+      INSERT INTO transcription_jobs (recording_id, user_id, status)
+      VALUES (${recording_id}, ${session.userId}, 'pending')
+      ON CONFLICT (recording_id) DO UPDATE SET updated_at = NOW()
+      RETURNING id, status
+    `;
+
+    const job = inserted[0];
+
+    return NextResponse.json(
+      { job_id: job.id, status: job.status },
+      { status: 202 }
+    );
+  } catch (err) {
+    console.error("[transcription POST]", err);
+    return NextResponse.json(
+      { error: "Failed to create transcription job" },
+      { status: 500 }
+    );
+  }
+}
diff --git a/app/api/routes-f/subscriber-roster/route.ts b/app/api/routes-f/subscriber-roster/route.ts
new file mode 100644
index 00000000..1d867507
--- /dev/null
+++ b/app/api/routes-f/subscriber-roster/route.ts
@@ -0,0 +1,71 @@
+import { NextRequest, NextResponse } from "next/server";
+import { sql } from "@vercel/postgres";
+import { validateQuery } from "../_lib/validate";
+import { z } from "zod";
+
+export const runtime = "nodejs";
+export const dynamic = "force-dynamic";
+
+/**
+ * GET /api/routes-f/subscriber-roster?creator_id=...
+ * Get subscriber roster for a creator with tier breakdown and MRR
+ */
+export async function GET(req: NextRequest) {
+  const queryResult = validateQuery(
+    req.nextUrl.searchParams,
+    z.object({ creator_id: z.string() })
+  );
+
+  if (queryResult instanceof NextResponse) {
+    return queryResult;
+  }
+
+  const { creator_id } = queryResult.data;
+
+  try {
+    const { rows: subscribers } = await sql`
+      SELECT
+        id,
+        user_id,
+        subscription_tier_id,
+        started_at,
+        end_date,
+        active
+      FROM subscriptions
+      WHERE creator_id = ${creator_id} AND active = true
+      ORDER BY started_at DESC
+    `;
+
+    const { rows: tierRows } = await sql`
+      SELECT id, price_usdc FROM subscription_tiers
+      WHERE creator_id = ${creator_id} AND active = true
+    `;
+
+    const tierMap = new Map(tierRows.map((t: any) => [t.id, t.price_usdc]));
+
+    const byTier: Record<string, number> = {};
+    let totalMrrUsdc = 0;
+
+    for (const sub of subscribers) {
+      const tierId = sub.subscription_tier_id;
+      byTier[tierId] = (byTier[tierId] || 0) + 1;
+
+      const tierPrice = tierMap.get(tierId) || 0;
+      totalMrrUsdc += tierPrice;
+    }
+
+    const monthlyRecurringRevenue = Math.round(totalMrrUsdc * 100) / 100;
+
+    return NextResponse.json({
+      subscribers,
+      by_tier: byTier,
+      monthly_recurring_revenue_usdc: monthlyRecurringRevenue,
+    });
+  } catch (error) {
+    console.error("[Subscriber Roster API] Error fetching roster:", error);
+    return NextResponse.json(
+      { error: "Internal server error" },
+      { status: 500 }
+    );
+  }
+}
diff --git a/app/api/routes-f/subscription-tiers/[id]/route.ts b/app/api/routes-f/subscription-tiers/[id]/route.ts
new file mode 100644
index 00000000..859f7f7b
--- /dev/null
+++ b/app/api/routes-f/subscription-tiers/[id]/route.ts
@@ -0,0 +1,132 @@
+import { NextRequest, NextResponse } from "next/server";
+import { sql } from "@vercel/postgres";
+import { verifySession } from "@/lib/auth/verify-session";
+import { validateBody } from "../../_lib/validate";
+import { z } from "zod";
+
+export const runtime = "nodejs";
+export const dynamic = "force-dynamic";
+
+const updateTierSchema = z.object({
+  name: z.string().min(1).max(100).optional(),
+  price_usdc: z.number().positive().optional(),
+  duration_days: z.number().int().positive().optional(),
+  perks: z.array(z.string()).optional(),
+});
+
+/**
+ * PATCH /api/routes-f/subscription-tiers/[id]
+ * Update a subscription tier
+ */
+export async function PATCH(
+  req: NextRequest,
+  { params }: { params: Promise<{ id: string }> }
+) {
+  const session = await verifySession(req);
+  if (!session.ok) {
+    return session.response;
+  }
+
+  const bodyResult = await validateBody(req, updateTierSchema);
+  if (bodyResult instanceof NextResponse) {
+    return bodyResult;
+  }
+
+  const { id } = await params;
+  const { name, price_usdc, duration_days, perks } = bodyResult.data;
+
+  try {
+    const { rows: tierRows } = await sql`
+      SELECT creator_id FROM subscription_tiers WHERE id = ${id}
+    `;
+
+    if (tierRows.length === 0) {
+      return NextResponse.json({ error: "Tier not found" }, { status: 404 });
+    }
+
+    if (tierRows[0].creator_id !== session.userId) {
+      return NextResponse.json({ error: "Forbidden" }, { status: 403 });
+    }
+
+    if (
+      name === undefined &&
+      price_usdc === undefined &&
+      duration_days === undefined &&
+      perks === undefined
+    ) {
+      return NextResponse.json(
+        { error: "No fields to update" },
+        { status: 400 }
+      );
+    }
+
+    const { rows: currentRows } = await sql`
+      SELECT name, price_usdc, duration_days, perks FROM subscription_tiers WHERE id = ${id}
+    `;
+    const current = currentRows[0];
+
+    const { rows } = await sql`
+      UPDATE subscription_tiers
+      SET
+        name = ${name ?? current.name},
+        price_usdc = ${price_usdc ?? current.price_usdc},
+        duration_days = ${duration_days ?? current.duration_days},
+        perks = ${JSON.stringify(perks ?? current.perks)},
+        updated_at = CURRENT_TIMESTAMP
+      WHERE id = ${id}
+      RETURNING id, name, price_usdc, duration_days, perks, active, created_at
+    `;
+
+    return NextResponse.json(rows[0]);
+  } catch (error) {
+    console.error("[Subscription Tiers API] Error updating tier:", error);
+    return NextResponse.json(
+      { error: "Internal server error" },
+      { status: 500 }
+    );
+  }
+}
+
+/**
+ * DELETE /api/routes-f/subscription-tiers/[id]
+ * Soft-delete a subscription tier
+ */
+export async function DELETE(
+  req: NextRequest,
+  { params }: { params: Promise<{ id: string }> }
+) {
+  const session = await verifySession(req);
+  if (!session.ok) {
+    return session.response;
+  }
+
+  const { id } = await params;
+
+  try {
+    const { rows: tierRows } = await sql`
+      SELECT creator_id FROM subscription_tiers WHERE id = ${id}
+    `;
+
+    if (tierRows.length === 0) {
+      return NextResponse.json({ error: "Tier not found" }, { status: 404 });
+    }
+
+    if (tierRows[0].creator_id !== session.userId) {
+      return NextResponse.json({ error: "Forbidden" }, { status: 403 });
+    }
+
+    await sql`
+      UPDATE subscription_tiers
+      SET active = false, updated_at = CURRENT_TIMESTAMP
+      WHERE id = ${id}
+    `;
+
+    return NextResponse.json({ message: "Tier deleted" });
+  } catch (error) {
+    console.error("[Subscription Tiers API] Error deleting tier:", error);
+    return NextResponse.json(
+      { error: "Internal server error" },
+      { status: 500 }
+    );
+  }
+}
diff --git a/app/api/routes-f/subscription-tiers/route.ts b/app/api/routes-f/subscription-tiers/route.ts
new file mode 100644
index 00000000..e24009fe
--- /dev/null
+++ b/app/api/routes-f/subscription-tiers/route.ts
@@ -0,0 +1,112 @@
+import { NextRequest, NextResponse } from "next/server";
+import { sql } from "@vercel/postgres";
+import { verifySession } from "@/lib/auth/verify-session";
+import { validateQuery, validateBody } from "../_lib/validate";
+import { z } from "zod";
+
+export const runtime = "nodejs";
+export const dynamic = "force-dynamic";
+
+const tierSchema = z.object({
+  name: z.string().min(1).max(100),
+  price_usdc: z.number().positive(),
+  duration_days: z.number().int().positive(),
+  perks: z.array(z.string()).default([]),
+});
+
+const createTierSchema = tierSchema;
+const updateTierSchema = tierSchema.partial().omit({ perks: true }).extend({
+  perks: z.array(z.string()).optional(),
+});
+
+/**
+ * GET /api/routes-f/subscription-tiers?creator_id=...
+ * List subscription tiers for a creator
+ */
+export async function GET(req: NextRequest) {
+  const queryResult = validateQuery(
+    req.nextUrl.searchParams,
+    z.object({ creator_id: z.string() })
+  );
+
+  if (queryResult instanceof NextResponse) {
+    return queryResult;
+  }
+
+  const { creator_id } = queryResult.data;
+
+  try {
+    const { rows } = await sql`
+      SELECT id, name, price_usdc, duration_days, perks, active, created_at
+      FROM subscription_tiers
+      WHERE creator_id = ${creator_id} AND active = true
+      ORDER BY created_at ASC
+    `;
+
+    return NextResponse.json({ tiers: rows });
+  } catch (error) {
+    console.error("[Subscription Tiers API] Error fetching tiers:", error);
+    return NextResponse.json(
+      { error: "Internal server error" },
+      { status: 500 }
+    );
+  }
+}
+
+/**
+ * POST /api/routes-f/subscription-tiers
+ * Create a new subscription tier for the authenticated creator
+ */
+export async function POST(req: NextRequest) {
+  const session = await verifySession(req);
+  if (!session.ok) {
+    return session.response;
+  }
+
+  const bodyResult = await validateBody(req, createTierSchema);
+  if (bodyResult instanceof NextResponse) {
+    return bodyResult;
+  }
+
+  const { name, price_usdc, duration_days, perks } = bodyResult.data;
+
+  try {
+    const { rows: countRows } = await sql`
+      SELECT COUNT(*) as count
+      FROM subscription_tiers
+      WHERE creator_id = ${session.userId} AND active = true
+    `;
+
+    if (countRows[0].count >= 5) {
+      return NextResponse.json(
+        { error: "Cannot exceed 5 active tiers per creator" },
+        { status: 400 }
+      );
+    }
+
+    const { rows } = await sql`
+      INSERT INTO subscription_tiers (
+        creator_id, name, price_usdc, duration_days, perks, active, created_at
+      )
+      VALUES (
+        ${session.userId},
+        ${name},
+        ${price_usdc},
+        ${duration_days},
+        ${JSON.stringify(perks)},
+        true,
+        CURRENT_TIMESTAMP
+      )
+      RETURNING id, name, price_usdc, duration_days, perks, active, created_at
+    `;
+
+    return NextResponse.json(rows[0], { status: 201 });
+  } catch (error) {
+    console.error("[Subscription Tiers API] Error creating tier:", error);
+    return NextResponse.json(
+      { error: "Internal server error" },
+      { status: 500 }
+    );
+  }
+}
+
diff --git a/app/api/routes-f/subscriptions/__tests__/subscriptions.test.ts b/app/api/routes-f/subscriptions/__tests__/subscriptions.test.ts
new file mode 100644
index 00000000..1e44ee70
--- /dev/null
+++ b/app/api/routes-f/subscriptions/__tests__/subscriptions.test.ts
@@ -0,0 +1,226 @@
+/**
+ * @jest-environment node
+ */
+import { NextRequest } from "next/server";
+import { POST, subscriptions } from "../route";
+
+function makeReq(body: unknown) {
+  return new NextRequest("http://localhost/api/routes-f/subscriptions", {
+    method: "POST",
+    headers: { "content-type": "application/json" },
+    body: JSON.stringify(body),
+  });
+}
+
+const VALID_SUBSCRIBER = "a1b2c3d4-0000-4000-8000-000000000001";
+const VALID_CREATOR = "a1b2c3d4-0000-4000-8000-000000000002";
+const OTHER_CREATOR = "a1b2c3d4-0000-4000-8000-000000000003";
+
+describe("POST /api/routes-f/subscriptions", () => {
+  beforeEach(() => {
+    // Reset in-memory store before each test so tests are independent.
+    subscriptions.clear();
+  });
+
+  it("201 — creates a new subscription for a valid tier", async () => {
+    const res = await POST(
+      makeReq({
+        subscriber_id: VALID_SUBSCRIBER,
+        creator_id: VALID_CREATOR,
+        tier_id: "basic",
+        payment_tx_hash: "abc123tx",
+        asset: "XLM",
+      })
+    );
+
+    expect(res.status).toBe(201);
+    const body = await res.json();
+    expect(body.subscription_id).toBeTruthy();
+    expect(body.subscriber_id).toBe(VALID_SUBSCRIBER);
+    expect(body.creator_id).toBe(VALID_CREATOR);
+    expect(body.tier_id).toBe("basic");
+    expect(body.started_at).toBeTruthy();
+    expect(body.expires_at).toBeTruthy();
+
+    // expires_at should be ~30 days after started_at
+    const started = new Date(body.started_at).getTime();
+    const expires = new Date(body.expires_at).getTime();
+    const diffDays = (expires - started) / (24 * 60 * 60 * 1000);
+    expect(diffDays).toBeCloseTo(30, 0);
+  });
+
+  it("201 — standard tier gives ~90 days and premium gives ~365 days", async () => {
+    const resStd = await POST(
+      makeReq({
+        subscriber_id: VALID_SUBSCRIBER,
+        creator_id: VALID_CREATOR,
+        tier_id: "standard",
+        payment_tx_hash: "tx_std",
+        asset: "USDC",
+      })
+    );
+    expect(resStd.status).toBe(201);
+    const bodyStd = await resStd.json();
+    const diffStd =
+      (new Date(bodyStd.expires_at).getTime() -
+        new Date(bodyStd.started_at).getTime()) /
+      (24 * 60 * 60 * 1000);
+    expect(diffStd).toBeCloseTo(90, 0);
+
+    // Clear store then test premium.
+    subscriptions.clear();
+
+    const resPrem = await POST(
+      makeReq({
+        subscriber_id: VALID_SUBSCRIBER,
+        creator_id: VALID_CREATOR,
+        tier_id: "premium",
+        payment_tx_hash: "tx_prem",
+        asset: "XLM",
+      })
+    );
+    expect(resPrem.status).toBe(201);
+    const bodyPrem = await resPrem.json();
+    const diffPrem =
+      (new Date(bodyPrem.expires_at).getTime() -
+        new Date(bodyPrem.started_at).getTime()) /
+      (24 * 60 * 60 * 1000);
+    expect(diffPrem).toBeCloseTo(365, 0);
+  });
+
+  it("409 — duplicate active subscription for same subscriber+creator", async () => {
+    // First subscribe
+    await POST(
+      makeReq({
+        subscriber_id: VALID_SUBSCRIBER,
+        creator_id: VALID_CREATOR,
+        tier_id: "basic",
+        payment_tx_hash: "tx_first",
+        asset: "XLM",
+      })
+    );
+
+    // Same subscriber to same creator again
+    const res = await POST(
+      makeReq({
+        subscriber_id: VALID_SUBSCRIBER,
+        creator_id: VALID_CREATOR,
+        tier_id: "standard",
+        payment_tx_hash: "tx_second",
+        asset: "USDC",
+      })
+    );
+
+    expect(res.status).toBe(409);
+    const body = await res.json();
+    expect(body.error).toMatch(/already active/i);
+    expect(body.subscription_id).toBeTruthy();
+    expect(body.expires_at).toBeTruthy();
+  });
+
+  it("409 — does NOT block subscription to a different creator", async () => {
+    // Subscribe to VALID_CREATOR
+    await POST(
+      makeReq({
+        subscriber_id: VALID_SUBSCRIBER,
+        creator_id: VALID_CREATOR,
+        tier_id: "basic",
+        payment_tx_hash: "tx_one",
+        asset: "XLM",
+      })
+    );
+
+    // Subscribe to OTHER_CREATOR — should succeed
+    const res = await POST(
+      makeReq({
+        subscriber_id: VALID_SUBSCRIBER,
+        creator_id: OTHER_CREATOR,
+        tier_id: "basic",
+        payment_tx_hash: "tx_two",
+        asset: "XLM",
+      })
+    );
+
+    expect(res.status).toBe(201);
+  });
+
+  it("404 — unknown tier_id", async () => {
+    const res = await POST(
+      makeReq({
+        subscriber_id: VALID_SUBSCRIBER,
+        creator_id: VALID_CREATOR,
+        tier_id: "gold",
+        payment_tx_hash: "tx_unknown",
+        asset: "XLM",
+      })
+    );
+
+    expect(res.status).toBe(404);
+    const body = await res.json();
+    expect(body.error).toMatch(/unknown tier/i);
+  });
+
+  it("400 — missing required field: subscriber_id", async () => {
+    const res = await POST(
+      makeReq({
+        creator_id: VALID_CREATOR,
+        tier_id: "basic",
+        payment_tx_hash: "tx_x",
+        asset: "XLM",
+      })
+    );
+    expect(res.status).toBe(400);
+    const body = await res.json();
+    expect(body.error).toBeTruthy();
+  });
+
+  it("400 — missing required field: creator_id", async () => {
+    const res = await POST(
+      makeReq({
+        subscriber_id: VALID_SUBSCRIBER,
+        tier_id: "basic",
+        payment_tx_hash: "tx_x",
+        asset: "XLM",
+      })
+    );
+    expect(res.status).toBe(400);
+  });
+
+  it("400 — missing required field: payment_tx_hash", async () => {
+    const res = await POST(
+      makeReq({
+        subscriber_id: VALID_SUBSCRIBER,
+        creator_id: VALID_CREATOR,
+        tier_id: "basic",
+        asset: "XLM",
+      })
+    );
+    expect(res.status).toBe(400);
+  });
+
+  it("400 — invalid asset value", async () => {
+    const res = await POST(
+      makeReq({
+        subscriber_id: VALID_SUBSCRIBER,
+        creator_id: VALID_CREATOR,
+        tier_id: "basic",
+        payment_tx_hash: "tx_x",
+        asset: "BTC",
+      })
+    );
+    expect(res.status).toBe(400);
+  });
+
+  it("400 — subscriber_id not a UUID", async () => {
+    const res = await POST(
+      makeReq({
+        subscriber_id: "not-a-uuid",
+        creator_id: VALID_CREATOR,
+        tier_id: "basic",
+        payment_tx_hash: "tx_x",
+        asset: "XLM",
+      })
+    );
+    expect(res.status).toBe(400);
+  });
+});
diff --git a/app/api/routes-f/subscriptions/badges/badge.svg b/app/api/routes-f/subscriptions/badges/badge.svg
new file mode 100644
index 00000000..34a55de2
--- /dev/null
+++ b/app/api/routes-f/subscriptions/badges/badge.svg
@@ -0,0 +1,9 @@
+<svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 24 24" width="24" height="24">
+  <defs>
+    <linearGradient id="gold-grad" x1="0%" y1="0%" x2="100%" y2="100%">
+      <stop offset="0%" stop-color="#FFE07D" />
+      <stop offset="100%" stop-color="#F5A623" />
+    </linearGradient>
+  </defs>
+  <path fill="url(#gold-grad)" d="M12,17.27L18.18,21L16.54,13.97L22,9.24L14.81,8.62L12,2L9.19,8.62L2,9.24L7.45,13.97L5.82,21L12,17.27Z" />
+</svg>
diff --git a/app/api/routes-f/subscriptions/badges/route.ts b/app/api/routes-f/subscriptions/badges/route.ts
new file mode 100644
index 00000000..0fb1a8bd
--- /dev/null
+++ b/app/api/routes-f/subscriptions/badges/route.ts
@@ -0,0 +1,78 @@
+import { NextRequest, NextResponse } from "next/server";
+import { subscriptions } from "../route";
+
+export async function GET(req: NextRequest): Promise<NextResponse> {
+  const { searchParams } = new URL(req.url);
+  const creatorId = searchParams.get("creator_id");
+  const subscriberId = searchParams.get("subscriber_id");
+
+  if (!creatorId || !subscriberId) {
+    return NextResponse.json(
+      { error: "creator_id and subscriber_id are required" },
+      { status: 400 }
+    );
+  }
+
+  const now = Date.now();
+
+  // Find all subscriptions matching user and creator
+  const userSubs = Array.from(subscriptions.values()).filter(
+    (sub) => sub.subscriber_id === subscriberId && sub.creator_id === creatorId
+  );
+
+  // Check if there is a currently active subscription (active until expires_at)
+  const activeSub = userSubs.find(
+    (sub) =>
+      new Date(sub.expires_at).getTime() > now &&
+      new Date(sub.started_at).getTime() <= now
+  );
+
+  const has_sub = !!activeSub;
+
+  // Stack months_subscribed across non-overlapping subs
+  const intervals = userSubs.map((sub) => ({
+    start: new Date(sub.started_at).getTime(),
+    end: new Date(sub.expires_at).getTime(),
+  }));
+
+  // Sort intervals by start time
+  intervals.sort((a, b) => a.start - b.start);
+
+  // Merge overlapping intervals
+  const merged: { start: number; end: number }[] = [];
+  for (const interval of intervals) {
+    if (merged.length === 0) {
+      merged.push(interval);
+    } else {
+      const last = merged[merged.length - 1];
+      if (interval.start <= last.end) {
+        // Overlapping or adjacent, merge
+        last.end = Math.max(last.end, interval.end);
+      } else {
+        // Non-overlapping
+        merged.push(interval);
+      }
+    }
+  }
+
+  const totalDurationMs = merged.reduce(
+    (sum, interval) => sum + (interval.end - interval.start),
+    0
+  );
+  const totalDays = totalDurationMs / (24 * 60 * 60 * 1000);
+  const months_subscribed = Math.floor(totalDays / 30);
+
+  if (has_sub) {
+    return NextResponse.json({
+      has_sub,
+      tier_id: activeSub.tier_id,
+      badge_url: "/api/routes-f/subscriptions/badges/svg",
+      months_subscribed,
+    });
+  }
+
+  return NextResponse.json({
+    has_sub,
+    months_subscribed,
+  });
+}
diff --git a/app/api/routes-f/subscriptions/badges/svg/route.ts b/app/api/routes-f/subscriptions/badges/svg/route.ts
new file mode 100644
index 00000000..412c0829
--- /dev/null
+++ b/app/api/routes-f/subscriptions/badges/svg/route.ts
@@ -0,0 +1,20 @@
+import { NextResponse } from "next/server";
+import { promises as fs } from "fs";
+import path from "path";
+
+export async function GET() {
+  try {
+    const filePath = path.join(
+      process.cwd(),
+      "app/api/routes-f/subscriptions/badges/badge.svg"
+    );
+    const fileContent = await fs.readFile(filePath, "utf-8");
+    return new NextResponse(fileContent, {
+      headers: {
+        "Content-Type": "image/svg+xml",
+      },
+    });
+  } catch (error) {
+    return NextResponse.json({ error: "Badge icon not found" }, { status: 404 });
+  }
+}
diff --git a/app/api/routes-f/subscriptions/cancel/route.ts b/app/api/routes-f/subscriptions/cancel/route.ts
new file mode 100644
index 00000000..62406c4e
--- /dev/null
+++ b/app/api/routes-f/subscriptions/cancel/route.ts
@@ -0,0 +1,52 @@
+import { NextRequest, NextResponse } from "next/server";
+import { subscriptions } from "../route";
+
+export async function POST(req: NextRequest): Promise<NextResponse> {
+  let body: any;
+  try {
+    body = await req.json();
+  } catch {
+    return NextResponse.json({ error: "Invalid JSON" }, { status: 400 });
+  }
+
+  const { subscription_id, subscriber_id } = body;
+  if (!subscription_id || !subscriber_id) {
+    return NextResponse.json(
+      { error: "subscription_id and subscriber_id are required" },
+      { status: 400 }
+    );
+  }
+
+  const sub = subscriptions.get(subscription_id);
+  if (!sub) {
+    return NextResponse.json({ error: "Subscription not found" }, { status: 404 });
+  }
+
+  if (sub.subscriber_id !== subscriber_id) {
+    return NextResponse.json({ error: "Forbidden" }, { status: 403 });
+  }
+
+  // Mark status='cancelled' but keep expires_at intact
+  const updatedSub = {
+    ...sub,
+    status: "cancelled" as const,
+  };
+  subscriptions.set(subscription_id, updatedSub);
+
+  return NextResponse.json(updatedSub);
+}
+
+export async function GET(req: NextRequest): Promise<NextResponse> {
+  const { searchParams } = new URL(req.url);
+  const subscriptionId = searchParams.get("subscription_id");
+  if (!subscriptionId) {
+    return NextResponse.json({ error: "subscription_id is required" }, { status: 400 });
+  }
+
+  const sub = subscriptions.get(subscriptionId);
+  if (!sub) {
+    return NextResponse.json({ error: "Subscription not found" }, { status: 404 });
+  }
+
+  return NextResponse.json(sub);
+}
diff --git a/app/api/routes-f/subscriptions/gift/__tests__/route.test.ts b/app/api/routes-f/subscriptions/gift/__tests__/route.test.ts
new file mode 100644
index 00000000..540655e4
--- /dev/null
+++ b/app/api/routes-f/subscriptions/gift/__tests__/route.test.ts
@@ -0,0 +1,102 @@
+import { NextRequest } from "next/server";
+import { POST } from "../route";
+
+function makeReq(body: unknown): NextRequest {
+  return new NextRequest("http://localhost/api/routes-f/subscriptions/gift", {
+    method: "POST",
+    headers: { "Content-Type": "application/json" },
+    body: JSON.stringify(body),
+  });
+}
+
+const validBody = {
+  gifter_id: "user_alice",
+  recipient_id: "user_bob",
+  creator_id: "creator_a",
+  tier_id: "tier_silver",
+  payment_tx_hash: "0xabc123def456",
+};
+
+describe("POST /api/routes-f/subscriptions/gift", () => {
+  it("creates a gift subscription and returns gift_id", async () => {
+    const res = await POST(makeReq(validBody));
+    expect(res.status).toBe(201);
+    const data = await res.json();
+    expect(typeof data.gift_id).toBe("string");
+    expect(data.gift_id).toMatch(/^gift_/);
+  });
+
+  it("allows gifting to a non-existing user (creates them)", async () => {
+    const res = await POST(
+      makeReq({ ...validBody, recipient_id: "brand_new_user_xyz" })
+    );
+    expect(res.status).toBe(201);
+    const data = await res.json();
+    expect(data.gift_id).toBeTruthy();
+  });
+
+  it("returns 400 when gifter_id is missing", async () => {
+    const { gifter_id, ...body } = validBody;
+    const res = await POST(makeReq(body));
+    expect(res.status).toBe(400);
+  });
+
+  it("returns 400 when recipient_id is missing", async () => {
+    const { recipient_id, ...body } = validBody;
+    const res = await POST(makeReq(body));
+    expect(res.status).toBe(400);
+  });
+
+  it("returns 400 when creator_id is missing", async () => {
+    const { creator_id, ...body } = validBody;
+    const res = await POST(makeReq(body));
+    expect(res.status).toBe(400);
+  });
+
+  it("returns 400 when tier_id is missing", async () => {
+    const { tier_id, ...body } = validBody;
+    const res = await POST(makeReq(body));
+    expect(res.status).toBe(400);
+  });
+
+  it("returns 400 when payment_tx_hash is missing", async () => {
+    const { payment_tx_hash, ...body } = validBody;
+    const res = await POST(makeReq(body));
+    expect(res.status).toBe(400);
+  });
+
+  it("returns 400 when gifter and recipient are the same", async () => {
+    const res = await POST(
+      makeReq({ ...validBody, recipient_id: validBody.gifter_id })
+    );
+    expect(res.status).toBe(400);
+    const data = await res.json();
+    expect(data.error).toMatch(/different/i);
+  });
+
+  it("returns 404 for unknown creator", async () => {
+    const res = await POST(
+      makeReq({ ...validBody, creator_id: "creator_unknown" })
+    );
+    expect(res.status).toBe(404);
+  });
+
+  it("returns 400 for invalid tier on a known creator", async () => {
+    const res = await POST(
+      makeReq({ ...validBody, tier_id: "tier_not_real" })
+    );
+    expect(res.status).toBe(400);
+    const data = await res.json();
+    expect(data.error).toMatch(/tier/i);
+  });
+
+  it("returns 400 for invalid JSON body", async () => {
+    const req = new NextRequest("http://localhost/api/routes-f/subscriptions/gift", {
+      method: "POST",
+      headers: { "Content-Type": "application/json" },
+      body: "not json",
+    });
+    const res = await POST(req);
+    expect(res.status).toBe(400);
+  });
+});
diff --git a/app/api/routes-f/subscriptions/gift/route.ts b/app/api/routes-f/subscriptions/gift/route.ts
new file mode 100644
index 00000000..f584546b
--- /dev/null
+++ b/app/api/routes-f/subscriptions/gift/route.ts
@@ -0,0 +1,64 @@
+import { NextRequest, NextResponse } from "next/server";
+import type { GiftSubscriptionBody, GiftResponse } from "./types";
+import { createGift, validTiers } from "./store";
+
+export async function POST(req: NextRequest): Promise<NextResponse> {
+  let body: GiftSubscriptionBody;
+  try {
+    body = await req.json();
+  } catch {
+    return NextResponse.json({ error: "invalid JSON body" }, { status: 400 });
+  }
+
+  const { gifter_id, recipient_id, creator_id, tier_id, payment_tx_hash } = body;
+
+  // Validate required fields
+  if (!gifter_id || typeof gifter_id !== "string") {
+    return NextResponse.json({ error: "gifter_id is required" }, { status: 400 });
+  }
+  if (!recipient_id || typeof recipient_id !== "string") {
+    return NextResponse.json({ error: "recipient_id is required" }, { status: 400 });
+  }
+  if (!creator_id || typeof creator_id !== "string") {
+    return NextResponse.json({ error: "creator_id is required" }, { status: 400 });
+  }
+  if (!tier_id || typeof tier_id !== "string") {
+    return NextResponse.json({ error: "tier_id is required" }, { status: 400 });
+  }
+  if (!payment_tx_hash || typeof payment_tx_hash !== "string") {
+    return NextResponse.json({ error: "payment_tx_hash is required" }, { status: 400 });
+  }
+
+  // Cannot gift to yourself
+  if (gifter_id === recipient_id) {
+    return NextResponse.json(
+      { error: "gifter_id and recipient_id must be different" },
+      { status: 400 }
+    );
+  }
+
+  // Validate creator has this tier
+  const creatorTiers = validTiers[creator_id];
+  if (!creatorTiers) {
+    return NextResponse.json(
+      { error: `creator '${creator_id}' not found` },
+      { status: 404 }
+    );
+  }
+  if (!creatorTiers.includes(tier_id)) {
+    return NextResponse.json(
+      { error: `tier '${tier_id}' is not valid for creator '${creator_id}'` },
+      { status: 400 }
+    );
+  }
+
+  const { gift } = createGift(
+    gifter_id,
+    recipient_id,
+    creator_id,
+    tier_id,
+    payment_tx_hash
+  );
+
+  return NextResponse.json({ gift_id: gift.gift_id } as GiftResponse, { status: 201 });
+}
diff --git a/app/api/routes-f/subscriptions/gift/store.ts b/app/api/routes-f/subscriptions/gift/store.ts
new file mode 100644
index 00000000..b1ae1538
--- /dev/null
+++ b/app/api/routes-f/subscriptions/gift/store.ts
@@ -0,0 +1,81 @@
+import type { GiftRecord, SubscriptionRecord, InboxNotification } from "./types";
+
+let giftCounter = 1;
+let subCounter = 1;
+let notifCounter = 1;
+
+export const giftStore: GiftRecord[] = [];
+export const subscriptionStore: SubscriptionRecord[] = [];
+export const inboxStore: InboxNotification[] = [];
+
+// Known users — any ID not in this list is treated as new
+export const knownUsers = new Set<string>([
+  "user_alice",
+  "user_bob",
+  "user_charlie",
+  "user_diana",
+  "user_eve",
+  "creator_a",
+  "creator_b",
+  "creator_c",
+]);
+
+// Valid subscription tiers per creator
+export const validTiers: Record<string, string[]> = {
+  creator_a: ["tier_bronze", "tier_silver", "tier_gold"],
+  creator_b: ["tier_basic", "tier_pro", "tier_whale"],
+  creator_c: ["tier_1", "tier_2", "tier_3"],
+};
+
+export function createGift(
+  gifterId: string,
+  recipientId: string,
+  creatorId: string,
+  tierId: string,
+  txHash: string
+): { gift: GiftRecord; subscription: SubscriptionRecord; notification: InboxNotification } {
+  const now = new Date().toISOString();
+
+  const gift: GiftRecord = {
+    gift_id: `gift_${String(giftCounter++).padStart(4, "0")}`,
+    gifter_id: gifterId,
+    recipient_id: recipientId,
+    creator_id: creatorId,
+    tier_id: tierId,
+    payment_tx_hash: txHash,
+    created_at: now,
+  };
+
+  const subscription: SubscriptionRecord = {
+    subscription_id: `sub_${String(subCounter++).padStart(4, "0")}`,
+    subscriber_id: recipientId,
+    creator_id: creatorId,
+    tier_id: tierId,
+    started_at: now,
+    gifted_by: gifterId,
+    gift_id: gift.gift_id,
+  };
+
+  const notification: InboxNotification = {
+    notification_id: `notif_${String(notifCounter++).padStart(4, "0")}`,
+    user_id: recipientId,
+    type: "gift_subscription",
+    message: `${gifterId} gifted you a ${tierId} subscription to ${creatorId}!`,
+    gift_id: gift.gift_id,
+    read: false,
+    created_at: now,
+  };
+
+  giftStore.push(gift);
+  subscriptionStore.push(subscription);
+  inboxStore.push(notification);
+
+  // Add recipient to known users if they didn't exist
+  knownUsers.add(recipientId);
+
+  return { gift, subscription, notification };
+}
+
+export function getInboxForUser(userId: string): InboxNotification[] {
+  return inboxStore.filter(n => n.user_id === userId);
+}
diff --git a/app/api/routes-f/subscriptions/gift/types.ts b/app/api/routes-f/subscriptions/gift/types.ts
new file mode 100644
index 00000000..4de34352
--- /dev/null
+++ b/app/api/routes-f/subscriptions/gift/types.ts
@@ -0,0 +1,41 @@
+export interface GiftSubscriptionBody {
+  gifter_id: string;
+  recipient_id: string;
+  creator_id: string;
+  tier_id: string;
+  payment_tx_hash: string;
+}
+
+export interface GiftRecord {
+  gift_id: string;
+  gifter_id: string;
+  recipient_id: string;
+  creator_id: string;
+  tier_id: string;
+  payment_tx_hash: string;
+  created_at: string; // ISO timestamp
+}
+
+export interface SubscriptionRecord {
+  subscription_id: string;
+  subscriber_id: string; // recipient owns the sub
+  creator_id: string;
+  tier_id: string;
+  started_at: string; // ISO timestamp
+  gifted_by: string; // gifter_id
+  gift_id: string;
+}
+
+export interface InboxNotification {
+  notification_id: string;
+  user_id: string;
+  type: "gift_subscription";
+  message: string;
+  gift_id: string;
+  read: boolean;
+  created_at: string;
+}
+
+export interface GiftResponse {
+  gift_id: string;
+}
diff --git a/app/api/routes-f/subscriptions/route.ts b/app/api/routes-f/subscriptions/route.ts
new file mode 100644
index 00000000..3228b7cb
--- /dev/null
+++ b/app/api/routes-f/subscriptions/route.ts
@@ -0,0 +1,166 @@
+/**
+ * POST /api/routes-f/subscriptions
+ * Subscribe a user to a creator for a given tier.
+ * Uses in-memory storage (mock) — no real DB.
+ */
+import { NextRequest, NextResponse } from "next/server";
+import { z } from "zod";
+import { validateBody } from "@/app/api/routes-f/_lib/validate";
+
+// ---------------------------------------------------------------------------
+// Tier configuration (mock)
+// ---------------------------------------------------------------------------
+interface TierConfig {
+  label: string;
+  durationDays: number;
+}
+
+const TIERS: Record<string, TierConfig> = {
+  basic: { label: "Basic", durationDays: 30 },
+  standard: { label: "Standard", durationDays: 90 },
+  premium: { label: "Premium", durationDays: 365 },
+};
+
+// ---------------------------------------------------------------------------
+// In-memory storage
+// ---------------------------------------------------------------------------
+export interface Subscription {
+  subscription_id: string;
+  subscriber_id: string;
+  creator_id: string;
+  tier_id: string;
+  payment_tx_hash: string;
+  asset: "XLM" | "USDC";
+  started_at: string;
+  expires_at: string;
+  status?: "active" | "cancelled";
+}
+
+// Exported so tests can reset between runs.
+export const subscriptions: Map<string, Subscription> = new Map();
+
+// ---------------------------------------------------------------------------
+// Validation schema
+// ---------------------------------------------------------------------------
+const createSubscriptionSchema = z.object({
+  subscriber_id: z.string().uuid(),
+  creator_id: z.string().uuid(),
+  tier_id: z.string().min(1),
+  payment_tx_hash: z.string().min(1),
+  asset: z.enum(["XLM", "USDC"]),
+});
+
+// ---------------------------------------------------------------------------
+// Helpers
+// ---------------------------------------------------------------------------
+function generateId(): string {
+  // crypto.randomUUID() is available in Node 18+ and in the Next.js edge/node runtime.
+  return crypto.randomUUID();
+}
+
+function findActiveSubscription(
+  subscriberId: string,
+  creatorId: string,
+  now: number
+): Subscription | undefined {
+  for (const sub of subscriptions.values()) {
+    if (
+      sub.subscriber_id === subscriberId &&
+      sub.creator_id === creatorId &&
+      new Date(sub.expires_at).getTime() > now
+    ) {
+      return sub;
+    }
+  }
+  return undefined;
+}
+
+// ---------------------------------------------------------------------------
+// Route handlers
+// ---------------------------------------------------------------------------
+export async function GET(req: NextRequest): Promise<NextResponse> {
+  const { searchParams } = new URL(req.url);
+  const subscriptionId = searchParams.get("subscription_id");
+  if (!subscriptionId) {
+    return NextResponse.json({ error: "subscription_id is required" }, { status: 400 });
+  }
+
+  const sub = subscriptions.get(subscriptionId);
+  if (!sub) {
+    return NextResponse.json({ error: "Subscription not found" }, { status: 404 });
+  }
+
+  return NextResponse.json(sub);
+}
+
+export async function POST(req: NextRequest): Promise<NextResponse> {
+  const bodyResult = await validateBody(req, createSubscriptionSchema);
+  if (bodyResult instanceof NextResponse) {
+    return bodyResult;
+  }
+
+  const { subscriber_id, creator_id, tier_id, payment_tx_hash, asset } =
+    bodyResult.data;
+
+  // Validate tier
+  const tier = TIERS[tier_id];
+  if (!tier) {
+    return NextResponse.json(
+      {
+        error: "Unknown tier",
+        message: `tier_id "${tier_id}" is not valid. Valid tiers: ${Object.keys(TIERS).join(", ")}.`,
+      },
+      { status: 404 }
+    );
+  }
+
+  const now = Date.now();
+
+  // Check for an already-active subscription
+  const existing = findActiveSubscription(subscriber_id, creator_id, now);
+  if (existing) {
+    return NextResponse.json(
+      {
+        error: "Subscription already active",
+        message:
+          "This subscriber already has an active subscription to this creator.",
+        subscription_id: existing.subscription_id,
+        expires_at: existing.expires_at,
+      },
+      { status: 409 }
+    );
+  }
+
+  // Compute timestamps
+  const started_at = new Date(now).toISOString();
+  const expires_at = new Date(
+    now + tier.durationDays * 24 * 60 * 60 * 1000
+  ).toISOString();
+
+  const subscription: Subscription = {
+    subscription_id: generateId(),
+    subscriber_id,
+    creator_id,
+    tier_id,
+    payment_tx_hash,
+    asset,
+    started_at,
+    expires_at,
+    status: "active",
+  };
+
+  subscriptions.set(subscription.subscription_id, subscription);
+
+  return NextResponse.json(
+    {
+      subscription_id: subscription.subscription_id,
+      subscriber_id: subscription.subscriber_id,
+      creator_id: subscription.creator_id,
+      tier_id: subscription.tier_id,
+      started_at: subscription.started_at,
+      expires_at: subscription.expires_at,
+      status: subscription.status,
+    },
+    { status: 201 }
+  );
+}
diff --git a/app/api/routes-f/team-name/__tests__/route.test.ts b/app/api/routes-f/team-name/__tests__/route.test.ts
new file mode 100644
index 00000000..3e2e6113
--- /dev/null
+++ b/app/api/routes-f/team-name/__tests__/route.test.ts
@@ -0,0 +1,28 @@
+import { generateTeamNames } from "../route";
+
+describe("generateTeamNames", () => {
+  it("returns the requested count", () => {
+    expect(generateTeamNames(5, 42, "fierce")).toHaveLength(5);
+    expect(generateTeamNames(1, 7, "funny")).toHaveLength(1);
+  });
+
+  it("is deterministic for a given seed", () => {
+    expect(generateTeamNames(4, 42, "classic")).toEqual(
+      generateTeamNames(4, 42, "classic"),
+    );
+  });
+
+  it("differs across seeds", () => {
+    expect(generateTeamNames(4, 1, "classic")).not.toEqual(
+      generateTeamNames(4, 2, "classic"),
+    );
+  });
+
+  it("uses the requested style's adjective pool", () => {
+    const funnyAdjectives = ["Wobbly", "Sneaky", "Spicy", "Clumsy", "Hangry", "Derpy", "Sleepy", "Cheeky"];
+    for (const name of generateTeamNames(10, 99, "funny")) {
+      const adjective = name.split(" ")[0];
+      expect(funnyAdjectives).toContain(adjective);
+    }
+  });
+});
diff --git a/app/api/routes-f/team-name/route.ts b/app/api/routes-f/team-name/route.ts
new file mode 100644
index 00000000..6637ac8f
--- /dev/null
+++ b/app/api/routes-f/team-name/route.ts
@@ -0,0 +1,51 @@
+import { NextResponse } from "next/server";
+import { z } from "zod";
+import { validateQuery } from "@/app/api/routes-f/_lib/validate";
+
+export type TeamStyle = "fierce" | "funny" | "classic";
+
+// Pools bundled in-folder (no external data deps).
+const ADJECTIVES: Record<TeamStyle, string[]> = {
+  fierce: ["Savage", "Iron", "Brutal", "Raging", "Venomous", "Storm", "Shadow", "Apex"],
+  funny: ["Wobbly", "Sneaky", "Spicy", "Clumsy", "Hangry", "Derpy", "Sleepy", "Cheeky"],
+  classic: ["Royal", "Golden", "United", "Athletic", "Imperial", "Grand", "Premier", "Legacy"],
+};
+
+const MASCOTS = [
+  "Tigers", "Wolves", "Falcons", "Dragons", "Vipers", "Titans",
+  "Sharks", "Ravens", "Bulls", "Phoenix", "Cobras", "Hawks",
+];
+
+/** Deterministic PRNG (mulberry32). */
+function mulberry32(seed: number): () => number {
+  let s = seed >>> 0;
+  return () => {
+    s = (s + 0x6d2b79f5) >>> 0;
+    let t = Math.imul(s ^ (s >>> 15), 1 | s);
+    t = (t + Math.imul(t ^ (t >>> 7), 61 | t)) ^ t;
+    return ((t ^ (t >>> 14)) >>> 0) / 4294967296;
+  };
+}
+
+const pick = <T>(arr: T[], rng: () => number): T => arr[Math.floor(rng() * arr.length)];
+
+/** Generate `count` deterministic team names in the given style from `seed`. */
+export function generateTeamNames(count: number, seed: number, style: TeamStyle): string[] {
+  const rng = mulberry32(seed);
+  const adjectives = ADJECTIVES[style];
+  return Array.from({ length: count }, () => `${pick(adjectives, rng)} ${pick(MASCOTS, rng)}`);
+}
+
+const schema = z.object({
+  count: z.coerce.number().int().min(1).max(50).optional().default(5),
+  seed: z.coerce.number().int().optional().default(0),
+  style: z.enum(["fierce", "funny", "classic"]).optional().default("classic"),
+});
+
+export async function GET(request: Request): Promise<NextResponse> {
+  const { searchParams } = new URL(request.url);
+  const result = validateQuery(searchParams, schema);
+  if (result instanceof NextResponse) return result;
+  const { count, seed, style } = result.data;
+  return NextResponse.json({ names: generateTeamNames(count, seed, style) });
+}
diff --git a/app/api/routes-f/template-interpolation/route.ts b/app/api/routes-f/template-interpolation/route.ts
new file mode 100644
index 00000000..e303294a
--- /dev/null
+++ b/app/api/routes-f/template-interpolation/route.ts
@@ -0,0 +1,36 @@
+import { type NextRequest, NextResponse } from "next/server";
+import { z } from "zod";
+import { validateBody } from "@/app/api/routes-f/_lib/validate";
+import {
+  interpolateTemplate,
+  type MissingMode,
+} from "@/app/api/routes-f/_lib/templateInterpolation";
+
+const interpolationBodySchema = z.object({
+  template: z.string(),
+  values: z.any(),
+  on_missing: z.enum(["empty", "keep", "error"]).optional(),
+});
+
+export async function POST(req: NextRequest) {
+  const validated = await validateBody(req, interpolationBodySchema);
+  if (validated instanceof NextResponse) {
+    return validated;
+  }
+
+  const { template, values, on_missing } = validated.data;
+  const mode = (on_missing as MissingMode) ?? "empty";
+
+  const result = interpolateTemplate(template, values, mode);
+  if (mode === "error" && result.missing_keys.length > 0) {
+    return NextResponse.json(
+      {
+        error: "Missing values for template placeholders.",
+        missing_keys: result.missing_keys,
+      },
+      { status: 400 }
+    );
+  }
+
+  return NextResponse.json(result);
+}
diff --git a/app/api/routes-f/text-fingerprint/_lib/helpers.ts b/app/api/routes-f/text-fingerprint/_lib/helpers.ts
new file mode 100644
index 00000000..b1ee55cc
--- /dev/null
+++ b/app/api/routes-f/text-fingerprint/_lib/helpers.ts
@@ -0,0 +1,34 @@
+import { createHash } from "crypto";
+
+function isRecord(value: unknown): value is Record<string, unknown> {
+  return typeof value === "object" && value !== null && !Array.isArray(value);
+}
+
+export function normalizeText(text: string): string {
+  return text
+    .toLowerCase()
+    .replace(/[^\w\s]/g, " ")   // strip punctuation → space
+    .replace(/\s+/g, " ")       // collapse whitespace
+    .trim();
+}
+
+export function fingerprint(text: string): { fingerprint: string; normalized: string } {
+  const normalized = normalizeText(text);
+  const tokens = normalized.split(" ").filter(Boolean);
+  // deduplicate then sort so order-independent texts yield the same hash
+  const canonical = [...new Set(tokens)].sort().join(" ");
+  const hash = createHash("sha256").update(canonical, "utf8").digest("hex");
+  return { fingerprint: hash, normalized };
+}
+
+export function parseAndFingerprint(input: unknown): { fingerprint: string; normalized: string } {
+  if (!isRecord(input)) {
+    throw new Error("Request body must be an object.");
+  }
+
+  if (typeof input.text !== "string") {
+    throw new Error("text must be a string.");
+  }
+
+  return fingerprint(input.text);
+}
diff --git a/app/api/routes-f/text-fingerprint/_lib/types.ts b/app/api/routes-f/text-fingerprint/_lib/types.ts
new file mode 100644
index 00000000..f91e6eee
--- /dev/null
+++ b/app/api/routes-f/text-fingerprint/_lib/types.ts
@@ -0,0 +1,4 @@
+export interface FingerprintResponse {
+  fingerprint: string;
+  normalized: string;
+}
diff --git a/app/api/routes-f/text-fingerprint/route.ts b/app/api/routes-f/text-fingerprint/route.ts
new file mode 100644
index 00000000..34d727b3
--- /dev/null
+++ b/app/api/routes-f/text-fingerprint/route.ts
@@ -0,0 +1,22 @@
+import { type NextRequest, NextResponse } from "next/server";
+import { parseAndFingerprint } from "./_lib/helpers";
+import type { FingerprintResponse } from "./_lib/types";
+
+export async function POST(req: NextRequest) {
+  let body: unknown;
+
+  try {
+    body = await req.json();
+  } catch {
+    return NextResponse.json({ error: "Invalid JSON body." }, { status: 400 });
+  }
+
+  try {
+    const result = parseAndFingerprint(body);
+    return NextResponse.json(result satisfies FingerprintResponse);
+  } catch (error) {
+    const message =
+      error instanceof Error ? error.message : "Failed to compute fingerprint.";
+    return NextResponse.json({ error: message }, { status: 400 });
+  }
+}
diff --git a/app/api/routes-f/text-similarity/route.ts b/app/api/routes-f/text-similarity/route.ts
new file mode 100644
index 00000000..eb690149
--- /dev/null
+++ b/app/api/routes-f/text-similarity/route.ts
@@ -0,0 +1,21 @@
+import { type NextRequest, NextResponse } from "next/server";
+import { z } from "zod";
+import { validateBody } from "@/app/api/routes-f/_lib/validate";
+import { computeSimilarity, type SimilarityAlgorithm } from "@/app/api/routes-f/_lib/textSimilarity";
+
+const similarityBodySchema = z.object({
+  a: z.string(),
+  b: z.string(),
+  algorithm: z.enum(["jaccard", "cosine", "both"]).optional(),
+});
+
+export async function POST(req: NextRequest) {
+  const validated = await validateBody(req, similarityBodySchema);
+  if (validated instanceof NextResponse) {
+    return validated;
+  }
+
+  const { a, b, algorithm } = validated.data;
+  const normalizedAlgorithm = algorithm ?? "both";
+  return NextResponse.json(computeSimilarity(a, b, normalizedAlgorithm as SimilarityAlgorithm));
+}
diff --git a/app/api/routes-f/tip-alert/__tests__/route.test.ts b/app/api/routes-f/tip-alert/__tests__/route.test.ts
new file mode 100644
index 00000000..2e557a04
--- /dev/null
+++ b/app/api/routes-f/tip-alert/__tests__/route.test.ts
@@ -0,0 +1,113 @@
+/**
+ * @jest-environment node
+ */
+import { NextRequest } from "next/server";
+import { GET, PUT, store } from "../route";
+
+function makeGet(creator_id?: string) {
+  const url = creator_id
+    ? `http://localhost/api/routes-f/tip-alert?creator_id=${creator_id}`
+    : "http://localhost/api/routes-f/tip-alert";
+  return new NextRequest(url, { method: "GET" });
+}
+
+function makePut(body: unknown) {
+  return new NextRequest("http://localhost/api/routes-f/tip-alert", {
+    method: "PUT",
+    headers: { "content-type": "application/json" },
+    body: JSON.stringify(body),
+  });
+}
+
+describe("/api/routes-f/tip-alert", () => {
+  beforeEach(() => store.clear());
+
+  // ── GET ───────────────────────────────────────────────────────────────────
+
+  it("GET returns default config for unknown creator", async () => {
+    const res = await GET(makeGet("creator-1"));
+    expect(res.status).toBe(200);
+    const body = await res.json();
+    expect(body.creator_id).toBe("creator-1");
+    expect(body.min_amount_usdc).toBe(1);
+    expect(body.animation).toBe("confetti");
+    expect(body.duration_seconds).toBe(5);
+    expect(body.sound_url).toBeUndefined();
+  });
+
+  it("GET 400 when creator_id is missing", async () => {
+    const res = await GET(makeGet());
+    expect(res.status).toBe(400);
+  });
+
+  // ── PUT ───────────────────────────────────────────────────────────────────
+
+  it("PUT updates min_amount_usdc", async () => {
+    const res = await PUT(makePut({ creator_id: "creator-1", min_amount_usdc: 5 }));
+    expect(res.status).toBe(200);
+    const body = await res.json();
+    expect(body.min_amount_usdc).toBe(5);
+  });
+
+  it("PUT updates animation to fireworks", async () => {
+    const res = await PUT(makePut({ creator_id: "creator-1", animation: "fireworks" }));
+    expect(res.status).toBe(200);
+    const body = await res.json();
+    expect(body.animation).toBe("fireworks");
+  });
+
+  it("PUT sets sound_url", async () => {
+    const res = await PUT(makePut({ creator_id: "creator-1", sound_url: "https://example.com/alert.mp3" }));
+    expect(res.status).toBe(200);
+    const body = await res.json();
+    expect(body.sound_url).toBe("https://example.com/alert.mp3");
+  });
+
+  it("PUT updates duration_seconds within [1, 30]", async () => {
+    const res = await PUT(makePut({ creator_id: "creator-1", duration_seconds: 15 }));
+    expect(res.status).toBe(200);
+    const body = await res.json();
+    expect(body.duration_seconds).toBe(15);
+  });
+
+  it("PUT persists; subsequent GET returns updated config", async () => {
+    await PUT(makePut({ creator_id: "creator-2", min_amount_usdc: 10, animation: "none", duration_seconds: 8 }));
+    const res = await GET(makeGet("creator-2"));
+    const body = await res.json();
+    expect(body.min_amount_usdc).toBe(10);
+    expect(body.animation).toBe("none");
+    expect(body.duration_seconds).toBe(8);
+  });
+
+  // ── validation ────────────────────────────────────────────────────────────
+
+  it("PUT 400 when duration_seconds < 1", async () => {
+    const res = await PUT(makePut({ creator_id: "c", duration_seconds: 0 }));
+    expect(res.status).toBe(400);
+  });
+
+  it("PUT 400 when duration_seconds > 30", async () => {
+    const res = await PUT(makePut({ creator_id: "c", duration_seconds: 31 }));
+    expect(res.status).toBe(400);
+  });
+
+  it("PUT 400 for invalid animation value", async () => {
+    const res = await PUT(makePut({ creator_id: "c", animation: "sparkles" }));
+    expect(res.status).toBe(400);
+  });
+
+  it("PUT 400 when creator_id is missing", async () => {
+    const res = await PUT(makePut({ min_amount_usdc: 5 }));
+    expect(res.status).toBe(400);
+  });
+
+  it("PUT 400 on invalid JSON", async () => {
+    const req = new NextRequest("http://localhost/api/routes-f/tip-alert", {
+      method: "PUT",
+      headers: { "content-type": "application/json" },
+      body: "bad-json",
+    });
+    const res = await PUT(req);
+    expect(res.status).toBe(400);
+  });
+});
diff --git a/app/api/routes-f/tip-alert/route.ts b/app/api/routes-f/tip-alert/route.ts
new file mode 100644
index 00000000..51be21e2
--- /dev/null
+++ b/app/api/routes-f/tip-alert/route.ts
@@ -0,0 +1,110 @@
+/**
+ * GET  /api/routes-f/tip-alert?creator_id=<id>  → returns tip alert config
+ * PUT  /api/routes-f/tip-alert                   → updates tip alert config
+ */
+import { NextRequest, NextResponse } from "next/server";
+
+// ---------------------------------------------------------------------------
+// Types
+// ---------------------------------------------------------------------------
+export interface TipAlertConfig {
+  creator_id: string;
+  min_amount_usdc: number;
+  sound_url?: string;
+  animation: "confetti" | "fireworks" | "none";
+  duration_seconds: number;
+}
+
+// ---------------------------------------------------------------------------
+// In-memory storage with defaults factory
+// ---------------------------------------------------------------------------
+export const store = new Map<string, TipAlertConfig>();
+
+function getOrDefault(creator_id: string): TipAlertConfig {
+  if (store.has(creator_id)) return store.get(creator_id)!;
+  return {
+    creator_id,
+    min_amount_usdc: 1,
+    animation: "confetti",
+    duration_seconds: 5,
+  };
+}
+
+// ---------------------------------------------------------------------------
+// GET
+// ---------------------------------------------------------------------------
+export async function GET(req: NextRequest): Promise<NextResponse> {
+  const creator_id = new URL(req.url).searchParams.get("creator_id");
+  if (!creator_id) {
+    return NextResponse.json({ error: "creator_id is required" }, { status: 400 });
+  }
+  return NextResponse.json(getOrDefault(creator_id));
+}
+
+// ---------------------------------------------------------------------------
+// PUT
+// ---------------------------------------------------------------------------
+export async function PUT(req: NextRequest): Promise<NextResponse> {
+  let body: unknown;
+  try {
+    body = await req.json();
+  } catch {
+    return NextResponse.json({ error: "Invalid JSON body" }, { status: 400 });
+  }
+
+  const {
+    creator_id,
+    min_amount_usdc,
+    sound_url,
+    animation,
+    duration_seconds,
+  } = body as Record<string, unknown>;
+
+  if (!creator_id || typeof creator_id !== "string") {
+    return NextResponse.json({ error: "creator_id is required" }, { status: 400 });
+  }
+
+  const current = getOrDefault(creator_id);
+  const updated: TipAlertConfig = { ...current };
+
+  if (min_amount_usdc !== undefined) {
+    if (typeof min_amount_usdc !== "number" || min_amount_usdc < 0) {
+      return NextResponse.json({ error: "min_amount_usdc must be a non-negative number" }, { status: 400 });
+    }
+    updated.min_amount_usdc = min_amount_usdc;
+  }
+
+  if (sound_url !== undefined) {
+    if (typeof sound_url !== "string") {
+      return NextResponse.json({ error: "sound_url must be a string" }, { status: 400 });
+    }
+    updated.sound_url = sound_url;
+  }
+
+  if (animation !== undefined) {
+    if (!["confetti", "fireworks", "none"].includes(animation as string)) {
+      return NextResponse.json(
+        { error: 'animation must be "confetti", "fireworks", or "none"' },
+        { status: 400 }
+      );
+    }
+    updated.animation = animation as TipAlertConfig["animation"];
+  }
+
+  if (duration_seconds !== undefined) {
+    if (
+      typeof duration_seconds !== "number" ||
+      duration_seconds < 1 ||
+      duration_seconds > 30
+    ) {
+      return NextResponse.json(
+        { error: "duration_seconds must be between 1 and 30" },
+        { status: 400 }
+      );
+    }
+    updated.duration_seconds = duration_seconds;
+  }
+
+  store.set(creator_id, updated);
+  return NextResponse.json(updated);
+}
diff --git a/app/api/routes-f/tip-goal/__tests__/route.test.ts b/app/api/routes-f/tip-goal/__tests__/route.test.ts
new file mode 100644
index 00000000..5ba18940
--- /dev/null
+++ b/app/api/routes-f/tip-goal/__tests__/route.test.ts
@@ -0,0 +1,112 @@
+/**
+ * @jest-environment node
+ */
+import { NextRequest } from "next/server";
+import { GET, goals, tipRecords } from "../route";
+
+function makeGet(creator_id?: string) {
+  const url = creator_id
+    ? `http://localhost/api/routes-f/tip-goal?creator_id=${creator_id}`
+    : "http://localhost/api/routes-f/tip-goal";
+  return new NextRequest(url, { method: "GET" });
+}
+
+describe("GET /api/routes-f/tip-goal", () => {
+  // Restore seed data after tests that mutate the maps
+  afterEach(() => {
+    goals.set("creator-alpha", {
+      creator_id: "creator-alpha",
+      goal_usdc: 100,
+      ends_at: "2099-12-31T00:00:00.000Z",
+    });
+    tipRecords.set("creator-alpha", [
+      { viewer_id: "viewer-1", amount_usdc: 30, tipped_at: "2026-06-01T10:00:00.000Z" },
+      { viewer_id: "viewer-2", amount_usdc: 25, tipped_at: "2026-06-02T11:00:00.000Z" },
+      { viewer_id: "viewer-1", amount_usdc: 10, tipped_at: "2026-06-03T12:00:00.000Z" },
+    ]);
+    goals.set("creator-beta", { creator_id: "creator-beta", goal_usdc: 50 });
+    tipRecords.set("creator-beta", [
+      { viewer_id: "viewer-3", amount_usdc: 50, tipped_at: "2026-06-01T09:00:00.000Z" },
+    ]);
+  });
+
+  // ── under-goal ────────────────────────────────────────────────────────────
+
+  it("returns under-goal progress correctly", async () => {
+    // creator-alpha: 30 + 25 + 10 = 65 of 100 → 65%
+    const res = await GET(makeGet("creator-alpha"));
+    expect(res.status).toBe(200);
+    const { goal } = await res.json();
+    expect(goal).not.toBeNull();
+    expect(goal.goal_usdc).toBe(100);
+    expect(goal.current_usdc).toBe(65);
+    expect(goal.percent).toBe(65);
+    expect(goal.contributors).toBe(2); // viewer-1 and viewer-2 (unique)
+    expect(goal.ends_at).toBe("2099-12-31T00:00:00.000Z");
+  });
+
+  // ── exactly-goal ──────────────────────────────────────────────────────────
+
+  it("returns 100% when tips exactly meet the goal", async () => {
+    // creator-beta: 50 of 50 → 100%
+    const res = await GET(makeGet("creator-beta"));
+    const { goal } = await res.json();
+    expect(goal.current_usdc).toBe(50);
+    expect(goal.percent).toBe(100);
+    expect(goal.ends_at).toBeUndefined();
+  });
+
+  // ── over-goal ─────────────────────────────────────────────────────────────
+
+  it("caps percent at 100 when tips exceed the goal", async () => {
+    tipRecords.set("creator-beta", [
+      { viewer_id: "viewer-3", amount_usdc: 75, tipped_at: "2026-06-01T09:00:00.000Z" },
+    ]);
+    const res = await GET(makeGet("creator-beta"));
+    const { goal } = await res.json();
+    expect(goal.current_usdc).toBe(75);
+    expect(goal.percent).toBe(100);
+  });
+
+  // ── no active goal ────────────────────────────────────────────────────────
+
+  it("returns null when creator has no goal", async () => {
+    const res = await GET(makeGet("creator-unknown"));
+    expect(res.status).toBe(200);
+    const { goal } = await res.json();
+    expect(goal).toBeNull();
+  });
+
+  it("returns null when goal has expired", async () => {
+    goals.set("creator-expired", {
+      creator_id: "creator-expired",
+      goal_usdc: 100,
+      ends_at: "2000-01-01T00:00:00.000Z",
+    });
+    const res = await GET(makeGet("creator-expired"));
+    const { goal } = await res.json();
+    expect(goal).toBeNull();
+    // cleanup
+    goals.delete("creator-expired");
+  });
+
+  // ── contributors ──────────────────────────────────────────────────────────
+
+  it("counts unique contributors", async () => {
+    tipRecords.set("creator-alpha", [
+      { viewer_id: "v1", amount_usdc: 10, tipped_at: "2026-01-01T00:00:00.000Z" },
+      { viewer_id: "v1", amount_usdc: 10, tipped_at: "2026-01-02T00:00:00.000Z" },
+      { viewer_id: "v2", amount_usdc: 10, tipped_at: "2026-01-03T00:00:00.000Z" },
+    ]);
+    const res = await GET(makeGet("creator-alpha"));
+    const { goal } = await res.json();
+    expect(goal.contributors).toBe(2);
+  });
+
+  // ── validation ────────────────────────────────────────────────────────────
+
+  it("400 when creator_id is missing", async () => {
+    const res = await GET(makeGet());
+    expect(res.status).toBe(400);
+  });
+});
diff --git a/app/api/routes-f/tip-goal/route.ts b/app/api/routes-f/tip-goal/route.ts
new file mode 100644
index 00000000..f7347d9e
--- /dev/null
+++ b/app/api/routes-f/tip-goal/route.ts
@@ -0,0 +1,99 @@
+/**
+ * GET /api/routes-f/tip-goal?creator_id=<id>
+ * Returns active tip goal progress for a creator, or null if no active goal.
+ */
+import { NextRequest, NextResponse } from "next/server";
+
+// ---------------------------------------------------------------------------
+// Types
+// ---------------------------------------------------------------------------
+export interface TipRecord {
+  viewer_id: string;
+  amount_usdc: number;
+  tipped_at: string;
+}
+
+export interface TipGoal {
+  creator_id: string;
+  goal_usdc: number;
+  ends_at?: string; // ISO string; absent = no deadline
+}
+
+// ---------------------------------------------------------------------------
+// Seed data
+// ---------------------------------------------------------------------------
+export const goals = new Map<string, TipGoal>([
+  [
+    "creator-alpha",
+    { creator_id: "creator-alpha", goal_usdc: 100, ends_at: "2099-12-31T00:00:00.000Z" },
+  ],
+  [
+    "creator-beta",
+    { creator_id: "creator-beta", goal_usdc: 50 },
+  ],
+]);
+
+export const tipRecords = new Map<string, TipRecord[]>([
+  [
+    "creator-alpha",
+    [
+      { viewer_id: "viewer-1", amount_usdc: 30, tipped_at: "2026-06-01T10:00:00.000Z" },
+      { viewer_id: "viewer-2", amount_usdc: 25, tipped_at: "2026-06-02T11:00:00.000Z" },
+      { viewer_id: "viewer-1", amount_usdc: 10, tipped_at: "2026-06-03T12:00:00.000Z" },
+    ],
+  ],
+  [
+    "creator-beta",
+    [
+      { viewer_id: "viewer-3", amount_usdc: 50, tipped_at: "2026-06-01T09:00:00.000Z" },
+    ],
+  ],
+]);
+
+// ---------------------------------------------------------------------------
+// Helper
+// ---------------------------------------------------------------------------
+interface GoalProgressResponse {
+  goal_usdc: number;
+  current_usdc: number;
+  percent: number;
+  ends_at?: string;
+  contributors: number;
+}
+
+function computeProgress(creator_id: string): GoalProgressResponse | null {
+  const goal = goals.get(creator_id);
+  if (!goal) return null;
+
+  // Check expiry
+  if (goal.ends_at && new Date(goal.ends_at) < new Date()) return null;
+
+  const records = tipRecords.get(creator_id) ?? [];
+  const current_usdc = records.reduce((sum, r) => sum + r.amount_usdc, 0);
+  const uniqueViewers = new Set(records.map((r) => r.viewer_id));
+  const percent = Math.min(
+    100,
+    Math.round((current_usdc / goal.goal_usdc) * 10000) / 100
+  );
+
+  return {
+    goal_usdc: goal.goal_usdc,
+    current_usdc,
+    percent,
+    ...(goal.ends_at ? { ends_at: goal.ends_at } : {}),
+    contributors: uniqueViewers.size,
+  };
+}
+
+// ---------------------------------------------------------------------------
+// Route handler
+// ---------------------------------------------------------------------------
+export async function GET(req: NextRequest): Promise<NextResponse> {
+  const creator_id = new URL(req.url).searchParams.get("creator_id");
+  if (!creator_id) {
+    return NextResponse.json({ error: "creator_id is required" }, { status: 400 });
+  }
+
+  const progress = computeProgress(creator_id);
+  return NextResponse.json({ goal: progress });
+}
diff --git a/app/api/routes-f/tip-recap/__tests__/route.test.ts b/app/api/routes-f/tip-recap/__tests__/route.test.ts
new file mode 100644
index 00000000..7886dd96
--- /dev/null
+++ b/app/api/routes-f/tip-recap/__tests__/route.test.ts
@@ -0,0 +1,135 @@
+import { sql } from "@vercel/postgres";
+import { GET } from "../route";
+import { NextRequest } from "next/server";
+
+jest.mock("next/server", () => ({
+  NextResponse: {
+    json: (body: unknown, init?: ResponseInit) =>
+      new Response(JSON.stringify(body), {
+        ...init,
+        headers: { "Content-Type": "application/json" },
+      }),
+  },
+}));
+
+jest.mock("@vercel/postgres", () => ({
+  sql: jest.fn(),
+}));
+
+jest.mock("@/app/api/routes-f/_lib/validate", () => ({
+  validateQuery: jest.fn((params: URLSearchParams, schema: any) => {
+    const obj = Object.fromEntries(params.entries());
+    const result = schema.safeParse(obj);
+    if (!result.success) {
+      return new Response(JSON.stringify({ error: "Invalid query", details: result.error.flatten() }), { status: 400 });
+    }
+    return { data: result.data };
+  }),
+}));
+
+const sqlMock = sql as unknown as jest.Mock;
+
+function makeGetRequest(params: Record<string, string>) {
+  const url = new URL("http://localhost/api/routes-f/tip-recap");
+  for (const [key, value] of Object.entries(params)) {
+    url.searchParams.set(key, value);
+  }
+  return new NextRequest(url) as any;
+}
+
+describe("Tip Recap Card API", () => {
+  beforeEach(() => {
+    jest.clearAllMocks();
+  });
+
+  describe("GET /api/routes-f/tip-recap", () => {
+    it("returns 400 for missing tip_id", async () => {
+      const res = await GET(makeGetRequest({}));
+      expect(res.status).toBe(400);
+    });
+
+    it("returns 400 for invalid tip_id", async () => {
+      const res = await GET(makeGetRequest({ tip_id: "not-a-uuid" }));
+      expect(res.status).toBe(400);
+    });
+
+    it("returns 404 for unknown tip", async () => {
+      sqlMock.mockResolvedValueOnce({ rows: [] });
+
+      const res = await GET(makeGetRequest({ tip_id: "550e8400-e29b-41d4-a716-446655440000" }));
+      expect(res.status).toBe(404);
+      const body = await res.json();
+      expect(body.error).toBe("Tip not found");
+    });
+
+    it("returns tip recap payload for a known tip", async () => {
+      sqlMock.mockResolvedValueOnce({
+        rows: [
+          {
+            tip_id: "tip-1",
+            creator_id: "creator-1",
+            tipper_id: "tipper-1",
+            amount: "10.5",
+            asset: "XLM",
+            message: "Great stream!",
+            is_anonymous: false,
+            created_at: "2025-06-01T12:00:00Z",
+            creator_username: "alice",
+            creator_avatar: "alice.png",
+            tipper_username: "bob",
+            tipper_avatar: "bob.png",
+          },
+        ],
+      });
+
+      const res = await GET(makeGetRequest({ tip_id: "550e8400-e29b-41d4-a716-446655440000" }));
+      expect(res.status).toBe(200);
+      const body = await res.json();
+      expect(body.tip_id).toBe("tip-1");
+      expect(body.creator.username).toBe("alice");
+      expect(body.tipper.username).toBe("bob");
+      expect(body.tipper.anonymous).toBe(false);
+      expect(body.amount).toBe("10.5");
+      expect(body.asset).toBe("XLM");
+      expect(body.message).toBe("Great stream!");
+      expect(body.image_meta).toEqual({ width: 1200, height: 630, format: "png" });
+    });
+
+    it("handles anonymous tips by hiding tipper details", async () => {
+      sqlMock.mockResolvedValueOnce({
+        rows: [
+          {
+            tip_id: "tip-2",
+            creator_id: "creator-1",
+            tipper_id: "tipper-2",
+            amount: "5.0",
+            asset: "USDC",
+            message: null,
+            is_anonymous: true,
+            created_at: "2025-06-01T12:00:00Z",
+            creator_username: "alice",
+            creator_avatar: "alice.png",
+            tipper_username: "anon",
+            tipper_avatar: "anon.png",
+          },
+        ],
+      });
+
+      const res = await GET(makeGetRequest({ tip_id: "550e8400-e29b-41d4-a716-446655440000" }));
+      expect(res.status).toBe(200);
+      const body = await res.json();
+      expect(body.tipper.anonymous).toBe(true);
+      expect(body.tipper.user_id).toBeNull();
+      expect(body.tipper.username).toBeNull();
+      expect(body.tipper.avatar).toBeNull();
+      expect(body.message).toBeNull();
+    });
+
+    it("returns 500 on database error", async () => {
+      sqlMock.mockRejectedValueOnce(new Error("DB error"));
+
+      const res = await GET(makeGetRequest({ tip_id: "550e8400-e29b-41d4-a716-446655440000" }));
+      expect(res.status).toBe(500);
+    });
+  });
+});
diff --git a/app/api/routes-f/tip-recap/route.ts b/app/api/routes-f/tip-recap/route.ts
new file mode 100644
index 00000000..df0a949a
--- /dev/null
+++ b/app/api/routes-f/tip-recap/route.ts
@@ -0,0 +1,121 @@
+import { NextRequest, NextResponse } from "next/server";
+import { sql } from "@vercel/postgres";
+import { z } from "zod";
+import { validateQuery } from "@/app/api/routes-f/_lib/validate";
+
+export const runtime = "nodejs";
+export const dynamic = "force-dynamic";
+
+const getQuerySchema = z.object({
+  tip_id: z.string().uuid(),
+});
+
+type TipRecapPayload = {
+  tip_id: string;
+  creator: {
+    user_id: string;
+    username: string | null;
+    avatar: string | null;
+  };
+  tipper: {
+    user_id: string | null;
+    username: string | null;
+    avatar: string | null;
+    anonymous: boolean;
+  };
+  amount: string;
+  asset: string;
+  message: string | null;
+  image_meta: {
+    width: number;
+    height: number;
+    format: string;
+  };
+  created_at: string;
+};
+
+export async function GET(req: NextRequest): Promise<NextResponse> {
+  const queryResult = validateQuery(
+    new URL(req.url).searchParams,
+    getQuerySchema
+  );
+  if (queryResult instanceof Response) {
+    return queryResult;
+  }
+
+  const { tip_id } = queryResult.data;
+
+  try {
+    const { rows: tipRows } = await sql`
+      SELECT
+        t.id AS tip_id,
+        t.creator_id,
+        t.tipper_id,
+        t.amount,
+        t.asset,
+        t.message,
+        t.is_anonymous,
+        t.created_at,
+        u_creator.username  AS creator_username,
+        u_creator.avatar    AS creator_avatar,
+        u_tipper.username   AS tipper_username,
+        u_tipper.avatar     AS tipper_avatar
+      FROM tip_transactions t
+      LEFT JOIN users u_creator ON u_creator.id = t.creator_id
+      LEFT JOIN users u_tipper  ON u_tipper.id = t.tipper_id
+      WHERE t.id = ${tip_id}
+      LIMIT 1
+    `;
+
+    if (tipRows.length === 0) {
+      return NextResponse.json(
+        { error: "Tip not found" },
+        { status: 404 }
+      );
+    }
+
+    const tip = tipRows[0];
+    const isAnonymous = tip.is_anonymous === true;
+
+    const payload: TipRecapPayload = {
+      tip_id: tip.tip_id,
+      creator: {
+        user_id: tip.creator_id,
+        username: tip.creator_username,
+        avatar: tip.creator_avatar,
+      },
+      tipper: isAnonymous
+        ? {
+            user_id: null,
+            username: null,
+            avatar: null,
+            anonymous: true,
+          }
+        : {
+            user_id: tip.tipper_id,
+            username: tip.tipper_username,
+            avatar: tip.tipper_avatar,
+            anonymous: false,
+          },
+      amount: String(tip.amount),
+      asset: tip.asset ?? "XLM",
+      message: tip.message ?? null,
+      image_meta: {
+        width: 1200,
+        height: 630,
+        format: "png",
+      },
+      created_at: tip.created_at,
+    };
+
+    return NextResponse.json(payload, {
+      headers: { "Cache-Control": "public, max-age=3600" },
+    });
+  } catch (error) {
+    console.error("[routes-f tip-recap GET]", error);
+    return NextResponse.json(
+      { error: "Failed to fetch tip recap" },
+      { status: 500 }
+    );
+  }
+}
diff --git a/app/api/routes-f/tips/recent/route.ts b/app/api/routes-f/tips/recent/route.ts
new file mode 100644
index 00000000..c26c1689
--- /dev/null
+++ b/app/api/routes-f/tips/recent/route.ts
@@ -0,0 +1,63 @@
+import { NextRequest, NextResponse } from "next/server";
+
+export interface Tip {
+  tipper: string;
+  amount_usdc: number;
+  asset: "XLM" | "USDC";
+  tx_hash: string;
+  message?: string;
+  ts: string; // ISO 8601 string
+}
+
+// Generate 30 seed tips with varied assets, amounts, messages, and timestamps
+const SEED_TIPS: Tip[] = Array.from({ length: 30 }).map((_, idx) => {
+  const assets: ("XLM" | "USDC")[] = ["XLM", "USDC"];
+  const asset = assets[idx % 2];
+  const amount_usdc = Number((1.5 * (idx + 1) + (idx % 3) * 0.75).toFixed(2));
+  const messages = [
+    "Awesome stream!",
+    "Keep up the great work!",
+    "Love the content!",
+    "Super cool stream overlay!",
+    undefined,
+    "stellar network is so fast",
+    "greetings from the chat!",
+  ];
+  return {
+    tipper: `tipper_${idx + 1}`,
+    amount_usdc,
+    asset,
+    tx_hash: `0x${idx.toString().padStart(64, "0")}`, // Unique transaction hash
+    message: messages[idx % messages.length],
+    ts: new Date(Date.now() - idx * 3600 * 1000).toISOString(), // older as index increases (already sorted newest first!)
+  };
+});
+
+export async function GET(req: NextRequest): Promise<NextResponse> {
+  const { searchParams } = new URL(req.url);
+  const creatorId = searchParams.get("creator_id");
+  if (!creatorId) {
+    return NextResponse.json({ error: "creator_id is required" }, { status: 400 });
+  }
+
+  const limitParam = searchParams.get("limit");
+  const limit = limitParam ? parseInt(limitParam, 10) : 20;
+  if (isNaN(limit) || limit <= 0) {
+    return NextResponse.json({ error: "Invalid limit" }, { status: 400 });
+  }
+
+  const cursorParam = searchParams.get("cursor");
+  const startIndex = cursorParam ? parseInt(cursorParam, 10) : 0;
+  if (isNaN(startIndex) || startIndex < 0) {
+    return NextResponse.json({ error: "Invalid cursor" }, { status: 400 });
+  }
+
+  const paginatedTips = SEED_TIPS.slice(startIndex, startIndex + limit);
+  const nextCursor =
+    startIndex + limit < SEED_TIPS.length ? (startIndex + limit).toString() : null;
+
+  return NextResponse.json({
+    tips: paginatedTips,
+    next_cursor: nextCursor,
+  });
+}
diff --git a/app/api/routes-f/tips/route.ts b/app/api/routes-f/tips/route.ts
new file mode 100644
index 00000000..488fe935
--- /dev/null
+++ b/app/api/routes-f/tips/route.ts
@@ -0,0 +1,46 @@
+import { NextRequest, NextResponse } from "next/server";
+import { sql } from "@vercel/postgres";
+import { validateBody } from "../_lib/validate";
+import { z } from "zod";
+
+export const runtime = "nodejs";
+export const dynamic = "force-dynamic";
+
+const toggleAnonymousSchema = z.object({
+  tip_id: z.string(),
+  anonymous: z.boolean(),
+});
+
+/**
+ * POST /api/routes-f/tips
+ * Toggle anonymous flag on a tip
+ */
+export async function POST(req: NextRequest) {
+  const bodyResult = await validateBody(req, toggleAnonymousSchema);
+  if (bodyResult instanceof NextResponse) {
+    return bodyResult;
+  }
+
+  const { tip_id, anonymous } = bodyResult.data;
+
+  try {
+    const { rows } = await sql`
+      UPDATE tips
+      SET anonymous = ${anonymous}, updated_at = CURRENT_TIMESTAMP
+      WHERE id = ${tip_id}
+      RETURNING id, anonymous, updated_at
+    `;
+
+    if (rows.length === 0) {
+      return NextResponse.json({ error: "Tip not found" }, { status: 404 });
+    }
+
+    return NextResponse.json({ updated: true, tip: rows[0] });
+  } catch (error) {
+    console.error("[Tips API] Error updating tip:", error);
+    return NextResponse.json(
+      { error: "Internal server error" },
+      { status: 500 }
+    );
+  }
+}
diff --git a/app/api/routes-f/top-tippers/__tests__/route.test.ts b/app/api/routes-f/top-tippers/__tests__/route.test.ts
new file mode 100644
index 00000000..633fa8b0
--- /dev/null
+++ b/app/api/routes-f/top-tippers/__tests__/route.test.ts
@@ -0,0 +1,392 @@
+/**
+ * @jest-environment node
+ */
+import { NextRequest } from "next/server";
+import { GET } from "../route";
+import { generateSeedData, tipStore } from "../seedData";
+
+function makeReq(
+  creatorId: string,
+  timeframe: string,
+  limit?: number
+): NextRequest {
+  let url = `http://localhost/api/routes-f/top-tippers?creator_id=${creatorId}&timeframe=${timeframe}`;
+  if (limit !== undefined) {
+    url += `&limit=${limit}`;
+  }
+  return new NextRequest(url);
+}
+
+describe("GET /api/routes-f/top-tippers", () => {
+  describe("Required Parameters", () => {
+    it("returns 400 when creator_id is missing", async () => {
+      const req = new NextRequest(
+        "http://localhost/api/routes-f/top-tippers?timeframe=daily"
+      );
+      const res = await GET(req);
+      expect(res.status).toBe(400);
+      const body = await res.json();
+      expect(body.error).toContain("creator_id");
+    });
+
+    it("returns 400 when timeframe is missing", async () => {
+      const req = new NextRequest(
+        "http://localhost/api/routes-f/top-tippers?creator_id=creator123"
+      );
+      const res = await GET(req);
+      expect(res.status).toBe(400);
+      const body = await res.json();
+      expect(body.error).toContain("timeframe");
+    });
+
+    it("returns 400 for invalid timeframe", async () => {
+      const res = await GET(makeReq("creator123", "invalid_timeframe"));
+      expect(res.status).toBe(400);
+      const body = await res.json();
+      expect(body.error).toContain("daily, weekly, monthly, all-time");
+    });
+  });
+
+  describe("Timeframe Filtering", () => {
+    const seedCreatorId = "creator_xyz_123";
+
+    it("returns leaderboard for daily timeframe", async () => {
+      const res = await GET(makeReq(seedCreatorId, "daily"));
+      expect(res.status).toBe(200);
+      const body = await res.json();
+      expect(body.entries).toBeDefined();
+      expect(Array.isArray(body.entries)).toBe(true);
+    });
+
+    it("returns leaderboard for weekly timeframe", async () => {
+      const res = await GET(makeReq(seedCreatorId, "weekly"));
+      expect(res.status).toBe(200);
+      const body = await res.json();
+      expect(body.entries).toBeDefined();
+      expect(Array.isArray(body.entries)).toBe(true);
+    });
+
+    it("returns leaderboard for monthly timeframe", async () => {
+      const res = await GET(makeReq(seedCreatorId, "monthly"));
+      expect(res.status).toBe(200);
+      const body = await res.json();
+      expect(body.entries).toBeDefined();
+      expect(Array.isArray(body.entries)).toBe(true);
+    });
+
+    it("returns leaderboard for all-time timeframe", async () => {
+      const res = await GET(makeReq(seedCreatorId, "all-time"));
+      expect(res.status).toBe(200);
+      const body = await res.json();
+      expect(body.entries).toBeDefined();
+      expect(Array.isArray(body.entries)).toBe(true);
+    });
+
+    it("all-time has more entries than daily", async () => {
+      const dailyRes = await GET(makeReq(seedCreatorId, "daily"));
+      const allTimeRes = await GET(makeReq(seedCreatorId, "all-time"));
+
+      const dailyBody = await dailyRes.json();
+      const allTimeBody = await allTimeRes.json();
+
+      expect(allTimeBody.entries.length).toBeGreaterThanOrEqual(
+        dailyBody.entries.length
+      );
+    });
+
+    it("weekly has more entries than daily", async () => {
+      const dailyRes = await GET(makeReq(seedCreatorId, "daily"));
+      const weeklyRes = await GET(makeReq(seedCreatorId, "weekly"));
+
+      const dailyBody = await dailyRes.json();
+      const weeklyBody = await weeklyRes.json();
+
+      expect(weeklyBody.entries.length).toBeGreaterThanOrEqual(
+        dailyBody.entries.length
+      );
+    });
+
+    it("monthly has more entries than weekly", async () => {
+      const weeklyRes = await GET(makeReq(seedCreatorId, "weekly"));
+      const monthlyRes = await GET(makeReq(seedCreatorId, "monthly"));
+
+      const weeklyBody = await weeklyRes.json();
+      const monthlyBody = await monthlyRes.json();
+
+      expect(monthlyBody.entries.length).toBeGreaterThanOrEqual(
+        weeklyBody.entries.length
+      );
+    });
+  });
+
+  describe("Ranking and Sorting", () => {
+    const seedCreatorId = "creator_xyz_123";
+
+    it("ranks entries starting from 1", async () => {
+      const res = await GET(makeReq(seedCreatorId, "all-time"));
+      const body = await res.json();
+
+      if (body.entries.length > 0) {
+        expect(body.entries[0].rank).toBe(1);
+      }
+    });
+
+    it("ranks are sequential", async () => {
+      const res = await GET(makeReq(seedCreatorId, "all-time"));
+      const body = await res.json();
+
+      body.entries.forEach((entry, index) => {
+        expect(entry.rank).toBe(index + 1);
+      });
+    });
+
+    it("sorts by total_usdc descending", async () => {
+      const res = await GET(makeReq(seedCreatorId, "all-time"));
+      const body = await res.json();
+
+      for (let i = 1; i < body.entries.length; i++) {
+        expect(body.entries[i - 1].total_usdc).toBeGreaterThanOrEqual(
+          body.entries[i].total_usdc
+        );
+      }
+    });
+
+    it("tie-breaks by tip_count descending", async () => {
+      const res = await GET(makeReq(seedCreatorId, "all-time"));
+      const body = await res.json();
+
+      for (let i = 1; i < body.entries.length; i++) {
+        if (body.entries[i - 1].total_usdc === body.entries[i].total_usdc) {
+          expect(body.entries[i - 1].tip_count).toBeGreaterThanOrEqual(
+            body.entries[i].tip_count
+          );
+        }
+      }
+    });
+
+    it("entries have required fields", async () => {
+      const res = await GET(makeReq(seedCreatorId, "all-time"));
+      const body = await res.json();
+
+      if (body.entries.length > 0) {
+        const entry = body.entries[0];
+        expect(entry).toHaveProperty("rank");
+        expect(entry).toHaveProperty("tipper");
+        expect(entry).toHaveProperty("total_usdc");
+        expect(entry).toHaveProperty("tip_count");
+      }
+    });
+
+    it("tipper names are strings", async () => {
+      const res = await GET(makeReq(seedCreatorId, "all-time"));
+      const body = await res.json();
+
+      body.entries.forEach(entry => {
+        expect(typeof entry.tipper).toBe("string");
+        expect(entry.tipper.length).toBeGreaterThan(0);
+      });
+    });
+
+    it("totals are positive numbers", async () => {
+      const res = await GET(makeReq(seedCreatorId, "all-time"));
+      const body = await res.json();
+
+      body.entries.forEach(entry => {
+        expect(typeof entry.total_usdc).toBe("number");
+        expect(entry.total_usdc).toBeGreaterThan(0);
+      });
+    });
+
+    it("tip counts are positive integers", async () => {
+      const res = await GET(makeReq(seedCreatorId, "all-time"));
+      const body = await res.json();
+
+      body.entries.forEach(entry => {
+        expect(typeof entry.tip_count).toBe("number");
+        expect(Number.isInteger(entry.tip_count)).toBe(true);
+        expect(entry.tip_count).toBeGreaterThan(0);
+      });
+    });
+  });
+
+  describe("Limit Parameter", () => {
+    const seedCreatorId = "creator_xyz_123";
+
+    it("uses default limit of 10 when not specified", async () => {
+      const res = await GET(makeReq(seedCreatorId, "all-time"));
+      const body = await res.json();
+
+      expect(body.entries.length).toBeLessThanOrEqual(10);
+    });
+
+    it("respects custom limit", async () => {
+      const res = await GET(makeReq(seedCreatorId, "all-time", 5));
+      const body = await res.json();
+
+      expect(body.entries.length).toBeLessThanOrEqual(5);
+    });
+
+    it("allows limit of 1", async () => {
+      const res = await GET(makeReq(seedCreatorId, "all-time", 1));
+      expect(res.status).toBe(200);
+      const body = await res.json();
+      expect(body.entries.length).toBeLessThanOrEqual(1);
+    });
+
+    it("allows limit of 1000", async () => {
+      const res = await GET(makeReq(seedCreatorId, "all-time", 1000));
+      expect(res.status).toBe(200);
+    });
+
+    it("rejects limit of 0", async () => {
+      const res = await GET(makeReq(seedCreatorId, "all-time", 0));
+      expect(res.status).toBe(400);
+      const body = await res.json();
+      expect(body.error).toContain("at least 1");
+    });
+
+    it("rejects limit greater than 1000", async () => {
+      const res = await GET(makeReq(seedCreatorId, "all-time", 1001));
+      expect(res.status).toBe(400);
+      const body = await res.json();
+      expect(body.error).toContain("at most 1000");
+    });
+
+    it("rejects non-integer limit", async () => {
+      const req = new NextRequest(
+        `http://localhost/api/routes-f/top-tippers?creator_id=${seedCreatorId}&timeframe=all-time&limit=5.5`
+      );
+      const res = await GET(req);
+      expect(res.status).toBe(400);
+    });
+
+    it("rejects non-numeric limit", async () => {
+      const req = new NextRequest(
+        `http://localhost/api/routes-f/top-tippers?creator_id=${seedCreatorId}&timeframe=all-time&limit=not-a-number`
+      );
+      const res = await GET(req);
+      expect(res.status).toBe(400);
+    });
+  });
+
+  describe("Empty Results", () => {
+    it("returns empty entries for creator with no tips", async () => {
+      const res = await GET(makeReq("unknown_creator_xyz", "all-time"));
+      expect(res.status).toBe(200);
+      const body = await res.json();
+      expect(body.entries).toEqual([]);
+    });
+
+    it("returns empty entries for future-only timeframe", async () => {
+      const req = new NextRequest(
+        "http://localhost/api/routes-f/top-tippers?creator_id=future_creator&timeframe=daily"
+      );
+      const res = await GET(req);
+      expect(res.status).toBe(200);
+      const body = await res.json();
+      expect(Array.isArray(body.entries)).toBe(true);
+    });
+  });
+
+  describe("Integration: Full Workflow", () => {
+    const seedCreatorId = "creator_xyz_123";
+
+    it("returns valid leaderboard with seed data", async () => {
+      const res = await GET(makeReq(seedCreatorId, "all-time", 10));
+      expect(res.status).toBe(200);
+
+      const body = await res.json();
+      expect(body.entries).toBeDefined();
+      expect(Array.isArray(body.entries)).toBe(true);
+      expect(body.entries.length).toBeGreaterThan(0);
+
+      // Verify structure
+      body.entries.forEach((entry, idx) => {
+        expect(entry.rank).toBe(idx + 1);
+        expect(typeof entry.tipper).toBe("string");
+        expect(typeof entry.total_usdc).toBe("number");
+        expect(typeof entry.tip_count).toBe("number");
+      });
+    });
+
+    it("returns consistent ranking across calls", async () => {
+      const res1 = await GET(makeReq(seedCreatorId, "all-time", 5));
+      const body1 = await res1.json();
+
+      const res2 = await GET(makeReq(seedCreatorId, "all-time", 5));
+      const body2 = await res2.json();
+
+      expect(body1.entries).toEqual(body2.entries);
+    });
+
+    it("top tipper from all-time appears in monthly", async () => {
+      const allTimeRes = await GET(makeReq(seedCreatorId, "all-time", 1));
+      const allTimeBody = await allTimeRes.json();
+
+      if (allTimeBody.entries.length > 0) {
+        const topTipper = allTimeBody.entries[0].tipper;
+
+        const monthlyRes = await GET(makeReq(seedCreatorId, "monthly"));
+        const monthlyBody = await monthlyRes.json();
+
+        const tippersInMonthly = monthlyBody.entries.map(e => e.tipper);
+        // Might not always appear if they only tipped before the month window
+        // but if they do, their rank should be consistent
+      }
+    });
+
+    it("respects limit across all timeframes", async () => {
+      const timeframes = ["daily", "weekly", "monthly", "all-time"] as const;
+
+      for (const timeframe of timeframes) {
+        const res = await GET(makeReq(seedCreatorId, timeframe, 7));
+        expect(res.status).toBe(200);
+        const body = await res.json();
+        expect(body.entries.length).toBeLessThanOrEqual(7);
+      }
+    });
+  });
+
+  describe("Seed Data Validation", () => {
+    it("has seed data loaded", () => {
+      expect(tipStore.length).toBeGreaterThan(0);
+    });
+
+    it("seed data has ~50 records", () => {
+      expect(tipStore.length).toBeGreaterThanOrEqual(45);
+      expect(tipStore.length).toBeLessThanOrEqual(55);
+    });
+
+    it("seed data has creator_xyz_123", () => {
+      const hasSeededCreator = tipStore.some(
+        tip => tip.creator_id === "creator_xyz_123"
+      );
+      expect(hasSeededCreator).toBe(true);
+    });
+
+    it("seed data has various tippers", () => {
+      const seed = generateSeedData();
+      const uniqueTippers = new Set(seed.map(t => t.tipper));
+      expect(uniqueTippers.size).toBeGreaterThan(5);
+    });
+
+    it("seed data has realistic amounts", () => {
+      const seed = generateSeedData();
+      seed.forEach(tip => {
+        expect(tip.amount_usdc).toBeGreaterThanOrEqual(10);
+        expect(tip.amount_usdc).toBeLessThanOrEqual(600);
+      });
+    });
+
+    it("seed data has realistic timestamps", () => {
+      const seed = generateSeedData();
+      const now = Date.now();
+      const threeMonthsAgo = now - 90 * 24 * 60 * 60 * 1000;
+
+      seed.forEach(tip => {
+        expect(tip.timestamp).toBeLessThanOrEqual(now);
+        expect(tip.timestamp).toBeGreaterThanOrEqual(threeMonthsAgo);
+      });
+    });
+  });
+});
diff --git a/app/api/routes-f/top-tippers/route.ts b/app/api/routes-f/top-tippers/route.ts
new file mode 100644
index 00000000..26e7165c
--- /dev/null
+++ b/app/api/routes-f/top-tippers/route.ts
@@ -0,0 +1,64 @@
+import { NextRequest, NextResponse } from "next/server";
+import { getTipsForCreator } from "./seedData";
+import {
+  isValidTimeframe,
+  filterTipsByTimeframe,
+  buildLeaderboard,
+  validateLimit,
+} from "./utils";
+import type { LeaderboardResponse, Timeframe } from "./types";
+
+export async function GET(req: NextRequest): Promise<NextResponse> {
+  const { searchParams } = new URL(req.url);
+  const creatorId = searchParams.get("creator_id");
+  const timeframe = searchParams.get("timeframe");
+  const limit = searchParams.get("limit");
+
+  // Validate creator_id
+  if (!creatorId) {
+    return NextResponse.json(
+      { error: "creator_id is required" },
+      { status: 400 }
+    );
+  }
+
+  // Validate timeframe
+  if (!timeframe) {
+    return NextResponse.json(
+      { error: "timeframe is required (daily|weekly|monthly|all-time)" },
+      { status: 400 }
+    );
+  }
+
+  if (!isValidTimeframe(timeframe)) {
+    return NextResponse.json(
+      {
+        error:
+          "invalid timeframe, must be one of: daily, weekly, monthly, all-time",
+      },
+      { status: 400 }
+    );
+  }
+
+  // Validate limit
+  const limitValidation = validateLimit(limit);
+  if (!limitValidation.valid) {
+    return NextResponse.json({ error: limitValidation.error }, { status: 400 });
+  }
+
+  const finalLimit = limitValidation.value || 10;
+
+  // Get tips for creator
+  const allTips = getTipsForCreator(creatorId);
+
+  // Filter by timeframe
+  const filteredTips = filterTipsByTimeframe(allTips, timeframe as Timeframe);
+
+  // Build and limit leaderboard
+  const fullLeaderboard = buildLeaderboard(filteredTips);
+  const limitedLeaderboard = fullLeaderboard.slice(0, finalLimit);
+
+  return NextResponse.json({
+    entries: limitedLeaderboard,
+  } as LeaderboardResponse);
+}
diff --git a/app/api/routes-f/top-tippers/seedData.ts b/app/api/routes-f/top-tippers/seedData.ts
new file mode 100644
index 00000000..412c7d3e
--- /dev/null
+++ b/app/api/routes-f/top-tippers/seedData.ts
@@ -0,0 +1,99 @@
+import type { TipRecord } from "./types";
+
+// Generate realistic seed data with ~50 tip records
+// Distributed across different timeframes to test all filtering scenarios
+export function generateSeedData(): TipRecord[] {
+  const now = Date.now();
+  const oneDay = 24 * 60 * 60 * 1000;
+  const oneWeek = 7 * oneDay;
+  const oneMonth = 30 * oneDay;
+
+  const creatorId = "creator_xyz_123";
+  const tippers = [
+    "alice_fan",
+    "bob_supporter",
+    "charlie_whale",
+    "diana_casual",
+    "eve_regular",
+    "frank_loyal",
+    "grace_super",
+    "henry_vip",
+    "ivy_top",
+    "jack_monthly",
+  ];
+
+  const records: TipRecord[] = [];
+  let id = 1;
+
+  // All-time tips (spread across last 3 months)
+  for (let i = 0; i < 30; i++) {
+    const tipperIdx = i % tippers.length;
+    const daysAgo = Math.floor(Math.random() * 90); // Last 3 months
+    const amount = Math.floor(Math.random() * 500) + 10; // $10 - $510
+
+    records.push({
+      id: `tip_${id++}`,
+      creator_id: creatorId,
+      tipper: tippers[tipperIdx],
+      amount_usdc: amount,
+      timestamp: now - daysAgo * oneDay - Math.random() * oneDay,
+    });
+  }
+
+  // Monthly tips (last 30 days)
+  for (let i = 0; i < 10; i++) {
+    const tipperIdx = i % tippers.length;
+    const daysAgo = Math.floor(Math.random() * 30);
+    const amount = Math.floor(Math.random() * 300) + 20; // $20 - $320
+
+    records.push({
+      id: `tip_${id++}`,
+      creator_id: creatorId,
+      tipper: tippers[tipperIdx],
+      amount_usdc: amount,
+      timestamp: now - daysAgo * oneDay - Math.random() * oneDay,
+    });
+  }
+
+  // Weekly tips (last 7 days)
+  for (let i = 0; i < 8; i++) {
+    const tipperIdx = i % tippers.length;
+    const daysAgo = Math.floor(Math.random() * 7);
+    const amount = Math.floor(Math.random() * 200) + 25; // $25 - $225
+
+    records.push({
+      id: `tip_${id++}`,
+      creator_id: creatorId,
+      tipper: tippers[tipperIdx],
+      amount_usdc: amount,
+      timestamp: now - daysAgo * oneDay - Math.random() * 12 * 60 * 60 * 1000,
+    });
+  }
+
+  // Daily tips (today)
+  for (let i = 0; i < 5; i++) {
+    const tipperIdx = i % tippers.length;
+    const amount = Math.floor(Math.random() * 150) + 30; // $30 - $180
+
+    records.push({
+      id: `tip_${id++}`,
+      creator_id: creatorId,
+      tipper: tippers[tipperIdx],
+      amount_usdc: amount,
+      timestamp: now - Math.random() * oneDay,
+    });
+  }
+
+  return records;
+}
+
+// In-memory store for tip records
+export const tipStore: TipRecord[] = generateSeedData();
+
+export function addTip(tip: TipRecord): void {
+  tipStore.push(tip);
+}
+
+export function getTipsForCreator(creatorId: string): TipRecord[] {
+  return tipStore.filter(tip => tip.creator_id === creatorId);
+}
diff --git a/app/api/routes-f/top-tippers/types.ts b/app/api/routes-f/top-tippers/types.ts
new file mode 100644
index 00000000..2cfb7cd5
--- /dev/null
+++ b/app/api/routes-f/top-tippers/types.ts
@@ -0,0 +1,20 @@
+export interface TipRecord {
+  id: string;
+  creator_id: string;
+  tipper: string;
+  amount_usdc: number;
+  timestamp: number; // Unix timestamp in milliseconds
+}
+
+export interface LeaderboardEntry {
+  rank: number;
+  tipper: string;
+  total_usdc: number;
+  tip_count: number;
+}
+
+export interface LeaderboardResponse {
+  entries: LeaderboardEntry[];
+}
+
+export type Timeframe = "daily" | "weekly" | "monthly" | "all-time";
diff --git a/app/api/routes-f/top-tippers/utils.ts b/app/api/routes-f/top-tippers/utils.ts
new file mode 100644
index 00000000..42ca58e5
--- /dev/null
+++ b/app/api/routes-f/top-tippers/utils.ts
@@ -0,0 +1,116 @@
+import type { TipRecord, LeaderboardEntry, Timeframe } from "./types";
+
+const ONE_DAY = 24 * 60 * 60 * 1000;
+const ONE_WEEK = 7 * ONE_DAY;
+const ONE_MONTH = 30 * ONE_DAY;
+
+export function getTimeframeMs(timeframe: Timeframe): number | null {
+  switch (timeframe) {
+    case "daily":
+      return ONE_DAY;
+    case "weekly":
+      return ONE_WEEK;
+    case "monthly":
+      return ONE_MONTH;
+    case "all-time":
+      return null; // No cutoff
+    default:
+      return null;
+  }
+}
+
+export function isValidTimeframe(timeframe: unknown): timeframe is Timeframe {
+  return (
+    typeof timeframe === "string" &&
+    ["daily", "weekly", "monthly", "all-time"].includes(timeframe)
+  );
+}
+
+export function filterTipsByTimeframe(
+  tips: TipRecord[],
+  timeframe: Timeframe
+): TipRecord[] {
+  const timeframeMs = getTimeframeMs(timeframe);
+  if (timeframeMs === null) {
+    return tips; // all-time
+  }
+
+  const now = Date.now();
+  const cutoff = now - timeframeMs;
+
+  return tips.filter(tip => tip.timestamp >= cutoff);
+}
+
+export function buildLeaderboard(tips: TipRecord[]): LeaderboardEntry[] {
+  // Aggregate tips by tipper
+  const aggregated = new Map<
+    string,
+    { total_usdc: number; tip_count: number }
+  >();
+
+  for (const tip of tips) {
+    const existing = aggregated.get(tip.tipper) || {
+      total_usdc: 0,
+      tip_count: 0,
+    };
+    aggregated.set(tip.tipper, {
+      total_usdc: existing.total_usdc + tip.amount_usdc,
+      tip_count: existing.tip_count + 1,
+    });
+  }
+
+  // Convert to entries
+  const entries: LeaderboardEntry[] = Array.from(aggregated.entries()).map(
+    ([tipper, data]) => ({
+      rank: 0, // Will be set after sorting
+      tipper,
+      total_usdc: data.total_usdc,
+      tip_count: data.tip_count,
+    })
+  );
+
+  // Sort by total_usdc desc, then by tip_count desc
+  entries.sort((a, b) => {
+    if (a.total_usdc !== b.total_usdc) {
+      return b.total_usdc - a.total_usdc;
+    }
+    return b.tip_count - a.tip_count;
+  });
+
+  // Assign ranks
+  entries.forEach((entry, index) => {
+    entry.rank = index + 1;
+  });
+
+  return entries;
+}
+
+export function validateLimit(limit: unknown): {
+  valid: boolean;
+  value?: number;
+  error?: string;
+} {
+  if (limit === undefined) {
+    return { valid: true, value: 10 }; // Default
+  }
+
+  const parsed = typeof limit === "string" ? parseInt(limit, 10) : limit;
+
+  if (typeof parsed !== "number" || isNaN(parsed)) {
+    return { valid: false, error: "limit must be a number" };
+  }
+
+  if (!Number.isInteger(parsed)) {
+    return { valid: false, error: "limit must be an integer" };
+  }
+
+  if (parsed < 1) {
+    return { valid: false, error: "limit must be at least 1" };
+  }
+
+  if (parsed > 1000) {
+    return { valid: false, error: "limit must be at most 1000" };
+  }
+
+  return { valid: true, value: parsed };
+}
diff --git a/app/api/routes-f/triangle/route.ts b/app/api/routes-f/triangle/route.ts
new file mode 100644
index 00000000..c9e7fe0c
--- /dev/null
+++ b/app/api/routes-f/triangle/route.ts
@@ -0,0 +1,132 @@
+import { type NextRequest, NextResponse } from "next/server";
+
+function round6(n: number): number {
+  return Math.round(n * 1e6) / 1e6;
+}
+
+function isRecord(v: unknown): v is Record<string, unknown> {
+  return typeof v === "object" && v !== null && !Array.isArray(v);
+}
+
+function degFromRad(r: number): number {
+  return round6((r * 180) / Math.PI);
+}
+
+function solveFromSides(sides: [number, number, number]) {
+  const [a, b, c] = sides;
+
+  if (a + b <= c || a + c <= b || b + c <= a) {
+    throw new Error("Sides do not satisfy the triangle inequality.");
+  }
+
+  const perimeter = round6(a + b + c);
+  const s = perimeter / 2;
+  const area = round6(Math.sqrt(s * (s - a) * (s - b) * (s - c)));
+
+  if (area <= 0) throw new Error("Degenerate triangle (zero area).");
+
+  // Angles via law of cosines
+  const A = degFromRad(Math.acos((b * b + c * c - a * a) / (2 * b * c)));
+  const B = degFromRad(Math.acos((a * a + c * c - b * b) / (2 * a * c)));
+  const C = round6(180 - A - B);
+
+  const angles_deg = [A, B, C];
+  const maxAngle = Math.max(A, B, C);
+
+  const angle_type =
+    Math.abs(maxAngle - 90) < 0.0001 ? "right" : maxAngle > 90 ? "obtuse" : "acute";
+
+  const type =
+    a === b && b === c
+      ? "equilateral"
+      : a === b || b === c || a === c
+      ? "isosceles"
+      : "scalene";
+
+  const circumradius = round6((a * b * c) / (4 * area));
+  const inradius = round6(area / s);
+
+  return {
+    is_valid_triangle: true,
+    type,
+    angle_type,
+    angles_deg,
+    perimeter,
+    area,
+    circumradius,
+    inradius,
+  };
+}
+
+function vertexDistance(p1: [number, number], p2: [number, number]): number {
+  return Math.sqrt((p1[0] - p2[0]) ** 2 + (p1[1] - p2[1]) ** 2);
+}
+
+export async function POST(req: NextRequest) {
+  let body: unknown;
+  try {
+    body = await req.json();
+  } catch {
+    return NextResponse.json({ error: "Invalid JSON body." }, { status: 400 });
+  }
+
+  if (!isRecord(body)) {
+    return NextResponse.json({ error: "Request body must be an object." }, { status: 400 });
+  }
+
+  const { mode, sides, vertices } = body as Record<string, unknown>;
+
+  if (mode !== "sides" && mode !== "vertices") {
+    return NextResponse.json({ error: "mode must be 'sides' or 'vertices'." }, { status: 400 });
+  }
+
+  try {
+    if (mode === "sides") {
+      if (!Array.isArray(sides) || sides.length !== 3 || sides.some((s) => typeof s !== "number" || s <= 0)) {
+        return NextResponse.json(
+          { error: "sides must be an array of 3 positive numbers." },
+          { status: 400 }
+        );
+      }
+      return NextResponse.json(solveFromSides(sides as [number, number, number]));
+    }
+
+    // vertices mode
+    if (
+      !Array.isArray(vertices) ||
+      vertices.length !== 3 ||
+      vertices.some((v) => !Array.isArray(v) || v.length !== 2 || v.some((c) => typeof c !== "number"))
+    ) {
+      return NextResponse.json(
+        { error: "vertices must be an array of 3 [x, y] pairs." },
+        { status: 400 }
+      );
+    }
+
+    const [p0, p1, p2] = vertices as [number, number][];
+
+    // Check for collinear points using exact cross product (avoids float rounding issues)
+    const crossProduct =
+      p0[0] * (p1[1] - p2[1]) +
+      p1[0] * (p2[1] - p0[1]) +
+      p2[0] * (p0[1] - p1[1]);
+    if (crossProduct === 0) {
+      throw new Error("Degenerate triangle: vertices are collinear.");
+    }
+
+    const a = round6(vertexDistance(p1, p2));
+    const b = round6(vertexDistance(p0, p2));
+    const c = round6(vertexDistance(p0, p1));
+
+    const result = solveFromSides([a, b, c]);
+    const centroid = {
+      x: round6((p0[0] + p1[0] + p2[0]) / 3),
+      y: round6((p0[1] + p1[1] + p2[1]) / 3),
+    };
+
+    return NextResponse.json({ ...result, centroid });
+  } catch (err) {
+    const msg = err instanceof Error ? err.message : "Invalid triangle.";
+    return NextResponse.json({ error: msg }, { status: 400 });
+  }
+}
diff --git a/app/api/routes-f/unix-date/__tests__/route.test.ts b/app/api/routes-f/unix-date/__tests__/route.test.ts
new file mode 100644
index 00000000..d6f2580c
--- /dev/null
+++ b/app/api/routes-f/unix-date/__tests__/route.test.ts
@@ -0,0 +1,99 @@
+/**
+ * @jest-environment node
+ */
+import { NextRequest } from "next/server";
+import { POST } from "../route";
+
+function makeReq(body: unknown) {
+  return new NextRequest("http://localhost/api/routes-f/unix-date", {
+    method: "POST",
+    headers: { "content-type": "application/json" },
+    body: JSON.stringify(body),
+  });
+}
+
+describe("/api/routes-f/unix-date", () => {
+  it("converts unix seconds to ISO", async () => {
+    const res = await POST(makeReq({ mode: "to_iso", value: 0, unit: "s" }));
+
+    expect(res.status).toBe(200);
+    await expect(res.json()).resolves.toEqual({
+      result: "1970-01-01T00:00:00.000Z",
+      unit: "s",
+    });
+  });
+
+  it("converts unix milliseconds to ISO", async () => {
+    const res = await POST(makeReq({ mode: "to_iso", value: 1716243825123, unit: "ms" }));
+
+    expect(res.status).toBe(200);
+    await expect(res.json()).resolves.toEqual({
+      result: "2024-05-20T22:23:45.123Z",
+      unit: "ms",
+    });
+  });
+
+  it("converts negative unix seconds before 1970", async () => {
+    const res = await POST(makeReq({ mode: "to_iso", value: -1, unit: "s" }));
+
+    expect(res.status).toBe(200);
+    await expect(res.json()).resolves.toEqual({
+      result: "1969-12-31T23:59:59.000Z",
+      unit: "s",
+    });
+  });
+
+  it("converts ISO dates to unix seconds", async () => {
+    const res = await POST(
+      makeReq({ mode: "to_unix", value: "2024-05-20T22:23:45.000Z", unit: "s" })
+    );
+
+    expect(res.status).toBe(200);
+    await expect(res.json()).resolves.toEqual({
+      result: 1716243825,
+      unit: "s",
+    });
+  });
+
+  it("converts ISO dates to unix milliseconds", async () => {
+    const res = await POST(
+      makeReq({ mode: "to_unix", value: "2024-05-20T22:23:45.123Z", unit: "ms" })
+    );
+
+    expect(res.status).toBe(200);
+    await expect(res.json()).resolves.toEqual({
+      result: 1716243825123,
+      unit: "ms",
+    });
+  });
+
+  it("round-trips seconds", async () => {
+    const toIso = await POST(makeReq({ mode: "to_iso", value: -123456789, unit: "s" }));
+    const isoBody = await toIso.json();
+    const toUnix = await POST(makeReq({ mode: "to_unix", value: isoBody.result, unit: "s" }));
+
+    expect(toUnix.status).toBe(200);
+    await expect(toUnix.json()).resolves.toEqual({
+      result: -123456789,
+      unit: "s",
+    });
+  });
+
+  it("round-trips milliseconds", async () => {
+    const toIso = await POST(makeReq({ mode: "to_iso", value: -123456789123, unit: "ms" }));
+    const isoBody = await toIso.json();
+    const toUnix = await POST(makeReq({ mode: "to_unix", value: isoBody.result, unit: "ms" }));
+
+    expect(toUnix.status).toBe(200);
+    await expect(toUnix.json()).resolves.toEqual({
+      result: -123456789123,
+      unit: "ms",
+    });
+  });
+
+  it("rejects invalid modes", async () => {
+    const res = await POST(makeReq({ mode: "convert", value: 0, unit: "s" }));
+
+    expect(res.status).toBe(400);
+  });
+});
diff --git a/app/api/routes-f/unix-date/_lib/convert.ts b/app/api/routes-f/unix-date/_lib/convert.ts
new file mode 100644
index 00000000..7aa2b3b5
--- /dev/null
+++ b/app/api/routes-f/unix-date/_lib/convert.ts
@@ -0,0 +1,73 @@
+import type { UnixDateRequest, UnixDateResponse, UnixDateUnit } from "./types";
+
+function isRecord(value: unknown): value is Record<string, unknown> {
+  return typeof value === "object" && value !== null && !Array.isArray(value);
+}
+
+function normalizeUnit(value: unknown): UnixDateUnit {
+  if (value === undefined) {
+    return "s";
+  }
+
+  if (value === "s" || value === "ms") {
+    return value;
+  }
+
+  throw new Error("unit must be s or ms.");
+}
+
+function finiteNumber(value: unknown): number {
+  if (typeof value !== "number" || !Number.isFinite(value)) {
+    throw new Error("value must be a finite number.");
+  }
+
+  return value;
+}
+
+function assertValidDate(date: Date): void {
+  if (Number.isNaN(date.getTime())) {
+    throw new Error("value must be a valid ISO date or timestamp.");
+  }
+}
+
+export function convertUnixDate(input: unknown): UnixDateResponse {
+  if (!isRecord(input)) {
+    throw new Error("Request body must be an object.");
+  }
+
+  // `input` is an arbitrary record here; its fields are validated below, so
+  // assert through `unknown` rather than directly (the record type does not
+  // structurally overlap with UnixDateRequest's required fields).
+  const request = input as unknown as UnixDateRequest;
+  const unit = normalizeUnit(request.unit);
+
+  if (request.mode === "to_iso") {
+    const timestamp = finiteNumber(request.value);
+    const date = new Date(unit === "s" ? timestamp * 1000 : timestamp);
+
+    assertValidDate(date);
+
+    return {
+      result: date.toISOString(),
+      unit,
+    };
+  }
+
+  if (request.mode === "to_unix") {
+    if (typeof request.value !== "string") {
+      throw new Error("value must be an ISO date string.");
+    }
+
+    const date = new Date(request.value);
+    assertValidDate(date);
+
+    const timestampMs = date.getTime();
+
+    return {
+      result: unit === "s" ? timestampMs / 1000 : timestampMs,
+      unit,
+    };
+  }
+
+  throw new Error("mode must be to_iso or to_unix.");
+}
diff --git a/app/api/routes-f/unix-date/_lib/types.ts b/app/api/routes-f/unix-date/_lib/types.ts
new file mode 100644
index 00000000..d8c6b999
--- /dev/null
+++ b/app/api/routes-f/unix-date/_lib/types.ts
@@ -0,0 +1,13 @@
+export type UnixDateMode = "to_iso" | "to_unix";
+export type UnixDateUnit = "s" | "ms";
+
+export interface UnixDateRequest {
+  mode: UnixDateMode;
+  value: unknown;
+  unit?: UnixDateUnit;
+}
+
+export interface UnixDateResponse {
+  result: string | number;
+  unit: UnixDateUnit;
+}
diff --git a/app/api/routes-f/unix-date/route.ts b/app/api/routes-f/unix-date/route.ts
new file mode 100644
index 00000000..99babd7f
--- /dev/null
+++ b/app/api/routes-f/unix-date/route.ts
@@ -0,0 +1,19 @@
+import { type NextRequest, NextResponse } from "next/server";
+import { convertUnixDate } from "./_lib/convert";
+
+export async function POST(req: NextRequest) {
+  let body: unknown;
+
+  try {
+    body = await req.json();
+  } catch {
+    return NextResponse.json({ error: "Invalid JSON body." }, { status: 400 });
+  }
+
+  try {
+    return NextResponse.json(convertUnixDate(body));
+  } catch (error) {
+    const message = error instanceof Error ? error.message : "Failed to convert date.";
+    return NextResponse.json({ error: message }, { status: 400 });
+  }
+}
diff --git a/app/api/routes-f/url-parse/route.ts b/app/api/routes-f/url-parse/route.ts
new file mode 100644
index 00000000..ef54a038
--- /dev/null
+++ b/app/api/routes-f/url-parse/route.ts
@@ -0,0 +1,66 @@
+import { type NextRequest, NextResponse } from "next/server";
+
+const MAX_URL_LENGTH = 4096;
+
+function isRecord(v: unknown): v is Record<string, unknown> {
+  return typeof v === "object" && v !== null && !Array.isArray(v);
+}
+
+function parseQueryParams(search: string): Record<string, string | string[]> {
+  const params = new URLSearchParams(search);
+  const result: Record<string, string | string[]> = {};
+  for (const key of params.keys()) {
+    const values = params.getAll(key);
+    result[key] = values.length === 1 ? values[0] : values;
+  }
+  return result;
+}
+
+export async function POST(req: NextRequest) {
+  let body: unknown;
+  try {
+    body = await req.json();
+  } catch {
+    return NextResponse.json({ error: "Invalid JSON body." }, { status: 400 });
+  }
+
+  if (!isRecord(body)) {
+    return NextResponse.json({ error: "Request body must be an object." }, { status: 400 });
+  }
+
+  const { url } = body as Record<string, unknown>;
+
+  if (typeof url !== "string" || !url) {
+    return NextResponse.json({ error: "'url' field is required and must be a string." }, { status: 400 });
+  }
+
+  if (url.length > MAX_URL_LENGTH) {
+    return NextResponse.json({ error: `URL exceeds maximum length of ${MAX_URL_LENGTH} characters.` }, { status: 400 });
+  }
+
+  let parsed: URL;
+  try {
+    parsed = new URL(url);
+  } catch {
+    return NextResponse.json({ error: "Invalid URL." }, { status: 400 });
+  }
+
+  const path_segments = parsed.pathname
+    .split("/")
+    .filter(Boolean);
+
+  return NextResponse.json({
+    protocol: parsed.protocol,
+    host: parsed.host,
+    hostname: parsed.hostname,
+    port: parsed.port,
+    pathname: parsed.pathname,
+    search: parsed.search,
+    hash: parsed.hash,
+    username: parsed.username,
+    password: parsed.password,
+    origin: parsed.origin,
+    query: parseQueryParams(parsed.search),
+    path_segments,
+  });
+}
diff --git a/app/api/routes-f/validation-rules/_schemas/chat.ts b/app/api/routes-f/validation-rules/_schemas/chat.ts
new file mode 100644
index 00000000..1f7bf874
--- /dev/null
+++ b/app/api/routes-f/validation-rules/_schemas/chat.ts
@@ -0,0 +1,40 @@
+import { z } from "zod";
+
+// banned_words is server-side only — never exported in the API response
+const BANNED_WORDS: string[] = [];
+
+export const chatSchema = z
+  .object({
+    message: z
+      .string()
+      .min(1, "Message cannot be empty")
+      .max(500, "Message must not exceed 500 characters"),
+    emote_only: z.boolean().default(false),
+  })
+  .superRefine((data, ctx) => {
+    const lower = data.message.toLowerCase();
+    for (const word of BANNED_WORDS) {
+      if (lower.includes(word)) {
+        ctx.addIssue({
+          code: z.ZodIssueCode.custom,
+          path: ["message"],
+          message: "Message contains prohibited content",
+        });
+        break;
+      }
+    }
+  });
+
+export type ChatInput = z.infer<typeof chatSchema>;
+
+export const chatRules = {
+  message: {
+    min: 1,
+    max: 500,
+    required: true,
+  },
+  emote_only: {
+    type: "boolean",
+    default: false,
+  },
+};
diff --git a/app/api/routes-f/validation-rules/_schemas/gift.ts b/app/api/routes-f/validation-rules/_schemas/gift.ts
new file mode 100644
index 00000000..92111c47
--- /dev/null
+++ b/app/api/routes-f/validation-rules/_schemas/gift.ts
@@ -0,0 +1,38 @@
+import { z } from "zod";
+
+export const giftSchema = z.object({
+  amount: z
+    .number()
+    .positive("Amount must be greater than zero")
+    .max(10_000, "Maximum gift amount is 10,000"),
+  currency: z.enum(["STRFI", "USDC"], {
+    errorMap: () => ({ message: "Currency must be STRFI or USDC" }),
+  }),
+  message: z
+    .string()
+    .max(200, "Gift message must not exceed 200 characters")
+    .optional(),
+  recipient_id: z.string().min(1, "Recipient is required"),
+});
+
+export type GiftInput = z.infer<typeof giftSchema>;
+
+export const giftRules = {
+  amount: {
+    min: 0,
+    exclusive_min: true,
+    max: 10_000,
+    required: true,
+  },
+  currency: {
+    enum: ["STRFI", "USDC"],
+    required: true,
+  },
+  message: {
+    max: 200,
+    required: false,
+  },
+  recipient_id: {
+    required: true,
+  },
+};
diff --git a/app/api/routes-f/validation-rules/_schemas/stream.ts b/app/api/routes-f/validation-rules/_schemas/stream.ts
new file mode 100644
index 00000000..2c36758c
--- /dev/null
+++ b/app/api/routes-f/validation-rules/_schemas/stream.ts
@@ -0,0 +1,44 @@
+import { z } from "zod";
+
+export const streamSchema = z.object({
+  title: z
+    .string()
+    .min(3, "Title must be at least 3 characters")
+    .max(120, "Title must not exceed 120 characters"),
+  description: z
+    .string()
+    .max(500, "Description must not exceed 500 characters")
+    .optional(),
+  category: z.string().min(1, "Category is required"),
+  tags: z
+    .array(z.string().max(30))
+    .max(10, "You may add up to 10 tags")
+    .optional(),
+  is_mature: z.boolean().default(false),
+});
+
+export type StreamInput = z.infer<typeof streamSchema>;
+
+export const streamRules = {
+  title: {
+    min: 3,
+    max: 120,
+    required: true,
+  },
+  description: {
+    max: 500,
+    required: false,
+  },
+  category: {
+    required: true,
+  },
+  tags: {
+    max_items: 10,
+    item_max_length: 30,
+    required: false,
+  },
+  is_mature: {
+    type: "boolean",
+    default: false,
+  },
+};
diff --git a/app/api/routes-f/validation-rules/_schemas/user.ts b/app/api/routes-f/validation-rules/_schemas/user.ts
new file mode 100644
index 00000000..545541a3
--- /dev/null
+++ b/app/api/routes-f/validation-rules/_schemas/user.ts
@@ -0,0 +1,47 @@
+import { z } from "zod";
+
+export const userSchema = z.object({
+  username: z
+    .string()
+    .min(3, "Username must be at least 3 characters")
+    .max(30, "Username must not exceed 30 characters")
+    .regex(/^[a-zA-Z0-9_]+$/, "Username may only contain letters, numbers, and underscores"),
+  email: z
+    .string()
+    .min(1, "Email is required")
+    .email("Must be a valid email address"),
+  display_name: z
+    .string()
+    .min(1, "Display name is required")
+    .max(50, "Display name must not exceed 50 characters"),
+  bio: z.string().max(300, "Bio must not exceed 300 characters").optional(),
+  website_url: z.string().url("Must be a valid URL").optional().or(z.literal("")),
+});
+
+export type UserInput = z.infer<typeof userSchema>;
+
+export const userRules = {
+  username: {
+    min: 3,
+    max: 30,
+    pattern: "^[a-zA-Z0-9_]+$",
+    description: "Letters, numbers, and underscores only",
+  },
+  email: {
+    format: "email",
+    required: true,
+  },
+  display_name: {
+    min: 1,
+    max: 50,
+    required: true,
+  },
+  bio: {
+    max: 300,
+    required: false,
+  },
+  website_url: {
+    format: "url",
+    required: false,
+  },
+};
diff --git a/app/api/routes-f/validation-rules/route.ts b/app/api/routes-f/validation-rules/route.ts
new file mode 100644
index 00000000..ba83398d
--- /dev/null
+++ b/app/api/routes-f/validation-rules/route.ts
@@ -0,0 +1,42 @@
+import { type NextRequest, NextResponse } from "next/server";
+import { chatRules } from "./_schemas/chat";
+import { giftRules } from "./_schemas/gift";
+import { streamRules } from "./_schemas/stream";
+import { userRules } from "./_schemas/user";
+
+const ALL_RULES = {
+  user: userRules,
+  stream: streamRules,
+  chat: chatRules,
+  gift: giftRules,
+};
+
+type Scope = keyof typeof ALL_RULES;
+
+const VALID_SCOPES = new Set<string>(Object.keys(ALL_RULES));
+
+export async function GET(request: NextRequest) {
+  const scope = request.nextUrl.searchParams.get("scope");
+
+  if (scope !== null) {
+    if (!VALID_SCOPES.has(scope)) {
+      return NextResponse.json(
+        { error: `Unknown scope '${scope}'. Valid values: ${[...VALID_SCOPES].join(", ")}` },
+        { status: 400 }
+      );
+    }
+    return NextResponse.json(
+      { rules: { [scope]: ALL_RULES[scope as Scope] } },
+      {
+        headers: { "Cache-Control": "public, max-age=3600" },
+      }
+    );
+  }
+
+  return NextResponse.json(
+    { rules: ALL_RULES },
+    {
+      headers: { "Cache-Control": "public, max-age=3600" },
+    }
+  );
+}
diff --git a/app/api/routes-f/vector-ops/route.ts b/app/api/routes-f/vector-ops/route.ts
new file mode 100644
index 00000000..1b726688
--- /dev/null
+++ b/app/api/routes-f/vector-ops/route.ts
@@ -0,0 +1,82 @@
+import { NextResponse } from 'next/server';
+
+function dotProduct(a: number[], b: number[]): number {
+  if (a.length !== b.length) {
+    throw new Error('Vectors must have same dimension for dot product');
+  }
+  return a.reduce((sum, val, i) => sum + val * b[i], 0);
+}
+
+function crossProduct(a: number[], b: number[]): number[] {
+  if (a.length !== 3 || b.length !== 3) {
+    throw new Error('Cross product requires 3D vectors');
+  }
+  return [a[1] * b[2] - a[2] * b[1], a[2] * b[0] - a[0] * b[2], a[0] * b[1] - a[1] * b[0]];
+}
+
+function magnitude(a: number[]): number {
+  return Math.sqrt(a.reduce((sum, val) => sum + val * val, 0));
+}
+
+function normalize(a: number[]): number[] {
+  const mag = magnitude(a);
+  if (mag === 0) {
+    throw new Error('Cannot normalize zero vector');
+  }
+  return a.map((val) => val / mag);
+}
+
+export async function POST(request: Request) {
+  try {
+    const body = await request.json();
+    const { a, b, op } = body;
+
+    if (!Array.isArray(a) || !a.every((val) => typeof val === 'number')) {
+      return NextResponse.json({ error: 'a must be an array of numbers' }, { status: 400 });
+    }
+
+    if (!op || typeof op !== 'string') {
+      return NextResponse.json(
+        { error: 'op must be one of: dot, cross, magnitude, normalize' },
+        { status: 400 }
+      );
+    }
+
+    let result;
+
+    switch (op) {
+      case 'dot':
+        if (!Array.isArray(b) || !b.every((val) => typeof val === 'number')) {
+          return NextResponse.json({ error: 'b must be an array of numbers for dot product' }, { status: 400 });
+        }
+        result = dotProduct(a, b);
+        break;
+
+      case 'cross':
+        if (!Array.isArray(b) || !b.every((val) => typeof val === 'number')) {
+          return NextResponse.json({ error: 'b must be an array of numbers for cross product' }, { status: 400 });
+        }
+        result = crossProduct(a, b);
+        break;
+
+      case 'magnitude':
+        result = magnitude(a);
+        break;
+
+      case 'normalize':
+        result = normalize(a);
+        break;
+
+      default:
+        return NextResponse.json(
+          { error: 'op must be one of: dot, cross, magnitude, normalize' },
+          { status: 400 }
+        );
+    }
+
+    return NextResponse.json({ result });
+  } catch (error) {
+    const message = error instanceof Error ? error.message : 'Invalid request';
+    return NextResponse.json({ error: message }, { status: 400 });
+  }
+}
diff --git a/app/api/routes-f/viewer-badge/__tests__/route.test.ts b/app/api/routes-f/viewer-badge/__tests__/route.test.ts
new file mode 100644
index 00000000..2d26cc51
--- /dev/null
+++ b/app/api/routes-f/viewer-badge/__tests__/route.test.ts
@@ -0,0 +1,151 @@
+/**
+ * @jest-environment node
+ */
+import { NextRequest } from "next/server";
+import { GET, POST, DELETE, badgeStore } from "../route";
+
+const BASE_URL = "http://localhost/api/routes-f/viewer-badge";
+
+function makeGet(params?: { creator_id?: string; viewer_id?: string }) {
+  const url = params
+    ? `${BASE_URL}?creator_id=${params.creator_id}&viewer_id=${params.viewer_id}`
+    : BASE_URL;
+  return new NextRequest(url, { method: "GET" });
+}
+
+function makePost(body: unknown) {
+  return new NextRequest(BASE_URL, {
+    method: "POST",
+    headers: { "content-type": "application/json" },
+    body: JSON.stringify(body),
+  });
+}
+
+function makeDelete(body: unknown) {
+  return new NextRequest(BASE_URL, {
+    method: "DELETE",
+    headers: { "content-type": "application/json" },
+    body: JSON.stringify(body),
+  });
+}
+
+const CREATOR = "creator-xyz";
+const VIEWER = "viewer-abc";
+const GRANTER = "mod-user-1";
+
+describe("/api/routes-f/viewer-badge", () => {
+  beforeEach(() => badgeStore.clear());
+
+  // ── grant ─────────────────────────────────────────────────────────────────
+
+  it("POST 201 grants a badge and returns granted_at", async () => {
+    const res = await POST(makePost({ creator_id: CREATOR, viewer_id: VIEWER, badge: "mod", granted_by: GRANTER }));
+    expect(res.status).toBe(201);
+    const body = await res.json();
+    expect(body.granted_at).toBeTruthy();
+    expect(new Date(body.granted_at).toString()).not.toBe("Invalid Date");
+  });
+
+  it("POST 201 grants multiple different badges to the same viewer", async () => {
+    await POST(makePost({ creator_id: CREATOR, viewer_id: VIEWER, badge: "mod", granted_by: GRANTER }));
+    const res = await POST(makePost({ creator_id: CREATOR, viewer_id: VIEWER, badge: "vip", granted_by: GRANTER }));
+    expect(res.status).toBe(201);
+  });
+
+  it("POST 409 when viewer already has the same badge", async () => {
+    await POST(makePost({ creator_id: CREATOR, viewer_id: VIEWER, badge: "og", granted_by: GRANTER }));
+    const res = await POST(makePost({ creator_id: CREATOR, viewer_id: VIEWER, badge: "og", granted_by: GRANTER }));
+    expect(res.status).toBe(409);
+  });
+
+  it("POST 422 when viewer already has 5 badges (cap exceeded)", async () => {
+    // Pre-fill store with 5 entries; the target badge ("vip") is NOT among them
+    // so the duplicate check passes and the cap check fires.
+    const key = `${CREATOR}:viewer-capped`;
+    const ts = new Date().toISOString();
+    badgeStore.set(key, [
+      { badge: "mod", granted_by: GRANTER, granted_at: ts },
+      { badge: "og", granted_by: GRANTER, granted_at: ts },
+      { badge: "founder", granted_by: GRANTER, granted_at: ts },
+      { badge: "mod", granted_by: GRANTER, granted_at: ts },
+      { badge: "og", granted_by: GRANTER, granted_at: ts },
+    ]);
+    // Request "vip" — not a duplicate, but length is already 5
+    const res = await POST(makePost({ creator_id: CREATOR, viewer_id: "viewer-capped", badge: "vip", granted_by: GRANTER }));
+    expect(res.status).toBe(422);
+  });
+
+  // ── revoke ────────────────────────────────────────────────────────────────
+
+  it("DELETE revokes an existing badge", async () => {
+    await POST(makePost({ creator_id: CREATOR, viewer_id: VIEWER, badge: "mod", granted_by: GRANTER }));
+    const res = await DELETE(makeDelete({ creator_id: CREATOR, viewer_id: VIEWER, badge: "mod" }));
+    expect(res.status).toBe(200);
+    const body = await res.json();
+    expect(body.revoked).toBe(true);
+  });
+
+  it("DELETE 404 when viewer does not have the badge", async () => {
+    const res = await DELETE(makeDelete({ creator_id: CREATOR, viewer_id: VIEWER, badge: "vip" }));
+    expect(res.status).toBe(404);
+  });
+
+  it("DELETE removes only the specified badge, keeping others", async () => {
+    await POST(makePost({ creator_id: CREATOR, viewer_id: VIEWER, badge: "mod", granted_by: GRANTER }));
+    await POST(makePost({ creator_id: CREATOR, viewer_id: VIEWER, badge: "og", granted_by: GRANTER }));
+    await DELETE(makeDelete({ creator_id: CREATOR, viewer_id: VIEWER, badge: "mod" }));
+    const res = await GET(makeGet({ creator_id: CREATOR, viewer_id: VIEWER }));
+    const { badges } = await res.json();
+    expect(badges).toHaveLength(1);
+    expect(badges[0].badge).toBe("og");
+  });
+
+  // ── listing ───────────────────────────────────────────────────────────────
+
+  it("GET returns empty array for viewer with no badges", async () => {
+    const res = await GET(makeGet({ creator_id: CREATOR, viewer_id: VIEWER }));
+    expect(res.status).toBe(200);
+    const { badges } = await res.json();
+    expect(badges).toEqual([]);
+  });
+
+  it("GET returns all active badges for viewer", async () => {
+    await POST(makePost({ creator_id: CREATOR, viewer_id: VIEWER, badge: "mod", granted_by: GRANTER }));
+    await POST(makePost({ creator_id: CREATOR, viewer_id: VIEWER, badge: "founder", granted_by: GRANTER }));
+    const res = await GET(makeGet({ creator_id: CREATOR, viewer_id: VIEWER }));
+    const { badges } = await res.json();
+    expect(badges).toHaveLength(2);
+    const types = badges.map((b: { badge: string }) => b.badge);
+    expect(types).toContain("mod");
+    expect(types).toContain("founder");
+  });
+
+  it("GET badges are isolated per creator", async () => {
+    await POST(makePost({ creator_id: "creator-A", viewer_id: VIEWER, badge: "mod", granted_by: GRANTER }));
+    const res = await GET(makeGet({ creator_id: "creator-B", viewer_id: VIEWER }));
+    const { badges } = await res.json();
+    expect(badges).toHaveLength(0);
+  });
+
+  // ── validation ────────────────────────────────────────────────────────────
+
+  it("POST 400 for invalid badge type", async () => {
+    const res = await POST(makePost({ creator_id: CREATOR, viewer_id: VIEWER, badge: "supermod", granted_by: GRANTER }));
+    expect(res.status).toBe(400);
+  });
+
+  it("POST 400 when creator_id is missing", async () => {
+    const res = await POST(makePost({ viewer_id: VIEWER, badge: "mod", granted_by: GRANTER }));
+    expect(res.status).toBe(400);
+  });
+
+  it("POST 400 when granted_by is missing", async () => {
+    const res = await POST(makePost({ creator_id: CREATOR, viewer_id: VIEWER, badge: "mod" }));
+    expect(res.status).toBe(400);
+  });
+
+  it("GET 400 when creator_id or viewer_id is missing", async () => {
+    const res = await GET(new NextRequest(`${BASE_URL}?creator_id=${CREATOR}`, { method: "GET" }));
+    expect(res.status).toBe(400);
+  });
+});
diff --git a/app/api/routes-f/viewer-badge/route.ts b/app/api/routes-f/viewer-badge/route.ts
new file mode 100644
index 00000000..819c12ea
--- /dev/null
+++ b/app/api/routes-f/viewer-badge/route.ts
@@ -0,0 +1,144 @@
+/**
+ * POST   /api/routes-f/viewer-badge  → grant badge
+ * DELETE /api/routes-f/viewer-badge  → revoke badge
+ * GET    /api/routes-f/viewer-badge?creator_id=&viewer_id= → list active badges
+ */
+import { NextRequest, NextResponse } from "next/server";
+
+// ---------------------------------------------------------------------------
+// Types
+// ---------------------------------------------------------------------------
+export type BadgeType = "mod" | "vip" | "og" | "founder";
+
+export interface ViewerBadge {
+  badge: BadgeType;
+  granted_by: string;
+  granted_at: string;
+}
+
+// Key: `${creator_id}:${viewer_id}`
+export const badgeStore = new Map<string, ViewerBadge[]>();
+
+const MAX_BADGES = 5;
+const VALID_BADGES: BadgeType[] = ["mod", "vip", "og", "founder"];
+
+function storeKey(creator_id: string, viewer_id: string) {
+  return `${creator_id}:${viewer_id}`;
+}
+
+// ---------------------------------------------------------------------------
+// GET — list active badges
+// ---------------------------------------------------------------------------
+export async function GET(req: NextRequest): Promise<NextResponse> {
+  const { searchParams } = new URL(req.url);
+  const creator_id = searchParams.get("creator_id");
+  const viewer_id = searchParams.get("viewer_id");
+
+  if (!creator_id || !viewer_id) {
+    return NextResponse.json(
+      { error: "creator_id and viewer_id are required" },
+      { status: 400 }
+    );
+  }
+
+  const badges = badgeStore.get(storeKey(creator_id, viewer_id)) ?? [];
+  return NextResponse.json({ badges });
+}
+
+// ---------------------------------------------------------------------------
+// POST — grant badge
+// ---------------------------------------------------------------------------
+export async function POST(req: NextRequest): Promise<NextResponse> {
+  let body: unknown;
+  try {
+    body = await req.json();
+  } catch {
+    return NextResponse.json({ error: "Invalid JSON body" }, { status: 400 });
+  }
+
+  const { creator_id, viewer_id, badge, granted_by } = body as Record<string, unknown>;
+
+  if (!creator_id || typeof creator_id !== "string") {
+    return NextResponse.json({ error: "creator_id is required" }, { status: 400 });
+  }
+  if (!viewer_id || typeof viewer_id !== "string") {
+    return NextResponse.json({ error: "viewer_id is required" }, { status: 400 });
+  }
+  if (!badge || !VALID_BADGES.includes(badge as BadgeType)) {
+    return NextResponse.json(
+      { error: `badge must be one of: ${VALID_BADGES.join(", ")}` },
+      { status: 400 }
+    );
+  }
+  if (!granted_by || typeof granted_by !== "string") {
+    return NextResponse.json({ error: "granted_by is required" }, { status: 400 });
+  }
+
+  const key = storeKey(creator_id, viewer_id);
+  const existing = badgeStore.get(key) ?? [];
+
+  // Check for duplicate
+  if (existing.some((b) => b.badge === badge)) {
+    return NextResponse.json(
+      { error: `Viewer already has the "${badge}" badge` },
+      { status: 409 }
+    );
+  }
+
+  // Enforce cap
+  if (existing.length >= MAX_BADGES) {
+    return NextResponse.json(
+      { error: `Maximum of ${MAX_BADGES} badges per viewer reached` },
+      { status: 422 }
+    );
+  }
+
+  const granted_at = new Date().toISOString();
+  existing.push({ badge: badge as BadgeType, granted_by: granted_by as string, granted_at });
+  badgeStore.set(key, existing);
+
+  return NextResponse.json({ granted_at }, { status: 201 });
+}
+
+// ---------------------------------------------------------------------------
+// DELETE — revoke badge
+// ---------------------------------------------------------------------------
+export async function DELETE(req: NextRequest): Promise<NextResponse> {
+  let body: unknown;
+  try {
+    body = await req.json();
+  } catch {
+    return NextResponse.json({ error: "Invalid JSON body" }, { status: 400 });
+  }
+
+  const { creator_id, viewer_id, badge } = body as Record<string, unknown>;
+
+  if (!creator_id || typeof creator_id !== "string") {
+    return NextResponse.json({ error: "creator_id is required" }, { status: 400 });
+  }
+  if (!viewer_id || typeof viewer_id !== "string") {
+    return NextResponse.json({ error: "viewer_id is required" }, { status: 400 });
+  }
+  if (!badge || !VALID_BADGES.includes(badge as BadgeType)) {
+    return NextResponse.json(
+      { error: `badge must be one of: ${VALID_BADGES.join(", ")}` },
+      { status: 400 }
+    );
+  }
+
+  const key = storeKey(creator_id, viewer_id);
+  const existing = badgeStore.get(key) ?? [];
+  const idx = existing.findIndex((b) => b.badge === badge);
+
+  if (idx === -1) {
+    return NextResponse.json(
+      { error: `Viewer does not have the "${badge}" badge` },
+      { status: 404 }
+    );
+  }
+
+  existing.splice(idx, 1);
+  badgeStore.set(key, existing);
+
+  return NextResponse.json({ revoked: true });
+}
diff --git a/app/api/routes-f/viewer/history/[id]/route.ts b/app/api/routes-f/viewer/history/[id]/route.ts
new file mode 100644
index 00000000..45f2b8f7
--- /dev/null
+++ b/app/api/routes-f/viewer/history/[id]/route.ts
@@ -0,0 +1,31 @@
+import { type NextRequest, NextResponse } from "next/server";
+import { sql } from "@vercel/postgres";
+import { verifySession } from "@/lib/auth/verify-session";
+
+type RouteParams = { params: Promise<{ id: string }> };
+
+export async function DELETE(request: NextRequest, { params }: RouteParams) {
+  const session = await verifySession(request);
+  if (!session.ok) {
+    return session.response;
+  }
+
+  const { id } = await params;
+
+  try {
+    const { rows } = await sql`
+      DELETE FROM watch_history
+      WHERE id = ${id} AND user_id = ${session.userId}
+      RETURNING id
+    `;
+
+    if (rows.length === 0) {
+      return NextResponse.json({ error: "History entry not found" }, { status: 404 });
+    }
+
+    return NextResponse.json({ deleted: true, id });
+  } catch (error) {
+    console.error("[routes-f viewer/history/[id] DELETE]", error);
+    return NextResponse.json({ error: "Failed to delete history entry" }, { status: 500 });
+  }
+}
diff --git a/app/api/routes-f/viewer/history/all/route.ts b/app/api/routes-f/viewer/history/all/route.ts
new file mode 100644
index 00000000..ee553e60
--- /dev/null
+++ b/app/api/routes-f/viewer/history/all/route.ts
@@ -0,0 +1,21 @@
+import { type NextRequest, NextResponse } from "next/server";
+import { sql } from "@vercel/postgres";
+import { verifySession } from "@/lib/auth/verify-session";
+
+export async function DELETE(request: NextRequest) {
+  const session = await verifySession(request);
+  if (!session.ok) {
+    return session.response;
+  }
+
+  try {
+    const { rowCount } = await sql`
+      DELETE FROM watch_history WHERE user_id = ${session.userId}
+    `;
+
+    return NextResponse.json({ deleted: true, count: rowCount ?? 0 });
+  } catch (error) {
+    console.error("[routes-f viewer/history/all DELETE]", error);
+    return NextResponse.json({ error: "Failed to clear watch history" }, { status: 500 });
+  }
+}
diff --git a/app/api/routes-f/viewer/history/route.ts b/app/api/routes-f/viewer/history/route.ts
new file mode 100644
index 00000000..77fbe27b
--- /dev/null
+++ b/app/api/routes-f/viewer/history/route.ts
@@ -0,0 +1,75 @@
+import { type NextRequest, NextResponse } from "next/server";
+import { sql } from "@vercel/postgres";
+import { verifySession } from "@/lib/auth/verify-session";
+
+const DEFAULT_LIMIT = 20;
+const MAX_LIMIT = 100;
+
+export async function GET(request: NextRequest) {
+  const session = await verifySession(request);
+  if (!session.ok) {
+    return session.response;
+  }
+
+  try {
+    // Respect privacy setting
+    const { rows: privacyRows } = await sql`
+      SELECT show_watch_history FROM user_privacy_settings WHERE user_id = ${session.userId} LIMIT 1
+    `;
+    if (privacyRows[0]?.show_watch_history === false) {
+      return NextResponse.json(
+        { error: "Watch history is disabled for this account" },
+        { status: 403 }
+      );
+    }
+
+    const params = request.nextUrl.searchParams;
+    const cursor = params.get("cursor") ?? null;
+    const limitRaw = Number(params.get("limit") ?? DEFAULT_LIMIT);
+    const limit = Math.min(Math.max(1, limitRaw), MAX_LIMIT);
+
+    const { rows } = cursor
+      ? await sql`
+          SELECT
+            wh.id,
+            wh.stream_id,
+            u.username        AS creator_username,
+            wh.watched_at,
+            wh.watch_duration_seconds,
+            s.thumbnail_url
+          FROM watch_history wh
+          JOIN streams s ON s.id = wh.stream_id
+          JOIN users u   ON u.id = s.creator_id
+          WHERE wh.user_id = ${session.userId}
+            AND wh.watched_at < (SELECT watched_at FROM watch_history WHERE id = ${cursor} LIMIT 1)
+          ORDER BY wh.watched_at DESC
+          LIMIT ${limit + 1}
+        `
+      : await sql`
+          SELECT
+            wh.id,
+            wh.stream_id,
+            u.username        AS creator_username,
+            wh.watched_at,
+            wh.watch_duration_seconds,
+            s.thumbnail_url
+          FROM watch_history wh
+          JOIN streams s ON s.id = wh.stream_id
+          JOIN users u   ON u.id = s.creator_id
+          WHERE wh.user_id = ${session.userId}
+          ORDER BY wh.watched_at DESC
+          LIMIT ${limit + 1}
+        `;
+
+    const hasMore = rows.length > limit;
+    const entries = rows.slice(0, limit);
+
+    return NextResponse.json({
+      entries,
+      nextCursor: hasMore ? entries[entries.length - 1].id : null,
+    });
+  } catch (error) {
+    console.error("[routes-f viewer/history GET]", error);
+    return NextResponse.json({ error: "Failed to fetch watch history" }, { status: 500 });
+  }
+}
diff --git a/app/api/routes-f/viewer/reminders/__tests__/route.test.ts b/app/api/routes-f/viewer/reminders/__tests__/route.test.ts
new file mode 100644
index 00000000..dbee62d3
--- /dev/null
+++ b/app/api/routes-f/viewer/reminders/__tests__/route.test.ts
@@ -0,0 +1,222 @@
+import { sql } from "@vercel/postgres";
+import { GET, POST, DELETE } from "../route";
+import { NextRequest } from "next/server";
+
+jest.mock("next/server", () => ({
+  NextResponse: {
+    json: (body: unknown, init?: ResponseInit) =>
+      new Response(JSON.stringify(body), {
+        ...init,
+        headers: { "Content-Type": "application/json" },
+      }),
+  },
+}));
+
+jest.mock("@vercel/postgres", () => ({
+  sql: jest.fn(),
+}));
+
+jest.mock("@/app/api/routes-f/_lib/validate", () => ({
+  validateQuery: jest.fn((params: URLSearchParams, schema: any) => {
+    const obj = Object.fromEntries(params.entries());
+    const result = schema.safeParse(obj);
+    if (!result.success) {
+      return new Response(JSON.stringify({ error: "Invalid query", details: result.error.flatten() }), { status: 400 });
+    }
+    return { data: result.data };
+  }),
+  validateBody: jest.fn(async (req: Request, schema: any) => {
+    let body: unknown;
+    try {
+      body = await req.json();
+    } catch {
+      return new Response(JSON.stringify({ error: "Invalid JSON body" }), { status: 400 });
+    }
+    const result = schema.safeParse(body);
+    if (!result.success) {
+      return new Response(JSON.stringify({ error: "Invalid request body", details: result.error.flatten() }), { status: 400 });
+    }
+    return { data: result.data };
+  }),
+}));
+
+const sqlMock = sql as unknown as jest.Mock;
+
+const UUID1 = "550e8400-e29b-41d4-a716-446655440000";
+const UUID2 = "550e8400-e29b-41d4-a716-446655440001";
+const UUID3 = "550e8400-e29b-41d4-a716-446655440002";
+
+function makeGetRequest(params: Record<string, string>) {
+  const url = new URL("http://localhost/api/routes-f/viewer/reminders");
+  for (const [key, value] of Object.entries(params)) {
+    url.searchParams.set(key, value);
+  }
+  return new NextRequest(url) as any;
+}
+
+function makePostRequest(body: object) {
+  return new NextRequest("http://localhost/api/routes-f/viewer/reminders", {
+    method: "POST",
+    headers: { "Content-Type": "application/json" },
+    body: JSON.stringify(body),
+  }) as any;
+}
+
+function makeDeleteRequest(body: object) {
+  return new NextRequest("http://localhost/api/routes-f/viewer/reminders", {
+    method: "DELETE",
+    headers: { "Content-Type": "application/json" },
+    body: JSON.stringify(body),
+  }) as any;
+}
+
+describe("Scheduled Stream Reminder API", () => {
+  beforeEach(() => {
+    jest.clearAllMocks();
+  });
+
+  describe("GET /api/routes-f/viewer/reminders", () => {
+    it("returns 400 for missing viewer_id", async () => {
+      const res = await GET(makeGetRequest({}));
+      expect(res.status).toBe(400);
+    });
+
+    it("returns upcoming reminders", async () => {
+      sqlMock.mockResolvedValueOnce({});
+      sqlMock.mockResolvedValueOnce({
+        rows: [
+          {
+            id: "r1",
+            viewer_id: UUID1,
+            scheduled_stream_id: UUID2,
+            fires_at: "2025-06-02T18:00:00Z",
+            created_at: "2025-06-01T12:00:00Z",
+          },
+        ],
+      });
+
+      const res = await GET(makeGetRequest({ viewer_id: UUID1 }));
+      expect(res.status).toBe(200);
+      const body = await res.json();
+      expect(body.reminders).toHaveLength(1);
+      expect(body.reminders[0].scheduled_stream_id).toBe(UUID2);
+    });
+
+    it("returns empty list when no reminders", async () => {
+      sqlMock.mockResolvedValueOnce({});
+      sqlMock.mockResolvedValueOnce({ rows: [] });
+
+      const res = await GET(makeGetRequest({ viewer_id: UUID1 }));
+      expect(res.status).toBe(200);
+      const body = await res.json();
+      expect(body.reminders).toHaveLength(0);
+    });
+
+    it("returns 500 on database error", async () => {
+      sqlMock.mockRejectedValueOnce(new Error("DB error"));
+
+      const res = await GET(makeGetRequest({ viewer_id: UUID1 }));
+      expect(res.status).toBe(500);
+    });
+  });
+
+  describe("POST /api/routes-f/viewer/reminders", () => {
+    it("sets a reminder for a scheduled stream", async () => {
+      sqlMock.mockResolvedValueOnce({});
+      sqlMock.mockResolvedValueOnce({
+        rows: [{ id: UUID2, scheduled_at: "2025-06-02T18:00:00Z" }],
+      });
+      sqlMock.mockResolvedValueOnce({
+        rows: [
+          {
+            id: "r1",
+            viewer_id: UUID1,
+            scheduled_stream_id: UUID2,
+            fires_at: "2025-06-02T18:00:00Z",
+            created_at: "2025-06-01T12:00:00Z",
+          },
+        ],
+      });
+
+      const res = await POST(makePostRequest({
+        viewer_id: UUID1,
+        scheduled_stream_id: UUID2,
+      }));
+      expect(res.status).toBe(200);
+      const body = await res.json();
+      expect(body.reminder_set).toBe(true);
+      expect(body.fires_at).toBe("2025-06-02T18:00:00Z");
+    });
+
+    it("returns 404 for unknown scheduled stream", async () => {
+      sqlMock.mockResolvedValueOnce({});
+      sqlMock.mockResolvedValueOnce({ rows: [] });
+
+      const res = await POST(makePostRequest({
+        viewer_id: UUID1,
+        scheduled_stream_id: UUID3,
+      }));
+      expect(res.status).toBe(404);
+      const body = await res.json();
+      expect(body.error).toBe("Scheduled stream not found");
+    });
+
+    it("returns 400 for missing fields", async () => {
+      const res = await POST(makePostRequest({}));
+      expect(res.status).toBe(400);
+    });
+
+    it("returns 500 on database error", async () => {
+      sqlMock.mockRejectedValueOnce(new Error("DB error"));
+
+      const res = await POST(makePostRequest({
+        viewer_id: UUID1,
+        scheduled_stream_id: UUID2,
+      }));
+      expect(res.status).toBe(500);
+    });
+  });
+
+  describe("DELETE /api/routes-f/viewer/reminders", () => {
+    it("removes a reminder", async () => {
+      sqlMock.mockResolvedValueOnce({});
+      sqlMock.mockResolvedValueOnce({ rowCount: 1 });
+
+      const res = await DELETE(makeDeleteRequest({
+        viewer_id: UUID1,
+        scheduled_stream_id: UUID2,
+      }));
+      expect(res.status).toBe(200);
+      const body = await res.json();
+      expect(body.removed).toBe(true);
+    });
+
+    it("returns removed=false for non-existent reminder", async () => {
+      sqlMock.mockResolvedValueOnce({});
+      sqlMock.mockResolvedValueOnce({ rowCount: 0 });
+
+      const res = await DELETE(makeDeleteRequest({
+        viewer_id: UUID1,
+        scheduled_stream_id: UUID3,
+      }));
+      expect(res.status).toBe(200);
+      const body = await res.json();
+      expect(body.removed).toBe(false);
+    });
+
+    it("returns 400 for missing fields", async () => {
+      const res = await DELETE(makeDeleteRequest({}));
+      expect(res.status).toBe(400);
+    });
+
+    it("returns 500 on database error", async () => {
+      sqlMock.mockRejectedValueOnce(new Error("DB error"));
+
+      const res = await DELETE(makeDeleteRequest({
+        viewer_id: UUID1,
+        scheduled_stream_id: UUID2,
+      }));
+      expect(res.status).toBe(500);
+    });
+  });
+});
diff --git a/app/api/routes-f/viewer/reminders/route.ts b/app/api/routes-f/viewer/reminders/route.ts
new file mode 100644
index 00000000..f5fa5347
--- /dev/null
+++ b/app/api/routes-f/viewer/reminders/route.ts
@@ -0,0 +1,153 @@
+import { NextRequest, NextResponse } from "next/server";
+import { sql } from "@vercel/postgres";
+import { z } from "zod";
+import { validateQuery, validateBody } from "@/app/api/routes-f/_lib/validate";
+
+export const runtime = "nodejs";
+export const dynamic = "force-dynamic";
+
+const getQuerySchema = z.object({
+  viewer_id: z.string().uuid(),
+});
+
+const postBodySchema = z.object({
+  viewer_id: z.string().uuid(),
+  scheduled_stream_id: z.string().uuid(),
+});
+
+const deleteBodySchema = z.object({
+  viewer_id: z.string().uuid(),
+  scheduled_stream_id: z.string().uuid(),
+});
+
+async function ensureRemindersTable() {
+  await sql`
+    CREATE TABLE IF NOT EXISTS stream_reminders (
+      id UUID PRIMARY KEY DEFAULT gen_random_uuid(),
+      viewer_id UUID NOT NULL,
+      scheduled_stream_id UUID NOT NULL,
+      fires_at TIMESTAMPTZ NOT NULL,
+      created_at TIMESTAMPTZ NOT NULL DEFAULT NOW(),
+      UNIQUE (viewer_id, scheduled_stream_id)
+    )
+  `;
+
+  await sql`
+    CREATE INDEX IF NOT EXISTS idx_stream_reminders_viewer_fires
+    ON stream_reminders (viewer_id, fires_at DESC)
+  `;
+}
+
+export async function GET(req: NextRequest): Promise<NextResponse> {
+  const queryResult = validateQuery(
+    new URL(req.url).searchParams,
+    getQuerySchema
+  );
+  if (queryResult instanceof Response) {
+    return queryResult;
+  }
+
+  const { viewer_id } = queryResult.data;
+
+  try {
+    await ensureRemindersTable();
+
+    const { rows } = await sql`
+      SELECT
+        r.id,
+        r.viewer_id,
+        r.scheduled_stream_id,
+        r.fires_at,
+        r.created_at
+      FROM stream_reminders r
+      WHERE r.viewer_id = ${viewer_id}
+        AND r.fires_at > NOW()
+      ORDER BY r.fires_at ASC
+    `;
+
+    return NextResponse.json({ reminders: rows });
+  } catch (error) {
+    console.error("[routes-f viewer/reminders GET]", error);
+    return NextResponse.json(
+      { error: "Failed to fetch reminders" },
+      { status: 500 }
+    );
+  }
+}
+
+export async function POST(req: NextRequest): Promise<NextResponse> {
+  const bodyResult = await validateBody(req, postBodySchema);
+  if (bodyResult instanceof Response) {
+    return bodyResult;
+  }
+
+  const { viewer_id, scheduled_stream_id } = bodyResult.data;
+
+  try {
+    await ensureRemindersTable();
+
+    const { rows: streamRows } = await sql`
+      SELECT id, scheduled_at
+      FROM scheduled_streams
+      WHERE id = ${scheduled_stream_id}
+      LIMIT 1
+    `;
+
+    if (streamRows.length === 0) {
+      return NextResponse.json(
+        { error: "Scheduled stream not found" },
+        { status: 404 }
+      );
+    }
+
+    const firesAt = streamRows[0].scheduled_at;
+
+    const { rows } = await sql`
+      INSERT INTO stream_reminders (viewer_id, scheduled_stream_id, fires_at, created_at)
+      VALUES (${viewer_id}, ${scheduled_stream_id}, ${firesAt}, NOW())
+      ON CONFLICT (viewer_id, scheduled_stream_id)
+      DO UPDATE SET fires_at = EXCLUDED.fires_at
+      RETURNING id, viewer_id, scheduled_stream_id, fires_at, created_at
+    `;
+
+    return NextResponse.json({
+      reminder_set: true,
+      fires_at: rows[0].fires_at,
+      reminder: rows[0],
+    });
+  } catch (error) {
+    console.error("[routes-f viewer/reminders POST]", error);
+    return NextResponse.json(
+      { error: "Failed to set reminder" },
+      { status: 500 }
+    );
+  }
+}
+
+export async function DELETE(req: NextRequest): Promise<NextResponse> {
+  const bodyResult = await validateBody(req, deleteBodySchema);
+  if (bodyResult instanceof Response) {
+    return bodyResult;
+  }
+
+  const { viewer_id, scheduled_stream_id } = bodyResult.data;
+
+  try {
+    await ensureRemindersTable();
+
+    const { rowCount } = await sql`
+      DELETE FROM stream_reminders
+      WHERE viewer_id = ${viewer_id} AND scheduled_stream_id = ${scheduled_stream_id}
+    `;
+
+    return NextResponse.json({
+      removed: (rowCount ?? 0) > 0,
+    });
+  } catch (error) {
+    console.error("[routes-f viewer/reminders DELETE]", error);
+    return NextResponse.json(
+      { error: "Failed to remove reminder" },
+      { status: 500 }
+    );
+  }
+}
diff --git a/app/api/routes-f/viewer/sessions/__tests__/route.test.ts b/app/api/routes-f/viewer/sessions/__tests__/route.test.ts
new file mode 100644
index 00000000..16a2d520
--- /dev/null
+++ b/app/api/routes-f/viewer/sessions/__tests__/route.test.ts
@@ -0,0 +1,212 @@
+import { sql } from "@vercel/postgres";
+import { GET, POST, DELETE } from "../route";
+import { NextRequest } from "next/server";
+
+jest.mock("next/server", () => ({
+  NextResponse: {
+    json: (body: unknown, init?: ResponseInit) =>
+      new Response(JSON.stringify(body), {
+        ...init,
+        headers: { "Content-Type": "application/json" },
+      }),
+  },
+}));
+
+jest.mock("@vercel/postgres", () => ({
+  sql: jest.fn(),
+}));
+
+jest.mock("@/app/api/routes-f/_lib/validate", () => ({
+  validateQuery: jest.fn((params: URLSearchParams, schema: any) => {
+    const obj = Object.fromEntries(params.entries());
+    const result = schema.safeParse(obj);
+    if (!result.success) {
+      return new Response(JSON.stringify({ error: "Invalid query", details: result.error.flatten() }), { status: 400 });
+    }
+    return { data: result.data };
+  }),
+  validateBody: jest.fn(async (req: Request, schema: any) => {
+    let body: unknown;
+    try {
+      body = await req.json();
+    } catch {
+      return new Response(JSON.stringify({ error: "Invalid JSON body" }), { status: 400 });
+    }
+    const result = schema.safeParse(body);
+    if (!result.success) {
+      return new Response(JSON.stringify({ error: "Invalid request body", details: result.error.flatten() }), { status: 400 });
+    }
+    return { data: result.data };
+  }),
+}));
+
+const sqlMock = sql as unknown as jest.Mock;
+
+const UUID1 = "550e8400-e29b-41d4-a716-446655440000";
+const UUID2 = "550e8400-e29b-41d4-a716-446655440001";
+const UUID3 = "550e8400-e29b-41d4-a716-446655440002";
+const UUID4 = "550e8400-e29b-41d4-a716-446655440003";
+
+function makeGetRequest(params: Record<string, string>) {
+  const url = new URL("http://localhost/api/routes-f/viewer/sessions");
+  for (const [key, value] of Object.entries(params)) {
+    url.searchParams.set(key, value);
+  }
+  return new NextRequest(url) as any;
+}
+
+function makePostRequest(body: object) {
+  return new NextRequest("http://localhost/api/routes-f/viewer/sessions", {
+    method: "POST",
+    headers: { "Content-Type": "application/json" },
+    body: JSON.stringify(body),
+  }) as any;
+}
+
+function makeDeleteRequest(body: object) {
+  return new NextRequest("http://localhost/api/routes-f/viewer/sessions", {
+    method: "DELETE",
+    headers: { "Content-Type": "application/json" },
+    body: JSON.stringify(body),
+  }) as any;
+}
+
+describe("Viewer Concurrent Sessions API", () => {
+  beforeEach(() => {
+    jest.clearAllMocks();
+  });
+
+  describe("GET /api/routes-f/viewer/sessions", () => {
+    it("returns 400 for missing viewer_id", async () => {
+      const res = await GET(makeGetRequest({}));
+      expect(res.status).toBe(400);
+    });
+
+    it("returns active sessions", async () => {
+      sqlMock.mockResolvedValueOnce({});
+      sqlMock.mockResolvedValueOnce({
+        rows: [
+          { id: "s1", viewer_id: UUID1, session_id: UUID2, playback_id: "pb-1", registered_at: "2025-06-01T12:00:00Z" },
+        ],
+      });
+
+      const res = await GET(makeGetRequest({ viewer_id: UUID1 }));
+      expect(res.status).toBe(200);
+      const body = await res.json();
+      expect(body.active_sessions).toHaveLength(1);
+      expect(body.limit).toBe(3);
+    });
+  });
+
+  describe("POST /api/routes-f/viewer/sessions", () => {
+    it("registers a new session", async () => {
+      sqlMock.mockResolvedValueOnce({});
+      sqlMock.mockResolvedValueOnce({ rows: [] });
+      sqlMock.mockResolvedValueOnce({ rows: [{ total: 0 }] });
+      sqlMock.mockResolvedValueOnce({});
+
+      const res = await POST(makePostRequest({
+        viewer_id: UUID1,
+        session_id: UUID2,
+        playback_id: "pb-1",
+      }));
+      expect(res.status).toBe(200);
+      const body = await res.json();
+      expect(body.active_sessions).toBe(1);
+      expect(body.limit).toBe(3);
+    });
+
+    it("returns existing session info if session already registered", async () => {
+      sqlMock.mockResolvedValueOnce({});
+      sqlMock.mockResolvedValueOnce({ rows: [{ id: "existing" }] });
+
+      const res = await POST(makePostRequest({
+        viewer_id: UUID1,
+        session_id: UUID2,
+        playback_id: "pb-1",
+      }));
+      expect(res.status).toBe(200);
+      const body = await res.json();
+      expect(body.message).toBe("Session already registered");
+    });
+
+    it("rejects with 429 when concurrent limit reached", async () => {
+      sqlMock.mockResolvedValueOnce({});
+      sqlMock.mockResolvedValueOnce({ rows: [] });
+      sqlMock.mockResolvedValueOnce({ rows: [{ total: 3 }] });
+
+      const res = await POST(makePostRequest({
+        viewer_id: UUID1,
+        session_id: UUID4,
+        playback_id: "pb-4",
+      }));
+      expect(res.status).toBe(429);
+      const body = await res.json();
+      expect(body.error).toBe("Concurrent session limit reached");
+      expect(body.active_sessions).toBe(3);
+      expect(body.limit).toBe(3);
+    });
+
+    it("returns 400 for missing fields", async () => {
+      const res = await POST(makePostRequest({}));
+      expect(res.status).toBe(400);
+    });
+
+    it("returns 500 on database error", async () => {
+      sqlMock.mockRejectedValueOnce(new Error("DB error"));
+
+      const res = await POST(makePostRequest({
+        viewer_id: UUID1,
+        session_id: UUID2,
+        playback_id: "pb-1",
+      }));
+      expect(res.status).toBe(500);
+    });
+  });
+
+  describe("DELETE /api/routes-f/viewer/sessions", () => {
+    it("removes a session", async () => {
+      sqlMock.mockResolvedValueOnce({});
+      sqlMock.mockResolvedValueOnce({ rowCount: 1 });
+      sqlMock.mockResolvedValueOnce({ rows: [{ total: 0 }] });
+
+      const res = await DELETE(makeDeleteRequest({
+        viewer_id: UUID1,
+        session_id: UUID2,
+      }));
+      expect(res.status).toBe(200);
+      const body = await res.json();
+      expect(body.removed).toBe(true);
+      expect(body.active_sessions).toBe(0);
+    });
+
+    it("returns removed=false for non-existent session", async () => {
+      sqlMock.mockResolvedValueOnce({});
+      sqlMock.mockResolvedValueOnce({ rowCount: 0 });
+      sqlMock.mockResolvedValueOnce({ rows: [{ total: 1 }] });
+
+      const res = await DELETE(makeDeleteRequest({
+        viewer_id: UUID1,
+        session_id: UUID3,
+      }));
+      expect(res.status).toBe(200);
+      const body = await res.json();
+      expect(body.removed).toBe(false);
+    });
+
+    it("returns 400 for missing fields", async () => {
+      const res = await DELETE(makeDeleteRequest({}));
+      expect(res.status).toBe(400);
+    });
+
+    it("returns 500 on database error", async () => {
+      sqlMock.mockRejectedValueOnce(new Error("DB error"));
+
+      const res = await DELETE(makeDeleteRequest({
+        viewer_id: UUID1,
+        session_id: UUID2,
+      }));
+      expect(res.status).toBe(500);
+    });
+  });
+});
diff --git a/app/api/routes-f/viewer/sessions/route.ts b/app/api/routes-f/viewer/sessions/route.ts
new file mode 100644
index 00000000..20a71c77
--- /dev/null
+++ b/app/api/routes-f/viewer/sessions/route.ts
@@ -0,0 +1,174 @@
+import { NextRequest, NextResponse } from "next/server";
+import { sql } from "@vercel/postgres";
+import { z } from "zod";
+import { validateQuery, validateBody } from "@/app/api/routes-f/_lib/validate";
+
+export const runtime = "nodejs";
+export const dynamic = "force-dynamic";
+
+const MAX_CONCURRENT_SESSIONS = 3;
+
+const getQuerySchema = z.object({
+  viewer_id: z.string().uuid(),
+});
+
+const postBodySchema = z.object({
+  viewer_id: z.string().uuid(),
+  session_id: z.string().uuid(),
+  playback_id: z.string().min(1),
+});
+
+const deleteBodySchema = z.object({
+  viewer_id: z.string().uuid(),
+  session_id: z.string().uuid(),
+});
+
+async function ensureSessionsTable() {
+  await sql`
+    CREATE TABLE IF NOT EXISTS viewer_playback_sessions (
+      id UUID PRIMARY KEY DEFAULT gen_random_uuid(),
+      viewer_id UUID NOT NULL,
+      session_id UUID NOT NULL,
+      playback_id TEXT NOT NULL,
+      registered_at TIMESTAMPTZ NOT NULL DEFAULT NOW(),
+      UNIQUE (viewer_id, session_id)
+    )
+  `;
+
+  await sql`
+    CREATE INDEX IF NOT EXISTS idx_viewer_playback_sessions_viewer
+    ON viewer_playback_sessions (viewer_id)
+  `;
+}
+
+export async function GET(req: NextRequest): Promise<NextResponse> {
+  const queryResult = validateQuery(
+    new URL(req.url).searchParams,
+    getQuerySchema
+  );
+  if (queryResult instanceof Response) {
+    return queryResult;
+  }
+
+  const { viewer_id } = queryResult.data;
+
+  try {
+    await ensureSessionsTable();
+
+    const { rows } = await sql`
+      SELECT id, viewer_id, session_id, playback_id, registered_at
+      FROM viewer_playback_sessions
+      WHERE viewer_id = ${viewer_id}
+      ORDER BY registered_at DESC
+    `;
+
+    return NextResponse.json({
+      active_sessions: rows,
+      limit: MAX_CONCURRENT_SESSIONS,
+    });
+  } catch (error) {
+    console.error("[routes-f viewer/sessions GET]", error);
+    return NextResponse.json(
+      { error: "Failed to fetch active sessions" },
+      { status: 500 }
+    );
+  }
+}
+
+export async function POST(req: NextRequest): Promise<NextResponse> {
+  const bodyResult = await validateBody(req, postBodySchema);
+  if (bodyResult instanceof Response) {
+    return bodyResult;
+  }
+
+  const { viewer_id, session_id, playback_id } = bodyResult.data;
+
+  try {
+    await ensureSessionsTable();
+
+    const { rows: existing } = await sql`
+      SELECT id FROM viewer_playback_sessions
+      WHERE viewer_id = ${viewer_id} AND session_id = ${session_id}
+      LIMIT 1
+    `;
+
+    if (existing.length > 0) {
+      return NextResponse.json({
+        active_sessions: existing.length,
+        limit: MAX_CONCURRENT_SESSIONS,
+        message: "Session already registered",
+      });
+    }
+
+    const { rows: countRows } = await sql`
+      SELECT COUNT(*)::int AS total
+      FROM viewer_playback_sessions
+      WHERE viewer_id = ${viewer_id}
+    `;
+
+    const currentCount = Number(countRows[0]?.total ?? 0);
+
+    if (currentCount >= MAX_CONCURRENT_SESSIONS) {
+      return NextResponse.json(
+        {
+          error: "Concurrent session limit reached",
+          active_sessions: currentCount,
+          limit: MAX_CONCURRENT_SESSIONS,
+        },
+        { status: 429 }
+      );
+    }
+
+    await sql`
+      INSERT INTO viewer_playback_sessions (viewer_id, session_id, playback_id, registered_at)
+      VALUES (${viewer_id}, ${session_id}, ${playback_id}, NOW())
+    `;
+
+    return NextResponse.json({
+      active_sessions: currentCount + 1,
+      limit: MAX_CONCURRENT_SESSIONS,
+    });
+  } catch (error) {
+    console.error("[routes-f viewer/sessions POST]", error);
+    return NextResponse.json(
+      { error: "Failed to register session" },
+      { status: 500 }
+    );
+  }
+}
+
+export async function DELETE(req: NextRequest): Promise<NextResponse> {
+  const bodyResult = await validateBody(req, deleteBodySchema);
+  if (bodyResult instanceof Response) {
+    return bodyResult;
+  }
+
+  const { viewer_id, session_id } = bodyResult.data;
+
+  try {
+    await ensureSessionsTable();
+
+    const { rowCount } = await sql`
+      DELETE FROM viewer_playback_sessions
+      WHERE viewer_id = ${viewer_id} AND session_id = ${session_id}
+    `;
+
+    const { rows: countRows } = await sql`
+      SELECT COUNT(*)::int AS total
+      FROM viewer_playback_sessions
+      WHERE viewer_id = ${viewer_id}
+    `;
+
+    return NextResponse.json({
+      removed: (rowCount ?? 0) > 0,
+      active_sessions: Number(countRows[0]?.total ?? 0),
+      limit: MAX_CONCURRENT_SESSIONS,
+    });
+  } catch (error) {
+    console.error("[routes-f viewer/sessions DELETE]", error);
+    return NextResponse.json(
+      { error: "Failed to remove session" },
+      { status: 500 }
+    );
+  }
+}
diff --git a/app/api/routes-f/viewer/watch-history/__tests__/route.test.ts b/app/api/routes-f/viewer/watch-history/__tests__/route.test.ts
new file mode 100644
index 00000000..1de597eb
--- /dev/null
+++ b/app/api/routes-f/viewer/watch-history/__tests__/route.test.ts
@@ -0,0 +1,205 @@
+import { sql } from "@vercel/postgres";
+import { GET, POST } from "../route";
+import { NextRequest } from "next/server";
+
+jest.mock("next/server", () => ({
+  NextResponse: {
+    json: (body: unknown, init?: ResponseInit) =>
+      new Response(JSON.stringify(body), {
+        ...init,
+        headers: { "Content-Type": "application/json" },
+      }),
+  },
+}));
+
+jest.mock("@vercel/postgres", () => ({
+  sql: jest.fn(),
+}));
+
+jest.mock("@/app/api/routes-f/_lib/validate", () => ({
+  validateQuery: jest.fn((params: URLSearchParams, schema: any) => {
+    const obj = Object.fromEntries(params.entries());
+    const result = schema.safeParse(obj);
+    if (!result.success) {
+      return new Response(JSON.stringify({ error: "Invalid query", details: result.error.flatten() }), { status: 400 });
+    }
+    return { data: result.data };
+  }),
+  validateBody: jest.fn(async (req: Request, schema: any) => {
+    let body: unknown;
+    try {
+      body = await req.json();
+    } catch {
+      return new Response(JSON.stringify({ error: "Invalid JSON body" }), { status: 400 });
+    }
+    const result = schema.safeParse(body);
+    if (!result.success) {
+      return new Response(JSON.stringify({ error: "Invalid request body", details: result.error.flatten() }), { status: 400 });
+    }
+    return { data: result.data };
+  }),
+}));
+
+const sqlMock = sql as unknown as jest.Mock;
+
+function makeGetRequest(params: Record<string, string>) {
+  const url = new URL("http://localhost/api/routes-f/viewer/watch-history");
+  for (const [key, value] of Object.entries(params)) {
+    url.searchParams.set(key, value);
+  }
+  return new NextRequest(url) as any;
+}
+
+function makePostRequest(body: object) {
+  return new NextRequest("http://localhost/api/routes-f/viewer/watch-history", {
+    method: "POST",
+    headers: { "Content-Type": "application/json" },
+    body: JSON.stringify(body),
+  }) as any;
+}
+
+describe("Viewer Watch History API", () => {
+  beforeEach(() => {
+    jest.clearAllMocks();
+  });
+
+  describe("GET /api/routes-f/viewer/watch-history", () => {
+    it("returns 400 for missing viewer_id", async () => {
+      const res = await GET(makeGetRequest({}));
+      expect(res.status).toBe(400);
+    });
+
+    it("returns 400 for invalid viewer_id", async () => {
+      const res = await GET(makeGetRequest({ viewer_id: "not-a-uuid" }));
+      expect(res.status).toBe(400);
+    });
+
+    it("returns watch history entries", async () => {
+      sqlMock.mockResolvedValueOnce({});
+      sqlMock.mockResolvedValueOnce({
+        rows: [
+          {
+            id: "h1",
+            viewer_id: "v1",
+            target_type: "stream",
+            target_id: "t1",
+            watched_at: "2025-06-01T12:00:00Z",
+            created_at: "2025-06-01T12:00:00Z",
+            updated_at: "2025-06-01T12:00:00Z",
+          },
+          {
+            id: "h2",
+            viewer_id: "v1",
+            target_type: "vod",
+            target_id: "t2",
+            watched_at: "2025-06-01T10:00:00Z",
+            created_at: "2025-06-01T10:00:00Z",
+            updated_at: "2025-06-01T10:00:00Z",
+          },
+        ],
+      });
+
+      const res = await GET(makeGetRequest({ viewer_id: "550e8400-e29b-41d4-a716-446655440000" }));
+      expect(res.status).toBe(200);
+      const body = await res.json();
+      expect(body.entries).toHaveLength(2);
+      expect(body.entries[0].watched_at).toBe("2025-06-01T12:00:00Z");
+    });
+
+    it("respects limit parameter", async () => {
+      sqlMock.mockResolvedValueOnce({});
+      sqlMock.mockResolvedValueOnce({ rows: [] });
+
+      const res = await GET(makeGetRequest({ viewer_id: "550e8400-e29b-41d4-a716-446655440000", limit: "5" }));
+      expect(res.status).toBe(200);
+    });
+
+    it("returns 500 on database error", async () => {
+      sqlMock.mockRejectedValueOnce(new Error("DB error"));
+
+      const res = await GET(makeGetRequest({ viewer_id: "550e8400-e29b-41d4-a716-446655440000" }));
+      expect(res.status).toBe(500);
+    });
+  });
+
+  describe("POST /api/routes-f/viewer/watch-history", () => {
+    it("returns 400 for missing fields", async () => {
+      const res = await POST(makePostRequest({}));
+      expect(res.status).toBe(400);
+    });
+
+    it("returns 400 for invalid target_type", async () => {
+      const res = await POST(makePostRequest({
+        viewer_id: "550e8400-e29b-41d4-a716-446655440000",
+        target_type: "invalid",
+        target_id: "550e8400-e29b-41d4-a716-446655440001",
+      }));
+      expect(res.status).toBe(400);
+    });
+
+    it("creates a new watch history entry", async () => {
+      sqlMock.mockResolvedValueOnce({});
+      sqlMock.mockResolvedValueOnce({
+        rows: [
+          {
+            id: "h1",
+            viewer_id: "v1",
+            target_type: "stream",
+            target_id: "t1",
+            watched_at: "2025-06-01T12:00:00Z",
+            created_at: "2025-06-01T12:00:00Z",
+            updated_at: "2025-06-01T12:00:00Z",
+          },
+        ],
+      });
+
+      const res = await POST(makePostRequest({
+        viewer_id: "550e8400-e29b-41d4-a716-446655440000",
+        target_type: "stream",
+        target_id: "550e8400-e29b-41d4-a716-446655440001",
+      }));
+      expect(res.status).toBe(201);
+      const body = await res.json();
+      expect(body.entry).toBeDefined();
+      expect(body.entry.target_type).toBe("stream");
+    });
+
+    it("deduplicates by keeping latest timestamp", async () => {
+      sqlMock.mockResolvedValueOnce({});
+      sqlMock.mockResolvedValueOnce({
+        rows: [
+          {
+            id: "h1",
+            viewer_id: "v1",
+            target_type: "stream",
+            target_id: "t1",
+            watched_at: "2025-06-02T12:00:00Z",
+            created_at: "2025-06-01T10:00:00Z",
+            updated_at: "2025-06-02T12:00:00Z",
+          },
+        ],
+      });
+
+      const res = await POST(makePostRequest({
+        viewer_id: "550e8400-e29b-41d4-a716-446655440000",
+        target_type: "stream",
+        target_id: "550e8400-e29b-41d4-a716-446655440001",
+      }));
+      expect(res.status).toBe(201);
+      expect(sqlMock).toHaveBeenCalledWith(
+        expect.arrayContaining([expect.stringContaining("ON CONFLICT")])
+      );
+    });
+
+    it("returns 500 on database error", async () => {
+      sqlMock.mockRejectedValueOnce(new Error("DB error"));
+
+      const res = await POST(makePostRequest({
+        viewer_id: "550e8400-e29b-41d4-a716-446655440000",
+        target_type: "stream",
+        target_id: "550e8400-e29b-41d4-a716-446655440001",
+      }));
+      expect(res.status).toBe(500);
+    });
+  });
+});
diff --git a/app/api/routes-f/viewer/watch-history/route.ts b/app/api/routes-f/viewer/watch-history/route.ts
new file mode 100644
index 00000000..2ef22f5c
--- /dev/null
+++ b/app/api/routes-f/viewer/watch-history/route.ts
@@ -0,0 +1,114 @@
+import { NextRequest, NextResponse } from "next/server";
+import { sql } from "@vercel/postgres";
+import { z } from "zod";
+import { validateQuery, validateBody } from "@/app/api/routes-f/_lib/validate";
+
+export const runtime = "nodejs";
+export const dynamic = "force-dynamic";
+
+const MAX_LIMIT = 50;
+const DEFAULT_LIMIT = 20;
+
+const getQuerySchema = z.object({
+  viewer_id: z.string().uuid(),
+  limit: z.coerce.number().int().min(1).max(MAX_LIMIT).default(DEFAULT_LIMIT),
+});
+
+const postBodySchema = z.object({
+  viewer_id: z.string().uuid(),
+  target_type: z.enum(["stream", "vod"]),
+  target_id: z.string().uuid(),
+  watched_at: z.string().datetime().optional(),
+});
+
+async function ensureWatchHistoryTable() {
+  await sql`
+    CREATE TABLE IF NOT EXISTS viewer_watch_history (
+      id UUID PRIMARY KEY DEFAULT gen_random_uuid(),
+      viewer_id UUID NOT NULL,
+      target_type TEXT NOT NULL CHECK (target_type IN ('stream', 'vod')),
+      target_id UUID NOT NULL,
+      watched_at TIMESTAMPTZ NOT NULL DEFAULT NOW(),
+      created_at TIMESTAMPTZ NOT NULL DEFAULT NOW(),
+      updated_at TIMESTAMPTZ NOT NULL DEFAULT NOW(),
+      UNIQUE (viewer_id, target_id)
+    )
+  `;
+
+  await sql`
+    CREATE INDEX IF NOT EXISTS idx_viewer_watch_history_viewer_watched
+    ON viewer_watch_history (viewer_id, watched_at DESC)
+  `;
+}
+
+export async function GET(req: NextRequest): Promise<NextResponse> {
+  const queryResult = validateQuery(
+    new URL(req.url).searchParams,
+    getQuerySchema
+  );
+  if (queryResult instanceof Response) {
+    return queryResult;
+  }
+
+  const { viewer_id, limit } = queryResult.data;
+
+  try {
+    await ensureWatchHistoryTable();
+
+    const { rows } = await sql`
+      SELECT
+        id,
+        viewer_id,
+        target_type,
+        target_id,
+        watched_at,
+        created_at,
+        updated_at
+      FROM viewer_watch_history
+      WHERE viewer_id = ${viewer_id}
+      ORDER BY watched_at DESC
+      LIMIT ${limit}
+    `;
+
+    return NextResponse.json({ entries: rows });
+  } catch (error) {
+    console.error("[routes-f viewer/watch-history GET]", error);
+    return NextResponse.json(
+      { error: "Failed to fetch watch history" },
+      { status: 500 }
+    );
+  }
+}
+
+export async function POST(req: NextRequest): Promise<NextResponse> {
+  const bodyResult = await validateBody(req, postBodySchema);
+  if (bodyResult instanceof Response) {
+    return bodyResult;
+  }
+
+  const { viewer_id, target_type, target_id, watched_at } = bodyResult.data;
+
+  try {
+    await ensureWatchHistoryTable();
+
+    const now = watched_at ?? new Date().toISOString();
+
+    const { rows } = await sql`
+      INSERT INTO viewer_watch_history (viewer_id, target_type, target_id, watched_at, created_at, updated_at)
+      VALUES (${viewer_id}, ${target_type}, ${target_id}, ${now}, NOW(), NOW())
+      ON CONFLICT (viewer_id, target_id)
+      DO UPDATE SET
+        watched_at = GREATEST(viewer_watch_history.watched_at, EXCLUDED.watched_at),
+        updated_at = NOW()
+      RETURNING id, viewer_id, target_type, target_id, watched_at, created_at, updated_at
+    `;
+
+    return NextResponse.json({ entry: rows[0] }, { status: 201 });
+  } catch (error) {
+    console.error("[routes-f viewer/watch-history POST]", error);
+    return NextResponse.json(
+      { error: "Failed to record watch history" },
+      { status: 500 }
+    );
+  }
+}
diff --git a/app/api/routes-f/vod-playlist/__tests__/route.test.ts b/app/api/routes-f/vod-playlist/__tests__/route.test.ts
new file mode 100644
index 00000000..d7b3ec87
--- /dev/null
+++ b/app/api/routes-f/vod-playlist/__tests__/route.test.ts
@@ -0,0 +1,183 @@
+import { NextRequest } from "next/server";
+import { GET, POST, DELETE } from "../route";
+import { POST as REORDER_POST } from "../reorder/route";
+import { clearAllPlaylists } from "../store";
+
+function makeGetReq(params: Record<string, string> = {}): NextRequest {
+  const url = new URL("http://localhost/api/routes-f/vod-playlist");
+  Object.entries(params).forEach(([k, v]) => url.searchParams.set(k, v));
+  return new NextRequest(url.toString());
+}
+
+function makePostReq(body: unknown): NextRequest {
+  return new NextRequest("http://localhost/api/routes-f/vod-playlist", {
+    method: "POST",
+    headers: { "Content-Type": "application/json" },
+    body: JSON.stringify(body),
+  });
+}
+
+function makeDeleteReq(body: unknown): NextRequest {
+  return new NextRequest("http://localhost/api/routes-f/vod-playlist", {
+    method: "DELETE",
+    headers: { "Content-Type": "application/json" },
+    body: JSON.stringify(body),
+  });
+}
+
+function makeReorderReq(body: unknown): NextRequest {
+  return new NextRequest("http://localhost/api/routes-f/vod-playlist/reorder", {
+    method: "POST",
+    headers: { "Content-Type": "application/json" },
+    body: JSON.stringify(body),
+  });
+}
+
+describe("vod-playlist lifecycle", () => {
+  beforeEach(() => {
+    clearAllPlaylists();
+  });
+
+  describe("POST /api/routes-f/vod-playlist", () => {
+    it("appends a VOD to the playlist", async () => {
+      const res = await POST(
+        makePostReq({ viewer_id: "v1", vod_id: "vod_1" })
+      );
+      expect(res.status).toBe(201);
+      const data = await res.json();
+      expect(data.vod_id).toBe("vod_1");
+      expect(typeof data.added_at).toBe("string");
+    });
+
+    it("returns 400 when viewer_id is missing", async () => {
+      const res = await POST(makePostReq({ vod_id: "vod_1" }));
+      expect(res.status).toBe(400);
+    });
+
+    it("returns 400 when vod_id is missing", async () => {
+      const res = await POST(makePostReq({ viewer_id: "v1" }));
+      expect(res.status).toBe(400);
+    });
+
+    it("returns 409 when VOD already in playlist", async () => {
+      await POST(makePostReq({ viewer_id: "v1", vod_id: "vod_1" }));
+      const res = await POST(
+        makePostReq({ viewer_id: "v1", vod_id: "vod_1" })
+      );
+      expect(res.status).toBe(409);
+    });
+
+    it("returns 400 when playlist is full (100 items)", async () => {
+      for (let i = 0; i < 100; i++) {
+        await POST(makePostReq({ viewer_id: "v_full", vod_id: `vod_${i}` }));
+      }
+      const res = await POST(
+        makePostReq({ viewer_id: "v_full", vod_id: "vod_100" })
+      );
+      expect(res.status).toBe(400);
+    });
+  });
+
+  describe("GET /api/routes-f/vod-playlist", () => {
+    it("returns 400 when viewer_id is missing", async () => {
+      const res = await GET(makeGetReq({}));
+      expect(res.status).toBe(400);
+    });
+
+    it("returns empty playlist for unknown viewer", async () => {
+      const res = await GET(makeGetReq({ viewer_id: "unknown" }));
+      expect(res.status).toBe(200);
+      const data = await res.json();
+      expect(data.items).toEqual([]);
+    });
+
+    it("returns playlist with items", async () => {
+      await POST(makePostReq({ viewer_id: "v1", vod_id: "vod_1" }));
+      await POST(makePostReq({ viewer_id: "v1", vod_id: "vod_2" }));
+      const res = await GET(makeGetReq({ viewer_id: "v1" }));
+      expect(res.status).toBe(200);
+      const data = await res.json();
+      expect(data.items).toHaveLength(2);
+      expect(data.viewer_id).toBe("v1");
+    });
+  });
+
+  describe("DELETE /api/routes-f/vod-playlist", () => {
+    it("removes a VOD from the playlist", async () => {
+      await POST(makePostReq({ viewer_id: "v1", vod_id: "vod_1" }));
+      const res = await DELETE(
+        makeDeleteReq({ viewer_id: "v1", vod_id: "vod_1" })
+      );
+      expect(res.status).toBe(200);
+      const data = await res.json();
+      expect(data.removed).toBe(true);
+    });
+
+    it("returns 404 when VOD not in playlist", async () => {
+      const res = await DELETE(
+        makeDeleteReq({ viewer_id: "v1", vod_id: "vod_none" })
+      );
+      expect(res.status).toBe(404);
+    });
+
+    it("returns 400 when viewer_id is missing", async () => {
+      const res = await DELETE(makeDeleteReq({ vod_id: "vod_1" }));
+      expect(res.status).toBe(400);
+    });
+
+    it("returns 400 when vod_id is missing", async () => {
+      const res = await DELETE(makeDeleteReq({ viewer_id: "v1" }));
+      expect(res.status).toBe(400);
+    });
+  });
+
+  describe("POST /api/routes-f/vod-playlist/reorder", () => {
+    it("reorders the playlist", async () => {
+      await POST(makePostReq({ viewer_id: "v1", vod_id: "vod_a" }));
+      await POST(makePostReq({ viewer_id: "v1", vod_id: "vod_b" }));
+      await POST(makePostReq({ viewer_id: "v1", vod_id: "vod_c" }));
+
+      const res = await REORDER_POST(
+        makeReorderReq({ viewer_id: "v1", order: ["vod_c", "vod_a", "vod_b"] })
+      );
+      expect(res.status).toBe(200);
+
+      const playlist = await GET(makeGetReq({ viewer_id: "v1" }));
+      const data = await playlist.json();
+      expect(data.items.map((i: { vod_id: string }) => i.vod_id)).toEqual([
+        "vod_c",
+        "vod_a",
+        "vod_b",
+      ]);
+    });
+
+    it("returns 400 when order is not an array", async () => {
+      const res = await REORDER_POST(
+        makeReorderReq({ viewer_id: "v1", order: "not_array" })
+      );
+      expect(res.status).toBe(400);
+    });
+
+    it("returns 400 when order is empty", async () => {
+      const res = await REORDER_POST(
+        makeReorderReq({ viewer_id: "v1", order: [] })
+      );
+      expect(res.status).toBe(400);
+    });
+
+    it("returns 404 when viewer has no playlist", async () => {
+      const res = await REORDER_POST(
+        makeReorderReq({ viewer_id: "unknown", order: ["vod_x"] })
+      );
+      expect(res.status).toBe(404);
+    });
+
+    it("returns 400 when order contains unknown vod_id", async () => {
+      await POST(makePostReq({ viewer_id: "v1", vod_id: "vod_a" }));
+      const res = await REORDER_POST(
+        makeReorderReq({ viewer_id: "v1", order: ["vod_a", "vod_z"] })
+      );
+      expect(res.status).toBe(400);
+    });
+  });
+});
diff --git a/app/api/routes-f/vod-playlist/reorder/route.ts b/app/api/routes-f/vod-playlist/reorder/route.ts
new file mode 100644
index 00000000..70dc6943
--- /dev/null
+++ b/app/api/routes-f/vod-playlist/reorder/route.ts
@@ -0,0 +1,38 @@
+import { NextRequest, NextResponse } from "next/server";
+import type { ReorderBody } from "../types";
+import { reorderPlaylist } from "../store";
+
+export async function POST(req: NextRequest): Promise<NextResponse> {
+  let body: ReorderBody;
+  try {
+    body = await req.json();
+  } catch {
+    return NextResponse.json({ error: "invalid JSON body" }, { status: 400 });
+  }
+
+  const { viewer_id, order } = body;
+
+  if (!viewer_id || typeof viewer_id !== "string") {
+    return NextResponse.json(
+      { error: "viewer_id is required" },
+      { status: 400 }
+    );
+  }
+  if (!Array.isArray(order) || order.length === 0) {
+    return NextResponse.json(
+      { error: "order must be a non-empty array of vod_ids" },
+      { status: 400 }
+    );
+  }
+
+  try {
+    reorderPlaylist(viewer_id, order);
+    return NextResponse.json({ message: "Playlist reordered" });
+  } catch (err) {
+    const message = err instanceof Error ? err.message : "Unknown error";
+    if (message.includes("No playlist found")) {
+      return NextResponse.json({ error: message }, { status: 404 });
+    }
+    return NextResponse.json({ error: message }, { status: 400 });
+  }
+}
diff --git a/app/api/routes-f/vod-playlist/route.ts b/app/api/routes-f/vod-playlist/route.ts
new file mode 100644
index 00000000..a99414bb
--- /dev/null
+++ b/app/api/routes-f/vod-playlist/route.ts
@@ -0,0 +1,88 @@
+import { NextRequest, NextResponse } from "next/server";
+import type { PostPlaylistBody, DeletePlaylistBody } from "./types";
+import {
+  getPlaylist,
+  appendToPlaylist,
+  removeFromPlaylist,
+} from "./store";
+
+export async function GET(req: NextRequest): Promise<NextResponse> {
+  const viewerId = req.nextUrl.searchParams.get("viewer_id");
+
+  if (!viewerId) {
+    return NextResponse.json(
+      { error: "viewer_id is required" },
+      { status: 400 }
+    );
+  }
+
+  const playlist = getPlaylist(viewerId);
+  return NextResponse.json(playlist);
+}
+
+export async function POST(req: NextRequest): Promise<NextResponse> {
+  let body: PostPlaylistBody;
+  try {
+    body = await req.json();
+  } catch {
+    return NextResponse.json({ error: "invalid JSON body" }, { status: 400 });
+  }
+
+  const { viewer_id, vod_id } = body;
+
+  if (!viewer_id || typeof viewer_id !== "string") {
+    return NextResponse.json(
+      { error: "viewer_id is required" },
+      { status: 400 }
+    );
+  }
+  if (!vod_id || typeof vod_id !== "string") {
+    return NextResponse.json(
+      { error: "vod_id is required" },
+      { status: 400 }
+    );
+  }
+
+  try {
+    const item = appendToPlaylist(viewer_id, vod_id);
+    return NextResponse.json(item, { status: 201 });
+  } catch (err) {
+    const message = err instanceof Error ? err.message : "Unknown error";
+    const status = message.includes("full") ? 400 : 409;
+    return NextResponse.json({ error: message }, { status });
+  }
+}
+
+export async function DELETE(req: NextRequest): Promise<NextResponse> {
+  let body: DeletePlaylistBody;
+  try {
+    body = await req.json();
+  } catch {
+    return NextResponse.json({ error: "invalid JSON body" }, { status: 400 });
+  }
+
+  const { viewer_id, vod_id } = body;
+
+  if (!viewer_id || typeof viewer_id !== "string") {
+    return NextResponse.json(
+      { error: "viewer_id is required" },
+      { status: 400 }
+    );
+  }
+  if (!vod_id || typeof vod_id !== "string") {
+    return NextResponse.json(
+      { error: "vod_id is required" },
+      { status: 400 }
+    );
+  }
+
+  const removed = removeFromPlaylist(viewer_id, vod_id);
+  if (!removed) {
+    return NextResponse.json(
+      { error: "VOD not found in playlist" },
+      { status: 404 }
+    );
+  }
+
+  return NextResponse.json({ removed: true });
+}
diff --git a/app/api/routes-f/vod-playlist/store.ts b/app/api/routes-f/vod-playlist/store.ts
new file mode 100644
index 00000000..7d9779ab
--- /dev/null
+++ b/app/api/routes-f/vod-playlist/store.ts
@@ -0,0 +1,75 @@
+import type { ViewerPlaylist, PlaylistItem } from "./types";
+
+const MAX_PLAYLIST_ITEMS = 100;
+
+const playlists = new Map<string, PlaylistItem[]>();
+
+export function getPlaylist(viewerId: string): ViewerPlaylist {
+  const items = playlists.get(viewerId) ?? [];
+  return { viewer_id: viewerId, items: [...items] };
+}
+
+export function appendToPlaylist(viewerId: string, vodId: string): PlaylistItem {
+  const items = playlists.get(viewerId) ?? [];
+
+  if (items.length >= MAX_PLAYLIST_ITEMS) {
+    throw new Error("Playlist is full (max 100 items)");
+  }
+
+  const existing = items.find(i => i.vod_id === vodId);
+  if (existing) {
+    throw new Error("VOD already in playlist");
+  }
+
+  const item: PlaylistItem = {
+    vod_id: vodId,
+    added_at: new Date().toISOString(),
+  };
+  items.push(item);
+  playlists.set(viewerId, items);
+  return item;
+}
+
+export function removeFromPlaylist(viewerId: string, vodId: string): boolean {
+  const items = playlists.get(viewerId);
+  if (!items) {
+    return false;
+  }
+
+  const idx = items.findIndex(i => i.vod_id === vodId);
+  if (idx === -1) {
+    return false;
+  }
+
+  items.splice(idx, 1);
+  playlists.set(viewerId, items);
+  return true;
+}
+
+export function reorderPlaylist(viewerId: string, order: string[]): void {
+  const items = playlists.get(viewerId);
+  if (!items) {
+    throw new Error("No playlist found for viewer");
+  }
+
+  const itemMap = new Map(items.map(i => [i.vod_id, i]));
+  const reordered: PlaylistItem[] = [];
+
+  for (const vodId of order) {
+    const item = itemMap.get(vodId);
+    if (!item) {
+      throw new Error(`vod_id '${vodId}' not found in playlist`);
+    }
+    reordered.push(item);
+  }
+
+  if (reordered.length !== items.length) {
+    throw new Error("Reorder list does not contain all playlist items");
+  }
+
+  playlists.set(viewerId, reordered);
+}
+
+export function clearAllPlaylists(): void {
+  playlists.clear();
+}
diff --git a/app/api/routes-f/vod-playlist/types.ts b/app/api/routes-f/vod-playlist/types.ts
new file mode 100644
index 00000000..9b6bd6ab
--- /dev/null
+++ b/app/api/routes-f/vod-playlist/types.ts
@@ -0,0 +1,24 @@
+export interface PlaylistItem {
+  vod_id: string;
+  added_at: string;
+}
+
+export interface ViewerPlaylist {
+  viewer_id: string;
+  items: PlaylistItem[];
+}
+
+export interface PostPlaylistBody {
+  viewer_id: string;
+  vod_id: string;
+}
+
+export interface DeletePlaylistBody {
+  viewer_id: string;
+  vod_id: string;
+}
+
+export interface ReorderBody {
+  viewer_id: string;
+  order: string[];
+}
diff --git a/app/api/routes-f/vod/comment/__tests__/route.test.ts b/app/api/routes-f/vod/comment/__tests__/route.test.ts
new file mode 100644
index 00000000..10d7fa68
--- /dev/null
+++ b/app/api/routes-f/vod/comment/__tests__/route.test.ts
@@ -0,0 +1,120 @@
+import { NextRequest } from "next/server";
+import { POST, GET } from "../route";
+
+function makeGetReq(params: Record<string, string> = {}): NextRequest {
+  const url = new URL("http://localhost/api/routes-f/vod/comment");
+  Object.entries(params).forEach(([k, v]) => url.searchParams.set(k, v));
+  return new NextRequest(url.toString());
+}
+
+function makePostReq(body: unknown): NextRequest {
+  return new NextRequest("http://localhost/api/routes-f/vod/comment", {
+    method: "POST",
+    headers: { "Content-Type": "application/json" },
+    body: JSON.stringify(body),
+  });
+}
+
+describe("POST /api/routes-f/vod/comment", () => {
+  it("creates a comment and returns comment_id + created_at", async () => {
+    const res = await POST(
+      makePostReq({ vod_id: "vod_a1", time_seconds: 500, user_id: "viewer_x", text: "Great moment!" })
+    );
+    expect(res.status).toBe(201);
+    const data = await res.json();
+    expect(typeof data.comment_id).toBe("string");
+    expect(typeof data.created_at).toBe("string");
+  });
+
+  it("returns 400 when vod_id is missing", async () => {
+    const res = await POST(
+      makePostReq({ time_seconds: 10, user_id: "u1", text: "hi" })
+    );
+    expect(res.status).toBe(400);
+  });
+
+  it("returns 400 when user_id is missing", async () => {
+    const res = await POST(
+      makePostReq({ vod_id: "vod_a1", time_seconds: 10, text: "hi" })
+    );
+    expect(res.status).toBe(400);
+  });
+
+  it("returns 400 when text is empty string", async () => {
+    const res = await POST(
+      makePostReq({ vod_id: "vod_a1", time_seconds: 10, user_id: "u1", text: "" })
+    );
+    expect(res.status).toBe(400);
+  });
+
+  it("returns 404 for unknown vod_id", async () => {
+    const res = await POST(
+      makePostReq({ vod_id: "vod_zzz", time_seconds: 10, user_id: "u1", text: "test" })
+    );
+    expect(res.status).toBe(404);
+  });
+
+  it("returns 400 when time_seconds exceeds vod duration", async () => {
+    // vod_a1 duration is 7200s
+    const res = await POST(
+      makePostReq({ vod_id: "vod_a1", time_seconds: 9999, user_id: "u1", text: "too far" })
+    );
+    expect(res.status).toBe(400);
+    const data = await res.json();
+    expect(data.error).toMatch(/duration/i);
+  });
+
+  it("returns 400 for negative time_seconds", async () => {
+    const res = await POST(
+      makePostReq({ vod_id: "vod_a1", time_seconds: -1, user_id: "u1", text: "nope" })
+    );
+    expect(res.status).toBe(400);
+  });
+});
+
+describe("GET /api/routes-f/vod/comment", () => {
+  it("returns 400 when vod_id is missing", async () => {
+    const res = await GET(makeGetReq({}));
+    expect(res.status).toBe(400);
+  });
+
+  it("returns 404 for unknown vod_id", async () => {
+    const res = await GET(makeGetReq({ vod_id: "vod_zzz" }));
+    expect(res.status).toBe(404);
+  });
+
+  it("returns comments for a vod", async () => {
+    const res = await GET(makeGetReq({ vod_id: "vod_a1" }));
+    expect(res.status).toBe(200);
+    const data = await res.json();
+    expect(Array.isArray(data.comments)).toBe(true);
+    expect(typeof data.total).toBe("number");
+    expect(data.total).toBeGreaterThan(0); // seed data exists
+  });
+
+  it("near_time filter returns only comments within default 30s radius", async () => {
+    // Seed has comment at 120s and 125s, and one at 300s
+    const res = await GET(makeGetReq({ vod_id: "vod_a1", near_time: "120" }));
+    expect(res.status).toBe(200);
+    const data = await res.json();
+    for (const c of data.comments) {
+      expect(Math.abs(c.time_seconds - 120)).toBeLessThanOrEqual(30);
+    }
+  });
+
+  it("near_time with custom radius filters correctly", async () => {
+    const res = await GET(
+      makeGetReq({ vod_id: "vod_a1", near_time: "120", radius_seconds: "5" })
+    );
+    expect(res.status).toBe(200);
+    const data = await res.json();
+    for (const c of data.comments) {
+      expect(Math.abs(c.time_seconds - 120)).toBeLessThanOrEqual(5);
+    }
+  });
+
+  it("returns 400 for invalid near_time", async () => {
+    const res = await GET(makeGetReq({ vod_id: "vod_a1", near_time: "abc" }));
+    expect(res.status).toBe(400);
+  });
+});
diff --git a/app/api/routes-f/vod/comment/route.ts b/app/api/routes-f/vod/comment/route.ts
new file mode 100644
index 00000000..ed62717b
--- /dev/null
+++ b/app/api/routes-f/vod/comment/route.ts
@@ -0,0 +1,108 @@
+import { NextRequest, NextResponse } from "next/server";
+import type {
+  PostCommentBody,
+  PostCommentResponse,
+  GetCommentsResponse,
+} from "./types";
+import {
+  findVod,
+  addComment,
+  getCommentsByVod,
+} from "./store";
+
+export async function POST(req: NextRequest): Promise<NextResponse> {
+  let body: PostCommentBody;
+  try {
+    body = await req.json();
+  } catch {
+    return NextResponse.json({ error: "invalid JSON body" }, { status: 400 });
+  }
+
+  const { vod_id, time_seconds, user_id, text } = body;
+
+  if (!vod_id || typeof vod_id !== "string") {
+    return NextResponse.json({ error: "vod_id is required" }, { status: 400 });
+  }
+  if (!user_id || typeof user_id !== "string") {
+    return NextResponse.json({ error: "user_id is required" }, { status: 400 });
+  }
+  if (!text || typeof text !== "string" || text.trim().length === 0) {
+    return NextResponse.json({ error: "text is required and must be non-empty" }, { status: 400 });
+  }
+  if (typeof time_seconds !== "number" || time_seconds < 0) {
+    return NextResponse.json(
+      { error: "time_seconds must be a non-negative number" },
+      { status: 400 }
+    );
+  }
+
+  // Validate vod exists and time is within duration
+  const vod = findVod(vod_id);
+  if (!vod) {
+    return NextResponse.json({ error: `vod_id '${vod_id}' not found` }, { status: 404 });
+  }
+  if (time_seconds > vod.duration_seconds) {
+    return NextResponse.json(
+      {
+        error: `time_seconds ${time_seconds} exceeds VOD duration of ${vod.duration_seconds}s`,
+      },
+      { status: 400 }
+    );
+  }
+
+  const comment = addComment({ vod_id, user_id, text, time_seconds });
+
+  return NextResponse.json(
+    { comment_id: comment.comment_id, created_at: comment.created_at } as PostCommentResponse,
+    { status: 201 }
+  );
+}
+
+export async function GET(req: NextRequest): Promise<NextResponse> {
+  const { searchParams } = new URL(req.url);
+  const vodId = searchParams.get("vod_id");
+  const nearTimeParam = searchParams.get("near_time");
+  const radiusParam = searchParams.get("radius_seconds");
+
+  if (!vodId) {
+    return NextResponse.json({ error: "vod_id is required" }, { status: 400 });
+  }
+
+  const vod = findVod(vodId);
+  if (!vod) {
+    return NextResponse.json({ error: `vod_id '${vodId}' not found` }, { status: 404 });
+  }
+
+  let comments = getCommentsByVod(vodId);
+
+  // Apply near-time filter if provided
+  if (nearTimeParam !== null) {
+    const nearTime = parseFloat(nearTimeParam);
+    if (isNaN(nearTime) || nearTime < 0) {
+      return NextResponse.json(
+        { error: "near_time must be a non-negative number" },
+        { status: 400 }
+      );
+    }
+
+    const radius = radiusParam !== null ? parseFloat(radiusParam) : 30;
+    if (isNaN(radius) || radius < 0) {
+      return NextResponse.json(
+        { error: "radius_seconds must be a non-negative number" },
+        { status: 400 }
+      );
+    }
+
+    comments = comments.filter(
+      c => Math.abs(c.time_seconds - nearTime) <= radius
+    );
+  }
+
+  // Sort by timestamp ascending
+  comments.sort((a, b) => new Date(a.created_at).getTime() - new Date(b.created_at).getTime());
+
+  return NextResponse.json({
+    comments,
+    total: comments.length,
+  } as GetCommentsResponse);
+}
diff --git a/app/api/routes-f/vod/comment/store.ts b/app/api/routes-f/vod/comment/store.ts
new file mode 100644
index 00000000..8275dc29
--- /dev/null
+++ b/app/api/routes-f/vod/comment/store.ts
@@ -0,0 +1,97 @@
+import type { TimestampComment, VodRecord } from "./types";
+
+let commentIdCounter = 1;
+
+// Seed VOD records so we can validate time_seconds against duration
+export const vodStore: VodRecord[] = [
+  {
+    vod_id: "vod_a1",
+    creator_id: "creator_a",
+    title: "Epic Gameplay Session",
+    duration_seconds: 7200,
+    created_at: Date.now() - 2 * 24 * 60 * 60 * 1000,
+  },
+  {
+    vod_id: "vod_a2",
+    creator_id: "creator_a",
+    title: "World Record Attempt",
+    duration_seconds: 3600,
+    created_at: Date.now() - 5 * 24 * 60 * 60 * 1000,
+  },
+  {
+    vod_id: "vod_b1",
+    creator_id: "creator_b",
+    title: "Tip Milestone Stream",
+    duration_seconds: 5400,
+    created_at: Date.now() - 1 * 24 * 60 * 60 * 1000,
+  },
+  {
+    vod_id: "vod_c1",
+    creator_id: "creator_c",
+    title: "Blockchain Tutorial",
+    duration_seconds: 2700,
+    created_at: Date.now() - 3 * 24 * 60 * 60 * 1000,
+  },
+];
+
+// Pre-seed some comments for testing
+export const commentStore: TimestampComment[] = [
+  {
+    comment_id: "cmt_001",
+    vod_id: "vod_a1",
+    user_id: "viewer_alice",
+    text: "This play was insane!",
+    time_seconds: 120,
+    created_at: new Date(Date.now() - 3600000).toISOString(),
+  },
+  {
+    comment_id: "cmt_002",
+    vod_id: "vod_a1",
+    user_id: "viewer_bob",
+    text: "Best moment of the stream right here",
+    time_seconds: 125,
+    created_at: new Date(Date.now() - 3000000).toISOString(),
+  },
+  {
+    comment_id: "cmt_003",
+    vod_id: "vod_a1",
+    user_id: "viewer_charlie",
+    text: "The setup at this timestamp is perfect",
+    time_seconds: 300,
+    created_at: new Date(Date.now() - 1800000).toISOString(),
+  },
+  {
+    comment_id: "cmt_004",
+    vod_id: "vod_a1",
+    user_id: "viewer_diana",
+    text: "Stream starting to heat up",
+    time_seconds: 600,
+    created_at: new Date(Date.now() - 900000).toISOString(),
+  },
+  {
+    comment_id: "cmt_005",
+    vod_id: "vod_b1",
+    user_id: "viewer_eve",
+    text: "That XLM tip drop was legendary",
+    time_seconds: 1800,
+    created_at: new Date(Date.now() - 7200000).toISOString(),
+  },
+];
+
+export function findVod(vodId: string): VodRecord | undefined {
+  return vodStore.find(v => v.vod_id === vodId);
+}
+
+export function addComment(comment: Omit<TimestampComment, "comment_id" | "created_at">): TimestampComment {
+  const newComment: TimestampComment = {
+    ...comment,
+    comment_id: `cmt_${String(commentIdCounter++).padStart(3, "0")}`,
+    created_at: new Date().toISOString(),
+  };
+  commentStore.push(newComment);
+  return newComment;
+}
+
+export function getCommentsByVod(vodId: string): TimestampComment[] {
+  return commentStore.filter(c => c.vod_id === vodId);
+}
diff --git a/app/api/routes-f/vod/comment/types.ts b/app/api/routes-f/vod/comment/types.ts
new file mode 100644
index 00000000..7e76a8b4
--- /dev/null
+++ b/app/api/routes-f/vod/comment/types.ts
@@ -0,0 +1,33 @@
+export interface VodRecord {
+  vod_id: string;
+  creator_id: string;
+  title: string;
+  duration_seconds: number;
+  created_at: number; // epoch ms
+}
+
+export interface TimestampComment {
+  comment_id: string;
+  vod_id: string;
+  user_id: string;
+  text: string;
+  time_seconds: number;
+  created_at: string; // ISO timestamp
+}
+
+export interface PostCommentBody {
+  vod_id: string;
+  time_seconds: number;
+  user_id: string;
+  text: string;
+}
+
+export interface PostCommentResponse {
+  comment_id: string;
+  created_at: string;
+}
+
+export interface GetCommentsResponse {
+  comments: TimestampComment[];
+  total: number;
+}
diff --git a/app/api/routes-f/vowel-syllable/__tests__/route.test.ts b/app/api/routes-f/vowel-syllable/__tests__/route.test.ts
new file mode 100644
index 00000000..32814beb
--- /dev/null
+++ b/app/api/routes-f/vowel-syllable/__tests__/route.test.ts
@@ -0,0 +1,26 @@
+import { NextRequest } from "next/server";
+import { POST } from "../route";
+
+function makeReq(text: string) {
+  return new NextRequest("http://localhost/api/routes-f/vowel-syllable", {
+    method: "POST",
+    body: JSON.stringify({ text }),
+    headers: { "Content-Type": "application/json" },
+  });
+}
+
+describe("POST /api/routes-f/vowel-syllable", () => {
+  it("counts vowels, consonants, words", async () => {
+    const res = await POST(makeReq("Hello world"));
+    const body = await res.json();
+    expect(body.vowels).toBe(3);
+    expect(body.consonants).toBe(7);
+    expect(body.words).toBe(2);
+  });
+
+  it("estimates syllables with silent e handling", async () => {
+    const res = await POST(makeReq("make table"));
+    const body = await res.json();
+    expect(body.syllables).toBe(3);
+  });
+});
diff --git a/app/api/routes-f/vowel-syllable/route.ts b/app/api/routes-f/vowel-syllable/route.ts
new file mode 100644
index 00000000..7f7f4b95
--- /dev/null
+++ b/app/api/routes-f/vowel-syllable/route.ts
@@ -0,0 +1,48 @@
+import { NextRequest, NextResponse } from "next/server";
+
+function countSyllablesInWord(rawWord: string) {
+  const word = rawWord.toLowerCase().replace(/[^a-z]/g, "");
+  if (!word) return 0;
+
+  const groups = word.match(/[aeiouy]+/g)?.length ?? 0;
+  const hasConsonantLeEnding = /[^aeiou]le$/.test(word);
+  const silentE =
+    word.length > 2 &&
+    /e$/.test(word) &&
+    !/[aeiouy]{2}e$/.test(word) &&
+    !hasConsonantLeEnding;
+  const syllables = groups - (silentE ? 1 : 0);
+  return Math.max(1, syllables);
+}
+
+export async function POST(request: NextRequest) {
+  let body: { text?: string };
+  try {
+    body = await request.json();
+  } catch {
+    return NextResponse.json({ error: "Invalid JSON body" }, { status: 400 });
+  }
+
+  if (typeof body.text !== "string") {
+    return NextResponse.json(
+      { error: "text must be a string" },
+      { status: 400 }
+    );
+  }
+
+  const letters = body.text.match(/[a-z]/gi) ?? [];
+  const vowels = letters.filter(char => /[aeiou]/i.test(char)).length;
+  const consonants = letters.length - vowels;
+  const words = body.text.match(/[a-z]+/gi) ?? [];
+  const syllables = words.reduce(
+    (sum, word) => sum + countSyllablesInWord(word),
+    0
+  );
+
+  return NextResponse.json({
+    vowels,
+    consonants,
+    syllables,
+    words: words.length,
+  });
+}
diff --git a/app/api/routes-f/welcome/__tests__/welcome.test.ts b/app/api/routes-f/welcome/__tests__/welcome.test.ts
new file mode 100644
index 00000000..676041d3
--- /dev/null
+++ b/app/api/routes-f/welcome/__tests__/welcome.test.ts
@@ -0,0 +1,216 @@
+/**
+ * @jest-environment node
+ */
+import { NextRequest } from "next/server";
+import { GET, PUT, welcomeStore } from "../route";
+import { POST as renderPOST } from "../render/route";
+
+const BASE_URL = "http://localhost/api/routes-f/welcome";
+const RENDER_URL = `${BASE_URL}/render`;
+
+const CREATOR_ID = "c0ffeec0-0000-4000-8000-000000000001";
+const OTHER_CREATOR = "c0ffeec0-0000-4000-8000-000000000002";
+
+function makeGetReq(params: Record<string, string>) {
+  const url = new URL(BASE_URL);
+  for (const [k, v] of Object.entries(params)) {
+    url.searchParams.set(k, v);
+  }
+  return new NextRequest(url.toString(), { method: "GET" });
+}
+
+function makePutReq(body: unknown) {
+  return new NextRequest(BASE_URL, {
+    method: "PUT",
+    headers: { "content-type": "application/json" },
+    body: JSON.stringify(body),
+  });
+}
+
+function makeRenderReq(body: unknown) {
+  return new NextRequest(RENDER_URL, {
+    method: "POST",
+    headers: { "content-type": "application/json" },
+    body: JSON.stringify(body),
+  });
+}
+
+describe("/api/routes-f/welcome — GET + PUT", () => {
+  beforeEach(() => {
+    welcomeStore.clear();
+  });
+
+  // -------------------------------------------------------------------------
+  // GET
+  // -------------------------------------------------------------------------
+  describe("GET", () => {
+    it("returns the default template when nothing is stored", async () => {
+      const res = await GET(makeGetReq({ creator_id: CREATOR_ID }));
+      expect(res.status).toBe(200);
+      const body = await res.json();
+      expect(body.creator_id).toBe(CREATOR_ID);
+      expect(body.template).toBe("Welcome, {{username}}! Thanks for following.");
+    });
+
+    it("returns the stored template after a PUT", async () => {
+      await PUT(
+        makePutReq({
+          creator_id: CREATOR_ID,
+          template: "Hey {{username}}, welcome aboard!",
+        })
+      );
+
+      const res = await GET(makeGetReq({ creator_id: CREATOR_ID }));
+      expect(res.status).toBe(200);
+      const body = await res.json();
+      expect(body.template).toBe("Hey {{username}}, welcome aboard!");
+    });
+
+    it("400 — missing creator_id", async () => {
+      const res = await GET(makeGetReq({}));
+      expect(res.status).toBe(400);
+    });
+
+    it("each creator has its own template", async () => {
+      await PUT(
+        makePutReq({
+          creator_id: CREATOR_ID,
+          template: "Hi {{username}}!",
+        })
+      );
+
+      // OTHER_CREATOR should still see the default.
+      const res = await GET(makeGetReq({ creator_id: OTHER_CREATOR }));
+      const body = await res.json();
+      expect(body.template).toContain("{{username}}");
+      expect(body.template).toBe("Welcome, {{username}}! Thanks for following.");
+    });
+  });
+
+  // -------------------------------------------------------------------------
+  // PUT
+  // -------------------------------------------------------------------------
+  describe("PUT", () => {
+    it("stores a custom template and returns it", async () => {
+      const res = await PUT(
+        makePutReq({
+          creator_id: CREATOR_ID,
+          template: "Welcome {{username}}, enjoy the stream!",
+        })
+      );
+      expect(res.status).toBe(200);
+      const body = await res.json();
+      expect(body.creator_id).toBe(CREATOR_ID);
+      expect(body.template).toBe("Welcome {{username}}, enjoy the stream!");
+    });
+
+    it("400 — template missing {{username}} placeholder", async () => {
+      const res = await PUT(
+        makePutReq({
+          creator_id: CREATOR_ID,
+          template: "Hey there! Welcome to my stream.",
+        })
+      );
+      expect(res.status).toBe(400);
+      const body = await res.json();
+      expect(body.error).toMatch(/invalid template/i);
+    });
+
+    it("400 — missing template field", async () => {
+      const res = await PUT(makePutReq({ creator_id: CREATOR_ID }));
+      expect(res.status).toBe(400);
+    });
+
+    it("400 — missing creator_id", async () => {
+      const res = await PUT(
+        makePutReq({ template: "Hello {{username}}!" })
+      );
+      expect(res.status).toBe(400);
+    });
+
+    it("overwrites an existing template on subsequent PUT", async () => {
+      await PUT(
+        makePutReq({
+          creator_id: CREATOR_ID,
+          template: "First {{username}}!",
+        })
+      );
+
+      await PUT(
+        makePutReq({
+          creator_id: CREATOR_ID,
+          template: "Second {{username}}!",
+        })
+      );
+
+      const res = await GET(makeGetReq({ creator_id: CREATOR_ID }));
+      const body = await res.json();
+      expect(body.template).toBe("Second {{username}}!");
+    });
+  });
+});
+
+// ---------------------------------------------------------------------------
+// POST /api/routes-f/welcome/render
+// ---------------------------------------------------------------------------
+describe("POST /api/routes-f/welcome/render", () => {
+  beforeEach(() => {
+    welcomeStore.clear();
+  });
+
+  it("renders the stored template by replacing {{username}}", async () => {
+    await PUT(
+      makePutReq({
+        creator_id: CREATOR_ID,
+        template: "Hey {{username}}, welcome!",
+      })
+    );
+
+    const res = await renderPOST(
+      makeRenderReq({ creator_id: CREATOR_ID, username: "Alice" })
+    );
+    expect(res.status).toBe(200);
+    const body = await res.json();
+    expect(body.message).toBe("Hey Alice, welcome!");
+  });
+
+  it("replaces all occurrences of {{username}} if the template repeats it", async () => {
+    await PUT(
+      makePutReq({
+        creator_id: CREATOR_ID,
+        template: "{{username}} here! Hi {{username}}!",
+      })
+    );
+
+    const res = await renderPOST(
+      makeRenderReq({ creator_id: CREATOR_ID, username: "Bob" })
+    );
+    expect(res.status).toBe(200);
+    const body = await res.json();
+    expect(body.message).toBe("Bob here! Hi Bob!");
+  });
+
+  it("404 — creator has no stored template", async () => {
+    const res = await renderPOST(
+      makeRenderReq({ creator_id: OTHER_CREATOR, username: "Eve" })
+    );
+    expect(res.status).toBe(404);
+    const body = await res.json();
+    expect(body.error).toMatch(/no welcome template/i);
+  });
+
+  it("400 — missing creator_id", async () => {
+    const res = await renderPOST(makeRenderReq({ username: "Dave" }));
+    expect(res.status).toBe(400);
+  });
+
+  it("400 — missing username", async () => {
+    const res = await renderPOST(makeRenderReq({ creator_id: CREATOR_ID }));
+    expect(res.status).toBe(400);
+  });
+
+  it("400 — completely empty body", async () => {
+    const res = await renderPOST(makeRenderReq({}));
+    expect(res.status).toBe(400);
+  });
+});
diff --git a/app/api/routes-f/welcome/render/route.ts b/app/api/routes-f/welcome/render/route.ts
new file mode 100644
index 00000000..3674b33f
--- /dev/null
+++ b/app/api/routes-f/welcome/render/route.ts
@@ -0,0 +1,47 @@
+/**
+ * POST /api/routes-f/welcome/render
+ *
+ * Render a creator's welcome message by substituting {{username}}.
+ * Uses the same in-memory store as /api/routes-f/welcome.
+ * No real DB — mock only.
+ */
+import { NextRequest, NextResponse } from "next/server";
+import { z } from "zod";
+import { validateBody } from "@/app/api/routes-f/_lib/validate";
+import { welcomeStore } from "@/app/api/routes-f/welcome/route";
+
+// ---------------------------------------------------------------------------
+// Validation schema
+// ---------------------------------------------------------------------------
+const renderBodySchema = z.object({
+  creator_id: z.string().min(1, "creator_id is required"),
+  username: z.string().min(1, "username is required"),
+});
+
+// ---------------------------------------------------------------------------
+// Route handler
+// ---------------------------------------------------------------------------
+export async function POST(req: NextRequest): Promise<NextResponse> {
+  const bodyResult = await validateBody(req, renderBodySchema);
+  if (bodyResult instanceof NextResponse) {
+    return bodyResult;
+  }
+
+  const { creator_id, username } = bodyResult.data;
+
+  const template = welcomeStore.get(creator_id);
+  if (!template) {
+    return NextResponse.json(
+      {
+        error: "No welcome template found",
+        message: `Creator "${creator_id}" has not configured a welcome message template.`,
+      },
+      { status: 404 }
+    );
+  }
+
+  // Replace ALL occurrences of the placeholder (replaceAll for safety).
+  const message = template.replaceAll("{{username}}", username);
+
+  return NextResponse.json({ message });
+}
diff --git a/app/api/routes-f/welcome/route.ts b/app/api/routes-f/welcome/route.ts
new file mode 100644
index 00000000..110f6b56
--- /dev/null
+++ b/app/api/routes-f/welcome/route.ts
@@ -0,0 +1,75 @@
+/**
+ * GET /api/routes-f/welcome?creator_id=
+ * PUT /api/routes-f/welcome
+ *
+ * Manage the welcome message template for a creator.
+ * Template MUST contain the {{username}} placeholder.
+ * Uses in-memory storage (mock) — no real DB.
+ */
+import { NextRequest, NextResponse } from "next/server";
+import { z } from "zod";
+import { validateBody, validateQuery } from "@/app/api/routes-f/_lib/validate";
+
+// ---------------------------------------------------------------------------
+// Constants
+// ---------------------------------------------------------------------------
+const DEFAULT_TEMPLATE = "Welcome, {{username}}! Thanks for following.";
+const USERNAME_PLACEHOLDER = "{{username}}";
+
+// ---------------------------------------------------------------------------
+// In-memory storage
+// Key: creator_id
+// Exported so tests can reset between runs.
+// ---------------------------------------------------------------------------
+export const welcomeStore: Map<string, string> = new Map();
+
+// ---------------------------------------------------------------------------
+// Validation schemas
+// ---------------------------------------------------------------------------
+const getQuerySchema = z.object({
+  creator_id: z.string().min(1, "creator_id is required"),
+});
+
+const putBodySchema = z.object({
+  creator_id: z.string().min(1, "creator_id is required"),
+  template: z.string().min(1, "template is required"),
+});
+
+// ---------------------------------------------------------------------------
+// Route handlers
+// ---------------------------------------------------------------------------
+export async function GET(req: NextRequest): Promise<NextResponse> {
+  const { searchParams } = new URL(req.url);
+  const queryResult = validateQuery(searchParams, getQuerySchema);
+  if (queryResult instanceof NextResponse) {
+    return queryResult;
+  }
+
+  const { creator_id } = queryResult.data;
+  const template = welcomeStore.get(creator_id) ?? DEFAULT_TEMPLATE;
+
+  return NextResponse.json({ creator_id, template });
+}
+
+export async function PUT(req: NextRequest): Promise<NextResponse> {
+  const bodyResult = await validateBody(req, putBodySchema);
+  if (bodyResult instanceof NextResponse) {
+    return bodyResult;
+  }
+
+  const { creator_id, template } = bodyResult.data;
+
+  if (!template.includes(USERNAME_PLACEHOLDER)) {
+    return NextResponse.json(
+      {
+        error: "Invalid template",
+        message: `Template must contain the "${USERNAME_PLACEHOLDER}" placeholder.`,
+      },
+      { status: 400 }
+    );
+  }
+
+  welcomeStore.set(creator_id, template);
+
+  return NextResponse.json({ creator_id, template });
+}
diff --git a/app/api/routes-f/xml-to-json/route.ts b/app/api/routes-f/xml-to-json/route.ts
new file mode 100644
index 00000000..72bde94d
--- /dev/null
+++ b/app/api/routes-f/xml-to-json/route.ts
@@ -0,0 +1,198 @@
+import { type NextRequest, NextResponse } from "next/server";
+
+function isRecord(v: unknown): v is Record<string, unknown> {
+  return typeof v === "object" && v !== null && !Array.isArray(v);
+}
+
+type XmlNode = Record<string, unknown>;
+
+/**
+ * Minimal XML-to-JSON parser (no external deps).
+ * Handles: elements, attributes, text, CDATA.
+ */
+function parseXml(
+  xml: string,
+  attrPrefix: string,
+  textKey: string
+): XmlNode {
+  const trimmed = xml.trim();
+  if (!trimmed) throw new Error("XML string is empty.");
+
+  // Remove XML declaration
+  const src = trimmed.replace(/<\?xml[^?]*\?>/i, "").trim();
+
+  let pos = 0;
+
+  function error(msg: string): never {
+    throw new Error(msg);
+  }
+
+  function skipWhitespace() {
+    while (pos < src.length && /\s/.test(src[pos])) pos++;
+  }
+
+  function readUntil(end: string): string {
+    const start = pos;
+    const idx = src.indexOf(end, pos);
+    if (idx === -1) error(`Expected '${end}'`);
+    pos = idx + end.length;
+    return src.slice(start, idx);
+  }
+
+  function parseAttributes(raw: string): Record<string, string> {
+    const attrs: Record<string, string> = {};
+    const re = /(\S+?)=["']([^"']*)["']/g;
+    let m;
+    while ((m = re.exec(raw)) !== null) {
+      attrs[attrPrefix + m[1]] = m[2];
+    }
+    return attrs;
+  }
+
+  function parseNode(): [string, XmlNode] {
+    skipWhitespace();
+    if (src[pos] !== "<") error("Expected '<'");
+    pos++; // consume <
+
+    // CDATA
+    if (src.startsWith("![CDATA[", pos)) {
+      pos += 8;
+      const content = readUntil("]]>");
+      return ["#cdata", { [textKey]: content }];
+    }
+
+    // Comment
+    if (src.startsWith("!--", pos)) {
+      readUntil("-->");
+      return ["#comment", {}];
+    }
+
+    // Closing tag — caller handles
+    if (src[pos] === "/") {
+      return ["#close", {}];
+    }
+
+    // Opening tag
+    const tagStart = pos;
+    while (pos < src.length && src[pos] !== ">" && src[pos] !== " " && src[pos] !== "\n" && src[pos] !== "\t" && src[pos] !== "/") {
+      pos++;
+    }
+    const tagName = src.slice(tagStart, pos).trim();
+    if (!tagName) error("Empty tag name");
+
+    // Collect attribute string up to > or />
+    const attrStart = pos;
+    while (pos < src.length && src[pos] !== ">") pos++;
+    const attrRaw = src.slice(attrStart, pos).trim();
+    const selfClose = attrRaw.endsWith("/");
+    const attrStr = selfClose ? attrRaw.slice(0, -1) : attrRaw;
+    pos++; // consume >
+
+    const attrs = parseAttributes(attrStr);
+    const node: XmlNode = { ...attrs };
+
+    if (selfClose) return [tagName, node];
+
+    // Parse children
+    let text = "";
+    let closed = false;
+    while (pos < src.length) {
+      skipWhitespace();
+      if (pos >= src.length) break;
+
+      if (src[pos] !== "<") {
+        // Text content
+        const txtStart = pos;
+        while (pos < src.length && src[pos] !== "<") pos++;
+        text += src.slice(txtStart, pos).trim();
+        continue;
+      }
+
+      // Peek at what comes next
+      const saved = pos;
+      pos++; // consume <
+
+      if (src.startsWith("![CDATA[", pos)) {
+        pos += 8;
+        const cdata = readUntil("]]>");
+        text += cdata;
+        continue;
+      }
+
+      if (src.startsWith("!--", pos)) {
+        readUntil("-->");
+        continue;
+      }
+
+      if (src[pos] === "/") {
+        // Closing tag
+        pos++;
+        const closeStart = pos;
+        while (pos < src.length && src[pos] !== ">") pos++;
+        const closeName = src.slice(closeStart, pos).trim();
+        pos++; // consume >
+        if (closeName !== tagName) error(`Mismatched closing tag: </${closeName}> for <${tagName}>`);
+        closed = true;
+        break;
+      }
+
+      // Restore and parse child
+      pos = saved;
+      const [childName, childNode] = parseNode();
+      if (childName === "#comment") continue;
+
+      if (childName in node) {
+        const existing = node[childName];
+        node[childName] = Array.isArray(existing)
+          ? [...existing, childNode]
+          : [existing, childNode];
+      } else {
+        node[childName] = childNode;
+      }
+    }
+
+    if (!closed) error(`Unexpected end of input: unclosed tag <${tagName}>`);
+    if (text) node[textKey] = text;
+
+    return [tagName, node];
+  }
+
+  const [rootName, rootNode] = parseNode();
+  return { [rootName]: rootNode };
+}
+
+export async function POST(req: NextRequest) {
+  let body: unknown;
+  try {
+    body = await req.json();
+  } catch {
+    return NextResponse.json({ error: "Invalid JSON body." }, { status: 400 });
+  }
+
+  if (!isRecord(body)) {
+    return NextResponse.json({ error: "Request body must be an object." }, { status: 400 });
+  }
+
+  const { xml, attribute_prefix = "@", text_key = "#text" } = body as Record<string, unknown>;
+
+  if (typeof xml !== "string" || !xml.trim()) {
+    return NextResponse.json({ error: "'xml' field is required and must be a non-empty string." }, { status: 400 });
+  }
+
+  if (typeof attribute_prefix !== "string") {
+    return NextResponse.json({ error: "'attribute_prefix' must be a string." }, { status: 400 });
+  }
+
+  if (typeof text_key !== "string") {
+    return NextResponse.json({ error: "'text_key' must be a string." }, { status: 400 });
+  }
+
+  try {
+    const json = parseXml(xml, attribute_prefix, text_key);
+    const root_element = Object.keys(json)[0];
+    return NextResponse.json({ json, root_element });
+  } catch (err) {
+    const msg = err instanceof Error ? err.message : "Failed to parse XML.";
+    return NextResponse.json({ error: msg }, { status: 400 });
+  }
+}
diff --git a/app/api/routes-f/z-score/route.ts b/app/api/routes-f/z-score/route.ts
new file mode 100644
index 00000000..eaacd799
--- /dev/null
+++ b/app/api/routes-f/z-score/route.ts
@@ -0,0 +1,37 @@
+import { NextRequest, NextResponse } from "next/server";
+
+function mean(data: number[]): number {
+  return data.reduce((s, v) => s + v, 0) / data.length;
+}
+
+function sampleStddev(data: number[], avg: number): number {
+  const variance = data.reduce((s, v) => s + (v - avg) ** 2, 0) / (data.length - 1);
+  return Math.sqrt(variance);
+}
+
+export async function POST(req: NextRequest) {
+  let body: { data?: unknown };
+  try {
+    body = await req.json();
+  } catch {
+    return NextResponse.json({ error: "Invalid JSON" }, { status: 400 });
+  }
+
+  const data = body.data;
+  if (!Array.isArray(data) || data.length < 2 || data.some((v) => typeof v !== "number")) {
+    return NextResponse.json({ error: "data must be an array of at least 2 numbers" }, { status: 400 });
+  }
+
+  const avg = mean(data);
+  const stddev = sampleStddev(data, avg);
+
+  if (stddev === 0) {
+    return NextResponse.json({ error: "Zero variance — z-scores are undefined" }, { status: 400 });
+  }
+
+  return NextResponse.json({
+    mean: avg,
+    stddev,
+    z_scores: data.map((v) => (v - avg) / stddev),
+  });
+}
diff --git a/app/api/routesF/__tests__/business-days.test.ts b/app/api/routesF/__tests__/business-days.test.ts
new file mode 100644
index 00000000..8a10922c
--- /dev/null
+++ b/app/api/routesF/__tests__/business-days.test.ts
@@ -0,0 +1,83 @@
+/**
+ * @jest-environment node
+ */
+import { NextRequest } from "next/server";
+import { POST } from "../business-days/route";
+
+type RequestBody = {
+  date: string;
+  days: number;
+  country?: string;
+  custom_holidays?: string[];
+};
+
+function makeReq(body: RequestBody) {
+  return new NextRequest("http://localhost/api/routesF/business-days", {
+    method: "POST",
+    headers: { "content-type": "application/json" },
+    body: JSON.stringify(body),
+  });
+}
+
+describe("/api/routesF/business-days", () => {
+  it("adds one business day and skips a weekend", async () => {
+    const res = await POST(makeReq({ date: "2026-03-13", days: 1 }));
+    const data = await res.json();
+
+    expect(res.status).toBe(200);
+    expect(data.result).toBe("2026-03-15T00:00:00.000Z");
+    expect(data.skipped_days).toBe(2);
+  });
+
+  it("subtracts one business day and skips a weekend", async () => {
+    const res = await POST(makeReq({ date: "2026-03-15", days: -1 }));
+    const data = await res.json();
+
+    expect(res.status).toBe(200);
+    expect(data.result).toBe("2026-03-13T00:00:00.000Z");
+    expect(data.skipped_days).toBe(2);
+  });
+
+  it("skips a holiday from bundled country holidays", async () => {
+    const res = await POST(
+      makeReq({ date: "2026-12-24", days: 1, country: "US" })
+    );
+    const data = await res.json();
+
+    expect(res.status).toBe(200);
+    expect(data.result).toBe("2026-12-27T00:00:00.000Z");
+    expect(data.skipped_days).toBe(3);
+  });
+
+  it("uses custom_holidays to skip additional dates", async () => {
+    const res = await POST(
+      makeReq({
+        date: "2026-03-13",
+        days: 1,
+        custom_holidays: ["2026-03-15"],
+      })
+    );
+    const data = await res.json();
+
+    expect(res.status).toBe(200);
+    expect(data.result).toBe("2026-03-16T00:00:00.000Z");
+    expect(data.skipped_days).toBe(2);
+  });
+
+  it("rejects invalid date values", async () => {
+    const res = await POST(
+      makeReq({ date: "invalid", days: 1 } as unknown as RequestBody)
+    );
+    expect(res.status).toBe(400);
+  });
+
+  it("rejects non-integer days", async () => {
+    const req = new NextRequest("http://localhost/api/routesF/business-days", {
+      method: "POST",
+      headers: { "content-type": "application/json" },
+      body: JSON.stringify({ date: "2026-03-13", days: 1.5 }),
+    });
+    const res = await POST(req);
+    expect(res.status).toBe(400);
+  });
+});
diff --git a/app/api/routesF/__tests__/clamp-normalize.test.ts b/app/api/routesF/__tests__/clamp-normalize.test.ts
new file mode 100644
index 00000000..5e4d110a
--- /dev/null
+++ b/app/api/routesF/__tests__/clamp-normalize.test.ts
@@ -0,0 +1,53 @@
+/**
+ * @jest-environment node
+ */
+import { NextRequest } from "next/server";
+import { POST } from "../clamp-normalize/route";
+
+function makeReq(body: unknown) {
+  return new NextRequest("http://localhost/api/routesF/clamp-normalize", {
+    method: "POST",
+    headers: { "content-type": "application/json" },
+    body: JSON.stringify(body),
+  });
+}
+
+describe("/api/routesF/clamp-normalize", () => {
+  it("clamps values below the range", async () => {
+    const res = await POST(makeReq({ value: -5, min: 0, max: 10 }));
+    const data = await res.json();
+
+    expect(res.status).toBe(200);
+    expect(data).toEqual({ clamped: 0 });
+  });
+
+  it("keeps values within the range", async () => {
+    const res = await POST(makeReq({ value: 6, min: 0, max: 10 }));
+    const data = await res.json();
+
+    expect(res.status).toBe(200);
+    expect(data).toEqual({ clamped: 6 });
+  });
+
+  it("clamps values above the range", async () => {
+    const res = await POST(makeReq({ value: 15, min: 0, max: 10, normalize: true }));
+    const data = await res.json();
+
+    expect(res.status).toBe(200);
+    expect(data).toEqual({ clamped: 10, normalized: 1 });
+  });
+
+  it("normalizes clamped values to the 0-1 range", async () => {
+    const res = await POST(makeReq({ value: 5, min: 0, max: 10, normalize: true }));
+    const data = await res.json();
+
+    expect(res.status).toBe(200);
+    expect(data).toEqual({ clamped: 5, normalized: 0.5 });
+  });
+
+  it("rejects ranges where min is greater than max", async () => {
+    const res = await POST(makeReq({ value: 5, min: 10, max: 0 }));
+
+    expect(res.status).toBe(400);
+  });
+});
diff --git a/app/api/routesF/__tests__/company-name-generator.test.ts b/app/api/routesF/__tests__/company-name-generator.test.ts
new file mode 100644
index 00000000..94931802
--- /dev/null
+++ b/app/api/routesF/__tests__/company-name-generator.test.ts
@@ -0,0 +1,113 @@
+/**
+ * @jest-environment node
+ */
+import { NextRequest } from "next/server";
+import { GET } from "../company-name-generator/route";
+
+function makeReq(params: Record<string, string> = {}) {
+  const url = new URL("http://localhost/api/routesF/company-name-generator");
+  Object.entries(params).forEach(([key, value]) => {
+    url.searchParams.set(key, value);
+  });
+  
+  return new NextRequest(url.toString(), { method: "GET" });
+}
+
+describe("/api/routesF/company-name-generator", () => {
+  it("generates default 5 company names", async () => {
+    const res = await GET(makeReq());
+    const data = await res.json();
+
+    expect(res.status).toBe(200);
+    expect(data.names).toHaveLength(5);
+    expect(data.count).toBe(5);
+    expect(data.industry).toBe("any");
+    expect(typeof data.seed).toBe("string");
+  });
+
+  it("respects count parameter", async () => {
+    const res = await GET(makeReq({ count: "3" }));
+    const data = await res.json();
+
+    expect(res.status).toBe(200);
+    expect(data.names).toHaveLength(3);
+    expect(data.count).toBe(3);
+  });
+
+  it("filters by tech industry", async () => {
+    const res = await GET(makeReq({ industry: "tech", count: "10" }));
+    const data = await res.json();
+
+    expect(res.status).toBe(200);
+    expect(data.industry).toBe("tech");
+    expect(data.names).toHaveLength(10);
+    
+    // Check that names contain tech-related words
+    const allNames = data.names.join(" ");
+    const techWords = ["Tech", "Digital", "Cyber", "Smart", "Data", "Cloud", "System", "Network", "Labs", "Solutions"];
+    const containsTechWords = techWords.some(word => allNames.includes(word));
+    expect(containsTechWords).toBe(true);
+  });
+
+  it("produces deterministic results with seed", async () => {
+    const res1 = await GET(makeReq({ seed: "42", count: "3" }));
+    const data1 = await res1.json();
+
+    const res2 = await GET(makeReq({ seed: "42", count: "3" }));
+    const data2 = await res2.json();
+
+    expect(data1.names).toEqual(data2.names);
+    expect(data1.seed).toBe(42);
+    expect(data2.seed).toBe(42);
+  });
+
+  it("produces different results with different seeds", async () => {
+    const res1 = await GET(makeReq({ seed: "42", count: "5" }));
+    const data1 = await res1.json();
+
+    const res2 = await GET(makeReq({ seed: "123", count: "5" }));
+    const data2 = await res2.json();
+
+    expect(data1.names).not.toEqual(data2.names);
+  });
+
+  it("handles finance industry filter", async () => {
+    const res = await GET(makeReq({ industry: "finance", count: "5" }));
+    const data = await res.json();
+
+    expect(res.status).toBe(200);
+    expect(data.industry).toBe("finance");
+    
+    const allNames = data.names.join(" ");
+    const financeWords = ["Capital", "Bank", "Fund", "Investment", "Trust", "Partners", "Holdings"];
+    const containsFinanceWords = financeWords.some(word => allNames.includes(word));
+    expect(containsFinanceWords).toBe(true);
+  });
+
+  it("handles food industry filter", async () => {
+    const res = await GET(makeReq({ industry: "food", count: "5" }));
+    const data = await res.json();
+
+    expect(res.status).toBe(200);
+    expect(data.industry).toBe("food");
+    
+    const allNames = data.names.join(" ");
+    const foodWords = ["Fresh", "Organic", "Kitchen", "Bistro", "Cafe", "Foods", "Grill"];
+    const containsFoodWords = foodWords.some(word => allNames.includes(word));
+    expect(containsFoodWords).toBe(true);
+  });
+
+  it("clamps count to reasonable limits", async () => {
+    const res = await GET(makeReq({ count: "100" }));
+    const data = await res.json();
+
+    expect(res.status).toBe(200);
+    expect(data.count).toBe(50); // Should be clamped to max 50
+  });
+
+  it("handles invalid industry gracefully", async () => {
+    const res = await GET(makeReq({ industry: "invalid" }));
+
+    expect(res.status).toBe(400);
+  });
+});
\ No newline at end of file
diff --git a/app/api/routesF/__tests__/emoji-picker.test.ts b/app/api/routesF/__tests__/emoji-picker.test.ts
new file mode 100644
index 00000000..a56b2b79
--- /dev/null
+++ b/app/api/routesF/__tests__/emoji-picker.test.ts
@@ -0,0 +1,67 @@
+// @ts-nocheck
+/**
+ * @jest-environment node
+ */
+import { GET } from "../emoji-picker/route";
+
+function makeReq(query: string) {
+  return new globalThis.Request(
+    `http://localhost/api/routesF/emoji-picker?${query}`
+  );
+}
+
+describe("/api/routesF/emoji-picker", () => {
+  it("returns emojis filtered by category", async () => {
+    const res = await GET(makeReq("count=4&category=animals&seed=42"));
+    const data = await res.json();
+
+    expect(res.status).toBe(200);
+    expect(data).toHaveProperty("emojis");
+    expect(data.emojis).toHaveLength(4);
+    expect(
+      data.emojis.every((item: unknown) => item?.category === "animals")
+    ).toBe(true);
+    expect(data.emojis[0]).toEqual(
+      expect.objectContaining({
+        emoji: expect.any(String),
+        name: expect.any(String),
+        category: "animals",
+      })
+    );
+  });
+
+  it("returns deterministic results for the same seed and category", async () => {
+    const first = await GET(makeReq("count=5&category=faces&seed=123"));
+    const second = await GET(makeReq("count=5&category=faces&seed=123"));
+
+    expect(first.status).toBe(200);
+    expect(second.status).toBe(200);
+
+    const firstData = await first.json();
+    const secondData = await second.json();
+
+    expect(firstData).toEqual(secondData);
+  });
+
+  it("allows category any and returns mixed category emojis", async () => {
+    const res = await GET(makeReq("count=6&category=any&seed=99"));
+    const data = await res.json();
+
+    expect(res.status).toBe(200);
+    expect(data.emojis).toHaveLength(6);
+    const categories = Array.from(
+      new Set(data.emojis.map((item: unknown) => item?.category))
+    );
+    expect(categories.length).toBeGreaterThanOrEqual(1);
+    expect(
+      categories.every(category =>
+        ["faces", "animals", "food"].includes(category)
+      )
+    ).toBe(true);
+  });
+
+  it("rejects invalid category values", async () => {
+    const res = await GET(makeReq("count=3&category=vehicles&seed=1"));
+    expect(res.status).toBe(400);
+  });
+});
diff --git a/app/api/routesF/__tests__/interpolation.test.ts b/app/api/routesF/__tests__/interpolation.test.ts
new file mode 100644
index 00000000..7a677aa6
--- /dev/null
+++ b/app/api/routesF/__tests__/interpolation.test.ts
@@ -0,0 +1,57 @@
+/**
+ * @jest-environment node
+ */
+import { NextRequest } from "next/server";
+import { POST } from "../interpolation/route";
+
+function makeReq(body: unknown) {
+  return new NextRequest("http://localhost/api/routesF/interpolation", {
+    method: "POST",
+    headers: { "content-type": "application/json" },
+    body: JSON.stringify(body),
+  });
+}
+
+describe("/api/routesF/interpolation", () => {
+  it("returns the midpoint between two values in lerp mode", async () => {
+    const res = await POST(makeReq({ mode: "lerp", a: 10, b: 20, t: 0.5 }));
+    const data = await res.json();
+
+    expect(res.status).toBe(200);
+    expect(data).toEqual({ result: 15 });
+  });
+
+  it("maps a value from one range to another", async () => {
+    const res = await POST(
+      makeReq({ mode: "map", value: 5, in_min: 0, in_max: 10, out_min: 0, out_max: 100 })
+    );
+    const data = await res.json();
+
+    expect(res.status).toBe(200);
+    expect(data).toEqual({ result: 50 });
+  });
+
+  it("maps reversed output ranges", async () => {
+    const res = await POST(
+      makeReq({ mode: "map", value: 25, in_min: 0, in_max: 100, out_min: 1, out_max: 0 })
+    );
+    const data = await res.json();
+
+    expect(res.status).toBe(200);
+    expect(data).toEqual({ result: 0.75 });
+  });
+
+  it("rejects unknown modes", async () => {
+    const res = await POST(makeReq({ mode: "scale", value: 5 }));
+
+    expect(res.status).toBe(400);
+  });
+
+  it("rejects zero-width input ranges in map mode", async () => {
+    const res = await POST(
+      makeReq({ mode: "map", value: 5, in_min: 1, in_max: 1, out_min: 0, out_max: 10 })
+    );
+
+    expect(res.status).toBe(400);
+  });
+});
diff --git a/app/api/routesF/__tests__/pascal-triangle.test.ts b/app/api/routesF/__tests__/pascal-triangle.test.ts
new file mode 100644
index 00000000..e686c872
--- /dev/null
+++ b/app/api/routesF/__tests__/pascal-triangle.test.ts
@@ -0,0 +1,123 @@
+/**
+ * @jest-environment node
+ */
+import { NextRequest } from "next/server";
+import { GET } from "../pascal-triangle/route";
+
+function makeReq(params: Record<string, string> = {}) {
+  const url = new URL("http://localhost/api/routesF/pascal-triangle");
+  Object.entries(params).forEach(([key, value]) => {
+    url.searchParams.set(key, value);
+  });
+  
+  return new NextRequest(url.toString(), { method: "GET" });
+}
+
+describe("/api/routesF/pascal-triangle", () => {
+  it("generates default 5 rows of Pascal's triangle", async () => {
+    const res = await GET(makeReq());
+    const data = await res.json();
+
+    expect(res.status).toBe(200);
+    expect(data.triangle).toHaveLength(5);
+    expect(data.rows).toBe(5);
+    
+    // Verify the structure of first 5 rows
+    expect(data.triangle[0]).toEqual([1]);
+    expect(data.triangle[1]).toEqual([1, 1]);
+    expect(data.triangle[2]).toEqual([1, 2, 1]);
+    expect(data.triangle[3]).toEqual([1, 3, 3, 1]);
+    expect(data.triangle[4]).toEqual([1, 4, 6, 4, 1]);
+  });
+
+  it("generates single row", async () => {
+    const res = await GET(makeReq({ rows: "1" }));
+    const data = await res.json();
+
+    expect(res.status).toBe(200);
+    expect(data.triangle).toEqual([[1]]);
+    expect(data.rows).toBe(1);
+  });
+
+  it("generates 10 rows correctly", async () => {
+    const res = await GET(makeReq({ rows: "10" }));
+    const data = await res.json();
+
+    expect(res.status).toBe(200);
+    expect(data.triangle).toHaveLength(10);
+    
+    // Verify row 9 (10th row, 0-indexed)
+    expect(data.triangle[9]).toEqual([1, 9, 36, 84, 126, 126, 84, 36, 9, 1]);
+  });
+
+  it("verifies row sums are powers of 2", async () => {
+    const res = await GET(makeReq({ rows: "8" }));
+    const data = await res.json();
+
+    expect(res.status).toBe(200);
+    
+    data.triangle.forEach((row: number[], index: number) => {
+      const sum = row.reduce((acc, val) => acc + val, 0);
+      expect(sum).toBe(Math.pow(2, index));
+    });
+  });
+
+  it("verifies symmetry of rows", async () => {
+    const res = await GET(makeReq({ rows: "7" }));
+    const data = await res.json();
+
+    expect(res.status).toBe(200);
+    
+    data.triangle.forEach((row: number[]) => {
+      const reversed = [...row].reverse();
+      expect(row).toEqual(reversed);
+    });
+  });
+
+  it("handles large row counts with BigInt", async () => {
+    const res = await GET(makeReq({ rows: "20" }));
+    const data = await res.json();
+
+    expect(res.status).toBe(200);
+    expect(data.triangle).toHaveLength(20);
+    
+    // Row 19 should have large numbers but still be accurate
+    const row19 = data.triangle[19];
+    expect(row19[0]).toBe(1);
+    expect(row19[1]).toBe(19);
+    expect(row19[10]).toBe(92378); // C(19,10)
+  });
+
+  it("rejects rows less than 1", async () => {
+    const res = await GET(makeReq({ rows: "0" }));
+
+    expect(res.status).toBe(400);
+  });
+
+  it("rejects rows greater than 50", async () => {
+    const res = await GET(makeReq({ rows: "51" }));
+
+    expect(res.status).toBe(400);
+  });
+
+  it("rejects invalid row parameter", async () => {
+    const res = await GET(makeReq({ rows: "invalid" }));
+
+    expect(res.status).toBe(400);
+  });
+
+  it("verifies binomial coefficient properties", async () => {
+    const res = await GET(makeReq({ rows: "6" }));
+    const data = await res.json();
+
+    expect(res.status).toBe(200);
+    
+    // Row 5 (6th row): [1, 5, 10, 10, 5, 1]
+    const row5 = data.triangle[5];
+    expect(row5).toEqual([1, 5, 10, 10, 5, 1]);
+    
+    // Verify C(5,2) = C(5,3) = 10 (symmetry)
+    expect(row5[2]).toBe(row5[3]);
+    expect(row5[2]).toBe(10);
+  });
+});
\ No newline at end of file
diff --git a/app/api/routesF/__tests__/sentence-case-capitalizer.test.ts b/app/api/routesF/__tests__/sentence-case-capitalizer.test.ts
new file mode 100644
index 00000000..cd0cd144
--- /dev/null
+++ b/app/api/routesF/__tests__/sentence-case-capitalizer.test.ts
@@ -0,0 +1,55 @@
+/**
+ * @jest-environment node
+ */
+import { NextRequest } from "next/server";
+import { POST } from "../sentence-case-capitalizer/route";
+
+function makeReq(body: unknown) {
+  return new NextRequest(
+    "http://localhost/api/routesF/sentence-case-capitalizer",
+    {
+      method: "POST",
+      headers: { "content-type": "application/json" },
+      body: JSON.stringify(body),
+    }
+  );
+}
+
+describe("/api/routesF/sentence-case-capitalizer", () => {
+  it("capitalizes the first letter of each sentence", async () => {
+    const res = await POST(
+      makeReq({ text: "hello world. this is a test! is it working? yes." })
+    );
+    const data = await res.json();
+
+    expect(res.status).toBe(200);
+    expect(data.result).toBe(
+      "Hello world. This is a test! Is it working? Yes."
+    );
+  });
+
+  it("does not split sentences on common abbreviations", async () => {
+    const res = await POST(
+      makeReq({ text: "dr. smith arrived at 10 a.m. he said hello." })
+    );
+    const data = await res.json();
+
+    expect(res.status).toBe(200);
+    expect(data.result).toBe("Dr. Smith arrived at 10 a.m. He said hello.");
+  });
+
+  it("handles a paragraph with mixed punctuation", async () => {
+    const res = await POST(
+      makeReq({ text: "wow! this is great? yes it is. fantastic." })
+    );
+    const data = await res.json();
+
+    expect(res.status).toBe(200);
+    expect(data.result).toBe("Wow! This is great? Yes it is. Fantastic.");
+  });
+
+  it("rejects invalid request bodies", async () => {
+    const res = await POST(makeReq({ text: 123 }));
+    expect(res.status).toBe(400);
+  });
+});
diff --git a/app/api/routesF/__tests__/text-excerpt.test.ts b/app/api/routesF/__tests__/text-excerpt.test.ts
new file mode 100644
index 00000000..e23e6bff
--- /dev/null
+++ b/app/api/routesF/__tests__/text-excerpt.test.ts
@@ -0,0 +1,190 @@
+/**
+ * @jest-environment node
+ */
+import { NextRequest } from "next/server";
+import { POST } from "../text-excerpt/route";
+
+function makeReq(body: unknown) {
+  return new NextRequest("http://localhost/api/routesF/text-excerpt", {
+    method: "POST",
+    headers: { "content-type": "application/json" },
+    body: JSON.stringify(body),
+  });
+}
+
+describe("/api/routesF/text-excerpt", () => {
+  const sampleText = "The quick brown fox jumps over the lazy dog. This is a sample text for testing purposes.";
+
+  it("extracts excerpt around keyword in middle of text", async () => {
+    const res = await POST(makeReq({
+      text: sampleText,
+      keyword: "fox",
+      radius: 10
+    }));
+    const data = await res.json();
+
+    expect(res.status).toBe(200);
+    expect(data.excerpt).toBe("brown fox jumps ov");
+    expect(data.match_index).toBe(16);
+    expect(data.highlighted).toBeUndefined();
+  });
+
+  it("extracts excerpt with highlighting", async () => {
+    const res = await POST(makeReq({
+      text: sampleText,
+      keyword: "fox",
+      radius: 10,
+      highlight: true
+    }));
+    const data = await res.json();
+
+    expect(res.status).toBe(200);
+    expect(data.excerpt).toBe("brown fox jumps ov");
+    expect(data.highlighted).toBe("brown <mark>fox</mark> jumps ov");
+    expect(data.match_index).toBe(16);
+  });
+
+  it("handles keyword at start of text", async () => {
+    const res = await POST(makeReq({
+      text: sampleText,
+      keyword: "The",
+      radius: 15
+    }));
+    const data = await res.json();
+
+    expect(res.status).toBe(200);
+    expect(data.excerpt).toBe("The quick brown f");
+    expect(data.match_index).toBe(0);
+  });
+
+  it("handles keyword at end of text", async () => {
+    const res = await POST(makeReq({
+      text: sampleText,
+      keyword: "purposes",
+      radius: 20
+    }));
+    const data = await res.json();
+
+    expect(res.status).toBe(200);
+    expect(data.excerpt).toBe("for testing purposes.");
+    expect(data.match_index).toBe(75);
+  });
+
+  it("uses default radius of 50", async () => {
+    const res = await POST(makeReq({
+      text: sampleText,
+      keyword: "fox"
+    }));
+    const data = await res.json();
+
+    expect(res.status).toBe(200);
+    expect(data.excerpt).toBe("The quick brown fox jumps over the lazy dog. This is a sample text for testing purposes.");
+    expect(data.match_index).toBe(16);
+  });
+
+  it("handles case-insensitive matching", async () => {
+    const res = await POST(makeReq({
+      text: sampleText,
+      keyword: "QUICK",
+      radius: 10
+    }));
+    const data = await res.json();
+
+    expect(res.status).toBe(200);
+    expect(data.excerpt).toBe("The quick brown f");
+    expect(data.match_index).toBe(4);
+  });
+
+  it("preserves original case in excerpt", async () => {
+    const res = await POST(makeReq({
+      text: "Hello WORLD this is a Test",
+      keyword: "world",
+      radius: 10,
+      highlight: true
+    }));
+    const data = await res.json();
+
+    expect(res.status).toBe(200);
+    expect(data.excerpt).toBe("Hello WORLD this i");
+    expect(data.highlighted).toBe("Hello <mark>WORLD</mark> this i");
+  });
+
+  it("returns 404 when keyword not found", async () => {
+    const res = await POST(makeReq({
+      text: sampleText,
+      keyword: "elephant"
+    }));
+
+    expect(res.status).toBe(404);
+    const data = await res.json();
+    expect(data.error).toBe("Keyword not found in text");
+  });
+
+  it("handles empty keyword", async () => {
+    const res = await POST(makeReq({
+      text: sampleText,
+      keyword: ""
+    }));
+
+    expect(res.status).toBe(400);
+  });
+
+  it("handles missing text field", async () => {
+    const res = await POST(makeReq({
+      keyword: "test"
+    }));
+
+    expect(res.status).toBe(400);
+  });
+
+  it("handles invalid JSON", async () => {
+    const req = new NextRequest("http://localhost/api/routesF/text-excerpt", {
+      method: "POST",
+      headers: { "content-type": "application/json" },
+      body: "invalid json",
+    });
+
+    const res = await POST(req);
+    expect(res.status).toBe(400);
+  });
+
+  it("handles radius of 0", async () => {
+    const res = await POST(makeReq({
+      text: sampleText,
+      keyword: "fox",
+      radius: 0
+    }));
+    const data = await res.json();
+
+    expect(res.status).toBe(200);
+    expect(data.excerpt).toBe("fox");
+    expect(data.match_index).toBe(16);
+  });
+
+  it("handles very large radius", async () => {
+    const res = await POST(makeReq({
+      text: "Short text with keyword here",
+      keyword: "keyword",
+      radius: 1000
+    }));
+    const data = await res.json();
+
+    expect(res.status).toBe(200);
+    expect(data.excerpt).toBe("Short text with keyword here");
+    expect(data.match_index).toBe(16);
+  });
+
+  it("finds first occurrence when keyword appears multiple times", async () => {
+    const text = "The cat and the dog and the cat again";
+    const res = await POST(makeReq({
+      text,
+      keyword: "cat",
+      radius: 5
+    }));
+    const data = await res.json();
+
+    expect(res.status).toBe(200);
+    expect(data.match_index).toBe(4); // First occurrence
+    expect(data.excerpt).toBe("The cat and t");
+  });
+});
\ No newline at end of file
diff --git a/app/api/routesF/__tests__/trailing-zeros-factorial.test.ts b/app/api/routesF/__tests__/trailing-zeros-factorial.test.ts
new file mode 100644
index 00000000..dd5a4c36
--- /dev/null
+++ b/app/api/routesF/__tests__/trailing-zeros-factorial.test.ts
@@ -0,0 +1,52 @@
+/**
+ * @jest-environment node
+ */
+import { NextRequest } from "next/server";
+import { GET } from "../trailing-zeros-factorial/route";
+
+function makeReq(query: string) {
+  return new NextRequest(
+    `http://localhost/api/routesF/trailing-zeros-factorial?${query}`
+  );
+}
+
+describe("/api/routesF/trailing-zeros-factorial", () => {
+  it("returns trailing zeros for n=100", async () => {
+    const res = await GET(makeReq("n=100"));
+    const data = await res.json();
+
+    expect(res.status).toBe(200);
+    expect(data.n).toBe(100);
+    expect(data.trailing_zeros).toBe(24);
+  });
+
+  it("returns zero trailing zeros for n=0", async () => {
+    const res = await GET(makeReq("n=0"));
+    const data = await res.json();
+
+    expect(res.status).toBe(200);
+    expect(data.n).toBe(0);
+    expect(data.trailing_zeros).toBe(0);
+  });
+
+  it("returns the correct count for a large n", async () => {
+    const res = await GET(makeReq("n=1000000"));
+    const data = await res.json();
+
+    expect(res.status).toBe(200);
+    expect(data.n).toBe(1000000);
+    expect(data.trailing_zeros).toBe(249998);
+  });
+
+  it("rejects missing n parameter", async () => {
+    const res = await GET(
+      new NextRequest("http://localhost/api/routesF/trailing-zeros-factorial")
+    );
+    expect(res.status).toBe(400);
+  });
+
+  it("rejects invalid n values", async () => {
+    const res = await GET(makeReq("n=-1"));
+    expect(res.status).toBe(400);
+  });
+});
diff --git a/app/api/routesF/__tests__/uuid-validator.test.ts b/app/api/routesF/__tests__/uuid-validator.test.ts
new file mode 100644
index 00000000..8e9df2df
--- /dev/null
+++ b/app/api/routesF/__tests__/uuid-validator.test.ts
@@ -0,0 +1,198 @@
+/**
+ * @jest-environment node
+ */
+import { NextRequest } from "next/server";
+import { POST } from "../uuid-validator/route";
+
+function makeReq(body: unknown) {
+  return new NextRequest("http://localhost/api/routesF/uuid-validator", {
+    method: "POST",
+    headers: { "content-type": "application/json" },
+    body: JSON.stringify(body),
+  });
+}
+
+describe("/api/routesF/uuid-validator", () => {
+  it("validates a version 4 UUID", async () => {
+    const res = await POST(makeReq({
+      uuid: "550e8400-e29b-41d4-a716-446655440000"
+    }));
+    const data = await res.json();
+
+    expect(res.status).toBe(200);
+    expect(data.valid).toBe(true);
+    expect(data.version).toBe(4);
+    expect(data.variant).toBe("rfc4122");
+    expect(data.normalized).toBe("550e8400-e29b-41d4-a716-446655440000");
+  });
+
+  it("validates a version 1 UUID", async () => {
+    const res = await POST(makeReq({
+      uuid: "6ba7b810-9dad-11d1-80b4-00c04fd430c8"
+    }));
+    const data = await res.json();
+
+    expect(res.status).toBe(200);
+    expect(data.valid).toBe(true);
+    expect(data.version).toBe(1);
+    expect(data.variant).toBe("rfc4122");
+  });
+
+  it("validates a version 3 UUID", async () => {
+    const res = await POST(makeReq({
+      uuid: "6ba7b811-9dad-11d1-80b4-00c04fd430c8"
+    }));
+    const data = await res.json();
+
+    expect(res.status).toBe(200);
+    expect(data.valid).toBe(true);
+    expect(data.version).toBe(1);
+    expect(data.variant).toBe("rfc4122");
+  });
+
+  it("validates a version 5 UUID", async () => {
+    const res = await POST(makeReq({
+      uuid: "6ba7b815-9dad-11d1-80b4-00c04fd430c8"
+    }));
+    const data = await res.json();
+
+    expect(res.status).toBe(200);
+    expect(data.valid).toBe(true);
+    expect(data.version).toBe(5);
+    expect(data.variant).toBe("rfc4122");
+  });
+
+  it("validates a version 7 UUID", async () => {
+    const res = await POST(makeReq({
+      uuid: "6ba7b817-9dad-11d1-80b4-00c04fd430c8"
+    }));
+    const data = await res.json();
+
+    expect(res.status).toBe(200);
+    expect(data.valid).toBe(true);
+    expect(data.version).toBe(7);
+    expect(data.variant).toBe("rfc4122");
+  });
+
+  it("handles nil UUID", async () => {
+    const res = await POST(makeReq({
+      uuid: "00000000-0000-0000-0000-000000000000"
+    }));
+    const data = await res.json();
+
+    expect(res.status).toBe(200);
+    expect(data.valid).toBe(true);
+    expect(data.version).toBe(0);
+    expect(data.variant).toBe("nil");
+    expect(data.normalized).toBe("00000000-0000-0000-0000-000000000000");
+  });
+
+  it("normalizes UUID without hyphens", async () => {
+    const res = await POST(makeReq({
+      uuid: "550e8400e29b41d4a716446655440000"
+    }));
+    const data = await res.json();
+
+    expect(res.status).toBe(200);
+    expect(data.valid).toBe(true);
+    expect(data.normalized).toBe("550e8400-e29b-41d4-a716-446655440000");
+  });
+
+  it("normalizes uppercase UUID", async () => {
+    const res = await POST(makeReq({
+      uuid: "550E8400-E29B-41D4-A716-446655440000"
+    }));
+    const data = await res.json();
+
+    expect(res.status).toBe(200);
+    expect(data.valid).toBe(true);
+    expect(data.normalized).toBe("550e8400-e29b-41d4-a716-446655440000");
+  });
+
+  it("rejects malformed UUID - too short", async () => {
+    const res = await POST(makeReq({
+      uuid: "550e8400-e29b-41d4-a716-44665544000"
+    }));
+
+    expect(res.status).toBe(400);
+    const data = await res.json();
+    expect(data.valid).toBe(false);
+  });
+
+  it("rejects malformed UUID - invalid characters", async () => {
+    const res = await POST(makeReq({
+      uuid: "550e8400-e29b-41d4-a716-44665544000g"
+    }));
+
+    expect(res.status).toBe(400);
+    const data = await res.json();
+    expect(data.valid).toBe(false);
+  });
+
+  it("rejects malformed UUID - wrong format", async () => {
+    const res = await POST(makeReq({
+      uuid: "550e8400e29b41d4a716446655440000123"
+    }));
+
+    expect(res.status).toBe(400);
+    const data = await res.json();
+    expect(data.valid).toBe(false);
+  });
+
+  it("rejects unsupported version", async () => {
+    const res = await POST(makeReq({
+      uuid: "550e8400-e29b-21d4-a716-446655440000" // version 2
+    }));
+
+    expect(res.status).toBe(400);
+    const data = await res.json();
+    expect(data.valid).toBe(false);
+    expect(data.version).toBe(2);
+  });
+
+  it("handles missing uuid field", async () => {
+    const res = await POST(makeReq({}));
+
+    expect(res.status).toBe(400);
+  });
+
+  it("handles invalid JSON", async () => {
+    const req = new NextRequest("http://localhost/api/routesF/uuid-validator", {
+      method: "POST",
+      headers: { "content-type": "application/json" },
+      body: "invalid json",
+    });
+
+    const res = await POST(req);
+    expect(res.status).toBe(400);
+  });
+
+  it("detects different variants", async () => {
+    // Test NCS variant (first bit is 0)
+    const res1 = await POST(makeReq({
+      uuid: "550e8400-e29b-41d4-0716-446655440000"
+    }));
+    const data1 = await res1.json();
+    expect(data1.variant).toBe("ncs");
+
+    // Test RFC 4122 variant (first two bits are 10)
+    const res2 = await POST(makeReq({
+      uuid: "550e8400-e29b-41d4-8716-446655440000"
+    }));
+    const data2 = await res2.json();
+    expect(data2.variant).toBe("rfc4122");
+  });
+
+  it("handles edge case UUIDs", async () => {
+    // Test with all F's except version and variant bits
+    const res = await POST(makeReq({
+      uuid: "ffffffff-ffff-4fff-8fff-ffffffffffff"
+    }));
+    const data = await res.json();
+
+    expect(res.status).toBe(200);
+    expect(data.valid).toBe(true);
+    expect(data.version).toBe(4);
+    expect(data.variant).toBe("rfc4122");
+  });
+});
\ No newline at end of file
diff --git a/app/api/routesF/__tests__/word-count-reading-time.test.ts b/app/api/routesF/__tests__/word-count-reading-time.test.ts
new file mode 100644
index 00000000..22d22b7b
--- /dev/null
+++ b/app/api/routesF/__tests__/word-count-reading-time.test.ts
@@ -0,0 +1,57 @@
+/**
+ * @jest-environment node
+ */
+import { NextRequest } from "next/server";
+import { POST } from "../word-count-reading-time/route";
+
+function makeReq(body: unknown) {
+  return new NextRequest(
+    "http://localhost/api/routesF/word-count-reading-time",
+    {
+      method: "POST",
+      headers: { "content-type": "application/json" },
+      body: JSON.stringify(body),
+    }
+  );
+}
+
+describe("/api/routesF/word-count-reading-time", () => {
+  it("counts words, characters, sentences, and reading time with default WPM", async () => {
+    const text = "Hello world. This is a test.";
+    const res = await POST(makeReq({ text }));
+    const data = await res.json();
+
+    expect(res.status).toBe(200);
+    expect(data.words).toBe(6);
+    expect(data.characters).toBe(28);
+    expect(data.characters_no_spaces).toBe(23);
+    expect(data.sentences).toBe(2);
+    expect(data.reading_time_seconds).toBe(2);
+  });
+
+  it("uses custom WPM when provided", async () => {
+    const text = "One two three four five six seven eight nine ten.";
+    const res = await POST(makeReq({ text, wpm: 250 }));
+    const data = await res.json();
+
+    expect(res.status).toBe(200);
+    expect(data.words).toBe(10);
+    expect(data.reading_time_seconds).toBe(3);
+  });
+
+  it("rejects text larger than 1MB", async () => {
+    const largeText = "a".repeat(1024 * 1024 + 1);
+    const res = await POST(makeReq({ text: largeText }));
+    expect(res.status).toBe(400);
+  });
+
+  it("rejects non-string text values", async () => {
+    const res = await POST(makeReq({ text: 123 }));
+    expect(res.status).toBe(400);
+  });
+
+  it("rejects invalid wpm values", async () => {
+    const res = await POST(makeReq({ text: "Hello world.", wpm: 0 }));
+    expect(res.status).toBe(400);
+  });
+});
diff --git a/app/api/routesF/acronym-generator/route.test.ts b/app/api/routesF/acronym-generator/route.test.ts
new file mode 100644
index 00000000..8256b2b3
--- /dev/null
+++ b/app/api/routesF/acronym-generator/route.test.ts
@@ -0,0 +1,87 @@
+import { POST } from './route';
+
+describe('Acronym Generator API', () => {
+  it('should return 400 when phrase is missing', async () => {
+    const req = new Request('http://localhost/api/routesF/acronym-generator', {
+      method: 'POST',
+      body: JSON.stringify({}),
+    });
+    const res = await POST(req);
+    expect(res.status).toBe(400);
+  });
+
+  it('should return 400 when phrase is empty', async () => {
+    const req = new Request('http://localhost/api/routesF/acronym-generator', {
+      method: 'POST',
+      body: JSON.stringify({ phrase: '   ' }),
+    });
+    const res = await POST(req);
+    expect(res.status).toBe(400);
+  });
+
+  it('should skip stopwords by default', async () => {
+    const req = new Request('http://localhost/api/routesF/acronym-generator', {
+      method: 'POST',
+      body: JSON.stringify({ phrase: 'The Quick Brown Fox' }),
+    });
+    const res = await POST(req);
+    const data = await res.json();
+    expect(data.acronym).toBe('QBF');
+    expect(data.words_used).toEqual(['quick', 'brown', 'fox']);
+  });
+
+  it('should generate acronym with stopwords when include_stopwords is true', async () => {
+    const req = new Request('http://localhost/api/routesF/acronym-generator', {
+      method: 'POST',
+      body: JSON.stringify({ phrase: 'The Quick Brown Fox', include_stopwords: true }),
+    });
+    const res = await POST(req);
+    const data = await res.json();
+    expect(data.acronym).toBe('TQBF');
+    expect(data.words_used).toEqual(['the', 'quick', 'brown', 'fox']);
+  });
+
+  it('should handle multiple stopwords', async () => {
+    const req = new Request('http://localhost/api/routesF/acronym-generator', {
+      method: 'POST',
+      body: JSON.stringify({ phrase: 'as if the world is round' }),
+    });
+    const res = await POST(req);
+    const data = await res.json();
+    expect(data.acronym).toBe('WR');
+    expect(data.words_used).toEqual(['world', 'round']);
+  });
+
+  it('should handle single word phrases', async () => {
+    const req = new Request('http://localhost/api/routesF/acronym-generator', {
+      method: 'POST',
+      body: JSON.stringify({ phrase: 'hello' }),
+    });
+    const res = await POST(req);
+    const data = await res.json();
+    expect(data.acronym).toBe('H');
+    expect(data.words_used).toEqual(['hello']);
+  });
+
+  it('should handle phrases with only stopwords', async () => {
+    const req = new Request('http://localhost/api/routesF/acronym-generator', {
+      method: 'POST',
+      body: JSON.stringify({ phrase: 'the and or' }),
+    });
+    const res = await POST(req);
+    const data = await res.json();
+    expect(data.acronym).toBe('');
+    expect(data.words_used).toEqual([]);
+  });
+
+  it('should handle extra whitespace', async () => {
+    const req = new Request('http://localhost/api/routesF/acronym-generator', {
+      method: 'POST',
+      body: JSON.stringify({ phrase: '  Natural   Language   Processing  ' }),
+    });
+    const res = await POST(req);
+    const data = await res.json();
+    expect(data.acronym).toBe('NLP');
+    expect(data.words_used).toEqual(['natural', 'language', 'processing']);
+  });
+});
diff --git a/app/api/routesF/acronym-generator/route.ts b/app/api/routesF/acronym-generator/route.ts
new file mode 100644
index 00000000..261c2464
--- /dev/null
+++ b/app/api/routesF/acronym-generator/route.ts
@@ -0,0 +1,49 @@
+import { NextResponse } from 'next/server';
+
+const DEFAULT_STOPWORDS = new Set([
+  'the', 'a', 'an', 'and', 'or', 'but', 'in', 'on', 'at', 'to', 'for',
+  'of', 'with', 'by', 'from', 'as', 'is', 'was', 'are', 'been', 'be',
+  'have', 'has', 'had', 'do', 'does', 'did', 'will', 'would', 'could',
+  'should', 'may', 'might', 'must', 'can', 'if', 'because', 'than',
+]);
+
+function generateAcronym(phrase: string, includeStopwords: boolean = false): { acronym: string; words_used: string[] } {
+  const words = phrase
+    .toLowerCase()
+    .split(/\s+/)
+    .filter((word) => word.length > 0);
+
+  const filteredWords = includeStopwords
+    ? words
+    : words.filter((word) => !DEFAULT_STOPWORDS.has(word));
+
+  const acronym = filteredWords.map((word) => word.charAt(0).toUpperCase()).join('');
+
+  return {
+    acronym,
+    words_used: filteredWords,
+  };
+}
+
+export async function POST(request: Request) {
+  try {
+    const body = await request.json();
+    const { phrase, include_stopwords = false } = body;
+
+    if (!phrase || typeof phrase !== 'string' || phrase.trim().length === 0) {
+      return NextResponse.json(
+        { error: 'Missing or invalid phrase' },
+        { status: 400 }
+      );
+    }
+
+    const result = generateAcronym(phrase, include_stopwords);
+
+    return NextResponse.json(result);
+  } catch (error) {
+    return NextResponse.json(
+      { error: 'Invalid JSON body' },
+      { status: 400 }
+    );
+  }
+}
diff --git a/app/api/routesF/ascii-maze/maze.ts b/app/api/routesF/ascii-maze/maze.ts
new file mode 100644
index 00000000..ab8eacb9
--- /dev/null
+++ b/app/api/routesF/ascii-maze/maze.ts
@@ -0,0 +1,114 @@
+import { createSeededRng } from "./rng";
+
+type Cell = {
+  top: boolean;
+  right: boolean;
+  bottom: boolean;
+  left: boolean;
+};
+
+function createGrid(width: number, height: number) {
+  return Array.from({ length: height }, () =>
+    Array.from(
+      { length: width },
+      (): Cell => ({
+        top: true,
+        right: true,
+        bottom: true,
+        left: true,
+      })
+    )
+  );
+}
+
+function shuffleDirections(
+  directions: Array<
+    [dx: number, dy: number, wall: keyof Cell, opposite: keyof Cell]
+  >,
+  random: () => number
+) {
+  const copy = [...directions];
+  for (let i = copy.length - 1; i > 0; i--) {
+    const j = Math.floor(random() * (i + 1));
+    [copy[i], copy[j]] = [copy[j], copy[i]];
+  }
+  return copy;
+}
+
+export function generateMaze(width: number, height: number, seed: number) {
+  const random = createSeededRng(seed);
+  const grid = createGrid(width, height);
+  const visited = Array.from({ length: height }, () =>
+    Array<boolean>(width).fill(false)
+  );
+  const directions: Array<[number, number, keyof Cell, keyof Cell]> = [
+    [0, -1, "top", "bottom"],
+    [1, 0, "right", "left"],
+    [0, 1, "bottom", "top"],
+    [-1, 0, "left", "right"],
+  ];
+
+  function carve(x: number, y: number) {
+    visited[y][x] = true;
+
+    for (const [dx, dy, wall, opposite] of shuffleDirections(
+      directions,
+      random
+    )) {
+      const nextX = x + dx;
+      const nextY = y + dy;
+
+      if (nextX < 0 || nextX >= width || nextY < 0 || nextY >= height) {
+        continue;
+      }
+
+      if (visited[nextY][nextX]) {
+        continue;
+      }
+
+      grid[y][x][wall] = false;
+      grid[nextY][nextX][opposite] = false;
+      carve(nextX, nextY);
+    }
+  }
+
+  carve(0, 0);
+  return grid;
+}
+
+export function renderMaze(width: number, height: number, seed: number) {
+  const grid = generateMaze(width, height, seed);
+  const rows = height * 2 + 1;
+  const cols = width * 2 + 1;
+  const output: string[][] = Array.from({ length: rows }, () =>
+    Array(cols).fill("#")
+  );
+
+  for (let y = 0; y < height; y++) {
+    for (let x = 0; x < width; x++) {
+      const cell = grid[y][x];
+      const row = y * 2 + 1;
+      const col = x * 2 + 1;
+
+      output[row][col] = " ";
+
+      if (!cell.top) {
+        output[row - 1][col] = " ";
+      }
+      if (!cell.right) {
+        output[row][col + 1] = " ";
+      }
+      if (!cell.bottom) {
+        output[row + 1][col] = " ";
+      }
+      if (!cell.left) {
+        output[row][col - 1] = " ";
+      }
+    }
+  }
+
+  output[0][1] = " ";
+  output[rows - 1][cols - 2] = " ";
+
+  return output.map(row => row.join("")).join("\n");
+}
diff --git a/app/api/routesF/ascii-maze/rng.ts b/app/api/routesF/ascii-maze/rng.ts
new file mode 100644
index 00000000..fea1c8b0
--- /dev/null
+++ b/app/api/routesF/ascii-maze/rng.ts
@@ -0,0 +1,8 @@
+export function createSeededRng(seed: number) {
+  let state = seed >>> 0;
+
+  return function next() {
+    state = (state * 1664525 + 1013904223) >>> 0;
+    return state / 0x100000000;
+  };
+}
diff --git a/app/api/routesF/ascii-maze/route.test.ts b/app/api/routesF/ascii-maze/route.test.ts
new file mode 100644
index 00000000..a3d2a877
--- /dev/null
+++ b/app/api/routesF/ascii-maze/route.test.ts
@@ -0,0 +1,50 @@
+import { NextRequest } from "next/server";
+import { GET } from "./route";
+
+function makeReq(query = "") {
+  return new NextRequest(`http://localhost/api/routesF/ascii-maze${query}`);
+}
+
+describe("/api/routesF/ascii-maze", () => {
+  it("returns a deterministic maze for a given seed", async () => {
+    const resA = await GET(makeReq("?width=4&height=3&seed=42"));
+    const resB = await GET(makeReq("?width=4&height=3&seed=42"));
+    const dataA = await resA.json();
+    const dataB = await resB.json();
+
+    expect(resA.status).toBe(200);
+    expect(dataA).toEqual(dataB);
+  });
+
+  it("renders the expected ASCII dimensions", async () => {
+    const res = await GET(makeReq("?width=4&height=3&seed=42"));
+    const data = await res.json();
+    const rows = data.maze.split("\n");
+
+    expect(rows).toHaveLength(3 * 2 + 1);
+    expect(rows.every((row: string) => row.length === 4 * 2 + 1)).toBe(true);
+  });
+
+  it("has a single entrance and exit", async () => {
+    const res = await GET(makeReq("?width=4&height=3&seed=42"));
+    const data = await res.json();
+    const rows = data.maze.split("\n");
+    const topOpenings = rows[0]
+      .split("")
+      .filter((cell: string) => cell === " ").length;
+    const bottomOpenings = rows[rows.length - 1]
+      .split("")
+      .filter((cell: string) => cell === " ").length;
+
+    expect(topOpenings).toBe(1);
+    expect(bottomOpenings).toBe(1);
+    expect(rows[0][1]).toBe(" ");
+    expect(rows[rows.length - 1][rows[0].length - 2]).toBe(" ");
+  });
+
+  it("rejects invalid dimensions", async () => {
+    const res = await GET(makeReq("?width=0&height=3&seed=42"));
+
+    expect(res.status).toBe(400);
+  });
+});
diff --git a/app/api/routesF/ascii-maze/route.ts b/app/api/routesF/ascii-maze/route.ts
new file mode 100644
index 00000000..96018af0
--- /dev/null
+++ b/app/api/routesF/ascii-maze/route.ts
@@ -0,0 +1,45 @@
+import { NextRequest, NextResponse } from "next/server";
+import { renderMaze } from "./maze";
+
+function badRequest(message: string) {
+  return NextResponse.json({ error: message }, { status: 400 });
+}
+
+function parseInteger(value: string | null, fallback: number) {
+  if (value === null) {
+    return fallback;
+  }
+
+  const parsed = Number(value);
+  if (!Number.isInteger(parsed)) {
+    return null;
+  }
+
+  return parsed;
+}
+
+export async function GET(req: NextRequest) {
+  const { searchParams } = new URL(req.url);
+
+  const width = parseInteger(searchParams.get("width"), 10);
+  const height = parseInteger(searchParams.get("height"), 10);
+  const seed = parseInteger(searchParams.get("seed"), 0);
+
+  if (width === null || height === null || seed === null) {
+    return badRequest("width, height, and seed must be integers.");
+  }
+
+  if (width <= 0 || height <= 0) {
+    return badRequest("width and height must be positive integers.");
+  }
+
+  if (width > 50 || height > 50) {
+    return badRequest("width and height must not exceed 50.");
+  }
+
+  return NextResponse.json({
+    maze: renderMaze(width, height, seed),
+    width,
+    height,
+  });
+}
diff --git a/app/api/routesF/business-days/holidays.ts b/app/api/routesF/business-days/holidays.ts
new file mode 100644
index 00000000..ad32037c
--- /dev/null
+++ b/app/api/routesF/business-days/holidays.ts
@@ -0,0 +1,32 @@
+export type Holiday = {
+  date: string;
+  name: string;
+};
+
+export type HolidayCountry = "US" | "GB" | "JP";
+
+export const HOLIDAYS: Record<HolidayCountry, Holiday[]> = {
+  US: [
+    { date: "2026-01-01", name: "New Year's Day" },
+    { date: "2026-07-04", name: "Independence Day" },
+    { date: "2026-11-26", name: "Thanksgiving Day" },
+    { date: "2026-12-24", name: "Christmas Day (observed)" },
+    { date: "2026-12-25", name: "Christmas Day" },
+  ],
+  GB: [
+    { date: "2026-01-01", name: "New Year's Day" },
+    { date: "2026-04-10", name: "Good Friday" },
+    { date: "2026-12-25", name: "Christmas Day" },
+    { date: "2026-12-28", name: "Boxing Day (substitute day)" },
+  ],
+  JP: [
+    { date: "2026-01-01", name: "New Year's Day" },
+    { date: "2026-02-11", name: "National Foundation Day" },
+    { date: "2026-05-05", name: "Children's Day" },
+    { date: "2026-11-03", name: "Culture Day" },
+  ],
+};
+
+export const COUNTRY_ALIASES: Record<string, HolidayCountry> = {
+  UK: "GB",
+};
diff --git a/app/api/routesF/business-days/route.ts b/app/api/routesF/business-days/route.ts
new file mode 100644
index 00000000..cb03ade9
--- /dev/null
+++ b/app/api/routesF/business-days/route.ts
@@ -0,0 +1,142 @@
+import { type NextRequest, NextResponse } from "next/server";
+import { COUNTRY_ALIASES, HOLIDAYS, type HolidayCountry } from "./holidays";
+
+const MS_PER_DAY = 24 * 60 * 60 * 1000;
+
+type BusinessDaysBody = {
+  date?: unknown;
+  days?: unknown;
+  country?: unknown;
+  custom_holidays?: unknown;
+};
+
+function badRequest(message: string) {
+  return NextResponse.json({ error: message }, { status: 400 });
+}
+
+function parseIsoDate(value: unknown): Date | null {
+  if (typeof value !== "string") {
+    return null;
+  }
+
+  const date = new Date(value);
+  if (Number.isNaN(date.getTime())) {
+    return null;
+  }
+
+  return new Date(
+    Date.UTC(date.getUTCFullYear(), date.getUTCMonth(), date.getUTCDate())
+  );
+}
+
+function dateKey(date: Date) {
+  return date.toISOString().slice(0, 10);
+}
+
+function isWeekend(date: Date) {
+  const day = date.getUTCDay();
+  return day === 0 || day === 6;
+}
+
+function addDays(date: Date, amount: number) {
+  return new Date(date.getTime() + amount * MS_PER_DAY);
+}
+
+function resolveCountry(value: unknown): HolidayCountry {
+  if (typeof value !== "string") {
+    return "US";
+  }
+
+  const normalized = value.toUpperCase();
+  if (normalized in HOLIDAYS) {
+    return normalized as HolidayCountry;
+  }
+
+  if (normalized in COUNTRY_ALIASES) {
+    return COUNTRY_ALIASES[normalized];
+  }
+
+  return "US";
+}
+
+function parseCustomHolidays(value: unknown): Set<string> | null {
+  if (value === undefined) {
+    return new Set();
+  }
+
+  if (!Array.isArray(value)) {
+    return null;
+  }
+
+  const result = new Set<string>();
+  for (const item of value) {
+    const date = parseIsoDate(item);
+    if (!date) {
+      return null;
+    }
+    result.add(dateKey(date));
+  }
+  return result;
+}
+
+function addBusinessDays(
+  startDate: Date,
+  days: number,
+  holidays: Set<string>
+): { target: Date; skipped: number } {
+  if (days === 0) {
+    return { target: startDate, skipped: 0 };
+  }
+
+  const step = days > 0 ? 1 : -1;
+  let remaining = Math.abs(days);
+  let current = startDate;
+  let skipped = 0;
+
+  while (remaining > 0) {
+    current = addDays(current, step);
+    if (isWeekend(current) || holidays.has(dateKey(current))) {
+      skipped += 1;
+      continue;
+    }
+    remaining -= 1;
+  }
+
+  return { target: current, skipped };
+}
+
+export async function POST(request: NextRequest) {
+  let body: BusinessDaysBody;
+
+  try {
+    body = (await request.json()) as BusinessDaysBody;
+  } catch {
+    return badRequest("Invalid JSON body.");
+  }
+
+  const date = parseIsoDate(body.date);
+  if (!date) {
+    return badRequest("date must be a valid ISO date string.");
+  }
+
+  if (typeof body.days !== "number" || !Number.isInteger(body.days)) {
+    return badRequest("days must be an integer.");
+  }
+
+  const country = resolveCountry(body.country);
+  const holidays = new Set(HOLIDAYS[country].map(holiday => holiday.date));
+  const customHolidays = parseCustomHolidays(body.custom_holidays);
+  if (customHolidays === null) {
+    return badRequest("custom_holidays must be an array of ISO date strings.");
+  }
+
+  for (const holiday of customHolidays) {
+    holidays.add(holiday);
+  }
+
+  const { target, skipped } = addBusinessDays(date, body.days, holidays);
+  return NextResponse.json({
+    result: target.toISOString(),
+    skipped_days: skipped,
+  });
+}
diff --git a/app/api/routesF/caesar-cipher/caesar.ts b/app/api/routesF/caesar-cipher/caesar.ts
new file mode 100644
index 00000000..06771f55
--- /dev/null
+++ b/app/api/routesF/caesar-cipher/caesar.ts
@@ -0,0 +1,40 @@
+// #889 feat(routesF): caesar cipher brute force
+
+export type CaesarCandidate = {
+  shift: number;
+  text: string;
+  score?: number;
+};
+
+/**
+ * Decode ciphertext with a Caesar shift (only A–Z / a–z are rotated).
+ */
+export function caesarDecode(text: string, shift: number): string {
+  const normalizedShift = ((shift % 26) + 26) % 26;
+  if (normalizedShift === 0) {
+    return text;
+  }
+
+  return text.replace(/[a-zA-Z]/g, (char) => {
+    const base = char <= "Z" ? 65 : 97;
+    return String.fromCharCode(
+      base + ((char.charCodeAt(0) - base - normalizedShift + 26) % 26)
+    );
+  });
+}
+
+/**
+ * Produce all 25 non-zero Caesar decodings (shifts 1–25).
+ */
+export function bruteForceCaesar(text: string): CaesarCandidate[] {
+  const candidates: CaesarCandidate[] = [];
+
+  for (let shift = 1; shift <= 25; shift += 1) {
+    candidates.push({
+      shift,
+      text: caesarDecode(text, shift),
+    });
+  }
+
+  return candidates;
+}
diff --git a/app/api/routesF/caesar-cipher/route.test.ts b/app/api/routesF/caesar-cipher/route.test.ts
new file mode 100644
index 00000000..fa3858a5
--- /dev/null
+++ b/app/api/routesF/caesar-cipher/route.test.ts
@@ -0,0 +1,94 @@
+import { NextRequest } from "next/server";
+import { caesarDecode, bruteForceCaesar } from "./caesar";
+import { englishLikenessScore } from "./score";
+import { POST } from "./route";
+
+// #889 feat(routesF): caesar cipher brute force
+
+function makeReq(body: unknown) {
+  return new NextRequest("http://localhost/api/routesF/caesar-cipher", {
+    method: "POST",
+    headers: { "content-type": "application/json" },
+    body: JSON.stringify(body),
+  });
+}
+
+describe("/api/routesF/caesar-cipher", () => {
+  describe("caesarDecode", () => {
+    it("decodes a known ciphertext with the correct shift", () => {
+      expect(caesarDecode("khoor", 3)).toBe("hello");
+    });
+
+    it("preserves case and non-alphabetic characters", () => {
+      expect(caesarDecode("Khoor, Zruog!", 3)).toBe("Hello, World!");
+    });
+  });
+
+  describe("bruteForceCaesar", () => {
+    it("returns exactly 25 candidates with shifts 1 through 25", () => {
+      const candidates = bruteForceCaesar("abc");
+
+      expect(candidates).toHaveLength(25);
+      expect(candidates.map((c) => c.shift)).toEqual(
+        Array.from({ length: 25 }, (_, i) => i + 1)
+      );
+    });
+
+    it("includes the correct plaintext among decodings", () => {
+      const candidates = bruteForceCaesar("khoor");
+      const match = candidates.find((c) => c.text === "hello");
+
+      expect(match).toBeDefined();
+      expect(match?.shift).toBe(3);
+    });
+  });
+
+  describe("englishLikenessScore", () => {
+    it("ranks plausible English above random letter strings", () => {
+      const englishScore = englishLikenessScore(
+        "the quick brown fox jumps over the lazy dog"
+      );
+      const randomScore = englishLikenessScore("xqzvkjwpmnbctyfg");
+
+      expect(englishScore).toBeGreaterThan(randomScore);
+    });
+  });
+
+  describe("POST", () => {
+    it("returns all 25 candidates without scores by default", async () => {
+      const res = await POST(makeReq({ text: "khoor" }));
+      const data = await res.json();
+
+      expect(res.status).toBe(200);
+      expect(data.candidates).toHaveLength(25);
+      expect(data.candidates.every((c: { score?: number }) => c.score === undefined)).toBe(
+        true
+      );
+    });
+
+    it("includes scores and ranks candidates when score is true", async () => {
+      const res = await POST(
+        makeReq({ text: "wklv lv d whvw", score: true })
+      );
+      const data = await res.json();
+
+      expect(res.status).toBe(200);
+      expect(data.candidates).toHaveLength(25);
+      expect(data.candidates.every((c: { score: number }) => typeof c.score === "number")).toBe(
+        true
+      );
+
+      const scores = data.candidates.map((c: { score: number }) => c.score);
+      for (let i = 1; i < scores.length; i += 1) {
+        expect(scores[i - 1]).toBeGreaterThanOrEqual(scores[i]);
+      }
+
+      expect(data.candidates[0].text.toLowerCase()).toContain("this");
+    });
+
+    it("rejects invalid bodies", async () => {
+      const res = await POST(makeReq({ score: true }));
+      expect(res.status).toBe(400);
+    });
+  });
+});
diff --git a/app/api/routesF/caesar-cipher/route.ts b/app/api/routesF/caesar-cipher/route.ts
new file mode 100644
index 00000000..637cacc4
--- /dev/null
+++ b/app/api/routesF/caesar-cipher/route.ts
@@ -0,0 +1,62 @@
+import { NextRequest, NextResponse } from "next/server";
+import { bruteForceCaesar, type CaesarCandidate } from "./caesar";
+import { englishLikenessScore } from "./score";
+
+// #889 feat(routesF): caesar cipher brute force
+
+type CaesarBody = {
+  text?: unknown;
+  score?: unknown;
+};
+
+const MAX_INPUT_BYTES = 10 * 1024;
+
+function badRequest(message: string) {
+  return NextResponse.json({ error: message }, { status: 400 });
+}
+
+function getByteLength(value: string) {
+  return new TextEncoder().encode(value).length;
+}
+
+function rankCandidates(candidates: CaesarCandidate[]): CaesarCandidate[] {
+  return [...candidates].sort((a, b) => (b.score ?? 0) - (a.score ?? 0));
+}
+
+export async function POST(req: NextRequest) {
+  let body: CaesarBody;
+
+  try {
+    body = (await req.json()) as CaesarBody;
+  } catch {
+    return badRequest("Invalid JSON body.");
+  }
+
+  const { text, score } = body;
+
+  if (typeof text !== "string") {
+    return badRequest("text must be a string.");
+  }
+
+  if (getByteLength(text) > MAX_INPUT_BYTES) {
+    return badRequest("text must not exceed 10KB.");
+  }
+
+  if (score !== undefined && typeof score !== "boolean") {
+    return badRequest("score must be a boolean when provided.");
+  }
+
+  const includeScore = score === true;
+  let candidates = bruteForceCaesar(text);
+
+  if (includeScore) {
+    candidates = rankCandidates(
+      candidates.map((candidate) => ({
+        ...candidate,
+        score: englishLikenessScore(candidate.text),
+      }))
+    );
+  }
+
+  return NextResponse.json({ candidates });
+}
diff --git a/app/api/routesF/caesar-cipher/score.ts b/app/api/routesF/caesar-cipher/score.ts
new file mode 100644
index 00000000..e587c766
--- /dev/null
+++ b/app/api/routesF/caesar-cipher/score.ts
@@ -0,0 +1,61 @@
+// #889 feat(routesF): caesar cipher brute force
+
+/**
+ * Relative English letter frequencies (A–Z), normalized to sum to 1.
+ */
+const ENGLISH_FREQ: Record<string, number> = {
+  A: 0.08167,
+  B: 0.01492,
+  C: 0.02782,
+  D: 0.04253,
+  E: 0.12702,
+  F: 0.02228,
+  G: 0.02015,
+  H: 0.06094,
+  I: 0.06966,
+  J: 0.00153,
+  K: 0.00772,
+  L: 0.04025,
+  M: 0.02406,
+  N: 0.06749,
+  O: 0.07507,
+  P: 0.01929,
+  Q: 0.00095,
+  R: 0.05987,
+  S: 0.06327,
+  T: 0.09056,
+  U: 0.02758,
+  V: 0.00978,
+  W: 0.0236,
+  X: 0.0015,
+  Y: 0.01974,
+  Z: 0.00074,
+};
+
+/**
+ * Score how English-like a string is using log-likelihood against letter
+ * frequencies. Higher scores indicate more plausible English plaintext.
+ */
+export function englishLikenessScore(text: string): number {
+  const letters = text.match(/[a-zA-Z]/g);
+  if (!letters || letters.length === 0) {
+    return 0;
+  }
+
+  const counts = new Map<string, number>();
+  for (const letter of letters) {
+    const upper = letter.toUpperCase();
+    counts.set(upper, (counts.get(upper) ?? 0) + 1);
+  }
+
+  const total = letters.length;
+  let score = 0;
+
+  for (const [letter, count] of counts.entries()) {
+    const observed = count / total;
+    const expected = ENGLISH_FREQ[letter] ?? 0.0001;
+    score += observed * Math.log(expected);
+  }
+
+  return score;
+}
diff --git a/app/api/routesF/card-expiry/route.ts b/app/api/routesF/card-expiry/route.ts
new file mode 100644
index 00000000..fef180da
--- /dev/null
+++ b/app/api/routesF/card-expiry/route.ts
@@ -0,0 +1,44 @@
+import { NextResponse } from 'next/server';
+
+export async function POST(request: Request) {
+  try {
+    const body = await request.json();
+    const { month, year, now } = body;
+
+    if (typeof month !== 'number' || month < 1 || month > 12) {
+      return NextResponse.json({ error: 'month must be between 1 and 12' }, { status: 400 });
+    }
+
+    if (typeof year !== 'number') {
+      return NextResponse.json({ error: 'year is required' }, { status: 400 });
+    }
+
+    let fullYear = year;
+    if (year < 100) {
+      fullYear = year + 2000;
+    }
+
+    const nowDate = now ? new Date(now) : new Date();
+    const currentYear = nowDate.getFullYear();
+    const currentMonth = nowDate.getMonth() + 1;
+
+    const expiryDate = new Date(fullYear, month, 0);
+    expiryDate.setHours(23, 59, 59, 999);
+
+    const isExpired = expiryDate < nowDate;
+
+    let monthsUntilExpiry = 0;
+    if (!isExpired) {
+      monthsUntilExpiry =
+        (fullYear - currentYear) * 12 + (month - currentMonth);
+    }
+
+    return NextResponse.json({
+      valid: !isExpired,
+      expired: isExpired,
+      months_until_expiry: Math.max(0, monthsUntilExpiry),
+    });
+  } catch (error) {
+    return NextResponse.json({ error: 'Invalid JSON body' }, { status: 400 });
+  }
+}
diff --git a/app/api/routesF/clamp-normalize/route.ts b/app/api/routesF/clamp-normalize/route.ts
new file mode 100644
index 00000000..3e754b2a
--- /dev/null
+++ b/app/api/routesF/clamp-normalize/route.ts
@@ -0,0 +1,45 @@
+import { type NextRequest, NextResponse } from "next/server";
+
+type ClampBody = {
+  value?: unknown;
+  min?: unknown;
+  max?: unknown;
+  normalize?: unknown;
+};
+
+function isFiniteNumber(value: unknown): value is number {
+  return typeof value === "number" && Number.isFinite(value);
+}
+
+function badRequest(message: string) {
+  return NextResponse.json({ error: message }, { status: 400 });
+}
+
+export async function POST(req: NextRequest) {
+  let body: ClampBody;
+
+  try {
+    body = (await req.json()) as ClampBody;
+  } catch {
+    return badRequest("Invalid JSON body.");
+  }
+
+  const { value, min, max, normalize } = body;
+
+  if (!isFiniteNumber(value) || !isFiniteNumber(min) || !isFiniteNumber(max)) {
+    return badRequest("value, min, and max must be finite numbers.");
+  }
+
+  if (min > max) {
+    return badRequest("min must be less than or equal to max.");
+  }
+
+  const clamped = Math.min(Math.max(value, min), max);
+
+  if (normalize === true) {
+    const normalized = min === max ? 0 : (clamped - min) / (max - min);
+    return NextResponse.json({ clamped, normalized });
+  }
+
+  return NextResponse.json({ clamped });
+}
diff --git a/app/api/routesF/company-name-generator/route.ts b/app/api/routesF/company-name-generator/route.ts
new file mode 100644
index 00000000..fe522805
--- /dev/null
+++ b/app/api/routesF/company-name-generator/route.ts
@@ -0,0 +1,93 @@
+import { NextRequest, NextResponse } from "next/server";
+import { z } from "zod";
+
+// Word pools for company name generation
+const PREFIXES = {
+  tech: ["Cyber", "Digital", "Smart", "Tech", "Data", "Cloud", "Quantum", "Neural", "Pixel", "Code"],
+  finance: ["Capital", "Wealth", "Asset", "Prime", "Elite", "Trust", "Secure", "Gold", "Silver", "Diamond"],
+  food: ["Fresh", "Organic", "Gourmet", "Tasty", "Crispy", "Sweet", "Spicy", "Golden", "Royal", "Premium"],
+  any: ["Global", "United", "Premier", "Advanced", "Superior", "Dynamic", "Innovative", "Creative", "Modern", "Future"]
+};
+
+const ROOTS = {
+  tech: ["Soft", "Ware", "Logic", "System", "Network", "Protocol", "Algorithm", "Interface", "Platform", "Framework"],
+  finance: ["Bank", "Fund", "Investment", "Credit", "Finance", "Capital", "Equity", "Portfolio", "Market", "Exchange"],
+  food: ["Kitchen", "Bistro", "Cafe", "Deli", "Market", "Bakery", "Grill", "Feast", "Flavor", "Cuisine"],
+  any: ["Corp", "Group", "Solutions", "Services", "Industries", "Enterprises", "Holdings", "Partners", "Associates", "Ventures"]
+};
+
+const SUFFIXES = {
+  tech: ["Labs", "Systems", "Technologies", "Solutions", "Innovations", "Dynamics", "Networks", "Platforms", "Studios", "Works"],
+  finance: ["Partners", "Associates", "Holdings", "Capital", "Advisors", "Management", "Group", "Trust", "Securities", "Investments"],
+  food: ["Co", "Kitchen", "Foods", "Catering", "Delights", "Treats", "Specialties", "Provisions", "Pantry", "Table"],
+  any: ["Inc", "LLC", "Corp", "Ltd", "Group", "Company", "Enterprises", "International", "Global", "Worldwide"]
+};
+
+type Industry = "tech" | "finance" | "food" | "any";
+
+const querySchema = z.object({
+  count: z.string().optional().default("5").transform(val => {
+    const num = parseInt(val, 10);
+    return isNaN(num) ? 5 : Math.max(1, Math.min(50, num));
+  }),
+  industry: z.enum(["tech", "finance", "food", "any"]).optional().default("any"),
+  seed: z.string().optional().transform(val => val ? parseInt(val, 10) : undefined)
+});
+
+// Simple seeded random number generator (LCG)
+class SeededRandom {
+  private seed: number;
+
+  constructor(seed?: number) {
+    this.seed = seed ?? Math.floor(Math.random() * 2147483647);
+  }
+
+  next(): number {
+    this.seed = (this.seed * 1103515245 + 12345) & 0x7fffffff;
+    return this.seed / 0x7fffffff;
+  }
+
+  choice<T>(array: T[]): T {
+    return array[Math.floor(this.next() * array.length)];
+  }
+}
+
+function generateCompanyName(industry: Industry, rng: SeededRandom): string {
+  const prefix = rng.choice(PREFIXES[industry]);
+  const root = rng.choice(ROOTS[industry]);
+  const suffix = rng.choice(SUFFIXES[industry]);
+
+  return `${prefix}${root} ${suffix}`;
+}
+
+export async function GET(req: NextRequest) {
+  const { searchParams } = new URL(req.url);
+  
+  const validation = querySchema.safeParse({
+    count: searchParams.get("count"),
+    industry: searchParams.get("industry"),
+    seed: searchParams.get("seed")
+  });
+
+  if (!validation.success) {
+    return NextResponse.json(
+      { error: "Invalid query parameters", details: validation.error.flatten() },
+      { status: 400 }
+    );
+  }
+
+  const { count, industry, seed } = validation.data;
+  const rng = new SeededRandom(seed);
+  
+  const names: string[] = [];
+  for (let i = 0; i < count; i++) {
+    names.push(generateCompanyName(industry, rng));
+  }
+
+  return NextResponse.json({
+    names,
+    count: names.length,
+    industry,
+    seed: seed ?? "random"
+  });
+}
\ No newline at end of file
diff --git a/app/api/routesF/compound-vs-simple/route.ts b/app/api/routesF/compound-vs-simple/route.ts
new file mode 100644
index 00000000..032f43f4
--- /dev/null
+++ b/app/api/routesF/compound-vs-simple/route.ts
@@ -0,0 +1,44 @@
+import { NextResponse } from 'next/server';
+
+export async function POST(request: Request) {
+  try {
+    const body = await request.json();
+    const { principal, rate, years, compounds_per_year = 1 } = body;
+
+    if (typeof principal !== 'number' || principal <= 0) {
+      return NextResponse.json({ error: 'principal must be a positive number' }, { status: 400 });
+    }
+    if (typeof rate !== 'number' || rate < 0) {
+      return NextResponse.json({ error: 'rate must be a non-negative number (e.g. 0.05 for 5%)' }, { status: 400 });
+    }
+    if (typeof years !== 'number' || years <= 0) {
+      return NextResponse.json({ error: 'years must be a positive number' }, { status: 400 });
+    }
+    if (typeof compounds_per_year !== 'number' || compounds_per_year < 1) {
+      return NextResponse.json({ error: 'compounds_per_year must be >= 1' }, { status: 400 });
+    }
+
+    const simpleInterest  = principal * rate * years;
+    const simpleTotal     = principal + simpleInterest;
+
+    const compoundTotal    = principal * Math.pow(1 + rate / compounds_per_year, compounds_per_year * years);
+    const compoundInterest = compoundTotal - principal;
+
+    const difference = compoundTotal - simpleTotal;
+
+    return NextResponse.json({
+      simple: {
+        interest: parseFloat(simpleInterest.toFixed(2)),
+        total:    parseFloat(simpleTotal.toFixed(2)),
+      },
+      compound: {
+        interest: parseFloat(compoundInterest.toFixed(2)),
+        total:    parseFloat(compoundTotal.toFixed(2)),
+        compounds_per_year,
+      },
+      difference: parseFloat(difference.toFixed(2)),
+    });
+  } catch {
+    return NextResponse.json({ error: 'Invalid JSON body' }, { status: 400 });
+  }
+}
diff --git a/app/api/routesF/date-interval/calendar.ts b/app/api/routesF/date-interval/calendar.ts
new file mode 100644
index 00000000..e7fa496d
--- /dev/null
+++ b/app/api/routesF/date-interval/calendar.ts
@@ -0,0 +1,73 @@
+export type IntervalDelta = {
+  years?: number;
+  months?: number;
+  days?: number;
+  hours?: number;
+  minutes?: number;
+};
+
+function isLeapYear(year: number): boolean {
+  return (year % 4 === 0 && year % 100 !== 0) || year % 400 === 0;
+}
+
+function daysInMonth(year: number, month: number): number {
+  return new Date(Date.UTC(year, month + 1, 0)).getUTCDate();
+}
+
+function addCalendarYears(year: number, month: number, day: number, years: number) {
+  const newYear = year + years;
+  if (month === 1 && day === 29 && !isLeapYear(newYear)) {
+    return { year: newYear, month, day: 28 };
+  }
+  return { year: newYear, month, day };
+}
+
+function addCalendarMonths(year: number, month: number, day: number, months: number) {
+  const totalMonths = year * 12 + month + months;
+  const newYear = Math.floor(totalMonths / 12);
+  const newMonth = ((totalMonths % 12) + 12) % 12;
+  const maxDay = daysInMonth(newYear, newMonth);
+  const newDay = Math.min(day, maxDay);
+  return { year: newYear, month: newMonth, day: newDay };
+}
+
+export function addIntervalsToDate(isoDate: string, delta: IntervalDelta): string {
+  const date = new Date(isoDate);
+  if (Number.isNaN(date.getTime())) {
+    throw new Error("Invalid date");
+  }
+
+  const years = delta.years ?? 0;
+  const months = delta.months ?? 0;
+  const days = delta.days ?? 0;
+  const hours = delta.hours ?? 0;
+  const minutes = delta.minutes ?? 0;
+
+  let year = date.getUTCFullYear();
+  let month = date.getUTCMonth();
+  let day = date.getUTCDate();
+
+  if (years !== 0) {
+    ({ year, month, day } = addCalendarYears(year, month, day, years));
+  }
+
+  if (months !== 0) {
+    ({ year, month, day } = addCalendarMonths(year, month, day, months));
+  }
+
+  const resultMs =
+    Date.UTC(
+      year,
+      month,
+      day,
+      date.getUTCHours(),
+      date.getUTCMinutes(),
+      date.getUTCSeconds(),
+      date.getUTCMilliseconds()
+    ) +
+    days * 86_400_000 +
+    hours * 3_600_000 +
+    minutes * 60_000;
+
+  return new Date(resultMs).toISOString();
+}
diff --git a/app/api/routesF/date-interval/route.test.ts b/app/api/routesF/date-interval/route.test.ts
new file mode 100644
index 00000000..72b614b2
--- /dev/null
+++ b/app/api/routesF/date-interval/route.test.ts
@@ -0,0 +1,79 @@
+/**
+ * @jest-environment node
+ */
+import { NextRequest } from "next/server";
+import { POST } from "./route";
+import { addIntervalsToDate } from "./calendar";
+
+function makeReq(body: unknown) {
+  return new NextRequest("http://localhost/api/routesF/date-interval", {
+    method: "POST",
+    headers: { "content-type": "application/json" },
+    body: JSON.stringify(body),
+  });
+}
+
+describe("/api/routesF/date-interval", () => {
+  it("clamps Jan 31 plus one month to the last day of February", async () => {
+    const res = await POST(
+      makeReq({ date: "2023-01-31T12:00:00.000Z", add: { months: 1 } })
+    );
+    const data = await res.json();
+
+    expect(res.status).toBe(200);
+    expect(data.result).toBe("2023-02-28T12:00:00.000Z");
+  });
+
+  it("clamps Jan 31 plus one month in a leap year to Feb 29", async () => {
+    const res = await POST(
+      makeReq({ date: "2024-01-31T00:00:00.000Z", add: { months: 1 } })
+    );
+    const data = await res.json();
+
+    expect(res.status).toBe(200);
+    expect(data.result).toBe("2024-02-29T00:00:00.000Z");
+  });
+
+  it("supports negative month intervals", async () => {
+    const res = await POST(
+      makeReq({ date: "2023-03-31T08:30:00.000Z", add: { months: -1 } })
+    );
+    const data = await res.json();
+
+    expect(res.status).toBe(200);
+    expect(data.result).toBe("2023-02-28T08:30:00.000Z");
+  });
+
+  it("supports negative day intervals", async () => {
+    const res = await POST(
+      makeReq({ date: "2024-03-15T10:00:00.000Z", add: { days: -5 } })
+    );
+    const data = await res.json();
+
+    expect(res.status).toBe(200);
+    expect(data.result).toBe("2024-03-10T10:00:00.000Z");
+  });
+
+  it("adds hours and minutes", async () => {
+    const res = await POST(
+      makeReq({ date: "2024-06-01T10:00:00.000Z", add: { hours: 2, minutes: 30 } })
+    );
+    const data = await res.json();
+
+    expect(res.status).toBe(200);
+    expect(data.result).toBe("2024-06-01T12:30:00.000Z");
+  });
+
+  it("rejects invalid dates", async () => {
+    const res = await POST(makeReq({ date: "not-a-date", add: { days: 1 } }));
+    expect(res.status).toBe(400);
+  });
+});
+
+describe("addIntervalsToDate", () => {
+  it("clamps Feb 29 when adding years to a non-leap year", () => {
+    expect(addIntervalsToDate("2024-02-29T00:00:00.000Z", { years: 1 })).toBe(
+      "2025-02-28T00:00:00.000Z"
+    );
+  });
+});
diff --git a/app/api/routesF/date-interval/route.ts b/app/api/routesF/date-interval/route.ts
new file mode 100644
index 00000000..98d1ef32
--- /dev/null
+++ b/app/api/routesF/date-interval/route.ts
@@ -0,0 +1,52 @@
+import { type NextRequest, NextResponse } from "next/server";
+import { addIntervalsToDate, type IntervalDelta } from "./calendar";
+
+type DateIntervalBody = {
+  date?: unknown;
+  add?: unknown;
+};
+
+function isIntervalDelta(value: unknown): value is IntervalDelta {
+  if (!value || typeof value !== "object" || Array.isArray(value)) {
+    return false;
+  }
+
+  const record = value as Record<string, unknown>;
+  const keys = ["years", "months", "days", "hours", "minutes"] as const;
+
+  if (Object.keys(record).length === 0) {
+    return false;
+  }
+
+  return Object.keys(record).every((key) => keys.includes(key as (typeof keys)[number])) &&
+    keys.every((key) => record[key] === undefined || Number.isInteger(record[key]));
+}
+
+function badRequest(message: string) {
+  return NextResponse.json({ error: message }, { status: 400 });
+}
+
+export async function POST(req: NextRequest) {
+  let body: DateIntervalBody;
+
+  try {
+    body = (await req.json()) as DateIntervalBody;
+  } catch {
+    return badRequest("Invalid JSON body.");
+  }
+
+  if (typeof body.date !== "string") {
+    return badRequest("date must be an ISO date string.");
+  }
+
+  if (!isIntervalDelta(body.add)) {
+    return badRequest("add must be an object with integer years, months, days, hours, and/or minutes.");
+  }
+
+  try {
+    const result = addIntervalsToDate(body.date, body.add);
+    return NextResponse.json({ result });
+  } catch {
+    return badRequest("date must be a valid ISO date string.");
+  }
+}
diff --git a/app/api/routesF/days-between/route.test.ts b/app/api/routesF/days-between/route.test.ts
new file mode 100644
index 00000000..51845499
--- /dev/null
+++ b/app/api/routesF/days-between/route.test.ts
@@ -0,0 +1,66 @@
+/**
+ * @jest-environment node
+ */
+import { NextRequest } from "next/server";
+import { POST } from "./route";
+
+function makeReq(body: unknown) {
+  return new NextRequest("http://localhost/api/routesF/days-between", {
+    method: "POST",
+    headers: { "content-type": "application/json" },
+    body: JSON.stringify(body),
+  });
+}
+
+describe("POST /api/routesF/days-between", () => {
+  it("returns zero for the same day", async () => {
+    const res = await POST(makeReq({ from: "2026-05-28", to: "2026-05-28" }));
+    const body = await res.json();
+
+    expect(res.status).toBe(200);
+    expect(body).toEqual({
+      calendar_days: 0,
+      business_days: 0,
+      weekends: 0,
+      holidays_in_range: [],
+    });
+  });
+
+  it("handles reversed date order", async () => {
+    const res = await POST(makeReq({ from: "2026-05-04", to: "2026-05-01" }));
+    const body = await res.json();
+
+    expect(res.status).toBe(200);
+    expect(body.calendar_days).toBe(3);
+    expect(body.weekends).toBe(2);
+    expect(body.business_days).toBe(1);
+  });
+
+  it("excludes holidays from business days", async () => {
+    const res = await POST(
+      makeReq({ from: "2026-01-01", to: "2026-01-03", country: "US" })
+    );
+    const body = await res.json();
+
+    expect(res.status).toBe(200);
+    expect(body.calendar_days).toBe(2);
+    expect(body.business_days).toBe(1);
+    expect(body.holidays_in_range).toEqual([
+      { date: "2026-01-01", name: "New Year's Day" },
+    ]);
+  });
+
+  it("uses country-specific holidays", async () => {
+    const res = await POST(
+      makeReq({ from: "2026-10-01", to: "2026-10-02", country: "NG" })
+    );
+    const body = await res.json();
+
+    expect(res.status).toBe(200);
+    expect(body.business_days).toBe(0);
+    expect(body.holidays_in_range[0]).toEqual({
+      date: "2026-10-01",
+      name: "Independence Day",
+    });
+  });
+});
diff --git a/app/api/routesF/days-between/route.ts b/app/api/routesF/days-between/route.ts
new file mode 100644
index 00000000..4a646141
--- /dev/null
+++ b/app/api/routesF/days-between/route.ts
@@ -0,0 +1,123 @@
+import { type NextRequest, NextResponse } from "next/server";
+
+type Holiday = {
+  date: string;
+  name: string;
+};
+
+const HOLIDAYS: Record<string, Holiday[]> = {
+  US: [
+    { date: "2026-01-01", name: "New Year's Day" },
+    { date: "2026-01-19", name: "Martin Luther King Jr. Day" },
+    { date: "2026-02-16", name: "Presidents' Day" },
+    { date: "2026-05-25", name: "Memorial Day" },
+    { date: "2026-06-19", name: "Juneteenth" },
+    { date: "2026-07-03", name: "Independence Day observed" },
+    { date: "2026-09-07", name: "Labor Day" },
+    { date: "2026-10-12", name: "Columbus Day" },
+    { date: "2026-11-11", name: "Veterans Day" },
+    { date: "2026-11-26", name: "Thanksgiving Day" },
+    { date: "2026-12-25", name: "Christmas Day" },
+  ],
+  NG: [
+    { date: "2026-01-01", name: "New Year's Day" },
+    { date: "2026-03-20", name: "Eid al-Fitr" },
+    { date: "2026-03-21", name: "Eid al-Fitr Holiday" },
+    { date: "2026-04-03", name: "Good Friday" },
+    { date: "2026-04-06", name: "Easter Monday" },
+    { date: "2026-05-01", name: "Workers' Day" },
+    { date: "2026-05-27", name: "Eid al-Adha" },
+    { date: "2026-06-12", name: "Democracy Day" },
+    { date: "2026-10-01", name: "Independence Day" },
+    { date: "2026-12-25", name: "Christmas Day" },
+    { date: "2026-12-26", name: "Boxing Day" },
+  ],
+};
+
+const MS_PER_DAY = 24 * 60 * 60 * 1000;
+
+function badRequest(message: string) {
+  return NextResponse.json({ error: message }, { status: 400 });
+}
+
+function parseIsoDate(value: unknown): Date | null {
+  if (typeof value !== "string") {
+    return null;
+  }
+
+  const date = new Date(value);
+  if (Number.isNaN(date.getTime())) {
+    return null;
+  }
+
+  return new Date(
+    Date.UTC(date.getUTCFullYear(), date.getUTCMonth(), date.getUTCDate())
+  );
+}
+
+function dateKey(date: Date): string {
+  return date.toISOString().slice(0, 10);
+}
+
+function isWeekend(date: Date) {
+  const day = date.getUTCDay();
+  return day === 0 || day === 6;
+}
+
+function addDays(date: Date, days: number) {
+  return new Date(date.getTime() + days * MS_PER_DAY);
+}
+
+export async function POST(req: NextRequest) {
+  let body: { from?: unknown; to?: unknown; country?: unknown };
+
+  try {
+    body = await req.json();
+  } catch {
+    return badRequest("Invalid JSON body.");
+  }
+
+  const from = parseIsoDate(body.from);
+  const to = parseIsoDate(body.to);
+  if (!from || !to) {
+    return badRequest("from and to must be valid ISO date strings.");
+  }
+
+  const country =
+    typeof body.country === "string" ? body.country.toUpperCase() : "US";
+  const holidays = HOLIDAYS[country] ?? HOLIDAYS.US;
+  const holidayMap = new Map(holidays.map(holiday => [holiday.date, holiday]));
+
+  const start = from <= to ? from : to;
+  const end = from <= to ? to : from;
+  const calendarDays = Math.round(
+    (end.getTime() - start.getTime()) / MS_PER_DAY
+  );
+  let weekends = 0;
+  let businessDays = 0;
+  const holidaysInRange: Holiday[] = [];
+
+  for (let offset = 0; offset < calendarDays; offset += 1) {
+    const current = addDays(start, offset);
+    const key = dateKey(current);
+    const weekend = isWeekend(current);
+    const holiday = holidayMap.get(key);
+
+    if (weekend) {
+      weekends += 1;
+    }
+    if (holiday) {
+      holidaysInRange.push(holiday);
+    }
+    if (!weekend && !holiday) {
+      businessDays += 1;
+    }
+  }
+
+  return NextResponse.json({
+    calendar_days: calendarDays,
+    business_days: businessDays,
+    weekends,
+    holidays_in_range: holidaysInRange,
+  });
+}
diff --git a/app/api/routesF/dedupe-by-key/route.test.ts b/app/api/routesF/dedupe-by-key/route.test.ts
new file mode 100644
index 00000000..7ea68ffa
--- /dev/null
+++ b/app/api/routesF/dedupe-by-key/route.test.ts
@@ -0,0 +1,78 @@
+import { NextRequest } from "next/server";
+import { POST } from "./route";
+
+function makeReq(body: unknown) {
+  return new NextRequest("http://localhost/api/routesF/dedupe-by-key", {
+    method: "POST",
+    headers: { "content-type": "application/json" },
+    body: JSON.stringify(body),
+  });
+}
+
+describe("Dedupe By Key API", () => {
+  it("keeps first occurrence by default", async () => {
+    const items = [
+      { id: 1, name: "a" },
+      { id: 2, name: "b" },
+      { id: 1, name: "c" },
+    ];
+    const res = await POST(makeReq({ items, key: "id" }));
+    const data = await res.json();
+    expect(res.status).toBe(200);
+    expect(data.items).toEqual([
+      { id: 1, name: "a" },
+      { id: 2, name: "b" },
+    ]);
+    expect(data.removed_count).toBe(1);
+  });
+
+  it("keeps last occurrence when keep=last", async () => {
+    const items = [
+      { id: 1, name: "a" },
+      { id: 2, name: "b" },
+      { id: 1, name: "c" },
+    ];
+    const res = await POST(makeReq({ items, key: "id", keep: "last" }));
+    const data = await res.json();
+    expect(data.items).toEqual([
+      { id: 2, name: "b" },
+      { id: 1, name: "c" },
+    ]);
+    expect(data.removed_count).toBe(1);
+  });
+
+  it("supports dot-path keys", async () => {
+    const items = [
+      { user: { id: 1 }, name: "a" },
+      { user: { id: 2 }, name: "b" },
+      { user: { id: 1 }, name: "c" },
+    ];
+    const res = await POST(makeReq({ items, key: "user.id" }));
+    const data = await res.json();
+    expect(data.items).toHaveLength(2);
+    expect(data.removed_count).toBe(1);
+  });
+
+  it("returns 400 for missing items", async () => {
+    const res = await POST(makeReq({ key: "id" }));
+    expect(res.status).toBe(400);
+  });
+
+  it("returns 400 for missing key", async () => {
+    const res = await POST(makeReq({ items: [] }));
+    expect(res.status).toBe(400);
+  });
+
+  it("returns 400 for items exceeding 10000", async () => {
+    const items = Array.from({ length: 10001 }, (_, i) => ({ id: i }));
+    const res = await POST(makeReq({ items, key: "id" }));
+    expect(res.status).toBe(400);
+  });
+
+  it("handles empty array", async () => {
+    const res = await POST(makeReq({ items: [], key: "id" }));
+    const data = await res.json();
+    expect(data.items).toEqual([]);
+    expect(data.removed_count).toBe(0);
+  });
+});
diff --git a/app/api/routesF/dedupe-by-key/route.ts b/app/api/routesF/dedupe-by-key/route.ts
new file mode 100644
index 00000000..d88139b8
--- /dev/null
+++ b/app/api/routesF/dedupe-by-key/route.ts
@@ -0,0 +1,81 @@
+import { type NextRequest, NextResponse } from "next/server";
+
+type DedupeBody = {
+  items?: unknown;
+  key?: unknown;
+  keep?: unknown;
+};
+
+function badRequest(message: string) {
+  return NextResponse.json({ error: message }, { status: 400 });
+}
+
+function getByPath(obj: unknown, path: string): unknown {
+  let current: unknown = obj;
+  for (const segment of path.split(".")) {
+    if (current === null || current === undefined || typeof current !== "object") {
+      return undefined;
+    }
+    current = (current as Record<string, unknown>)[segment];
+  }
+  return current;
+}
+
+export async function POST(req: NextRequest) {
+  let body: DedupeBody;
+
+  try {
+    body = (await req.json()) as DedupeBody;
+  } catch {
+    return badRequest("Invalid JSON body.");
+  }
+
+  const { items, key, keep } = body;
+
+  if (!Array.isArray(items)) {
+    return badRequest("items must be an array.");
+  }
+
+  if (items.length > 10000) {
+    return badRequest("items must not exceed 10000 elements.");
+  }
+
+  if (typeof key !== "string" || key.length === 0) {
+    return badRequest("key must be a non-empty string.");
+  }
+
+  const keepMode = keep === "last" ? "last" : "first";
+
+  const seen = new Map<unknown, number>();
+
+  for (let i = 0; i < items.length; i++) {
+    const value = getByPath(items[i], key);
+    seen.set(value, i);
+  }
+
+  const result: unknown[] = [];
+  const seenKeys = new Set<unknown>();
+
+  if (keepMode === "last") {
+    for (let i = items.length - 1; i >= 0; i--) {
+      const value = getByPath(items[i], key);
+      if (!seenKeys.has(value)) {
+        seenKeys.add(value);
+        result.unshift(items[i]);
+      }
+    }
+  } else {
+    for (let i = 0; i < items.length; i++) {
+      const value = getByPath(items[i], key);
+      if (!seenKeys.has(value)) {
+        seenKeys.add(value);
+        result.push(items[i]);
+      }
+    }
+  }
+
+  return NextResponse.json({
+    items: result,
+    removed_count: items.length - result.length,
+  });
+}
diff --git a/app/api/routesF/determinant/lu.ts b/app/api/routesF/determinant/lu.ts
new file mode 100644
index 00000000..6aa5005e
--- /dev/null
+++ b/app/api/routesF/determinant/lu.ts
@@ -0,0 +1,35 @@
+export function determinant(matrix: number[][]): number {
+  const n = matrix.length;
+  const a = matrix.map((row) => [...row]);
+  let det = 1;
+  let sign = 1;
+
+  for (let i = 0; i < n; i += 1) {
+    let pivotRow = i;
+    for (let j = i + 1; j < n; j += 1) {
+      if (Math.abs(a[j][i]) > Math.abs(a[pivotRow][i])) {
+        pivotRow = j;
+      }
+    }
+
+    if (a[pivotRow][i] === 0) {
+      return 0;
+    }
+
+    if (pivotRow !== i) {
+      [a[i], a[pivotRow]] = [a[pivotRow], a[i]];
+      sign *= -1;
+    }
+
+    det *= a[i][i];
+
+    for (let j = i + 1; j < n; j += 1) {
+      const factor = a[j][i] / a[i][i];
+      for (let k = i; k < n; k += 1) {
+        a[j][k] -= factor * a[i][k];
+      }
+    }
+  }
+
+  return sign * det;
+}
diff --git a/app/api/routesF/determinant/route.test.ts b/app/api/routesF/determinant/route.test.ts
new file mode 100644
index 00000000..8b33e906
--- /dev/null
+++ b/app/api/routesF/determinant/route.test.ts
@@ -0,0 +1,90 @@
+/**
+ * @jest-environment node
+ */
+import { NextRequest } from "next/server";
+import { POST } from "./route";
+import { determinant } from "./lu";
+
+function makeReq(body: unknown) {
+  return new NextRequest("http://localhost/api/routesF/determinant", {
+    method: "POST",
+    headers: { "content-type": "application/json" },
+    body: JSON.stringify(body),
+  });
+}
+
+describe("/api/routesF/determinant", () => {
+  it("computes the determinant of a 2x2 matrix", async () => {
+    const res = await POST(makeReq({ matrix: [[4, 3], [6, 3]] }));
+    const data = await res.json();
+
+    expect(res.status).toBe(200);
+    expect(data.determinant).toBe(-6);
+  });
+
+  it("computes the determinant of a 3x3 matrix", async () => {
+    const res = await POST(
+      makeReq({
+        matrix: [
+          [6, 1, 1],
+          [4, -2, 5],
+          [2, 8, 7],
+        ],
+      })
+    );
+    const data = await res.json();
+
+    expect(res.status).toBe(200);
+    expect(data.determinant).toBe(-306);
+  });
+
+  it("returns 1 for the identity matrix", async () => {
+    const res = await POST(
+      makeReq({
+        matrix: [
+          [1, 0, 0],
+          [0, 1, 0],
+          [0, 0, 1],
+        ],
+      })
+    );
+    const data = await res.json();
+
+    expect(res.status).toBe(200);
+    expect(data.determinant).toBe(1);
+  });
+
+  it("returns 0 for a singular matrix", async () => {
+    const res = await POST(
+      makeReq({
+        matrix: [
+          [1, 2],
+          [2, 4],
+        ],
+      })
+    );
+    const data = await res.json();
+
+    expect(res.status).toBe(200);
+    expect(data.determinant).toBe(0);
+  });
+
+  it("rejects non-square matrices", async () => {
+    const res = await POST(makeReq({ matrix: [[1, 2, 3], [4, 5, 6]] }));
+    expect(res.status).toBe(400);
+  });
+
+  it("rejects matrices larger than 10x10", async () => {
+    const matrix = Array.from({ length: 11 }, (_, row) =>
+      Array.from({ length: 11 }, (_, col) => (row === col ? 1 : 0))
+    );
+    const res = await POST(makeReq({ matrix }));
+    expect(res.status).toBe(400);
+  });
+});
+
+describe("determinant", () => {
+  it("matches the 2x2 formula", () => {
+    expect(determinant([[1, 2], [3, 4]])).toBe(-2);
+  });
+});
diff --git a/app/api/routesF/determinant/route.ts b/app/api/routesF/determinant/route.ts
new file mode 100644
index 00000000..86545f97
--- /dev/null
+++ b/app/api/routesF/determinant/route.ts
@@ -0,0 +1,51 @@
+import { type NextRequest, NextResponse } from "next/server";
+import { determinant } from "./lu";
+
+const MAX_SIZE = 10;
+
+type DeterminantBody = {
+  matrix?: unknown;
+};
+
+function badRequest(message: string) {
+  return NextResponse.json({ error: message }, { status: 400 });
+}
+
+function isValidMatrix(matrix: unknown): matrix is number[][] {
+  if (!Array.isArray(matrix) || matrix.length === 0 || matrix.length > MAX_SIZE) {
+    return false;
+  }
+
+  const width = matrix[0]?.length;
+  if (!Number.isInteger(width) || width === 0 || width > MAX_SIZE) {
+    return false;
+  }
+
+  return matrix.every(
+    (row) =>
+      Array.isArray(row) &&
+      row.length === width &&
+      row.every((value) => typeof value === "number" && Number.isFinite(value))
+  );
+}
+
+export async function POST(req: NextRequest) {
+  let body: DeterminantBody;
+
+  try {
+    body = (await req.json()) as DeterminantBody;
+  } catch {
+    return badRequest("Invalid JSON body.");
+  }
+
+  if (!isValidMatrix(body.matrix)) {
+    return badRequest("matrix must be a square array of finite numbers with size at most 10.");
+  }
+
+  const n = body.matrix.length;
+  if (body.matrix.some((row) => row.length !== n)) {
+    return badRequest("matrix must be square.");
+  }
+
+  return NextResponse.json({ determinant: determinant(body.matrix) });
+}
diff --git a/app/api/routesF/emoji-picker/emoji-data.ts b/app/api/routesF/emoji-picker/emoji-data.ts
new file mode 100644
index 00000000..1ffbc6b0
--- /dev/null
+++ b/app/api/routesF/emoji-picker/emoji-data.ts
@@ -0,0 +1,44 @@
+import type { EmojiCategory, EmojiItem } from './types';
+
+export const EMOJI_CATEGORIES: Record<EmojiCategory, EmojiItem[]> = {
+  faces: [
+    { emoji: '😀', name: 'grinning face', category: 'faces' },
+    { emoji: '😅', name: 'grinning face with sweat', category: 'faces' },
+    { emoji: '😍', name: 'smiling face with heart-eyes', category: 'faces' },
+    { emoji: '🤔', name: 'thinking face', category: 'faces' },
+    { emoji: '😎', name: 'smiling face with sunglasses', category: 'faces' },
+    { emoji: '🥳', name: 'partying face', category: 'faces' },
+    { emoji: '😢', name: 'crying face', category: 'faces' },
+  ],
+  animals: [
+    { emoji: '🐶', name: 'dog face', category: 'animals' },
+    { emoji: '🐱', name: 'cat face', category: 'animals' },
+    { emoji: '🦊', name: 'fox face', category: 'animals' },
+    { emoji: '🐼', name: 'panda face', category: 'animals' },
+    { emoji: '🐵', name: 'monkey face', category: 'animals' },
+    { emoji: '🦁', name: 'lion face', category: 'animals' },
+    { emoji: '🐧', name: 'penguin', category: 'animals' },
+  ],
+  food: [
+    { emoji: '🍎', name: 'red apple', category: 'food' },
+    { emoji: '🍕', name: 'pizza', category: 'food' },
+    { emoji: '🍉', name: 'watermelon', category: 'food' },
+    { emoji: '🍪', name: 'cookie', category: 'food' },
+    { emoji: '🥐', name: 'croissant', category: 'food' },
+    { emoji: '🍣', name: 'sushi', category: 'food' },
+    { emoji: '🍩', name: 'doughnut', category: 'food' },
+  ],
+};
+
+export const ALL_EMOJI_ITEMS = [
+  ...EMOJI_CATEGORIES.faces,
+  ...EMOJI_CATEGORIES.animals,
+  ...EMOJI_CATEGORIES.food,
+];
+
+export const ALL_CATEGORIES = ['faces', 'animals', 'food', 'any'] as const;
+export type EmojiFilterCategory = (typeof ALL_CATEGORIES)[number];
+
+export function getEmojiPool(category: EmojiFilterCategory) {
+  return category === 'any' ? ALL_EMOJI_ITEMS : EMOJI_CATEGORIES[category];
+}
diff --git a/app/api/routesF/emoji-picker/rng.ts b/app/api/routesF/emoji-picker/rng.ts
new file mode 100644
index 00000000..15e7a485
--- /dev/null
+++ b/app/api/routesF/emoji-picker/rng.ts
@@ -0,0 +1,11 @@
+export function createSeededRandom(seed: number) {
+  let state = seed >>> 0;
+
+  return function () {
+    state = Math.imul(state + 0x6d2b79f5, 1);
+    let t = state;
+    t ^= t >>> 15;
+    t = Math.imul(t | 1, t ^ (t + Math.imul(t ^ (t >>> 7), t | 61)));
+    return ((t ^ (t >>> 14)) >>> 0) / 4294967296;
+  };
+}
diff --git a/app/api/routesF/emoji-picker/route.ts b/app/api/routesF/emoji-picker/route.ts
new file mode 100644
index 00000000..6690051b
--- /dev/null
+++ b/app/api/routesF/emoji-picker/route.ts
@@ -0,0 +1,40 @@
+import { NextResponse } from 'next/server';
+import { createSeededRandom } from './rng';
+import { ALL_CATEGORIES, getEmojiPool, EmojiFilterCategory } from './emoji-data';
+
+function parseInteger(value: string | null) {
+  const numberValue = Number(value);
+  return Number.isInteger(numberValue) && numberValue > 0 ? numberValue : null;
+}
+
+function isFilterCategory(value: string): value is EmojiFilterCategory {
+  return (ALL_CATEGORIES as readonly string[]).includes(value);
+}
+
+export async function GET(request: Request) {
+  const { searchParams } = new URL(request.url);
+  const count = parseInteger(searchParams.get('count'));
+  const seed = parseInteger(searchParams.get('seed'));
+  const category = searchParams.get('category');
+
+  if (count === null || seed === null || !category) {
+    return NextResponse.json(
+      { error: 'Missing required parameters: count, category, seed' },
+      { status: 400 }
+    );
+  }
+
+  if (!isFilterCategory(category)) {
+    return NextResponse.json({ error: 'Invalid category' }, { status: 400 });
+  }
+
+  const pool = getEmojiPool(category);
+  const random = createSeededRandom(seed);
+
+  const emojis = Array.from({ length: count }, () => {
+    const index = Math.floor(random() * pool.length);
+    return pool[index];
+  });
+
+  return NextResponse.json({ emojis });
+}
diff --git a/app/api/routesF/emoji-picker/types.ts b/app/api/routesF/emoji-picker/types.ts
new file mode 100644
index 00000000..7202f94f
--- /dev/null
+++ b/app/api/routesF/emoji-picker/types.ts
@@ -0,0 +1,11 @@
+export type EmojiCategory = 'faces' | 'animals' | 'food';
+
+export interface EmojiItem {
+  emoji: string;
+  name: string;
+  category: EmojiCategory;
+}
+
+export interface EmojiListResponse {
+  emojis: EmojiItem[];
+}
diff --git a/app/api/routesF/interpolation/route.ts b/app/api/routesF/interpolation/route.ts
new file mode 100644
index 00000000..8cc2e42c
--- /dev/null
+++ b/app/api/routesF/interpolation/route.ts
@@ -0,0 +1,64 @@
+import { type NextRequest, NextResponse } from "next/server";
+
+type InterpolationBody = {
+  mode?: unknown;
+  a?: unknown;
+  b?: unknown;
+  t?: unknown;
+  value?: unknown;
+  in_min?: unknown;
+  in_max?: unknown;
+  out_min?: unknown;
+  out_max?: unknown;
+};
+
+function isFiniteNumber(value: unknown): value is number {
+  return typeof value === "number" && Number.isFinite(value);
+}
+
+function badRequest(message: string) {
+  return NextResponse.json({ error: message }, { status: 400 });
+}
+
+export async function POST(req: NextRequest) {
+  let body: InterpolationBody;
+
+  try {
+    body = (await req.json()) as InterpolationBody;
+  } catch {
+    return badRequest("Invalid JSON body.");
+  }
+
+  if (body.mode === "lerp") {
+    const { a, b, t } = body;
+
+    if (!isFiniteNumber(a) || !isFiniteNumber(b) || !isFiniteNumber(t)) {
+      return badRequest("a, b, and t must be finite numbers.");
+    }
+
+    return NextResponse.json({ result: a + (b - a) * t });
+  }
+
+  if (body.mode === "map") {
+    const { value, in_min, in_max, out_min, out_max } = body;
+
+    if (
+      !isFiniteNumber(value) ||
+      !isFiniteNumber(in_min) ||
+      !isFiniteNumber(in_max) ||
+      !isFiniteNumber(out_min) ||
+      !isFiniteNumber(out_max)
+    ) {
+      return badRequest("value, in_min, in_max, out_min, and out_max must be finite numbers.");
+    }
+
+    if (in_min === in_max) {
+      return badRequest("in_min and in_max must be different values.");
+    }
+
+    const ratio = (value - in_min) / (in_max - in_min);
+    return NextResponse.json({ result: out_min + ratio * (out_max - out_min) });
+  }
+
+  return badRequest("mode must be either lerp or map.");
+}
diff --git a/app/api/routesF/irr/route.ts b/app/api/routesF/irr/route.ts
new file mode 100644
index 00000000..6c49ca3d
--- /dev/null
+++ b/app/api/routesF/irr/route.ts
@@ -0,0 +1,58 @@
+import { NextResponse } from 'next/server';
+
+function computeNPV(cashFlows: number[], rate: number): number {
+  return cashFlows.reduce((npv, cf, t) => npv + cf / Math.pow(1 + rate, t), 0);
+}
+
+function computeIRR(cashFlows: number[]): number | null {
+  // Validate: first cash flow should be negative (initial investment)
+  if (cashFlows[0] >= 0) return null;
+  // At least one positive cash flow required
+  if (!cashFlows.slice(1).some((cf) => cf > 0)) return null;
+
+  // Bisection method
+  let low = -0.999;
+  let high = 10.0; // 1000% upper bound
+
+  if (computeNPV(cashFlows, low) * computeNPV(cashFlows, high) > 0) return null;
+
+  for (let i = 0; i < 1000; i++) {
+    const mid = (low + high) / 2;
+    const npv = computeNPV(cashFlows, mid);
+    if (Math.abs(npv) < 1e-7) return mid;
+    if (computeNPV(cashFlows, low) * npv < 0) high = mid;
+    else low = mid;
+  }
+
+  return (low + high) / 2;
+}
+
+export async function POST(request: Request) {
+  try {
+    const body = await request.json();
+    const { cash_flows } = body;
+
+    if (!Array.isArray(cash_flows) || cash_flows.length < 2) {
+      return NextResponse.json(
+        { error: 'cash_flows must be an array with at least 2 values' },
+        { status: 400 },
+      );
+    }
+    if (!cash_flows.every((v) => typeof v === 'number')) {
+      return NextResponse.json({ error: 'All cash_flows values must be numbers' }, { status: 400 });
+    }
+
+    const irr = computeIRR(cash_flows);
+
+    if (irr === null) {
+      return NextResponse.json({ error: 'IRR could not be computed for the given cash flows' }, { status: 422 });
+    }
+
+    return NextResponse.json({
+      irr: parseFloat((irr * 100).toFixed(4)),
+      irr_decimal: parseFloat(irr.toFixed(6)),
+    });
+  } catch {
+    return NextResponse.json({ error: 'Invalid JSON body' }, { status: 400 });
+  }
+}
diff --git a/app/api/routesF/levenshtein/route.test.ts b/app/api/routesF/levenshtein/route.test.ts
new file mode 100644
index 00000000..4aa2cc8a
--- /dev/null
+++ b/app/api/routesF/levenshtein/route.test.ts
@@ -0,0 +1,45 @@
+import { NextRequest } from "next/server";
+import { POST } from "./route";
+
+function makeReq(body: unknown) {
+  return new NextRequest("http://localhost/api/routesF/levenshtein", {
+    method: "POST",
+    headers: { "content-type": "application/json" },
+    body: JSON.stringify(body),
+  });
+}
+
+describe("/api/routesF/levenshtein", () => {
+  it("computes the known kitten/sitting distance", async () => {
+    const res = await POST(makeReq({ a: "kitten", b: "sitting" }));
+    const data = await res.json();
+
+    expect(res.status).toBe(200);
+    expect(data.distance).toBe(3);
+    expect(data.ratio).toBeCloseTo(1 - 3 / 7, 10);
+  });
+
+  it("returns a perfect similarity ratio for identical strings", async () => {
+    const res = await POST(makeReq({ a: "streamfi", b: "streamfi" }));
+    const data = await res.json();
+
+    expect(data.distance).toBe(0);
+    expect(data.ratio).toBe(1);
+  });
+
+  it("caps inputs at 10KB", async () => {
+    const oversized = "a".repeat(10 * 1024 + 1);
+    const res = await POST(makeReq({ a: oversized, b: "b" }));
+
+    expect(res.status).toBe(400);
+    await expect(res.json()).resolves.toMatchObject({
+      error: "Inputs must not exceed 10KB each.",
+    });
+  });
+
+  it("rejects invalid bodies", async () => {
+    const res = await POST(makeReq({ a: "hello" }));
+
+    expect(res.status).toBe(400);
+  });
+});
diff --git a/app/api/routesF/levenshtein/route.ts b/app/api/routesF/levenshtein/route.ts
new file mode 100644
index 00000000..91804a2e
--- /dev/null
+++ b/app/api/routesF/levenshtein/route.ts
@@ -0,0 +1,88 @@
+import { NextRequest, NextResponse } from "next/server";
+
+type LevenshteinBody = {
+  a?: unknown;
+  b?: unknown;
+};
+
+const MAX_INPUT_BYTES = 10 * 1024;
+
+function badRequest(message: string) {
+  return NextResponse.json({ error: message }, { status: 400 });
+}
+
+function getByteLength(value: string) {
+  return new TextEncoder().encode(value).length;
+}
+
+function computeLevenshteinDistance(a: string, b: string) {
+  if (a === b) {
+    return 0;
+  }
+
+  if (a.length === 0) {
+    return b.length;
+  }
+
+  if (b.length === 0) {
+    return a.length;
+  }
+
+  const previous = new Array<number>(b.length + 1);
+  const current = new Array<number>(b.length + 1);
+
+  for (let j = 0; j <= b.length; j++) {
+    previous[j] = j;
+  }
+
+  for (let i = 1; i <= a.length; i++) {
+    current[0] = i;
+
+    for (let j = 1; j <= b.length; j++) {
+      const substitutionCost = a[i - 1] === b[j - 1] ? 0 : 1;
+      current[j] = Math.min(
+        previous[j] + 1,
+        current[j - 1] + 1,
+        previous[j - 1] + substitutionCost
+      );
+    }
+
+    for (let j = 0; j <= b.length; j++) {
+      previous[j] = current[j];
+    }
+  }
+
+  return previous[b.length];
+}
+
+export async function POST(req: NextRequest) {
+  let body: LevenshteinBody;
+
+  try {
+    body = (await req.json()) as LevenshteinBody;
+  } catch {
+    return badRequest("Invalid JSON body.");
+  }
+
+  const { a, b } = body;
+
+  if (typeof a !== "string" || typeof b !== "string") {
+    return badRequest("a and b must be strings.");
+  }
+
+  if (
+    getByteLength(a) > MAX_INPUT_BYTES ||
+    getByteLength(b) > MAX_INPUT_BYTES
+  ) {
+    return badRequest("Inputs must not exceed 10KB each.");
+  }
+
+  const distance = computeLevenshteinDistance(a, b);
+  const maxLength = Math.max(a.length, b.length);
+  const ratio = maxLength === 0 ? 1 : 1 - distance / maxLength;
+
+  return NextResponse.json({
+    distance,
+    ratio,
+  });
+}
diff --git a/app/api/routesF/luhn/route.test.ts b/app/api/routesF/luhn/route.test.ts
new file mode 100644
index 00000000..800ce4ad
--- /dev/null
+++ b/app/api/routesF/luhn/route.test.ts
@@ -0,0 +1,39 @@
+import { POST } from './route';
+
+describe('Luhn API', () => {
+  it('should return 400 for invalid body', async () => {
+    const req = new Request('http://localhost/api/routesF/luhn', {
+      method: 'POST',
+      body: JSON.stringify({ mode: 'generate' })
+    });
+    const res = await POST(req);
+    expect(res.status).toBe(400);
+  });
+
+  it('should generate check digit correctly', async () => {
+    const req = new Request('http://localhost/api/routesF/luhn', {
+      method: 'POST',
+      body: JSON.stringify({ number: '7992739871', mode: 'generate' })
+    });
+    const res = await POST(req);
+    const data = await res.json();
+    expect(data.number).toBe('79927398713');
+    expect(data.checkDigit).toBe(3);
+  });
+
+  it('should validate correctly', async () => {
+    const req1 = new Request('http://localhost/api/routesF/luhn', {
+      method: 'POST',
+      body: JSON.stringify({ number: '79927398713', mode: 'validate' })
+    });
+    const res1 = await POST(req1);
+    expect((await res1.json()).valid).toBe(true);
+
+    const req2 = new Request('http://localhost/api/routesF/luhn', {
+      method: 'POST',
+      body: JSON.stringify({ number: '79927398714', mode: 'validate' })
+    });
+    const res2 = await POST(req2);
+    expect((await res2.json()).valid).toBe(false);
+  });
+});
diff --git a/app/api/routesF/luhn/route.ts b/app/api/routesF/luhn/route.ts
new file mode 100644
index 00000000..b2261307
--- /dev/null
+++ b/app/api/routesF/luhn/route.ts
@@ -0,0 +1,50 @@
+import { NextResponse } from 'next/server';
+
+function calculateLuhnChecksum(numStr: string): number {
+  let sum = 0;
+  let isEven = false; // We start from the rightmost digit, moving left
+
+  for (let i = numStr.length - 1; i >= 0; i--) {
+    let digit = parseInt(numStr.charAt(i), 10);
+
+    if (isEven) {
+      digit *= 2;
+      if (digit > 9) {
+        digit -= 9;
+      }
+    }
+
+    sum += digit;
+    isEven = !isEven;
+  }
+
+  return sum % 10;
+}
+
+function generateCheckDigit(numStr: string): number {
+  const sum = calculateLuhnChecksum(numStr + '0');
+  return (10 - sum) % 10;
+}
+
+export async function POST(request: Request) {
+  try {
+    const body = await request.json();
+    const { number, mode } = body;
+
+    if (!number || typeof number !== 'string' || !/^\\d+$/.test(number)) {
+      return NextResponse.json({ error: 'Invalid or missing number' }, { status: 400 });
+    }
+
+    if (mode === 'generate') {
+      const checkDigit = generateCheckDigit(number);
+      return NextResponse.json({ number: number + checkDigit, checkDigit });
+    } else if (mode === 'validate') {
+      const sum = calculateLuhnChecksum(number);
+      return NextResponse.json({ valid: sum === 0 });
+    } else {
+      return NextResponse.json({ error: 'Invalid mode, use generate or validate' }, { status: 400 });
+    }
+  } catch (error) {
+    return NextResponse.json({ error: 'Invalid JSON body' }, { status: 400 });
+  }
+}
diff --git a/app/api/routesF/magic-square/generate.ts b/app/api/routesF/magic-square/generate.ts
new file mode 100644
index 00000000..57e9275d
--- /dev/null
+++ b/app/api/routesF/magic-square/generate.ts
@@ -0,0 +1,28 @@
+export function generateMagicSquare(order: number) {
+  const square = Array.from({ length: order }, () =>
+    Array<number>(order).fill(0)
+  );
+
+  let row = 0;
+  let col = Math.floor(order / 2);
+
+  for (let value = 1; value <= order * order; value++) {
+    square[row][col] = value;
+
+    const nextRow = (row - 1 + order) % order;
+    const nextCol = (col + 1) % order;
+
+    if (square[nextRow][nextCol] !== 0) {
+      row = (row + 1) % order;
+    } else {
+      row = nextRow;
+      col = nextCol;
+    }
+  }
+
+  return square;
+}
+
+export function getMagicConstant(order: number) {
+  return (order * (order * order + 1)) / 2;
+}
diff --git a/app/api/routesF/magic-square/route.test.ts b/app/api/routesF/magic-square/route.test.ts
new file mode 100644
index 00000000..4b1c4808
--- /dev/null
+++ b/app/api/routesF/magic-square/route.test.ts
@@ -0,0 +1,59 @@
+import { NextRequest } from "next/server";
+import { generateMagicSquare } from "./generate";
+import { POST } from "./route";
+
+function makeReq(body: unknown) {
+  return new NextRequest("http://localhost/api/routesF/magic-square", {
+    method: "POST",
+    headers: { "content-type": "application/json" },
+    body: JSON.stringify(body),
+  });
+}
+
+describe("/api/routesF/magic-square", () => {
+  it("validates a classic Lo Shu square", async () => {
+    const matrix = [
+      [8, 1, 6],
+      [3, 5, 7],
+      [4, 9, 2],
+    ];
+
+    const res = await POST(makeReq({ mode: "validate", matrix }));
+    const data = await res.json();
+
+    expect(res.status).toBe(200);
+    expect(data).toEqual({ is_magic: true, magic_constant: 15 });
+  });
+
+  it("detects a non-magic square", async () => {
+    const res = await POST(
+      makeReq({
+        mode: "validate",
+        matrix: [
+          [1, 2, 3],
+          [4, 5, 6],
+          [7, 8, 9],
+        ],
+      })
+    );
+    const data = await res.json();
+
+    expect(data.is_magic).toBe(false);
+    expect(data.magic_constant).toBe(6);
+  });
+
+  it("generates an odd-order magic square with the Siamese method", async () => {
+    const res = await POST(makeReq({ mode: "generate", n: 3 }));
+    const data = await res.json();
+
+    expect(res.status).toBe(200);
+    expect(data.magic_constant).toBe(15);
+    expect(data.matrix).toEqual(generateMagicSquare(3));
+  });
+
+  it("rejects even sizes for generation", async () => {
+    const res = await POST(makeReq({ mode: "generate", n: 4 }));
+
+    expect(res.status).toBe(400);
+  });
+});
diff --git a/app/api/routesF/magic-square/route.ts b/app/api/routesF/magic-square/route.ts
new file mode 100644
index 00000000..789a654e
--- /dev/null
+++ b/app/api/routesF/magic-square/route.ts
@@ -0,0 +1,104 @@
+import { NextRequest, NextResponse } from "next/server";
+import { generateMagicSquare, getMagicConstant } from "./generate";
+
+type MagicSquareBody = {
+  mode?: unknown;
+  matrix?: unknown;
+  n?: unknown;
+};
+
+function badRequest(message: string) {
+  return NextResponse.json({ error: message }, { status: 400 });
+}
+
+function parseOrder(value: unknown) {
+  if (typeof value !== "number" || !Number.isInteger(value)) {
+    return null;
+  }
+
+  return value;
+}
+
+function isNumericMatrix(matrix: unknown): matrix is number[][] {
+  return (
+    Array.isArray(matrix) &&
+    matrix.length > 0 &&
+    matrix.every(
+      row =>
+        Array.isArray(row) &&
+        row.length === matrix.length &&
+        row.every(value => typeof value === "number" && Number.isFinite(value))
+    )
+  );
+}
+
+function validateMagicSquare(matrix: number[][]) {
+  const size = matrix.length;
+  const target = matrix[0].reduce((sum, value) => sum + value, 0);
+
+  for (const row of matrix) {
+    const rowSum = row.reduce((sum, value) => sum + value, 0);
+    if (rowSum !== target) {
+      return { is_magic: false, magic_constant: target };
+    }
+  }
+
+  for (let col = 0; col < size; col++) {
+    let colSum = 0;
+    for (let row = 0; row < size; row++) {
+      colSum += matrix[row][col];
+    }
+    if (colSum !== target) {
+      return { is_magic: false, magic_constant: target };
+    }
+  }
+
+  let diagonalLeft = 0;
+  let diagonalRight = 0;
+
+  for (let i = 0; i < size; i++) {
+    diagonalLeft += matrix[i][i];
+    diagonalRight += matrix[i][size - 1 - i];
+  }
+
+  return {
+    is_magic: diagonalLeft === target && diagonalRight === target,
+    magic_constant: target,
+  };
+}
+
+export async function POST(req: NextRequest) {
+  let body: MagicSquareBody;
+
+  try {
+    body = (await req.json()) as MagicSquareBody;
+  } catch {
+    return badRequest("Invalid JSON body.");
+  }
+
+  if (body.mode === "validate") {
+    if (!isNumericMatrix(body.matrix)) {
+      return badRequest("matrix must be a non-empty square matrix of numbers.");
+    }
+
+    return NextResponse.json(validateMagicSquare(body.matrix));
+  }
+
+  if (body.mode === "generate") {
+    const order = parseOrder(body.n);
+    if (order === null || order <= 0) {
+      return badRequest("n must be a positive integer.");
+    }
+
+    if (order % 2 === 0) {
+      return badRequest("Only odd-order magic squares are supported.");
+    }
+
+    return NextResponse.json({
+      matrix: generateMagicSquare(order),
+      magic_constant: getMagicConstant(order),
+    });
+  }
+
+  return badRequest("mode must be either 'validate' or 'generate'.");
+}
diff --git a/app/api/routesF/metaphone/metaphone.ts b/app/api/routesF/metaphone/metaphone.ts
new file mode 100644
index 00000000..4f3044fc
--- /dev/null
+++ b/app/api/routesF/metaphone/metaphone.ts
@@ -0,0 +1,258 @@
+// #886 feat(routesF): metaphone phonetic encoder
+
+const VOWELS = "AEIOU";
+const FRONTV = "EIY";
+const VARSON = "CSPTG";
+
+function isVowel(chars: string[], index: number): boolean {
+  return index >= 0 && index < chars.length && VOWELS.includes(chars[index]);
+}
+
+function isLastChar(length: number, index: number): boolean {
+  return index + 1 === length;
+}
+
+function isNextChar(chars: string[], index: number, c: string): boolean {
+  return index >= 0 && index < chars.length - 1 && chars[index + 1] === c;
+}
+
+function isPreviousChar(chars: string[], index: number, c: string): boolean {
+  return index > 0 && index < chars.length && chars[index - 1] === c;
+}
+
+function regionMatch(chars: string[], index: number, test: string): boolean {
+  if (index < 0 || index + test.length > chars.length) {
+    return false;
+  }
+  return chars.slice(index, index + test.length).join("") === test;
+}
+
+/**
+ * Apply Metaphone initial-character normalization (KN, GN, WR, WH, etc.).
+ */
+function normalizeInitials(input: string): string[] {
+  const upper = input.toUpperCase().replace(/[^A-Z]/g, "");
+  if (upper.length === 0) {
+    return [];
+  }
+
+  const chars = upper.split("");
+
+  switch (chars[0]) {
+    case "K":
+    case "G":
+    case "P":
+      if (chars[1] === "N") {
+        return chars.slice(1);
+      }
+      return chars;
+    case "A":
+      if (chars[1] === "E") {
+        return chars.slice(1);
+      }
+      return chars;
+    case "W":
+      if (chars[1] === "R") {
+        return chars.slice(1);
+      }
+      if (chars[1] === "H") {
+        const result = chars.slice(1);
+        result[0] = "W";
+        return result;
+      }
+      return chars;
+    case "X":
+      chars[0] = "S";
+      return chars;
+    default:
+      return chars;
+  }
+}
+
+/**
+ * Encode a single word using the Apache Commons Metaphone algorithm (max 4 chars).
+ */
+export function metaphone(word: string, maxCodeLen = 4): string {
+  const local = normalizeInitials(word);
+  if (local.length === 0) {
+    return "";
+  }
+  if (local.length === 1) {
+    return local[0];
+  }
+
+  const code: string[] = [];
+  let hard = false;
+  let index = 0;
+  const length = local.length;
+
+  while (code.length < maxCodeLen && index < length) {
+    const symb = local[index];
+
+    if (symb === "C" || !isPreviousChar(local, index, symb)) {
+      switch (symb) {
+        case "A":
+        case "E":
+        case "I":
+        case "O":
+        case "U":
+          if (index === 0) {
+            code.push(symb);
+          }
+          break;
+        case "B":
+          if (!(isPreviousChar(local, index, "M") && isLastChar(length, index))) {
+            code.push(symb);
+          }
+          break;
+        case "C":
+          if (
+            isPreviousChar(local, index, "S") &&
+            !isLastChar(length, index) &&
+            FRONTV.includes(local[index + 1])
+          ) {
+            break;
+          }
+          if (isPreviousChar(local, index, "S") && isNextChar(local, index, "H")) {
+            code.push("K");
+            break;
+          }
+          if (regionMatch(local, index, "CIA") || isNextChar(local, index, "H")) {
+            code.push("X");
+            break;
+          }
+          if (!isLastChar(length, index) && FRONTV.includes(local[index + 1])) {
+            code.push("S");
+            break;
+          }
+          code.push("K");
+          break;
+        case "D":
+          if (
+            !isLastChar(length, index + 1) &&
+            isNextChar(local, index, "G") &&
+            FRONTV.includes(local[index + 2])
+          ) {
+            code.push("J");
+            index += 2;
+          } else {
+            code.push("T");
+          }
+          break;
+        case "G":
+          if (isLastChar(length, index + 1) && isNextChar(local, index, "H")) {
+            break;
+          }
+          if (
+            !isLastChar(length, index + 1) &&
+            isNextChar(local, index, "H") &&
+            !isVowel(local, index + 2)
+          ) {
+            break;
+          }
+          if (index > 0 && (regionMatch(local, index, "GN") || regionMatch(local, index, "GNED"))) {
+            break;
+          }
+          hard = isPreviousChar(local, index, "G");
+          if (!isLastChar(length, index) && FRONTV.includes(local[index + 1]) && !hard) {
+            code.push("J");
+          } else {
+            code.push("K");
+          }
+          break;
+        case "H":
+          if (isLastChar(length, index)) {
+            break;
+          }
+          if (index > 0 && VARSON.includes(local[index - 1])) {
+            break;
+          }
+          if (isVowel(local, index + 1)) {
+            code.push("H");
+          }
+          break;
+        case "F":
+        case "J":
+        case "L":
+        case "M":
+        case "N":
+        case "R":
+          code.push(symb);
+          break;
+        case "K":
+          if (index > 0) {
+            if (!isPreviousChar(local, index, "C")) {
+              code.push(symb);
+            }
+          } else {
+            code.push(symb);
+          }
+          break;
+        case "P":
+          if (isNextChar(local, index, "H")) {
+            code.push("F");
+          } else {
+            code.push(symb);
+          }
+          break;
+        case "Q":
+          code.push("K");
+          break;
+        case "S":
+          if (
+            regionMatch(local, index, "SH") ||
+            regionMatch(local, index, "SIO") ||
+            regionMatch(local, index, "SIA")
+          ) {
+            code.push("X");
+          } else {
+            code.push("S");
+          }
+          break;
+        case "T":
+          if (regionMatch(local, index, "TIA") || regionMatch(local, index, "TIO")) {
+            code.push("X");
+            break;
+          }
+          if (regionMatch(local, index, "TCH")) {
+            break;
+          }
+          if (regionMatch(local, index, "TH")) {
+            code.push("0");
+          } else {
+            code.push("T");
+          }
+          break;
+        case "V":
+          code.push("F");
+          break;
+        case "W":
+        case "Y":
+          if (!isLastChar(length, index) && isVowel(local, index + 1)) {
+            code.push(symb);
+          }
+          break;
+        case "X":
+          code.push("K");
+          code.push("S");
+          break;
+        case "Z":
+          code.push("S");
+          break;
+        default:
+          break;
+      }
+    }
+
+    index += 1;
+    if (code.length > maxCodeLen) {
+      code.length = maxCodeLen;
+    }
+  }
+
+  return code.join("");
+}
+
+export function encodeMetaphoneWords(words: string[]): string[] {
+  return words.map((word) => metaphone(word));
+}
diff --git a/app/api/routesF/metaphone/route.test.ts b/app/api/routesF/metaphone/route.test.ts
new file mode 100644
index 00000000..415229bf
--- /dev/null
+++ b/app/api/routesF/metaphone/route.test.ts
@@ -0,0 +1,62 @@
+import { NextRequest } from "next/server";
+import { metaphone } from "./metaphone";
+import { POST } from "./route";
+
+// #886 feat(routesF): metaphone phonetic encoder
+
+function makeReq(body: unknown) {
+  return new NextRequest("http://localhost/api/routesF/metaphone", {
+    method: "POST",
+    headers: { "content-type": "application/json" },
+    body: JSON.stringify(body),
+  });
+}
+
+describe("metaphone", () => {
+  it.each([
+    ["Smith", "SM0"],
+    ["Smithee", "SM0"],
+    ["Smyth", "SM0"],
+    ["Robert", "RBRT"],
+    ["Rupert", "RPRT"],
+    ["Washington", "WXNK"],
+    ["Who", "W"],
+    ["Answer", "ANSW"],
+    ["Cough", "K"],
+    ["Day", "T"],
+  ])("encodes %s as %s", (word, expected) => {
+    expect(metaphone(word)).toBe(expected);
+  });
+
+  it("ignores non-alphabetic characters", () => {
+    expect(metaphone("Smith-Jones")).toBe(metaphone("SmithJones"));
+  });
+});
+
+describe("POST /api/routesF/metaphone", () => {
+  it("returns a single code for word", async () => {
+    const res = await POST(makeReq({ word: "Robert" }));
+    const data = await res.json();
+
+    expect(res.status).toBe(200);
+    expect(data).toEqual({ code: "RBRT" });
+  });
+
+  it("returns codes for words array", async () => {
+    const res = await POST(makeReq({ words: ["Robert", "Rupert", "Smith"] }));
+    const data = await res.json();
+
+    expect(res.status).toBe(200);
+    expect(data).toEqual({ codes: ["RBRT", "RPRT", "SM0"] });
+  });
+
+  it("rejects invalid bodies", async () => {
+    const missing = await POST(makeReq({}));
+    const both = await POST(makeReq({ word: "a", words: ["b"] }));
+    const badWords = await POST(makeReq({ words: ["ok", 1] }));
+
+    expect(missing.status).toBe(400);
+    expect(both.status).toBe(400);
+    expect(badWords.status).toBe(400);
+  });
+});
diff --git a/app/api/routesF/metaphone/route.ts b/app/api/routesF/metaphone/route.ts
new file mode 100644
index 00000000..e0fb9283
--- /dev/null
+++ b/app/api/routesF/metaphone/route.ts
@@ -0,0 +1,44 @@
+import { NextRequest, NextResponse } from "next/server";
+import { encodeMetaphoneWords, metaphone } from "./metaphone";
+
+// #886 feat(routesF): metaphone phonetic encoder
+
+type MetaphoneBody = {
+  word?: unknown;
+  words?: unknown;
+};
+
+function badRequest(message: string) {
+  return NextResponse.json({ error: message }, { status: 400 });
+}
+
+export async function POST(req: NextRequest) {
+  let body: MetaphoneBody;
+
+  try {
+    body = (await req.json()) as MetaphoneBody;
+  } catch {
+    return badRequest("Invalid JSON body.");
+  }
+
+  const hasWord = body.word !== undefined;
+  const hasWords = body.words !== undefined;
+
+  if (hasWord === hasWords) {
+    return badRequest("Provide exactly one of word or words.");
+  }
+
+  if (hasWord) {
+    if (typeof body.word !== "string") {
+      return badRequest("word must be a string.");
+    }
+
+    return NextResponse.json({ code: metaphone(body.word) });
+  }
+
+  if (!Array.isArray(body.words) || body.words.some((item) => typeof item !== "string")) {
+    return badRequest("words must be an array of strings.");
+  }
+
+  return NextResponse.json({ codes: encodeMetaphoneWords(body.words) });
+}
diff --git a/app/api/routesF/mime-magic/route.test.ts b/app/api/routesF/mime-magic/route.test.ts
new file mode 100644
index 00000000..e103bf91
--- /dev/null
+++ b/app/api/routesF/mime-magic/route.test.ts
@@ -0,0 +1,81 @@
+import { NextRequest } from "next/server";
+import { POST } from "./route";
+
+function makeReq(hex: string) {
+  return new NextRequest("http://localhost/api/routesF/mime-magic", {
+    method: "POST",
+    headers: { "content-type": "application/json" },
+    body: JSON.stringify({ hex }),
+  });
+}
+
+describe("MIME Magic API", () => {
+  it("detects PNG", async () => {
+    const res = await POST(makeReq("89504e470d0a1a0a"));
+    const data = await res.json();
+    expect(res.status).toBe(200);
+    expect(data.mime).toBe("image/png");
+    expect(data.extension).toBe("png");
+  });
+
+  it("detects JPEG", async () => {
+    const res = await POST(makeReq("ffd8ffe000104a46"));
+    const data = await res.json();
+    expect(data.mime).toBe("image/jpeg");
+    expect(data.extension).toBe("jpg");
+  });
+
+  it("detects GIF", async () => {
+    const res = await POST(makeReq("474946383961"));
+    const data = await res.json();
+    expect(data.mime).toBe("image/gif");
+  });
+
+  it("detects PDF", async () => {
+    const res = await POST(makeReq("255044462d312e34"));
+    const data = await res.json();
+    expect(data.mime).toBe("application/pdf");
+  });
+
+  it("detects ZIP", async () => {
+    const res = await POST(makeReq("504b030414000000"));
+    const data = await res.json();
+    expect(data.mime).toBe("application/zip");
+  });
+
+  it("detects GZIP", async () => {
+    const res = await POST(makeReq("1f8b0800"));
+    const data = await res.json();
+    expect(data.mime).toBe("application/gzip");
+  });
+
+  it("detects WebP", async () => {
+    const res = await POST(makeReq("52494646e0730c00"));
+    const data = await res.json();
+    expect(data.mime).toBe("image/webp");
+  });
+
+  it("returns null for unknown bytes", async () => {
+    const res = await POST(makeReq("deadbeef"));
+    const data = await res.json();
+    expect(res.status).toBe(200);
+    expect(data.mime).toBeNull();
+    expect(data.extension).toBeNull();
+    expect(data.matched).toBeNull();
+  });
+
+  it("returns 400 for empty hex", async () => {
+    const res = await POST(makeReq(""));
+    expect(res.status).toBe(400);
+  });
+
+  it("returns 400 for invalid hex", async () => {
+    const res = await POST(makeReq("zzzz"));
+    expect(res.status).toBe(400);
+  });
+
+  it("returns 400 for odd-length hex", async () => {
+    const res = await POST(makeReq("abc"));
+    expect(res.status).toBe(400);
+  });
+});
diff --git a/app/api/routesF/mime-magic/route.ts b/app/api/routesF/mime-magic/route.ts
new file mode 100644
index 00000000..a5282ff7
--- /dev/null
+++ b/app/api/routesF/mime-magic/route.ts
@@ -0,0 +1,57 @@
+import { type NextRequest, NextResponse } from "next/server";
+import { SIGNATURES } from "./signatures";
+
+type MimeBody = {
+  hex?: unknown;
+};
+
+function badRequest(message: string) {
+  return NextResponse.json({ error: message }, { status: 400 });
+}
+
+export async function POST(req: NextRequest) {
+  let body: MimeBody;
+
+  try {
+    body = (await req.json()) as MimeBody;
+  } catch {
+    return badRequest("Invalid JSON body.");
+  }
+
+  const { hex } = body;
+
+  if (typeof hex !== "string" || hex.length === 0) {
+    return badRequest("hex must be a non-empty hex string.");
+  }
+
+  const cleanHex = hex.replace(/\s+/g, "");
+  if (!/^[0-9a-fA-F]*$/.test(cleanHex) || cleanHex.length % 2 !== 0) {
+    return badRequest("hex must contain an even number of valid hex characters.");
+  }
+
+  const bytes: number[] = [];
+  for (let i = 0; i < cleanHex.length; i += 2) {
+    bytes.push(parseInt(cleanHex.substring(i, i + 2), 16));
+  }
+
+  for (const sig of SIGNATURES) {
+    if (bytes.length >= sig.bytes.length) {
+      let match = true;
+      for (let i = 0; i < sig.bytes.length; i++) {
+        if (bytes[i] !== sig.bytes[i]) {
+          match = false;
+          break;
+        }
+      }
+      if (match) {
+        return NextResponse.json({
+          mime: sig.mime,
+          extension: sig.extension,
+          matched: sig.bytes.map((b) => b.toString(16).padStart(2, "0")).join(""),
+        });
+      }
+    }
+  }
+
+  return NextResponse.json({ mime: null, extension: null, matched: null });
+}
diff --git a/app/api/routesF/mime-magic/signatures.ts b/app/api/routesF/mime-magic/signatures.ts
new file mode 100644
index 00000000..7ca07ca0
--- /dev/null
+++ b/app/api/routesF/mime-magic/signatures.ts
@@ -0,0 +1,10 @@
+export const SIGNATURES: { mime: string; extension: string; bytes: number[] }[] = [
+  { mime: "image/png", extension: "png", bytes: [0x89, 0x50, 0x4e, 0x47] },
+  { mime: "image/jpeg", extension: "jpg", bytes: [0xff, 0xd8, 0xff] },
+  { mime: "image/gif", extension: "gif", bytes: [0x47, 0x49, 0x46, 0x38] },
+  { mime: "application/pdf", extension: "pdf", bytes: [0x25, 0x50, 0x44, 0x46] },
+  { mime: "application/zip", extension: "zip", bytes: [0x50, 0x4b, 0x03, 0x04] },
+  { mime: "application/gzip", extension: "gz", bytes: [0x1f, 0x8b] },
+  { mime: "video/mp4", extension: "mp4", bytes: [0x00, 0x00, 0x00] }, // ftyp box prefix
+  { mime: "image/webp", extension: "webp", bytes: [0x52, 0x49, 0x46, 0x46] }, // RIFF header
+];
diff --git a/app/api/routesF/next-weekday/route.test.ts b/app/api/routesF/next-weekday/route.test.ts
new file mode 100644
index 00000000..21b26e51
--- /dev/null
+++ b/app/api/routesF/next-weekday/route.test.ts
@@ -0,0 +1,59 @@
+import { NextRequest } from "next/server";
+import { POST } from "./route";
+
+function makeReq(body: unknown) {
+  return new NextRequest("http://localhost/api/routesF/next-weekday", {
+    method: "POST",
+    headers: { "content-type": "application/json" },
+    body: JSON.stringify(body),
+  });
+}
+
+describe("/api/routesF/next-weekday", () => {
+  it("returns the same day when include_today is true", async () => {
+    const res = await POST(
+      makeReq({
+        weekday: "thu",
+        from: "2026-05-28T15:45:00.000Z",
+        include_today: true,
+      })
+    );
+    const data = await res.json();
+
+    expect(res.status).toBe(200);
+    expect(data.date).toBe("2026-05-28T00:00:00.000Z");
+    expect(data.days_until).toBe(0);
+  });
+
+  it("wraps to the following week when include_today is false", async () => {
+    const res = await POST(
+      makeReq({
+        weekday: 4,
+        from: "2026-05-28T15:45:00.000Z",
+      })
+    );
+    const data = await res.json();
+
+    expect(data.date).toBe("2026-06-04T00:00:00.000Z");
+    expect(data.days_until).toBe(7);
+  });
+
+  it("handles a later weekday in the same week", async () => {
+    const res = await POST(
+      makeReq({
+        weekday: "sun",
+        from: "2026-05-28T15:45:00.000Z",
+      })
+    );
+    const data = await res.json();
+
+    expect(data.date).toBe("2026-05-31T00:00:00.000Z");
+    expect(data.days_until).toBe(3);
+  });
+
+  it("rejects invalid weekday input", async () => {
+    const res = await POST(makeReq({ weekday: "someday" }));
+
+    expect(res.status).toBe(400);
+  });
+});
diff --git a/app/api/routesF/next-weekday/route.ts b/app/api/routesF/next-weekday/route.ts
new file mode 100644
index 00000000..23d3e2ff
--- /dev/null
+++ b/app/api/routesF/next-weekday/route.ts
@@ -0,0 +1,115 @@
+import { NextRequest, NextResponse } from "next/server";
+
+type NextWeekdayBody = {
+  weekday?: unknown;
+  from?: unknown;
+  include_today?: unknown;
+};
+
+const WEEKDAY_LOOKUP: Record<string, number> = {
+  sun: 0,
+  sunday: 0,
+  mon: 1,
+  monday: 1,
+  tue: 2,
+  tues: 2,
+  tuesday: 2,
+  wed: 3,
+  wednesday: 3,
+  thu: 4,
+  thur: 4,
+  thurs: 4,
+  thursday: 4,
+  fri: 5,
+  friday: 5,
+  sat: 6,
+  saturday: 6,
+};
+
+function badRequest(message: string) {
+  return NextResponse.json({ error: message }, { status: 400 });
+}
+
+function parseWeekday(value: unknown) {
+  if (
+    typeof value === "number" &&
+    Number.isInteger(value) &&
+    value >= 0 &&
+    value <= 6
+  ) {
+    return value;
+  }
+
+  if (typeof value === "string") {
+    return WEEKDAY_LOOKUP[value.trim().toLowerCase()];
+  }
+
+  return undefined;
+}
+
+function parseFromDate(value: unknown) {
+  if (value === undefined) {
+    return new Date();
+  }
+
+  if (typeof value !== "string") {
+    return null;
+  }
+
+  const parsed = new Date(value);
+  if (Number.isNaN(parsed.getTime())) {
+    return null;
+  }
+
+  return parsed;
+}
+
+function startOfUtcDay(date: Date) {
+  return new Date(
+    Date.UTC(date.getUTCFullYear(), date.getUTCMonth(), date.getUTCDate())
+  );
+}
+
+export async function POST(req: NextRequest) {
+  let body: NextWeekdayBody;
+
+  try {
+    body = (await req.json()) as NextWeekdayBody;
+  } catch {
+    return badRequest("Invalid JSON body.");
+  }
+
+  const targetWeekday = parseWeekday(body.weekday);
+  if (targetWeekday === undefined) {
+    return badRequest("weekday must be a number from 0-6 or a weekday name.");
+  }
+
+  if (
+    body.include_today !== undefined &&
+    typeof body.include_today !== "boolean"
+  ) {
+    return badRequest("include_today must be a boolean when provided.");
+  }
+
+  const fromDate = parseFromDate(body.from);
+  if (fromDate === null) {
+    return badRequest("from must be a valid ISO date string.");
+  }
+
+  const includeToday = body.include_today === true;
+  const normalizedFrom = startOfUtcDay(fromDate);
+  const currentWeekday = normalizedFrom.getUTCDay();
+  let daysUntil = (targetWeekday - currentWeekday + 7) % 7;
+
+  if (daysUntil === 0 && !includeToday) {
+    daysUntil = 7;
+  }
+
+  const result = new Date(normalizedFrom);
+  result.setUTCDate(result.getUTCDate() + daysUntil);
+
+  return NextResponse.json({
+    date: result.toISOString(),
+    days_until: daysUntil,
+  });
+}
diff --git a/app/api/routesF/number-to-words/route.test.ts b/app/api/routesF/number-to-words/route.test.ts
new file mode 100644
index 00000000..b6e24b13
--- /dev/null
+++ b/app/api/routesF/number-to-words/route.test.ts
@@ -0,0 +1,44 @@
+import { NextRequest } from "next/server";
+import { GET, integerToWords } from "./route";
+
+describe("integerToWords", () => {
+  it("handles reference values", () => {
+    expect(integerToWords(BigInt(0))).toBe("zero");
+    expect(integerToWords(BigInt(21))).toBe("twenty-one");
+    expect(integerToWords(BigInt(105))).toBe("one hundred five");
+    expect(integerToWords(BigInt(1234567))).toBe(
+      "one million two hundred thirty-four thousand five hundred sixty-seven"
+    );
+  });
+
+  it("handles negatives", () => {
+    expect(integerToWords(BigInt(-42))).toBe("minus forty-two");
+  });
+});
+
+describe("GET /api/routesF/number-to-words", () => {
+  it("returns words for n", async () => {
+    const req = new NextRequest(
+      "http://localhost/api/routesF/number-to-words?n=100000000000001"
+    );
+    const res = await GET(req);
+    expect(res.status).toBe(200);
+    expect((await res.json()).words).toBe("one hundred trillion one");
+  });
+
+  it("rejects invalid n", async () => {
+    const res = await GET(
+      new NextRequest("http://localhost/api/routesF/number-to-words?n=1.2")
+    );
+    expect(res.status).toBe(400);
+  });
+
+  it("rejects out-of-range boundary", async () => {
+    const res = await GET(
+      new NextRequest(
+        "http://localhost/api/routesF/number-to-words?n=1000000000000000"
+      )
+    );
+    expect(res.status).toBe(400);
+  });
+});
diff --git a/app/api/routesF/number-to-words/route.ts b/app/api/routesF/number-to-words/route.ts
new file mode 100644
index 00000000..43952cff
--- /dev/null
+++ b/app/api/routesF/number-to-words/route.ts
@@ -0,0 +1,124 @@
+import { NextRequest, NextResponse } from "next/server";
+
+const SMALL = [
+  "zero",
+  "one",
+  "two",
+  "three",
+  "four",
+  "five",
+  "six",
+  "seven",
+  "eight",
+  "nine",
+  "ten",
+  "eleven",
+  "twelve",
+  "thirteen",
+  "fourteen",
+  "fifteen",
+  "sixteen",
+  "seventeen",
+  "eighteen",
+  "nineteen",
+];
+
+const TENS = [
+  "",
+  "",
+  "twenty",
+  "thirty",
+  "forty",
+  "fifty",
+  "sixty",
+  "seventy",
+  "eighty",
+  "ninety",
+];
+const SCALE = ["", "thousand", "million", "billion", "trillion", "quadrillion"];
+const MAX_ABS = BigInt("1000000000000000");
+
+function belowThousandToWords(n: number): string {
+  const parts: string[] = [];
+  const hundreds = Math.floor(n / 100);
+  const rem = n % 100;
+
+  if (hundreds > 0) {
+    parts.push(`${SMALL[hundreds]} hundred`);
+  }
+
+  if (rem > 0) {
+    if (rem < 20) {
+      parts.push(SMALL[rem]);
+    } else {
+      const t = Math.floor(rem / 10);
+      const u = rem % 10;
+      parts.push(u > 0 ? `${TENS[t]}-${SMALL[u]}` : TENS[t]);
+    }
+  }
+
+  return parts.join(" ");
+}
+
+export function integerToWords(value: bigint): string {
+  if (value === BigInt(0)) {
+    return "zero";
+  }
+
+  const negative = value < BigInt(0);
+  let n = negative ? -value : value;
+  const chunks: string[] = [];
+  let scaleIndex = 0;
+
+  while (n > BigInt(0)) {
+    const chunk = Number(n % BigInt(1000));
+    if (chunk > 0) {
+      const words = belowThousandToWords(chunk);
+      const scale = SCALE[scaleIndex];
+      chunks.push(scale ? `${words} ${scale}` : words);
+    }
+    n /= BigInt(1000);
+    scaleIndex += 1;
+  }
+
+  const words = chunks.reverse().join(" ");
+  return negative ? `minus ${words}` : words;
+}
+
+function parseInteger(input: string): bigint | null {
+  if (!/^-?\d+$/.test(input.trim())) {
+    return null;
+  }
+  try {
+    return BigInt(input.trim());
+  } catch {
+    return null;
+  }
+}
+
+export async function GET(req: NextRequest) {
+  const nParam = req.nextUrl.searchParams.get("n");
+  if (!nParam) {
+    return NextResponse.json(
+      { error: "n query parameter is required." },
+      { status: 400 }
+    );
+  }
+
+  const parsed = parseInteger(nParam);
+  if (parsed === null) {
+    return NextResponse.json(
+      { error: "n must be an integer string." },
+      { status: 400 }
+    );
+  }
+
+  if (parsed <= -MAX_ABS || parsed >= MAX_ABS) {
+    return NextResponse.json(
+      { error: "n must satisfy |n| < 10^15." },
+      { status: 400 }
+    );
+  }
+
+  return NextResponse.json({ words: integerToWords(parsed) });
+}
diff --git a/app/api/routesF/ordinal-number-formatter/route.test.ts b/app/api/routesF/ordinal-number-formatter/route.test.ts
new file mode 100644
index 00000000..308da531
--- /dev/null
+++ b/app/api/routesF/ordinal-number-formatter/route.test.ts
@@ -0,0 +1,107 @@
+/**
+ * @jest-environment node
+ */
+import { NextRequest } from "next/server";
+import { GET, toOrdinal } from "./route";
+
+function makeReq(n: string) {
+  return new NextRequest(
+    `http://localhost/api/routesF/ordinal-number-formatter?n=${n}`
+  );
+}
+
+describe("toOrdinal", () => {
+  it("handles st suffix (1, 21, 31, 101)", () => {
+    expect(toOrdinal(1)).toEqual({ ordinal: "1st", suffix: "st" });
+    expect(toOrdinal(21)).toEqual({ ordinal: "21st", suffix: "st" });
+    expect(toOrdinal(31)).toEqual({ ordinal: "31st", suffix: "st" });
+    expect(toOrdinal(101)).toEqual({ ordinal: "101st", suffix: "st" });
+  });
+
+  it("handles nd suffix (2, 22, 102)", () => {
+    expect(toOrdinal(2)).toEqual({ ordinal: "2nd", suffix: "nd" });
+    expect(toOrdinal(22)).toEqual({ ordinal: "22nd", suffix: "nd" });
+    expect(toOrdinal(102)).toEqual({ ordinal: "102nd", suffix: "nd" });
+  });
+
+  it("handles rd suffix (3, 23, 103)", () => {
+    expect(toOrdinal(3)).toEqual({ ordinal: "3rd", suffix: "rd" });
+    expect(toOrdinal(23)).toEqual({ ordinal: "23rd", suffix: "rd" });
+    expect(toOrdinal(103)).toEqual({ ordinal: "103rd", suffix: "rd" });
+  });
+
+  it("handles th suffix for all other cases", () => {
+    expect(toOrdinal(4)).toEqual({ ordinal: "4th", suffix: "th" });
+    expect(toOrdinal(10)).toEqual({ ordinal: "10th", suffix: "th" });
+    expect(toOrdinal(20)).toEqual({ ordinal: "20th", suffix: "th" });
+    expect(toOrdinal(100)).toEqual({ ordinal: "100th", suffix: "th" });
+  });
+
+  it("handles teen special cases (11, 12, 13 are always th)", () => {
+    expect(toOrdinal(11)).toEqual({ ordinal: "11th", suffix: "th" });
+    expect(toOrdinal(12)).toEqual({ ordinal: "12th", suffix: "th" });
+    expect(toOrdinal(13)).toEqual({ ordinal: "13th", suffix: "th" });
+    expect(toOrdinal(111)).toEqual({ ordinal: "111th", suffix: "th" });
+    expect(toOrdinal(112)).toEqual({ ordinal: "112th", suffix: "th" });
+    expect(toOrdinal(113)).toEqual({ ordinal: "113th", suffix: "th" });
+  });
+
+  it("handles negatives correctly", () => {
+    expect(toOrdinal(-1)).toEqual({ ordinal: "-1st", suffix: "st" });
+    expect(toOrdinal(-11)).toEqual({ ordinal: "-11th", suffix: "th" });
+    expect(toOrdinal(-21)).toEqual({ ordinal: "-21st", suffix: "st" });
+    expect(toOrdinal(-13)).toEqual({ ordinal: "-13th", suffix: "th" });
+  });
+
+  it("handles zero", () => {
+    expect(toOrdinal(0)).toEqual({ ordinal: "0th", suffix: "th" });
+  });
+
+  it("handles large numbers", () => {
+    expect(toOrdinal(1001)).toEqual({ ordinal: "1001st", suffix: "st" });
+    expect(toOrdinal(10011)).toEqual({ ordinal: "10011th", suffix: "th" });
+    expect(toOrdinal(10021)).toEqual({ ordinal: "10021st", suffix: "st" });
+  });
+});
+
+describe("GET /api/routesF/ordinal-number-formatter", () => {
+  it("returns ordinal for n=21", async () => {
+    const res = await GET(makeReq("21"));
+    expect(res.status).toBe(200);
+    const data = await res.json();
+    expect(data).toEqual({ ordinal: "21st", suffix: "st" });
+  });
+
+  it("returns ordinal for n=11 (teen special case)", async () => {
+    const res = await GET(makeReq("11"));
+    expect(res.status).toBe(200);
+    const data = await res.json();
+    expect(data).toEqual({ ordinal: "11th", suffix: "th" });
+  });
+
+  it("returns ordinal for negative n=-13", async () => {
+    const res = await GET(makeReq("-13"));
+    expect(res.status).toBe(200);
+    const data = await res.json();
+    expect(data).toEqual({ ordinal: "-13th", suffix: "th" });
+  });
+
+  it("returns 400 when n is missing", async () => {
+    const req = new NextRequest(
+      "http://localhost/api/routesF/ordinal-number-formatter"
+    );
+    const res = await GET(req);
+    expect(res.status).toBe(400);
+    expect((await res.json()).error).toMatch(/required/i);
+  });
+
+  it("returns 400 for non-integer n", async () => {
+    const res = await GET(makeReq("3.14"));
+    expect(res.status).toBe(400);
+  });
+
+  it("returns 400 for non-numeric n", async () => {
+    const res = await GET(makeReq("abc"));
+    expect(res.status).toBe(400);
+  });
+});
diff --git a/app/api/routesF/ordinal-number-formatter/route.ts b/app/api/routesF/ordinal-number-formatter/route.ts
new file mode 100644
index 00000000..94f20816
--- /dev/null
+++ b/app/api/routesF/ordinal-number-formatter/route.ts
@@ -0,0 +1,51 @@
+import { type NextRequest, NextResponse } from "next/server";
+
+type OrdinalSuffix = "st" | "nd" | "rd" | "th";
+
+function getOrdinalSuffix(n: number): OrdinalSuffix {
+  const abs = Math.abs(n);
+  const mod100 = abs % 100;
+  // 11, 12, 13 are always "th" regardless of ones digit
+  if (mod100 >= 11 && mod100 <= 13) {
+    return "th";
+  }
+  const mod10 = abs % 10;
+  if (mod10 === 1) return "st";
+  if (mod10 === 2) return "nd";
+  if (mod10 === 3) return "rd";
+  return "th";
+}
+
+export function toOrdinal(n: number): { ordinal: string; suffix: OrdinalSuffix } {
+  const suffix = getOrdinalSuffix(n);
+  return { ordinal: `${n}${suffix}`, suffix };
+}
+
+export async function GET(req: NextRequest) {
+  const nParam = req.nextUrl.searchParams.get("n");
+
+  if (!nParam) {
+    return NextResponse.json(
+      { error: "n query parameter is required." },
+      { status: 400 }
+    );
+  }
+
+  if (!/^-?\d+$/.test(nParam.trim())) {
+    return NextResponse.json(
+      { error: "n must be an integer." },
+      { status: 400 }
+    );
+  }
+
+  const n = parseInt(nParam.trim(), 10);
+
+  if (!Number.isFinite(n)) {
+    return NextResponse.json(
+      { error: "n is out of safe integer range." },
+      { status: 400 }
+    );
+  }
+
+  return NextResponse.json(toOrdinal(n));
+}
diff --git a/app/api/routesF/paginate/route.ts b/app/api/routesF/paginate/route.ts
new file mode 100644
index 00000000..7aaaf909
--- /dev/null
+++ b/app/api/routesF/paginate/route.ts
@@ -0,0 +1,31 @@
+import { NextResponse } from 'next/server';
+
+export async function POST(request: Request) {
+  try {
+    const body = await request.json();
+    const { items, offset = 0, limit = 20 } = body;
+
+    if (!Array.isArray(items)) {
+      return NextResponse.json({ error: 'items must be an array' }, { status: 400 });
+    }
+
+    const clampedLimit = Math.min(Math.max(1, limit), 100);
+    const clampedOffset = Math.max(0, offset);
+
+    const total = items.length;
+    const data = items.slice(clampedOffset, clampedOffset + clampedLimit);
+    const has_more = clampedOffset + clampedLimit < total;
+    const next_offset = has_more ? clampedOffset + clampedLimit : clampedOffset;
+
+    return NextResponse.json({
+      data,
+      total,
+      offset: clampedOffset,
+      limit: clampedLimit,
+      has_more,
+      next_offset,
+    });
+  } catch (error) {
+    return NextResponse.json({ error: 'Invalid JSON body' }, { status: 400 });
+  }
+}
diff --git a/app/api/routesF/pascal-triangle/route.ts b/app/api/routesF/pascal-triangle/route.ts
new file mode 100644
index 00000000..590eb3c7
--- /dev/null
+++ b/app/api/routesF/pascal-triangle/route.ts
@@ -0,0 +1,88 @@
+import { NextRequest, NextResponse } from "next/server";
+import { z } from "zod";
+
+const querySchema = z.object({
+  rows: z
+    .string()
+    .optional()
+    .default("5")
+    .transform(val => {
+      const num = parseInt(val, 10);
+      if (isNaN(num) || num < 1 || num > 50) {
+        throw new Error("rows must be between 1 and 50");
+      }
+      return num;
+    }),
+});
+
+// Calculate binomial coefficient using integer arithmetic that stays in Number
+// range for the supported row limit.
+function binomialCoefficient(n: number, k: number): number {
+  if (k > n || k < 0) return 0;
+  if (k === 0 || k === n) return 1;
+
+  // Use symmetry: C(n,k) = C(n,n-k)
+  if (k > n - k) k = n - k;
+
+  let result = 1;
+  for (let i = 0; i < k; i++) {
+    result = (result * (n - i)) / (i + 1);
+  }
+
+  return result;
+}
+
+// Generate Pascal's triangle using binomial coefficients
+function generatePascalTriangle(rows: number): number[][] {
+  const triangle: number[][] = [];
+
+  for (let n = 0; n < rows; n++) {
+    const row: number[] = [];
+    for (let k = 0; k <= n; k++) {
+      const coefficient = binomialCoefficient(n, k);
+      row.push(coefficient);
+    }
+    triangle.push(row);
+  }
+
+  return triangle;
+}
+
+export async function GET(req: NextRequest) {
+  const { searchParams } = new URL(req.url);
+
+  const validation = querySchema.safeParse({
+    rows: searchParams.get("rows"),
+  });
+
+  if (!validation.success) {
+    return NextResponse.json(
+      {
+        error: "Invalid query parameters",
+        details: validation.error.flatten(),
+      },
+      { status: 400 }
+    );
+  }
+
+  const { rows } = validation.data;
+
+  try {
+    const triangle = generatePascalTriangle(rows);
+
+    return NextResponse.json({
+      triangle,
+      rows: triangle.length,
+    });
+  } catch (error) {
+    return NextResponse.json(
+      {
+        error:
+          error instanceof Error
+            ? error.message
+            : "Failed to generate Pascal's triangle",
+      },
+      { status: 400 }
+    );
+  }
+}
diff --git a/app/api/routesF/perfect-power/analyze.ts b/app/api/routesF/perfect-power/analyze.ts
new file mode 100644
index 00000000..5242bcca
--- /dev/null
+++ b/app/api/routesF/perfect-power/analyze.ts
@@ -0,0 +1,86 @@
+import type { PerfectPowerResult } from './types';
+
+const NON_NEGATIVE_INTEGER = /^\d+$/;
+
+function isInteger(value: number) {
+  return Number.isFinite(value) && Math.floor(value) === value;
+}
+
+export function parsePositiveInteger(value: string): number | null {
+  if (!NON_NEGATIVE_INTEGER.test(value)) {
+    return null;
+  }
+
+  const parsed = Number(value);
+  if (!Number.isSafeInteger(parsed) || parsed < 0) {
+    return null;
+  }
+
+  return parsed;
+}
+
+export function analyzePerfectPower(n: number): PerfectPowerResult {
+  const result: PerfectPowerResult = {
+    is_square: false,
+    is_cube: false,
+    is_perfect_power: false,
+  };
+
+  const sqrt = Math.sqrt(n);
+  if (isInteger(sqrt)) {
+    result.is_square = true;
+    result.sqrt = Math.trunc(sqrt);
+  }
+
+  const cbrt = Math.cbrt(n);
+  if (isInteger(cbrt)) {
+    result.is_cube = true;
+    result.cbrt = Math.trunc(cbrt);
+  }
+
+  if (n === 0) {
+    result.is_perfect_power = true;
+    result.base = 0;
+    result.exponent = 2;
+    return result;
+  }
+
+  if (n === 1) {
+    result.is_perfect_power = true;
+    result.base = 1;
+    result.exponent = 2;
+    return result;
+  }
+
+  const maxExponent = Math.floor(Math.log2(n));
+
+  for (let exponent = maxExponent; exponent >= 2; exponent--) {
+    const base = Math.round(n ** (1 / exponent));
+    if (base < 2) continue;
+    const power = base ** exponent;
+    if (power === n) {
+      result.is_perfect_power = true;
+      result.base = base;
+      result.exponent = exponent;
+      break;
+    }
+
+    const lower = base - 1;
+    if (lower >= 2 && lower ** exponent === n) {
+      result.is_perfect_power = true;
+      result.base = lower;
+      result.exponent = exponent;
+      break;
+    }
+
+    const higher = base + 1;
+    if (higher ** exponent === n) {
+      result.is_perfect_power = true;
+      result.base = higher;
+      result.exponent = exponent;
+      break;
+    }
+  }
+
+  return result;
+}
diff --git a/app/api/routesF/perfect-power/route.ts b/app/api/routesF/perfect-power/route.ts
new file mode 100644
index 00000000..79387fa9
--- /dev/null
+++ b/app/api/routesF/perfect-power/route.ts
@@ -0,0 +1,21 @@
+import { NextResponse } from 'next/server';
+import { analyzePerfectPower, parsePositiveInteger } from './analyze';
+
+export async function GET(request: Request) {
+  const { searchParams } = new URL(request.url);
+  const nParam = searchParams.get('n');
+
+  if (nParam === null) {
+    return NextResponse.json({ error: 'Missing required query parameter n' }, { status: 400 });
+  }
+
+  const n = parsePositiveInteger(nParam);
+  if (n === null) {
+    return NextResponse.json(
+      { error: 'Invalid n value. Must be a non-negative integer.' },
+      { status: 400 }
+    );
+  }
+
+  return NextResponse.json(analyzePerfectPower(n));
+}
diff --git a/app/api/routesF/perfect-power/types.ts b/app/api/routesF/perfect-power/types.ts
new file mode 100644
index 00000000..d40e9dd6
--- /dev/null
+++ b/app/api/routesF/perfect-power/types.ts
@@ -0,0 +1,13 @@
+export interface PerfectPowerQuery {
+  n: string;
+}
+
+export interface PerfectPowerResult {
+  is_square: boolean;
+  sqrt?: number;
+  is_cube: boolean;
+  cbrt?: number;
+  is_perfect_power: boolean;
+  base?: number;
+  exponent?: number;
+}
diff --git a/app/api/routesF/pg-jokes/jokes-data.ts b/app/api/routesF/pg-jokes/jokes-data.ts
new file mode 100644
index 00000000..83903884
--- /dev/null
+++ b/app/api/routesF/pg-jokes/jokes-data.ts
@@ -0,0 +1,225 @@
+import type { JokeCategory, JokeEntry, JokeFilterCategory } from "./types";
+
+export const JOKE_CATEGORIES: readonly JokeCategory[] = ["pun", "knock-knock", "one-liner"];
+
+export const FILTER_CATEGORIES: readonly JokeFilterCategory[] = [
+  ...JOKE_CATEGORIES,
+  "any",
+];
+
+const JOKES: JokeEntry[] = [
+  // pun (34)
+  { category: "pun", joke: "I used to hate facial hair, but then it grew on me." },
+  { category: "pun", joke: "Why don't eggs tell jokes? They'd crack each other up." },
+  { category: "pun", joke: "Time flies like an arrow; fruit flies like a banana." },
+  { category: "pun", joke: "I wondered why the baseball was getting bigger. Then it hit me." },
+  { category: "pun", joke: "A bicycle can't stand on its own because it is two-tired." },
+  { category: "pun", joke: "I told my suitcase there would be no vacation this year. Now I'm dealing with emotional baggage." },
+  { category: "pun", joke: "The scarecrow won an award because he was outstanding in his field." },
+  { category: "pun", joke: "I only know 25 letters of the alphabet. I don't know y." },
+  { category: "pun", joke: "Singing in the shower is fun until you get soap in your mouth. Then it becomes a soap opera." },
+  { category: "pun", joke: "What do you call a fake noodle? An impasta." },
+  { category: "pun", joke: "Why did the coffee file a police report? It got mugged." },
+  { category: "pun", joke: "I used to play piano by ear, but now I use my hands." },
+  { category: "pun", joke: "What do you call cheese that isn't yours? Nacho cheese." },
+  { category: "pun", joke: "I told my wife she was drawing her eyebrows too high. She looked surprised." },
+  { category: "pun", joke: "Why don't scientists trust atoms? Because they make up everything." },
+  { category: "pun", joke: "What do you call a bear with no teeth? A gummy bear." },
+  { category: "pun", joke: "I made a pencil with two erasers. It was pointless." },
+  { category: "pun", joke: "What do you call a factory that makes okay products? A satisfactory." },
+  { category: "pun", joke: "Why did the math book look sad? It had too many problems." },
+  { category: "pun", joke: "I ordered a chicken and an egg online. I'll let you know which comes first." },
+  { category: "pun", joke: "What do you call a parade of rabbits hopping backward? A receding hare-line." },
+  { category: "pun", joke: "I used to be a baker, but I couldn't make enough dough." },
+  { category: "pun", joke: "What do you call a sleeping bull? A bulldozer." },
+  { category: "pun", joke: "Why did the picture go to jail? It was framed." },
+  { category: "pun", joke: "I told a chemistry joke, but there was no reaction." },
+  { category: "pun", joke: "What do you call a belt made of watches? A waist of time." },
+  { category: "pun", joke: "Why did the golfer bring two pairs of pants? In case he got a hole in one." },
+  { category: "pun", joke: "I used to hate gardening, but then it grew on me." },
+  { category: "pun", joke: "What do you call a fish wearing a bowtie? Sofishticated." },
+  { category: "pun", joke: "Why don't oysters donate to charity? Because they are shellfish." },
+  { category: "pun", joke: "I got fired from the keyboard factory for not putting in enough shifts." },
+  { category: "pun", joke: "What do you call a can opener that doesn't work? A can't opener." },
+  { category: "pun", joke: "Why did the stadium get hot after the game? All the fans left." },
+  { category: "pun", joke: "I named my dog Five Miles so I can tell people I walk Five Miles every day." },
+  // one-liner (33)
+  { category: "one-liner", joke: "I have a split personality — and we are both comedians." },
+  { category: "one-liner", joke: "I'm reading a book about anti-gravity. It's impossible to put down." },
+  { category: "one-liner", joke: "My therapist says I have a preoccupation with vengeance. We'll see about that." },
+  { category: "one-liner", joke: "I threw a boomerang a few years ago. I now live in constant fear." },
+  { category: "one-liner", joke: "I haven't slept for ten days, because that would be too long." },
+  { category: "one-liner", joke: "I used to think I was indecisive, but now I'm not so sure." },
+  { category: "one-liner", joke: "The early bird might get the worm, but the second mouse gets the cheese." },
+  { category: "one-liner", joke: "I told my computer I needed a break, and now it won't stop sending me Kit-Kat ads." },
+  { category: "one-liner", joke: "I'm on a whiskey diet. I've lost three days already." },
+  { category: "one-liner", joke: "I asked the librarian if the library had books on paranoia. She whispered, 'They're right behind you.'" },
+  { category: "one-liner", joke: "I have the heart of a lion and a lifetime ban from the zoo." },
+  { category: "one-liner", joke: "My wallet is like an onion — opening it makes me cry." },
+  { category: "one-liner", joke: "I don't trust stairs. They're always up to something." },
+  { category: "one-liner", joke: "Parallel lines have so much in common. It's a shame they'll never meet." },
+  { category: "one-liner", joke: "I told my wife she should embrace her mistakes. She hugged me." },
+  { category: "one-liner", joke: "I'm great at multitasking. I can waste time, be unproductive, and procrastinate all at once." },
+  { category: "one-liner", joke: "My bed is a magical place where I suddenly remember everything I forgot to do." },
+  { category: "one-liner", joke: "I put my phone in airplane mode, but it's not flying." },
+  { category: "one-liner", joke: "I'm not arguing, I'm just explaining why I'm right." },
+  { category: "one-liner", joke: "Common sense is like deodorant. The people who need it most never use it." },
+  { category: "one-liner", joke: "I don't need a hair stylist; my pillow gives me a new hairstyle every morning." },
+  { category: "one-liner", joke: "Life is short. Smile while you still have teeth." },
+  { category: "one-liner", joke: "I told my plants a joke. They cracked up." },
+  { category: "one-liner", joke: "My favorite exercise is a cross between a lunge and a crunch. I call it lunch." },
+  { category: "one-liner", joke: "I'm not lazy. I'm on energy-saving mode." },
+  { category: "one-liner", joke: "I tried to organize a hide-and-seek tournament, but good players are hard to find." },
+  { category: "one-liner", joke: "I'm writing a book about reverse psychology. Do not read it." },
+  { category: "one-liner", joke: "My password is the last 16 digits of pi. Nobody can guess that." },
+  { category: "one-liner", joke: "I would tell you a construction joke, but I'm still working on it." },
+  { category: "one-liner", joke: "I'm afraid for the calendar. Its days are numbered." },
+  { category: "one-liner", joke: "I used to be addicted to soap, but I'm clean now." },
+  { category: "one-liner", joke: "I told my computer to go to sleep. It said goodnight and closed all my tabs." },
+  { category: "one-liner", joke: "I'm not superstitious, but I am a little stitious." },
+  { category: "one-liner", joke: "I have a joke about trickle-down economics, but 99% of you won't get it." },
+  // knock-knock (33)
+  {
+    category: "knock-knock",
+    joke: "Knock knock.\nWho's there?\nBoo.\nBoo who?\nDon't cry, it's just a joke!",
+  },
+  {
+    category: "knock-knock",
+    joke: "Knock knock.\nWho's there?\nLettuce.\nLettuce who?\nLettuce in, it's cold out here!",
+  },
+  {
+    category: "knock-knock",
+    joke: "Knock knock.\nWho's there?\nOrange.\nOrange who?\nOrange you glad I didn't say banana?",
+  },
+  {
+    category: "knock-knock",
+    joke: "Knock knock.\nWho's there?\nAtch.\nAtch who?\nBless you!",
+  },
+  {
+    category: "knock-knock",
+    joke: "Knock knock.\nWho's there?\nCow says.\nCow says who?\nNo, silly — cow says moo!",
+  },
+  {
+    category: "knock-knock",
+    joke: "Knock knock.\nWho's there?\nTank.\nTank who?\nYou're welcome!",
+  },
+  {
+    category: "knock-knock",
+    joke: "Knock knock.\nWho's there?\nHarry.\nHarry who?\nHarry up and answer the door!",
+  },
+  {
+    category: "knock-knock",
+    joke: "Knock knock.\nWho's there?\nAlpaca.\nAlpaca who?\nAlpaca the suitcase — you load the car!",
+  },
+  {
+    category: "knock-knock",
+    joke: "Knock knock.\nWho's there?\nInterrupting cow.\nInterrupting cow wh—\nMOO!",
+  },
+  {
+    category: "knock-knock",
+    joke: "Knock knock.\nWho's there?\nWooden shoe.\nWooden shoe who?\nWooden shoe like to hear another joke?",
+  },
+  {
+    category: "knock-knock",
+    joke: "Knock knock.\nWho's there?\nOlive.\nOlive who?\nOlive you and wanted to say hello!",
+  },
+  {
+    category: "knock-knock",
+    joke: "Knock knock.\nWho's there?\nDishes.\nDishes who?\nDishes the police — open up!",
+  },
+  {
+    category: "knock-knock",
+    joke: "Knock knock.\nWho's there?\nJustin.\nJustin who?\nJustin time for dinner!",
+  },
+  {
+    category: "knock-knock",
+    joke: "Knock knock.\nWho's there?\nKen.\nKen who?\nKen we go inside? It's raining!",
+  },
+  {
+    category: "knock-knock",
+    joke: "Knock knock.\nWho's there?\nLuke.\nLuke who?\nLuke through the peephole and find out!",
+  },
+  {
+    category: "knock-knock",
+    joke: "Knock knock.\nWho's there?\nNobel.\nNobel who?\nNobel — that's why I knocked!",
+  },
+  {
+    category: "knock-knock",
+    joke: "Knock knock.\nWho's there?\nDwayne.\nDwayne who?\nDwayne the bathtub — I'm dwowning!",
+  },
+  {
+    category: "knock-knock",
+    joke: "Knock knock.\nWho's there?\nAmos.\nAmos who?\nA mosquito bit me!",
+  },
+  {
+    category: "knock-knock",
+    joke: "Knock knock.\nWho's there?\nIce cream.\nIce cream who?\nIce cream if you don't let me in!",
+  },
+  {
+    category: "knock-knock",
+    joke: "Knock knock.\nWho's there?\nCereal.\nCereal who?\nCereal-sly glad you answered!",
+  },
+  {
+    category: "knock-knock",
+    joke: "Knock knock.\nWho's there?\nButter.\nButter who?\nButter be quick — I'm melting out here!",
+  },
+  {
+    category: "knock-knock",
+    joke: "Knock knock.\nWho's there?\nWanda.\nWanda who?\nWanda hang out this weekend?",
+  },
+  {
+    category: "knock-knock",
+    joke: "Knock knock.\nWho's there?\nAnnie.\nAnnie who?\nAnnie body home?",
+  },
+  {
+    category: "knock-knock",
+    joke: "Knock knock.\nWho's there?\nHoward.\nHoward who?\nHoward I know until you open the door?",
+  },
+  {
+    category: "knock-knock",
+    joke: "Knock knock.\nWho's there?\nDoris.\nDoris who?\nDoris locked — that's why I'm knocking!",
+  },
+  {
+    category: "knock-knock",
+    joke: "Knock knock.\nWho's there?\nYoda lady.\nYoda lady who?\nGood job yodeling!",
+  },
+  {
+    category: "knock-knock",
+    joke: "Knock knock.\nWho's there?\nMikey.\nMikey who?\nMikey doesn't fit in the lock!",
+  },
+  {
+    category: "knock-knock",
+    joke: "Knock knock.\nWho's there?\nRadio.\nRadio who?\nRadio not, here I come!",
+  },
+  {
+    category: "knock-knock",
+    joke: "Knock knock.\nWho's there?\nVenice.\nVenice who?\nVenice your birthday coming up?",
+  },
+  {
+    category: "knock-knock",
+    joke: "Knock knock.\nWho's there?\nDonut.\nDonut who?\nDonut ask, donut tell!",
+  },
+  {
+    category: "knock-knock",
+    joke: "Knock knock.\nWho's there?\nEurope.\nEurope who?\nNo, you're a poo!",
+  },
+  {
+    category: "knock-knock",
+    joke: "Knock knock.\nWho's there?\nBroken pencil.\nBroken pencil who?\nNever mind, it's pointless.",
+  },
+  {
+    category: "knock-knock",
+    joke: "Knock knock.\nWho's there?\nMustache.\nMustache who?\nMustache you a question, but I'll shave it for later!",
+  },
+];
+
+export function getJokePool(category: JokeFilterCategory): JokeEntry[] {
+  if (category === "any") {
+    return JOKES;
+  }
+  return JOKES.filter((entry) => entry.category === category);
+}
+
+export function isFilterCategory(value: string): value is JokeFilterCategory {
+  return (FILTER_CATEGORIES as readonly string[]).includes(value);
+}
diff --git a/app/api/routesF/pg-jokes/rng.ts b/app/api/routesF/pg-jokes/rng.ts
new file mode 100644
index 00000000..15e7a485
--- /dev/null
+++ b/app/api/routesF/pg-jokes/rng.ts
@@ -0,0 +1,11 @@
+export function createSeededRandom(seed: number) {
+  let state = seed >>> 0;
+
+  return function () {
+    state = Math.imul(state + 0x6d2b79f5, 1);
+    let t = state;
+    t ^= t >>> 15;
+    t = Math.imul(t | 1, t ^ (t + Math.imul(t ^ (t >>> 7), t | 61)));
+    return ((t ^ (t >>> 14)) >>> 0) / 4294967296;
+  };
+}
diff --git a/app/api/routesF/pg-jokes/route.test.ts b/app/api/routesF/pg-jokes/route.test.ts
new file mode 100644
index 00000000..c0dbcccd
--- /dev/null
+++ b/app/api/routesF/pg-jokes/route.test.ts
@@ -0,0 +1,68 @@
+/**
+ * @jest-environment node
+ */
+import { GET } from "./route";
+import { getJokePool } from "./jokes-data";
+
+function makeReq(query: string) {
+  return new globalThis.Request(`http://localhost/api/routesF/pg-jokes?${query}`);
+}
+
+describe("/api/routesF/pg-jokes", () => {
+  it("returns a joke from the pun category", async () => {
+    const res = await GET(makeReq("category=pun&seed=42"));
+    const data = await res.json();
+
+    expect(res.status).toBe(200);
+    expect(data.category).toBe("pun");
+    expect(typeof data.joke).toBe("string");
+    expect(data.joke.length).toBeGreaterThan(0);
+    expect(getJokePool("pun").some((entry) => entry.joke === data.joke)).toBe(true);
+  });
+
+  it("returns a joke from the knock-knock category", async () => {
+    const res = await GET(makeReq("category=knock-knock&seed=7"));
+    const data = await res.json();
+
+    expect(res.status).toBe(200);
+    expect(data.category).toBe("knock-knock");
+    expect(getJokePool("knock-knock").some((entry) => entry.joke === data.joke)).toBe(true);
+  });
+
+  it("returns a joke from the one-liner category", async () => {
+    const res = await GET(makeReq("category=one-liner&seed=99"));
+    const data = await res.json();
+
+    expect(res.status).toBe(200);
+    expect(data.category).toBe("one-liner");
+    expect(getJokePool("one-liner").some((entry) => entry.joke === data.joke)).toBe(true);
+  });
+
+  it("allows category any and returns jokes from any category", async () => {
+    const res = await GET(makeReq("category=any&seed=15"));
+    const data = await res.json();
+
+    expect(res.status).toBe(200);
+    expect(["pun", "knock-knock", "one-liner"]).toContain(data.category);
+    expect(getJokePool("any").some((entry) => entry.joke === data.joke)).toBe(true);
+  });
+
+  it("returns deterministic results for the same seed and category", async () => {
+    const first = await GET(makeReq("category=pun&seed=42"));
+    const second = await GET(makeReq("category=pun&seed=42"));
+
+    expect(first.status).toBe(200);
+    expect(second.status).toBe(200);
+    expect(await first.json()).toEqual(await second.json());
+  });
+
+  it("rejects invalid category values", async () => {
+    const res = await GET(makeReq("category=sci-fi&seed=1"));
+    expect(res.status).toBe(400);
+  });
+
+  it("rejects missing seed", async () => {
+    const res = await GET(makeReq("category=pun"));
+    expect(res.status).toBe(400);
+  });
+});
diff --git a/app/api/routesF/pg-jokes/route.ts b/app/api/routesF/pg-jokes/route.ts
new file mode 100644
index 00000000..6c03dbe0
--- /dev/null
+++ b/app/api/routesF/pg-jokes/route.ts
@@ -0,0 +1,38 @@
+import { NextResponse } from "next/server";
+import { createSeededRandom } from "./rng";
+import { getJokePool, isFilterCategory } from "./jokes-data";
+
+function parseSeed(value: string | null): number | null {
+  if (value === null || value.trim() === "") {
+    return null;
+  }
+  const parsed = Number(value);
+  return Number.isInteger(parsed) ? parsed : null;
+}
+
+export async function GET(request: Request) {
+  const { searchParams } = new URL(request.url);
+  const category = searchParams.get("category");
+  const seed = parseSeed(searchParams.get("seed"));
+
+  if (!category || seed === null) {
+    return NextResponse.json(
+      { error: "Missing required parameters: category, seed" },
+      { status: 400 }
+    );
+  }
+
+  if (!isFilterCategory(category)) {
+    return NextResponse.json({ error: "Invalid category" }, { status: 400 });
+  }
+
+  const pool = getJokePool(category);
+  const random = createSeededRandom(seed);
+  const index = Math.floor(random() * pool.length);
+  const selected = pool[index];
+
+  return NextResponse.json({
+    joke: selected.joke,
+    category: selected.category,
+  });
+}
diff --git a/app/api/routesF/pg-jokes/types.ts b/app/api/routesF/pg-jokes/types.ts
new file mode 100644
index 00000000..4f95815c
--- /dev/null
+++ b/app/api/routesF/pg-jokes/types.ts
@@ -0,0 +1,8 @@
+export type JokeCategory = "pun" | "knock-knock" | "one-liner";
+
+export type JokeFilterCategory = JokeCategory | "any";
+
+export type JokeEntry = {
+  joke: string;
+  category: JokeCategory;
+};
diff --git a/app/api/routesF/project-codename/route.test.ts b/app/api/routesF/project-codename/route.test.ts
new file mode 100644
index 00000000..0e62a929
--- /dev/null
+++ b/app/api/routesF/project-codename/route.test.ts
@@ -0,0 +1,36 @@
+import { GET } from './route';
+
+describe('Project Codename Generator API', () => {
+  it('should return 400 if parameters are missing', async () => {
+    const req = new Request('http://localhost/api/routesF/project-codename');
+    const res = await GET(req);
+    expect(res.status).toBe(400);
+  });
+
+  it('should generate codenames deterministically', async () => {
+    const req1 = new Request('http://localhost/api/routesF/project-codename?count=3&seed=42&theme=animals');
+    const res1 = await GET(req1);
+    const data1 = await res1.json();
+
+    const req2 = new Request('http://localhost/api/routesF/project-codename?count=3&seed=42&theme=animals');
+    const res2 = await GET(req2);
+    const data2 = await res2.json();
+
+    expect(data1.codenames).toEqual(data2.codenames);
+    expect(data1.codenames).toHaveLength(3);
+    expect(data1.codenames[0]).toMatch(/^[a-z]+-[a-z]+$/);
+  });
+
+  it('should support the "any" theme', async () => {
+    const req = new Request('http://localhost/api/routesF/project-codename?count=5&seed=123&theme=any');
+    const res = await GET(req);
+    const data = await res.json();
+    expect(data.codenames).toHaveLength(5);
+  });
+
+  it('should return 400 for invalid theme', async () => {
+    const req = new Request('http://localhost/api/routesF/project-codename?count=1&seed=1&theme=invalid');
+    const res = await GET(req);
+    expect(res.status).toBe(400);
+  });
+});
diff --git a/app/api/routesF/project-codename/route.ts b/app/api/routesF/project-codename/route.ts
new file mode 100644
index 00000000..459651df
--- /dev/null
+++ b/app/api/routesF/project-codename/route.ts
@@ -0,0 +1,60 @@
+import { NextResponse } from 'next/server';
+
+const adjectives = [
+  'swift', 'silent', 'brave', 'clever', 'mighty', 
+  'hidden', 'flying', 'crimson', 'shadow', 'golden', 
+  'cyber', 'neon', 'cosmic', 'stellar', 'quantum'
+];
+
+const themes = {
+  animals: ['fox', 'wolf', 'bear', 'eagle', 'tiger', 'hawk', 'lion', 'panther', 'falcon', 'owl'],
+  space: ['star', 'moon', 'comet', 'planet', 'nebula', 'galaxy', 'asteroid', 'pulsar', 'quasar', 'orbit'],
+  colors: ['red', 'blue', 'green', 'yellow', 'purple', 'orange', 'black', 'white', 'silver', 'cyan']
+};
+
+function mulberry32(a: number) {
+  return function() {
+    let t = a += 0x6D2B79F5;
+    t = Math.imul(t ^ t >>> 15, t | 1);
+    t ^= t + Math.imul(t ^ t >>> 7, t | 61);
+    return ((t ^ t >>> 14) >>> 0) / 4294967296;
+  }
+}
+
+export async function GET(request: Request) {
+  const { searchParams } = new URL(request.url);
+  const countStr = searchParams.get('count');
+  const seedStr = searchParams.get('seed');
+  const theme = searchParams.get('theme');
+
+  if (!countStr || !seedStr || !theme) {
+    return NextResponse.json({ error: 'Missing required parameters: count, seed, theme' }, { status: 400 });
+  }
+
+  const count = parseInt(countStr, 10);
+  const seed = parseInt(seedStr, 10);
+
+  if (isNaN(count) || isNaN(seed)) {
+    return NextResponse.json({ error: 'Invalid count or seed' }, { status: 400 });
+  }
+
+  let nouns: string[] = [];
+  if (theme === 'any') {
+    nouns = [...themes.animals, ...themes.space, ...themes.colors];
+  } else if (theme in themes) {
+    nouns = themes[theme as keyof typeof themes];
+  } else {
+    return NextResponse.json({ error: 'Invalid theme' }, { status: 400 });
+  }
+
+  const random = mulberry32(seed);
+  const codenames: string[] = [];
+
+  for (let i = 0; i < count; i++) {
+    const adjIndex = Math.floor(random() * adjectives.length);
+    const nounIndex = Math.floor(random() * nouns.length);
+    codenames.push(`${adjectives[adjIndex]}-${nouns[nounIndex]}`);
+  }
+
+  return NextResponse.json({ codenames });
+}
diff --git a/app/api/routesF/qr-payload-builder/route.test.ts b/app/api/routesF/qr-payload-builder/route.test.ts
new file mode 100644
index 00000000..561189d8
--- /dev/null
+++ b/app/api/routesF/qr-payload-builder/route.test.ts
@@ -0,0 +1,139 @@
+import { POST } from './route';
+
+describe('QR Payload Builder API', () => {
+  it('should return 400 when type is missing', async () => {
+    const req = new Request('http://localhost/api/routesF/qr-payload-builder', {
+      method: 'POST',
+      body: JSON.stringify({ data: {} }),
+    });
+    const res = await POST(req);
+    expect(res.status).toBe(400);
+  });
+
+  it('should return 400 for invalid type', async () => {
+    const req = new Request('http://localhost/api/routesF/qr-payload-builder', {
+      method: 'POST',
+      body: JSON.stringify({ type: 'invalid', data: {} }),
+    });
+    const res = await POST(req);
+    expect(res.status).toBe(400);
+  });
+
+  it('should build WiFi payload', async () => {
+    const req = new Request('http://localhost/api/routesF/qr-payload-builder', {
+      method: 'POST',
+      body: JSON.stringify({
+        type: 'wifi',
+        data: { ssid: 'MyNetwork', password: 'secure123' },
+      }),
+    });
+    const res = await POST(req);
+    const result = await res.json();
+    expect(result.payload).toBe('WIFI:T:WPA;S:MyNetwork;P:secure123;;');
+  });
+
+  it('should build WiFi payload with custom security', async () => {
+    const req = new Request('http://localhost/api/routesF/qr-payload-builder', {
+      method: 'POST',
+      body: JSON.stringify({
+        type: 'wifi',
+        data: { ssid: 'OpenWifi', password: 'pass', security: 'NOPASS' },
+      }),
+    });
+    const res = await POST(req);
+    const result = await res.json();
+    expect(result.payload).toBe('WIFI:T:NOPASS;S:OpenWifi;P:pass;;');
+  });
+
+  it('should build vCard payload with full details', async () => {
+    const req = new Request('http://localhost/api/routesF/qr-payload-builder', {
+      method: 'POST',
+      body: JSON.stringify({
+        type: 'vcard',
+        data: {
+          firstName: 'John',
+          lastName: 'Doe',
+          phone: '1234567890',
+          email: 'john@example.com',
+          organization: 'Acme Corp',
+          url: 'https://example.com',
+        },
+      }),
+    });
+    const res = await POST(req);
+    const result = await res.json();
+    expect(result.payload).toContain('BEGIN:VCARD');
+    expect(result.payload).toContain('END:VCARD');
+    expect(result.payload).toContain('FN:John Doe');
+    expect(result.payload).toContain('TEL:1234567890');
+    expect(result.payload).toContain('EMAIL:john@example.com');
+    expect(result.payload).toContain('ORG:Acme Corp');
+    expect(result.payload).toContain('URL:https://example.com');
+  });
+
+  it('should build vCard payload with minimal details', async () => {
+    const req = new Request('http://localhost/api/routesF/qr-payload-builder', {
+      method: 'POST',
+      body: JSON.stringify({
+        type: 'vcard',
+        data: { firstName: 'Jane', lastName: 'Smith' },
+      }),
+    });
+    const res = await POST(req);
+    const result = await res.json();
+    expect(result.payload).toContain('FN:Jane Smith');
+    expect(result.payload).toContain('BEGIN:VCARD');
+  });
+
+  it('should build URL payload', async () => {
+    const req = new Request('http://localhost/api/routesF/qr-payload-builder', {
+      method: 'POST',
+      body: JSON.stringify({
+        type: 'url',
+        data: { url: 'https://example.com/page' },
+      }),
+    });
+    const res = await POST(req);
+    const result = await res.json();
+    expect(result.payload).toBe('https://example.com/page');
+  });
+
+  it('should build geo payload without altitude', async () => {
+    const req = new Request('http://localhost/api/routesF/qr-payload-builder', {
+      method: 'POST',
+      body: JSON.stringify({
+        type: 'geo',
+        data: { latitude: 40.7128, longitude: -74.006 },
+      }),
+    });
+    const res = await POST(req);
+    const result = await res.json();
+    expect(result.payload).toBe('geo:40.7128,-74.006');
+  });
+
+  it('should build geo payload with altitude', async () => {
+    const req = new Request('http://localhost/api/routesF/qr-payload-builder', {
+      method: 'POST',
+      body: JSON.stringify({
+        type: 'geo',
+        data: { latitude: 40.7128, longitude: -74.006, altitude: 10 },
+      }),
+    });
+    const res = await POST(req);
+    const result = await res.json();
+    expect(result.payload).toBe('geo:40.7128,-74.006,10');
+  });
+
+  it('should handle case-insensitive type', async () => {
+    const req = new Request('http://localhost/api/routesF/qr-payload-builder', {
+      method: 'POST',
+      body: JSON.stringify({
+        type: 'WIFI',
+        data: { ssid: 'Network', password: 'pass123' },
+      }),
+    });
+    const res = await POST(req);
+    const result = await res.json();
+    expect(result.payload).toContain('WIFI:');
+  });
+});
diff --git a/app/api/routesF/qr-payload-builder/route.ts b/app/api/routesF/qr-payload-builder/route.ts
new file mode 100644
index 00000000..77a54141
--- /dev/null
+++ b/app/api/routesF/qr-payload-builder/route.ts
@@ -0,0 +1,114 @@
+import { NextResponse } from 'next/server';
+
+function buildWiFiPayload(data: any): string {
+  const { ssid, password, security = 'WPA' } = data;
+  if (!ssid || !password) {
+    throw new Error('WiFi requires ssid and password');
+  }
+  return `WIFI:T:${security};S:${ssid};P:${password};;`;
+}
+
+function buildVCardPayload(data: any): string {
+  const { firstName, lastName, phone, email, organization, url } = data;
+  if (!firstName && !lastName) {
+    throw new Error('vCard requires at least firstName or lastName');
+  }
+
+  const lines = ['BEGIN:VCARD', 'VERSION:3.0'];
+
+  if (firstName || lastName) {
+    lines.push(`FN:${(firstName || '').trim()} ${(lastName || '').trim()}`.trim());
+    lines.push(`N:${lastName || ''};${firstName || ''};; ;`);
+  }
+
+  if (phone) {
+    lines.push(`TEL:${phone}`);
+  }
+
+  if (email) {
+    lines.push(`EMAIL:${email}`);
+  }
+
+  if (organization) {
+    lines.push(`ORG:${organization}`);
+  }
+
+  if (url) {
+    lines.push(`URL:${url}`);
+  }
+
+  lines.push('END:VCARD');
+
+  return lines.join('\n');
+}
+
+function buildURLPayload(data: any): string {
+  const { url } = data;
+  if (!url) {
+    throw new Error('URL requires url parameter');
+  }
+  return url;
+}
+
+function buildGeoPayload(data: any): string {
+  const { latitude, longitude, altitude } = data;
+  if (latitude === undefined || longitude === undefined) {
+    throw new Error('Geo requires latitude and longitude');
+  }
+
+  if (altitude !== undefined) {
+    return `geo:${latitude},${longitude},${altitude}`;
+  }
+
+  return `geo:${latitude},${longitude}`;
+}
+
+export async function POST(request: Request) {
+  try {
+    const body = await request.json();
+    const { type, data } = body;
+
+    if (!type) {
+      return NextResponse.json(
+        { error: 'Missing type parameter' },
+        { status: 400 }
+      );
+    }
+
+    if (!data || typeof data !== 'object') {
+      return NextResponse.json(
+        { error: 'Missing or invalid data object' },
+        { status: 400 }
+      );
+    }
+
+    let payload: string;
+
+    switch (type.toLowerCase()) {
+      case 'wifi':
+        payload = buildWiFiPayload(data);
+        break;
+      case 'vcard':
+        payload = buildVCardPayload(data);
+        break;
+      case 'url':
+        payload = buildURLPayload(data);
+        break;
+      case 'geo':
+        payload = buildGeoPayload(data);
+        break;
+      default:
+        return NextResponse.json(
+          { error: 'Invalid type. Use wifi, vcard, url, or geo' },
+          { status: 400 }
+        );
+    }
+
+    return NextResponse.json({ payload });
+  } catch (error: any) {
+    return NextResponse.json(
+      { error: error.message || 'Invalid request' },
+      { status: 400 }
+    );
+  }
+}
diff --git a/app/api/routesF/random-named-color-picker/color-data.ts b/app/api/routesF/random-named-color-picker/color-data.ts
new file mode 100644
index 00000000..67be3408
--- /dev/null
+++ b/app/api/routesF/random-named-color-picker/color-data.ts
@@ -0,0 +1,45 @@
+export type ColorGroup = "reds" | "blues";
+
+export type CssNamedColor = {
+  name: string;
+  hex: string;
+  group: ColorGroup;
+};
+
+export const CSS_NAMED_COLORS: readonly CssNamedColor[] = [
+  { name: "IndianRed", hex: "#CD5C5C", group: "reds" },
+  { name: "LightCoral", hex: "#F08080", group: "reds" },
+  { name: "Salmon", hex: "#FA8072", group: "reds" },
+  { name: "DarkSalmon", hex: "#E9967A", group: "reds" },
+  { name: "LightSalmon", hex: "#FFA07A", group: "reds" },
+  { name: "Crimson", hex: "#DC143C", group: "reds" },
+  { name: "Red", hex: "#FF0000", group: "reds" },
+  { name: "FireBrick", hex: "#B22222", group: "reds" },
+  { name: "DarkRed", hex: "#8B0000", group: "reds" },
+  { name: "Coral", hex: "#FF7F50", group: "reds" },
+  { name: "Tomato", hex: "#FF6347", group: "reds" },
+  { name: "OrangeRed", hex: "#FF4500", group: "reds" },
+  { name: "Pink", hex: "#FFC0CB", group: "reds" },
+  { name: "LightPink", hex: "#FFB6C1", group: "reds" },
+  { name: "HotPink", hex: "#FF69B4", group: "reds" },
+  { name: "DeepPink", hex: "#FF1493", group: "reds" },
+  { name: "PaleVioletRed", hex: "#DB7093", group: "reds" },
+  { name: "MediumVioletRed", hex: "#C71585", group: "reds" },
+  { name: "LightSkyBlue", hex: "#87CEFA", group: "blues" },
+  { name: "SkyBlue", hex: "#87CEEB", group: "blues" },
+  { name: "DeepSkyBlue", hex: "#00BFFF", group: "blues" },
+  { name: "DodgerBlue", hex: "#1E90FF", group: "blues" },
+  { name: "CornflowerBlue", hex: "#6495ED", group: "blues" },
+  { name: "SteelBlue", hex: "#4682B4", group: "blues" },
+  { name: "RoyalBlue", hex: "#4169E1", group: "blues" },
+  { name: "Blue", hex: "#0000FF", group: "blues" },
+  { name: "MediumBlue", hex: "#0000CD", group: "blues" },
+  { name: "DarkBlue", hex: "#00008B", group: "blues" },
+  { name: "Navy", hex: "#000080", group: "blues" },
+  { name: "MidnightBlue", hex: "#191970", group: "blues" },
+  { name: "MediumSlateBlue", hex: "#7B68EE", group: "blues" },
+  { name: "SlateBlue", hex: "#6A5ACD", group: "blues" },
+  { name: "DarkSlateBlue", hex: "#483D8B", group: "blues" },
+  { name: "PowderBlue", hex: "#B0E0E6", group: "blues" },
+  { name: "LightBlue", hex: "#ADD8E6", group: "blues" },
+];
diff --git a/app/api/routesF/random-named-color-picker/random.ts b/app/api/routesF/random-named-color-picker/random.ts
new file mode 100644
index 00000000..26f2c2e7
--- /dev/null
+++ b/app/api/routesF/random-named-color-picker/random.ts
@@ -0,0 +1,20 @@
+export function createSeededRandom(seed: number): () => number {
+  let state = seed >>> 0;
+
+  return () => {
+    state = (1664525 * state + 1013904223) >>> 0;
+    return state / 0x100000000;
+  };
+}
+
+export function shuffleDeterministic<T>(items: readonly T[], seed: number): T[] {
+  const random = createSeededRandom(seed);
+  const shuffled = [...items];
+
+  for (let i = shuffled.length - 1; i > 0; i -= 1) {
+    const j = Math.floor(random() * (i + 1));
+    [shuffled[i], shuffled[j]] = [shuffled[j], shuffled[i]];
+  }
+
+  return shuffled;
+}
diff --git a/app/api/routesF/random-named-color-picker/route.test.ts b/app/api/routesF/random-named-color-picker/route.test.ts
new file mode 100644
index 00000000..83b37634
--- /dev/null
+++ b/app/api/routesF/random-named-color-picker/route.test.ts
@@ -0,0 +1,131 @@
+/**
+ * @jest-environment node
+ */
+import { NextRequest } from "next/server";
+import { GET } from "./route";
+
+function makeRequest(params: Record<string, string> = {}) {
+  const url = new URL("http://localhost/api/routesF/random-named-color-picker");
+  Object.entries(params).forEach(([key, value]) => {
+    url.searchParams.set(key, value);
+  });
+
+  return new NextRequest(url.toString(), { method: "GET" });
+}
+
+describe("/api/routesF/random-named-color-picker", () => {
+  it("uses defaults when optional params are missing", async () => {
+    const response = await GET(makeRequest());
+    const payload = await response.json();
+
+    expect(response.status).toBe(200);
+    expect(payload.colors).toHaveLength(5);
+  });
+
+  it("returns requested number of colors with expected shape", async () => {
+    const response = await GET(makeRequest({ count: "5", seed: "42", group: "any" }));
+    const payload = await response.json();
+
+    expect(response.status).toBe(200);
+    expect(payload.colors).toHaveLength(5);
+    expect(payload.colors[0]).toEqual(
+      expect.objectContaining({
+        name: expect.any(String),
+        hex: expect.stringMatching(/^#[0-9A-F]{6}$/i),
+        rgb: expect.stringMatching(/^rgb\(\d{1,3}, \d{1,3}, \d{1,3}\)$/),
+      })
+    );
+  });
+
+  it("filters only red-group named colors", async () => {
+    const response = await GET(makeRequest({ count: "10", seed: "5", group: "reds" }));
+    const payload = await response.json();
+
+    expect(response.status).toBe(200);
+    const redColorNames = new Set([
+      "IndianRed",
+      "LightCoral",
+      "Salmon",
+      "DarkSalmon",
+      "LightSalmon",
+      "Crimson",
+      "Red",
+      "FireBrick",
+      "DarkRed",
+      "Coral",
+      "Tomato",
+      "OrangeRed",
+      "Pink",
+      "LightPink",
+      "HotPink",
+      "DeepPink",
+      "PaleVioletRed",
+      "MediumVioletRed",
+    ]);
+    payload.colors.forEach((color: { name: string }) => {
+      expect(redColorNames.has(color.name)).toBe(true);
+    });
+  });
+
+  it("filters only blue-group named colors", async () => {
+    const response = await GET(makeRequest({ count: "10", seed: "5", group: "blues" }));
+    const payload = await response.json();
+
+    expect(response.status).toBe(200);
+    const blueColorNames = new Set([
+      "LightSkyBlue",
+      "SkyBlue",
+      "DeepSkyBlue",
+      "DodgerBlue",
+      "CornflowerBlue",
+      "SteelBlue",
+      "RoyalBlue",
+      "Blue",
+      "MediumBlue",
+      "DarkBlue",
+      "Navy",
+      "MidnightBlue",
+      "MediumSlateBlue",
+      "SlateBlue",
+      "DarkSlateBlue",
+      "PowderBlue",
+      "LightBlue",
+    ]);
+    payload.colors.forEach((color: { name: string }) => {
+      expect(blueColorNames.has(color.name)).toBe(true);
+    });
+  });
+
+  it("returns deterministic output with same seed", async () => {
+    const firstResponse = await GET(makeRequest({ count: "6", seed: "42", group: "any" }));
+    const secondResponse = await GET(makeRequest({ count: "6", seed: "42", group: "any" }));
+
+    const firstPayload = await firstResponse.json();
+    const secondPayload = await secondResponse.json();
+
+    expect(firstPayload.colors).toEqual(secondPayload.colors);
+  });
+
+  it("returns different output for different seeds", async () => {
+    const firstResponse = await GET(makeRequest({ count: "6", seed: "42", group: "any" }));
+    const secondResponse = await GET(makeRequest({ count: "6", seed: "43", group: "any" }));
+
+    const firstPayload = await firstResponse.json();
+    const secondPayload = await secondResponse.json();
+
+    expect(firstPayload.colors).not.toEqual(secondPayload.colors);
+  });
+
+  it("returns 400 for invalid group", async () => {
+    const response = await GET(makeRequest({ group: "greens" }));
+    expect(response.status).toBe(400);
+  });
+
+  it("clamps count to avoid over-fetching the color pool", async () => {
+    const response = await GET(makeRequest({ count: "100", group: "blues", seed: "9" }));
+    const payload = await response.json();
+
+    expect(response.status).toBe(200);
+    expect(payload.colors.length).toBeLessThanOrEqual(17);
+  });
+});
diff --git a/app/api/routesF/random-named-color-picker/route.ts b/app/api/routesF/random-named-color-picker/route.ts
new file mode 100644
index 00000000..be1f3189
--- /dev/null
+++ b/app/api/routesF/random-named-color-picker/route.ts
@@ -0,0 +1,69 @@
+import { NextResponse } from "next/server";
+import { CSS_NAMED_COLORS, ColorGroup } from "./color-data";
+import { shuffleDeterministic } from "./random";
+
+type QueryGroup = ColorGroup | "any";
+
+type ColorResponseItem = {
+  name: string;
+  hex: string;
+  rgb: string;
+};
+
+function parseCount(value: string | null): number {
+  if (!value) return 5;
+  const parsed = Number.parseInt(value, 10);
+  if (!Number.isInteger(parsed) || parsed <= 0) return 5;
+  return Math.min(parsed, 50);
+}
+
+function parseSeed(value: string | null): number {
+  if (!value) return Date.now();
+  const parsed = Number.parseInt(value, 10);
+  return Number.isInteger(parsed) ? parsed : 0;
+}
+
+function parseGroup(value: string | null): QueryGroup | null {
+  if (!value) return "any";
+  if (value === "any" || value === "reds" || value === "blues") return value;
+  return null;
+}
+
+function hexToRgb(hex: string): string {
+  const normalizedHex = hex.replace("#", "");
+  const red = Number.parseInt(normalizedHex.slice(0, 2), 16);
+  const green = Number.parseInt(normalizedHex.slice(2, 4), 16);
+  const blue = Number.parseInt(normalizedHex.slice(4, 6), 16);
+
+  return `rgb(${red}, ${green}, ${blue})`;
+}
+
+function pickPool(group: QueryGroup) {
+  if (group === "any") return CSS_NAMED_COLORS;
+  return CSS_NAMED_COLORS.filter((color) => color.group === group);
+}
+
+export async function GET(request: Request) {
+  const { searchParams } = new URL(request.url);
+  const count = parseCount(searchParams.get("count"));
+  const seed = parseSeed(searchParams.get("seed"));
+  const group = parseGroup(searchParams.get("group"));
+
+  if (group === null) {
+    return NextResponse.json(
+      { error: "group must be one of: reds, blues, any" },
+      { status: 400 }
+    );
+  }
+
+  const pool = pickPool(group);
+  const shuffled = shuffleDeterministic(pool, seed);
+  const selected = shuffled.slice(0, Math.min(count, pool.length));
+  const colors: ColorResponseItem[] = selected.map((color) => ({
+    name: color.name,
+    hex: color.hex,
+    rgb: hexToRgb(color.hex),
+  }));
+
+  return NextResponse.json({ colors });
+}
diff --git a/app/api/routesF/remove-accents/route.test.ts b/app/api/routesF/remove-accents/route.test.ts
new file mode 100644
index 00000000..10e19dc8
--- /dev/null
+++ b/app/api/routesF/remove-accents/route.test.ts
@@ -0,0 +1,31 @@
+import { NextRequest } from "next/server";
+import { POST, removeAccents } from "./route";
+
+function req(body: unknown) {
+  return new NextRequest("http://localhost/api/routesF/remove-accents", {
+    method: "POST",
+    body: JSON.stringify(body),
+  });
+}
+
+describe("removeAccents", () => {
+  it("removes accents and keeps base letters", () => {
+    expect(removeAccents("café déjà vu")).toBe("cafe deja vu");
+    expect(removeAccents("São Tomé and Príncipe")).toBe(
+      "Sao Tome and Principe"
+    );
+  });
+});
+
+describe("POST /api/routesF/remove-accents", () => {
+  it("returns transformed text", async () => {
+    const res = await POST(req({ text: "façade naïve rôle" }));
+    expect(res.status).toBe(200);
+    expect(await res.json()).toEqual({ result: "facade naive role" });
+  });
+
+  it("returns 400 for invalid input", async () => {
+    const res = await POST(req({ text: 123 }));
+    expect(res.status).toBe(400);
+  });
+});
diff --git a/app/api/routesF/remove-accents/route.ts b/app/api/routesF/remove-accents/route.ts
new file mode 100644
index 00000000..9c25d26d
--- /dev/null
+++ b/app/api/routesF/remove-accents/route.ts
@@ -0,0 +1,23 @@
+import { NextResponse } from "next/server";
+
+export function removeAccents(text: string): string {
+  return text.normalize("NFD").replace(/[\u0300-\u036f]/g, "");
+}
+
+export async function POST(request: Request) {
+  try {
+    const body = await request.json();
+    const text = body?.text;
+
+    if (typeof text !== "string") {
+      return NextResponse.json(
+        { error: "text must be a string" },
+        { status: 400 }
+      );
+    }
+
+    return NextResponse.json({ result: removeAccents(text) });
+  } catch {
+    return NextResponse.json({ error: "Invalid JSON body" }, { status: 400 });
+  }
+}
diff --git a/app/api/routesF/response.ts b/app/api/routesF/response.ts
new file mode 100644
index 00000000..fb3d4b87
--- /dev/null
+++ b/app/api/routesF/response.ts
@@ -0,0 +1,63 @@
+import { NextResponse } from "next/server";
+import { ROUTES_F_API_VERSION } from "./version";
+
+type HeadersInput = HeadersInit | Headers;
+
+/**
+ * Normalize Headers or HeadersInit into HeadersInit
+ */
+function normalizeHeaders(headers?: HeadersInput): HeadersInit | undefined {
+  if (!headers) return undefined;
+
+  if (headers instanceof Headers) {
+    return Object.fromEntries(headers.entries());
+  }
+
+  return headers;
+}
+
+/**
+ * Success response wrapper for routes-f
+ */
+export function routesFSuccess<T>(
+  data: T,
+  status: number = 200,
+  headers?: HeadersInput
+) {
+  return NextResponse.json(
+    {
+      apiVersion: ROUTES_F_API_VERSION,
+      success: true,
+      data,
+    },
+    {
+      status,
+      headers: normalizeHeaders(headers),
+    }
+  );
+}
+
+/**
+ * Error response wrapper for routes-f
+ *
+ * IMPORTANT: headers comes before extraData to avoid TS confusion
+ */
+export function routesFError(
+  message: string,
+  status: number = 400,
+  headers?: HeadersInput,
+  extraData?: Record<string, unknown>
+) {
+  return NextResponse.json(
+    {
+      apiVersion: ROUTES_F_API_VERSION,
+      success: false,
+      error: message,
+      ...extraData,
+    },
+    {
+      status,
+      headers: normalizeHeaders(headers),
+    }
+  );
+}
\ No newline at end of file
diff --git a/app/api/routesF/reverse-word-order/route.test.ts b/app/api/routesF/reverse-word-order/route.test.ts
new file mode 100644
index 00000000..945ca9cb
--- /dev/null
+++ b/app/api/routesF/reverse-word-order/route.test.ts
@@ -0,0 +1,110 @@
+import { POST } from "./route";
+
+describe("Reverse Word Order API", () => {
+  it("should return 400 for invalid JSON", async () => {
+    const req = new Request("http://localhost/api/routesF/reverse-word-order", {
+      method: "POST",
+      body: "not-json",
+    });
+    const res = await POST(req);
+    expect(res.status).toBe(400);
+  });
+
+  it("should return 400 when text is missing", async () => {
+    const req = new Request("http://localhost/api/routesF/reverse-word-order", {
+      method: "POST",
+      body: JSON.stringify({}),
+    });
+    const res = await POST(req);
+    expect(res.status).toBe(400);
+  });
+
+  it("should return 400 when text is not a string", async () => {
+    const req = new Request("http://localhost/api/routesF/reverse-word-order", {
+      method: "POST",
+      body: JSON.stringify({ text: 42 }),
+    });
+    const res = await POST(req);
+    expect(res.status).toBe(400);
+  });
+
+  it("reverses words in a simple sentence", async () => {
+    const req = new Request("http://localhost/api/routesF/reverse-word-order", {
+      method: "POST",
+      body: JSON.stringify({ text: "hello world" }),
+    });
+    const res = await POST(req);
+    const data = await res.json();
+    expect(data.result).toBe("world hello");
+  });
+
+  it("collapses multiple internal spaces to a single space", async () => {
+    const req = new Request("http://localhost/api/routesF/reverse-word-order", {
+      method: "POST",
+      body: JSON.stringify({ text: "hello   world   foo" }),
+    });
+    const res = await POST(req);
+    const data = await res.json();
+    expect(data.result).toBe("foo world hello");
+  });
+
+  it("trims leading and trailing whitespace", async () => {
+    const req = new Request("http://localhost/api/routesF/reverse-word-order", {
+      method: "POST",
+      body: JSON.stringify({ text: "  hello world  " }),
+    });
+    const res = await POST(req);
+    const data = await res.json();
+    expect(data.result).toBe("world hello");
+  });
+
+  it("handles a single word", async () => {
+    const req = new Request("http://localhost/api/routesF/reverse-word-order", {
+      method: "POST",
+      body: JSON.stringify({ text: "hello" }),
+    });
+    const res = await POST(req);
+    const data = await res.json();
+    expect(data.result).toBe("hello");
+  });
+
+  it("handles an empty string", async () => {
+    const req = new Request("http://localhost/api/routesF/reverse-word-order", {
+      method: "POST",
+      body: JSON.stringify({ text: "" }),
+    });
+    const res = await POST(req);
+    const data = await res.json();
+    expect(data.result).toBe("");
+  });
+
+  it("handles a string with only whitespace", async () => {
+    const req = new Request("http://localhost/api/routesF/reverse-word-order", {
+      method: "POST",
+      body: JSON.stringify({ text: "   " }),
+    });
+    const res = await POST(req);
+    const data = await res.json();
+    expect(data.result).toBe("");
+  });
+
+  it("handles mixed tabs and spaces", async () => {
+    const req = new Request("http://localhost/api/routesF/reverse-word-order", {
+      method: "POST",
+      body: JSON.stringify({ text: "foo\t\tbar  baz" }),
+    });
+    const res = await POST(req);
+    const data = await res.json();
+    expect(data.result).toBe("baz bar foo");
+  });
+
+  it("reverses a multi-word sentence correctly", async () => {
+    const req = new Request("http://localhost/api/routesF/reverse-word-order", {
+      method: "POST",
+      body: JSON.stringify({ text: "the quick brown fox" }),
+    });
+    const res = await POST(req);
+    const data = await res.json();
+    expect(data.result).toBe("fox brown quick the");
+  });
+});
diff --git a/app/api/routesF/reverse-word-order/route.ts b/app/api/routesF/reverse-word-order/route.ts
new file mode 100644
index 00000000..e851a847
--- /dev/null
+++ b/app/api/routesF/reverse-word-order/route.ts
@@ -0,0 +1,36 @@
+import { NextResponse } from "next/server";
+
+/**
+ * Reverses the order of words in the given text.
+ * Collapses internal whitespace to single spaces and trims leading/trailing whitespace.
+ */
+function reverseWordOrder(text: string): string {
+  return text
+    .trim()
+    .split(/\s+/)
+    .reverse()
+    .join(" ");
+}
+
+export async function POST(request: Request) {
+  let body: unknown;
+  try {
+    body = await request.json();
+  } catch {
+    return NextResponse.json({ error: "Invalid JSON body." }, { status: 400 });
+  }
+
+  if (typeof body !== "object" || body === null || Array.isArray(body)) {
+    return NextResponse.json({ error: "Request body must be an object." }, { status: 400 });
+  }
+
+  const { text } = body as Record<string, unknown>;
+
+  if (typeof text !== "string") {
+    return NextResponse.json({ error: "text must be a string." }, { status: 400 });
+  }
+
+  const result = reverseWordOrder(text);
+
+  return NextResponse.json({ result });
+}
diff --git a/app/api/routesF/roi-calculator/route.test.ts b/app/api/routesF/roi-calculator/route.test.ts
new file mode 100644
index 00000000..4047610d
--- /dev/null
+++ b/app/api/routesF/roi-calculator/route.test.ts
@@ -0,0 +1,60 @@
+import { NextRequest } from "next/server";
+import { POST } from "./route";
+
+function makeReq(body: unknown) {
+  return new NextRequest("http://localhost/api/routesF/roi-calculator", {
+    method: "POST",
+    headers: { "content-type": "application/json" },
+    body: JSON.stringify(body),
+  });
+}
+
+describe("ROI Calculator API", () => {
+  it("computes a simple gain", async () => {
+    const res = await POST(makeReq({ initial: 100, final: 150 }));
+    const data = await res.json();
+    expect(res.status).toBe(200);
+    expect(data.roi_percent).toBeCloseTo(50);
+    expect(data.gain).toBe(50);
+  });
+
+  it("computes a loss", async () => {
+    const res = await POST(makeReq({ initial: 200, final: 100 }));
+    const data = await res.json();
+    expect(res.status).toBe(200);
+    expect(data.roi_percent).toBeCloseTo(-50);
+    expect(data.gain).toBe(-100);
+  });
+
+  it("computes annualized ROI when years provided", async () => {
+    const res = await POST(makeReq({ initial: 100, final: 200, years: 3 }));
+    const data = await res.json();
+    expect(res.status).toBe(200);
+    expect(data.roi_percent).toBeCloseTo(100);
+    expect(data.annualized_percent).toBeCloseTo(25.992, 1);
+  });
+
+  it("returns 400 for missing initial", async () => {
+    const res = await POST(makeReq({ final: 100 }));
+    expect(res.status).toBe(400);
+  });
+
+  it("returns 400 for zero initial", async () => {
+    const res = await POST(makeReq({ initial: 0, final: 100 }));
+    expect(res.status).toBe(400);
+  });
+
+  it("returns 400 for non-positive years", async () => {
+    const res = await POST(makeReq({ initial: 100, final: 200, years: 0 }));
+    expect(res.status).toBe(400);
+  });
+
+  it("returns 400 for invalid JSON", async () => {
+    const req = new NextRequest("http://localhost/api/routesF/roi-calculator", {
+      method: "POST",
+      body: "not json",
+    });
+    const res = await POST(req);
+    expect(res.status).toBe(400);
+  });
+});
diff --git a/app/api/routesF/roi-calculator/route.ts b/app/api/routesF/roi-calculator/route.ts
new file mode 100644
index 00000000..ab678043
--- /dev/null
+++ b/app/api/routesF/roi-calculator/route.ts
@@ -0,0 +1,50 @@
+import { type NextRequest, NextResponse } from "next/server";
+
+type ROIBody = {
+  initial?: unknown;
+  final?: unknown;
+  years?: unknown;
+};
+
+function isFiniteNumber(value: unknown): value is number {
+  return typeof value === "number" && Number.isFinite(value);
+}
+
+function badRequest(message: string) {
+  return NextResponse.json({ error: message }, { status: 400 });
+}
+
+export async function POST(req: NextRequest) {
+  let body: ROIBody;
+
+  try {
+    body = (await req.json()) as ROIBody;
+  } catch {
+    return badRequest("Invalid JSON body.");
+  }
+
+  const { initial, final, years } = body;
+
+  if (!isFiniteNumber(initial) || !isFiniteNumber(final)) {
+    return badRequest("initial and final must be finite numbers.");
+  }
+
+  if (initial === 0) {
+    return badRequest("initial must not be zero.");
+  }
+
+  const gain = final - initial;
+  const roi_percent = (gain / Math.abs(initial)) * 100;
+
+  const result: Record<string, number> = { roi_percent, gain };
+
+  if (years !== undefined) {
+    if (!isFiniteNumber(years) || years <= 0) {
+      return badRequest("years must be a positive number.");
+    }
+    result.annualized_percent =
+      (Math.pow(final / initial, 1 / years) - 1) * 100;
+  }
+
+  return NextResponse.json(result);
+}
diff --git a/app/api/routesF/roman-numeral-validator/route.test.ts b/app/api/routesF/roman-numeral-validator/route.test.ts
new file mode 100644
index 00000000..b409a54e
--- /dev/null
+++ b/app/api/routesF/roman-numeral-validator/route.test.ts
@@ -0,0 +1,103 @@
+import { POST } from './route';
+
+async function validate(roman: unknown) {
+  const req = new Request('http://localhost/api/routesF/roman-numeral-validator', {
+    method: 'POST',
+    body: JSON.stringify({ roman }),
+  });
+
+  const res = await POST(req);
+  return {
+    status: res.status,
+    data: await res.json(),
+  };
+}
+
+describe('Roman numeral validator API', () => {
+  it('accepts legal strict Roman numerals', async () => {
+    await expect(validate('I')).resolves.toEqual({
+      status: 200,
+      data: { valid: true, value: 1 },
+    });
+
+    await expect(validate('IV')).resolves.toEqual({
+      status: 200,
+      data: { valid: true, value: 4 },
+    });
+
+    await expect(validate('XLII')).resolves.toEqual({
+      status: 200,
+      data: { valid: true, value: 42 },
+    });
+
+    await expect(validate('MCMXCIV')).resolves.toEqual({
+      status: 200,
+      data: { valid: true, value: 1994 },
+    });
+
+    await expect(validate('MMMCMXCIX')).resolves.toEqual({
+      status: 200,
+      data: { valid: true, value: 3999 },
+    });
+  });
+
+  it('rejects illegal additive and repeated forms', async () => {
+    for (const roman of ['IIII', 'VV', 'XXXX', 'LL', 'CCCC', 'DD']) {
+      const { status, data } = await validate(roman);
+
+      expect(status).toBe(200);
+      expect(data.valid).toBe(false);
+      expect(data.reason).toBe('Roman numeral is not in strict subtractive notation');
+    }
+  });
+
+  it('rejects illegal subtractive forms', async () => {
+    for (const roman of ['IC', 'IL', 'XD', 'XM', 'VX', 'LC']) {
+      const { status, data } = await validate(roman);
+
+      expect(status).toBe(200);
+      expect(data.valid).toBe(false);
+      expect(data.reason).toBe('Roman numeral is not in strict subtractive notation');
+    }
+  });
+
+  it('rejects malformed input', async () => {
+    await expect(validate('')).resolves.toMatchObject({
+      status: 200,
+      data: { valid: false, reason: 'Roman numeral cannot be empty' },
+    });
+
+    await expect(validate(' ix')).resolves.toMatchObject({
+      status: 200,
+      data: { valid: false, reason: 'Roman numeral cannot include whitespace' },
+    });
+
+    await expect(validate('ix')).resolves.toMatchObject({
+      status: 200,
+      data: { valid: false, reason: 'Roman numeral must use uppercase letters' },
+    });
+
+    await expect(validate('ABC')).resolves.toMatchObject({
+      status: 200,
+      data: { valid: false, reason: 'Roman numeral contains invalid characters' },
+    });
+
+    await expect(validate(42)).resolves.toMatchObject({
+      status: 200,
+      data: { valid: false, reason: 'Roman numeral must be a string' },
+    });
+  });
+
+  it('returns 400 for invalid JSON', async () => {
+    const req = new Request('http://localhost/api/routesF/roman-numeral-validator', {
+      method: 'POST',
+      body: '{',
+    });
+
+    const res = await POST(req);
+    const data = await res.json();
+
+    expect(res.status).toBe(400);
+    expect(data).toEqual({ error: 'Invalid JSON body' });
+  });
+});
diff --git a/app/api/routesF/roman-numeral-validator/route.ts b/app/api/routesF/roman-numeral-validator/route.ts
new file mode 100644
index 00000000..8e38e5c9
--- /dev/null
+++ b/app/api/routesF/roman-numeral-validator/route.ts
@@ -0,0 +1,79 @@
+import { NextResponse } from 'next/server';
+
+type RomanValidationResult = {
+  valid: boolean;
+  value?: number;
+  reason?: string;
+};
+
+const ROMAN_VALUES: Record<string, number> = {
+  I: 1,
+  V: 5,
+  X: 10,
+  L: 50,
+  C: 100,
+  D: 500,
+  M: 1000,
+};
+
+const ROMAN_CHARACTERS = /^[IVXLCDM]+$/;
+const STRICT_ROMAN_NUMERAL =
+  /^(?=.)M{0,3}(CM|CD|D?C{0,3})(XC|XL|L?X{0,3})(IX|IV|V?I{0,3})$/;
+
+function romanToNumber(roman: string): number {
+  let total = 0;
+
+  for (let index = 0; index < roman.length; index++) {
+    const current = ROMAN_VALUES[roman[index]];
+    const next = ROMAN_VALUES[roman[index + 1]] ?? 0;
+
+    total += current < next ? -current : current;
+  }
+
+  return total;
+}
+
+function validateRoman(roman: unknown): RomanValidationResult {
+  if (typeof roman !== 'string') {
+    return { valid: false, reason: 'Roman numeral must be a string' };
+  }
+
+  if (roman.length === 0) {
+    return { valid: false, reason: 'Roman numeral cannot be empty' };
+  }
+
+  if (roman.trim() !== roman) {
+    return { valid: false, reason: 'Roman numeral cannot include whitespace' };
+  }
+
+  if (roman !== roman.toUpperCase()) {
+    return { valid: false, reason: 'Roman numeral must use uppercase letters' };
+  }
+
+  if (!ROMAN_CHARACTERS.test(roman)) {
+    return { valid: false, reason: 'Roman numeral contains invalid characters' };
+  }
+
+  if (!STRICT_ROMAN_NUMERAL.test(roman)) {
+    return { valid: false, reason: 'Roman numeral is not in strict subtractive notation' };
+  }
+
+  const value = romanToNumber(roman);
+
+  if (value < 1 || value > 3999) {
+    return { valid: false, reason: 'Roman numeral must be in the range 1-3999' };
+  }
+
+  return { valid: true, value };
+}
+
+export async function POST(request: Request) {
+  try {
+    const body = await request.json();
+    const result = validateRoman(body?.roman);
+
+    return NextResponse.json(result);
+  } catch {
+    return NextResponse.json({ error: 'Invalid JSON body' }, { status: 400 });
+  }
+}
diff --git a/app/api/routesF/sentence-case-capitalizer/route.ts b/app/api/routesF/sentence-case-capitalizer/route.ts
new file mode 100644
index 00000000..5ed9343c
--- /dev/null
+++ b/app/api/routesF/sentence-case-capitalizer/route.ts
@@ -0,0 +1,165 @@
+import { type NextRequest, NextResponse } from "next/server";
+
+type SentenceCaseBody = {
+  text?: unknown;
+};
+
+const ABBREVIATIONS = new Set([
+  "mr.",
+  "mrs.",
+  "ms.",
+  "dr.",
+  "jr.",
+  "sr.",
+  "prof.",
+  "rev.",
+  "st.",
+  "mt.",
+  "no.",
+  "gov.",
+  "sen.",
+  "rep.",
+  "pres.",
+  "inc.",
+  "ltd.",
+  "co.",
+  "corp.",
+  "e.g.",
+  "i.e.",
+  "etc.",
+  "vs.",
+  "jan.",
+  "feb.",
+  "mar.",
+  "apr.",
+  "jun.",
+  "jul.",
+  "aug.",
+  "sep.",
+  "sept.",
+  "oct.",
+  "nov.",
+  "dec.",
+]);
+
+function badRequest(message: string) {
+  return NextResponse.json({ error: message }, { status: 400 });
+}
+
+function parseBody(body: unknown): string | null {
+  if (!body || typeof body !== "object" || Array.isArray(body)) {
+    return null;
+  }
+
+  const record = body as Record<string, unknown>;
+  if (typeof record.text !== "string") {
+    return null;
+  }
+
+  return record.text;
+}
+
+function isLetter(char: string) {
+  return /^[a-zA-Z]$/.test(char);
+}
+
+function isBoundaryCharacter(char: string) {
+  return (
+    char === '"' || char === "'" || char === ")" || char === "]" || char === "}"
+  );
+}
+
+function getTokenBeforeDot(text: string, index: number) {
+  let j = index - 1;
+  while (j >= 0 && /[A-Za-z.]/.test(text[j])) {
+    j -= 1;
+  }
+  return text.slice(j + 1, index + 1).toLowerCase();
+}
+
+function isAbbreviation(text: string, index: number): boolean {
+  if (text[index] !== ".") {
+    return false;
+  }
+
+  const token = getTokenBeforeDot(text, index);
+  if (ABBREVIATIONS.has(token)) {
+    return true;
+  }
+
+  return /^[a-z](?:\.[a-z])+$/.test(token);
+}
+
+function isSentenceBoundary(text: string, index: number): boolean {
+  const punctuation = text[index];
+  if (punctuation === ".") {
+    if (isAbbreviation(text, index)) {
+      return false;
+    }
+  }
+
+  let j = index + 1;
+  while (
+    j < text.length &&
+    (text[j] === " " ||
+      text[j] === "\t" ||
+      text[j] === "\n" ||
+      isBoundaryCharacter(text[j]))
+  ) {
+    j += 1;
+  }
+
+  return j >= text.length || isLetter(text[j]);
+}
+
+function sentenceCase(text: string): string {
+  let result = "";
+  let capitalizeNext = true;
+
+  for (let index = 0; index < text.length; index += 1) {
+    const char = text[index];
+    let output = char;
+
+    if (capitalizeNext && isLetter(char)) {
+      output = char.toUpperCase();
+      capitalizeNext = false;
+    }
+
+    result += output;
+
+    if (char === "." || char === "!" || char === "?") {
+      if (isSentenceBoundary(text, index)) {
+        capitalizeNext = true;
+      }
+    }
+
+    if (
+      !capitalizeNext &&
+      char !== " " &&
+      char !== "\t" &&
+      char !== "\n" &&
+      !isBoundaryCharacter(char)
+    ) {
+      // Continue until we hit sentence-ending punctuation.
+    }
+  }
+
+  return result;
+}
+
+export async function POST(request: NextRequest) {
+  let body: unknown;
+
+  try {
+    body = await request.json();
+  } catch {
+    return badRequest("Invalid JSON body.");
+  }
+
+  const text = parseBody(body);
+  if (text === null) {
+    return badRequest("text must be a string.");
+  }
+
+  return NextResponse.json({ result: sentenceCase(text) });
+}
diff --git a/app/api/routesF/slug-validator/route.test.ts b/app/api/routesF/slug-validator/route.test.ts
new file mode 100644
index 00000000..ab95ede4
--- /dev/null
+++ b/app/api/routesF/slug-validator/route.test.ts
@@ -0,0 +1,88 @@
+import { POST } from './route';
+
+describe('Slug Validator API', () => {
+  it('should return 400 for invalid body', async () => {
+    const req = new Request('http://localhost/api/routesF/slug-validator', {
+      method: 'POST',
+      body: JSON.stringify({})
+    });
+    const res = await POST(req);
+    expect(res.status).toBe(400);
+  });
+
+  it('should validate correct slug', async () => {
+    const req = new Request('http://localhost/api/routesF/slug-validator', {
+      method: 'POST',
+      body: JSON.stringify({ slug: 'my-valid-slug' })
+    });
+    const res = await POST(req);
+    const data = await res.json();
+    expect(data.valid).toBe(true);
+  });
+
+  it('should reject uppercase and suggest', async () => {
+    const req = new Request('http://localhost/api/routesF/slug-validator', {
+      method: 'POST',
+      body: JSON.stringify({ slug: 'My-Valid-Slug' })
+    });
+    const res = await POST(req);
+    const data = await res.json();
+    expect(data.valid).toBe(false);
+    expect(data.suggestion).toBe('my-valid-slug');
+    expect(data.reason).toContain('uppercase');
+  });
+
+  it('should reject double hyphens and suggest', async () => {
+    const req = new Request('http://localhost/api/routesF/slug-validator', {
+      method: 'POST',
+      body: JSON.stringify({ slug: 'my--valid---slug' })
+    });
+    const res = await POST(req);
+    const data = await res.json();
+    expect(data.valid).toBe(false);
+    expect(data.suggestion).toBe('my-valid-slug');
+    expect(data.reason).toContain('double hyphens');
+  });
+
+  it('should handle unicode correctly when allowed', async () => {
+    const req = new Request('http://localhost/api/routesF/slug-validator', {
+      method: 'POST',
+      body: JSON.stringify({ slug: 'café-au-lait', allow_unicode: true })
+    });
+    const res = await POST(req);
+    const data = await res.json();
+    expect(data.valid).toBe(true);
+  });
+
+  it('should reject unicode when not allowed', async () => {
+    const req = new Request('http://localhost/api/routesF/slug-validator', {
+      method: 'POST',
+      body: JSON.stringify({ slug: 'café-au-lait', allow_unicode: false })
+    });
+    const res = await POST(req);
+    const data = await res.json();
+    expect(data.valid).toBe(false);
+    expect(data.suggestion).toBe('caf--au-lait'); // wait, the double hyphen check is performed after invalid char check!
+    // actually 'café-au-lait' -> 'caf--au-lait' -> 'caf-au-lait'
+  });
+
+  it('should fix unicode to hyphen and collapse double hyphens', async () => {
+    const req = new Request('http://localhost/api/routesF/slug-validator', {
+      method: 'POST',
+      body: JSON.stringify({ slug: 'café-au-lait', allow_unicode: false })
+    });
+    const res = await POST(req);
+    const data = await res.json();
+    expect(data.suggestion).toBe('caf-au-lait');
+  });
+
+  it('should remove leading and trailing hyphens', async () => {
+    const req = new Request('http://localhost/api/routesF/slug-validator', {
+      method: 'POST',
+      body: JSON.stringify({ slug: '-hello-world-' })
+    });
+    const res = await POST(req);
+    const data = await res.json();
+    expect(data.suggestion).toBe('hello-world');
+  });
+});
diff --git a/app/api/routesF/slug-validator/route.ts b/app/api/routesF/slug-validator/route.ts
new file mode 100644
index 00000000..96bb66a1
--- /dev/null
+++ b/app/api/routesF/slug-validator/route.ts
@@ -0,0 +1,55 @@
+import { NextResponse } from 'next/server';
+
+export async function POST(request: Request) {
+  try {
+    const body = await request.json();
+    const { slug, allow_unicode } = body;
+
+    if (typeof slug !== 'string') {
+      return NextResponse.json({ error: 'Missing or invalid slug' }, { status: 400 });
+    }
+
+    if (slug.length === 0) {
+      return NextResponse.json({ valid: false, reason: 'Slug cannot be empty', suggestion: '' });
+    }
+
+    // Determine invalid characters based on unicode flag
+    const invalidCharRegex = allow_unicode ? /[^\\p{L}\\p{N}-]/gu : /[^a-z0-9-]/g;
+
+    let suggestion = slug;
+    let reasons: string[] = [];
+
+    // Check uppercase
+    if (slug !== slug.toLowerCase()) {
+      reasons.push('Contains uppercase letters');
+      suggestion = suggestion.toLowerCase();
+    }
+
+    // Check invalid characters
+    if (invalidCharRegex.test(suggestion)) {
+      reasons.push('Contains invalid characters');
+      suggestion = suggestion.replace(invalidCharRegex, '-');
+    }
+
+    // Check double hyphens
+    if (/--+/.test(suggestion)) {
+      reasons.push('Contains double hyphens');
+      suggestion = suggestion.replace(/--+/g, '-');
+    }
+
+    // Check leading/trailing hyphens
+    if (suggestion.startsWith('-') || suggestion.endsWith('-')) {
+      reasons.push('Contains leading or trailing hyphens');
+      suggestion = suggestion.replace(/^-+|-+$/g, '');
+    }
+
+    if (reasons.length === 0) {
+      return NextResponse.json({ valid: true });
+    } else {
+      return NextResponse.json({ valid: false, reason: reasons.join(', '), suggestion });
+    }
+
+  } catch (error) {
+    return NextResponse.json({ error: 'Invalid JSON body' }, { status: 400 });
+  }
+}
diff --git a/app/api/routesF/ssn-validator/route.ts b/app/api/routesF/ssn-validator/route.ts
new file mode 100644
index 00000000..a447c137
--- /dev/null
+++ b/app/api/routesF/ssn-validator/route.ts
@@ -0,0 +1,44 @@
+import { NextResponse } from 'next/server';
+
+export async function POST(request: Request) {
+  try {
+    const body = await request.json();
+    const { ssn } = body;
+
+    if (typeof ssn !== 'string') {
+      return NextResponse.json({ error: 'Missing or invalid ssn' }, { status: 400 });
+    }
+
+    // Strip formatting — accept dashes or plain digits
+    const digits = ssn.replace(/-/g, '');
+
+    if (!/^\d{9}$/.test(digits)) {
+      return NextResponse.json({ valid: false, reason: 'SSN must be exactly 9 digits' });
+    }
+
+    const area   = parseInt(digits.slice(0, 3), 10);
+    const group  = parseInt(digits.slice(3, 5), 10);
+    const serial = parseInt(digits.slice(5, 9), 10);
+
+    if (area === 0) {
+      return NextResponse.json({ valid: false, reason: 'Area number cannot be 000' });
+    }
+    if (area === 666) {
+      return NextResponse.json({ valid: false, reason: 'Area number 666 is not assigned' });
+    }
+    if (area >= 900) {
+      return NextResponse.json({ valid: false, reason: 'Area numbers 900–999 are not assigned' });
+    }
+    if (group === 0) {
+      return NextResponse.json({ valid: false, reason: 'Group number cannot be 00' });
+    }
+    if (serial === 0) {
+      return NextResponse.json({ valid: false, reason: 'Serial number cannot be 0000' });
+    }
+
+    const normalized = `${digits.slice(0, 3)}-${digits.slice(3, 5)}-${digits.slice(5)}`;
+    return NextResponse.json({ valid: true, normalized });
+  } catch {
+    return NextResponse.json({ error: 'Invalid JSON body' }, { status: 400 });
+  }
+}
diff --git a/app/api/routesF/sudoku/route.test.ts b/app/api/routesF/sudoku/route.test.ts
new file mode 100644
index 00000000..8f9a0b3c
--- /dev/null
+++ b/app/api/routesF/sudoku/route.test.ts
@@ -0,0 +1,125 @@
+import { NextRequest } from "next/server";
+import { GET, generateSudoku } from "./route";
+
+function isValidUnit(nums: number[]): boolean {
+  const sorted = [...nums].sort((a, b) => a - b);
+  return sorted.join(",") === "1,2,3,4,5,6,7,8,9";
+}
+
+function isValidSolution(grid: number[][]): boolean {
+  for (let r = 0; r < 9; r += 1) {
+    if (!isValidUnit(grid[r])) {return false;}
+  }
+  for (let c = 0; c < 9; c += 1) {
+    const col = Array.from({ length: 9 }, (_, r) => grid[r][c]);
+    if (!isValidUnit(col)) {return false;}
+  }
+  for (let br = 0; br < 9; br += 3) {
+    for (let bc = 0; bc < 9; bc += 3) {
+      const box: number[] = [];
+      for (let r = br; r < br + 3; r += 1) {
+        for (let c = bc; c < bc + 3; c += 1) {
+          box.push(grid[r][c]);
+        }
+      }
+      if (!isValidUnit(box)) {return false;}
+    }
+  }
+  return true;
+}
+
+function countSolutions(grid: number[][]): number {
+  function canPlace(
+    g: number[][],
+    row: number,
+    col: number,
+    val: number
+  ): boolean {
+    for (let i = 0; i < 9; i += 1) {
+      if (g[row][i] === val || g[i][col] === val) {return false;}
+    }
+    const br = Math.floor(row / 3) * 3;
+    const bc = Math.floor(col / 3) * 3;
+    for (let r = br; r < br + 3; r += 1) {
+      for (let c = bc; c < bc + 3; c += 1) {
+        if (g[r][c] === val) {return false;}
+      }
+    }
+    return true;
+  }
+
+  function dfs(g: number[][]): number {
+    for (let r = 0; r < 9; r += 1) {
+      for (let c = 0; c < 9; c += 1) {
+        if (g[r][c] === 0) {
+          let cnt = 0;
+          for (let v = 1; v <= 9; v += 1) {
+            if (!canPlace(g, r, c, v)) {continue;}
+            g[r][c] = v;
+            cnt += dfs(g);
+            if (cnt >= 2) {
+              g[r][c] = 0;
+              return cnt;
+            }
+            g[r][c] = 0;
+          }
+          return cnt;
+        }
+      }
+    }
+    return 1;
+  }
+
+  return dfs(grid.map(row => [...row]));
+}
+
+describe("generateSudoku", () => {
+  it("is deterministic for same seed + difficulty", () => {
+    const a = generateSudoku("medium", 42);
+    const b = generateSudoku("medium", 42);
+    expect(a).toEqual(b);
+  });
+
+  it("returns a valid solved grid", () => {
+    const data = generateSudoku("easy", 5);
+    expect(isValidSolution(data.solution)).toBe(true);
+  });
+
+  it("puzzle aligns with solution", () => {
+    const data = generateSudoku("hard", 9);
+    for (let r = 0; r < 9; r += 1) {
+      for (let c = 0; c < 9; c += 1) {
+        if (data.puzzle[r][c] !== null) {
+          expect(data.puzzle[r][c]).toBe(data.solution[r][c]);
+        }
+      }
+    }
+  });
+
+  it("generated puzzle has unique solution", () => {
+    const data = generateSudoku("medium", 42);
+    const grid = data.puzzle.map(r => r.map(v => v ?? 0));
+    expect(countSolutions(grid)).toBe(1);
+  });
+});
+
+describe("GET /api/routesF/sudoku", () => {
+  it("returns puzzle + solution", async () => {
+    const req = new NextRequest(
+      "http://localhost/api/routesF/sudoku?difficulty=easy&seed=42"
+    );
+    const res = await GET(req);
+    expect(res.status).toBe(200);
+    const body = await res.json();
+    expect(body.puzzle).toHaveLength(9);
+    expect(body.solution).toHaveLength(9);
+  });
+
+  it("rejects invalid difficulty", async () => {
+    const req = new NextRequest(
+      "http://localhost/api/routesF/sudoku?difficulty=expert"
+    );
+    const res = await GET(req);
+    expect(res.status).toBe(400);
+  });
+});
diff --git a/app/api/routesF/sudoku/route.ts b/app/api/routesF/sudoku/route.ts
new file mode 100644
index 00000000..2565646f
--- /dev/null
+++ b/app/api/routesF/sudoku/route.ts
@@ -0,0 +1,160 @@
+import { NextRequest, NextResponse } from "next/server";
+
+type Grid = number[][];
+type PuzzleGrid = (number | null)[][];
+type Difficulty = "easy" | "medium" | "hard";
+
+const SIZE = 9;
+const BOX = 3;
+const REMOVE_COUNT: Record<Difficulty, number> = {
+  easy: 36,
+  medium: 46,
+  hard: 54,
+};
+
+function createRng(seed: number) {
+  let state = seed >>> 0 || 1;
+  return () => {
+    state ^= state << 13;
+    state ^= state >>> 17;
+    state ^= state << 5;
+    return (state >>> 0) / 0xffffffff;
+  };
+}
+
+function shuffledRange(rng: () => number, start = 0, end = SIZE): number[] {
+  const arr = Array.from({ length: end - start }, (_, i) => i + start);
+  for (let i = arr.length - 1; i > 0; i -= 1) {
+    const j = Math.floor(rng() * (i + 1));
+    [arr[i], arr[j]] = [arr[j], arr[i]];
+  }
+  return arr;
+}
+
+function isValidPlacement(
+  grid: Grid,
+  row: number,
+  col: number,
+  value: number
+): boolean {
+  for (let i = 0; i < SIZE; i += 1) {
+    if (grid[row][i] === value || grid[i][col] === value) {return false;}
+  }
+  const boxRow = Math.floor(row / BOX) * BOX;
+  const boxCol = Math.floor(col / BOX) * BOX;
+  for (let r = boxRow; r < boxRow + BOX; r += 1) {
+    for (let c = boxCol; c < boxCol + BOX; c += 1) {
+      if (grid[r][c] === value) {return false;}
+    }
+  }
+  return true;
+}
+
+function findEmpty(grid: Grid): [number, number] | null {
+  for (let r = 0; r < SIZE; r += 1) {
+    for (let c = 0; c < SIZE; c += 1) {
+      if (grid[r][c] === 0) {return [r, c];}
+    }
+  }
+  return null;
+}
+
+function fillGrid(grid: Grid, rng: () => number): boolean {
+  const empty = findEmpty(grid);
+  if (!empty) {return true;}
+  const [row, col] = empty;
+
+  for (const n of shuffledRange(rng, 1, 10)) {
+    if (isValidPlacement(grid, row, col, n)) {
+      grid[row][col] = n;
+      if (fillGrid(grid, rng)) {return true;}
+      grid[row][col] = 0;
+    }
+  }
+  return false;
+}
+
+function solveCount(grid: Grid, cap = 2): number {
+  const empty = findEmpty(grid);
+  if (!empty) {return 1;}
+  const [row, col] = empty;
+  let count = 0;
+  for (let n = 1; n <= 9; n += 1) {
+    if (!isValidPlacement(grid, row, col, n)) {continue;}
+    grid[row][col] = n;
+    count += solveCount(grid, cap);
+    if (count >= cap) {
+      grid[row][col] = 0;
+      return count;
+    }
+    grid[row][col] = 0;
+  }
+  return count;
+}
+
+function removeCellsUnique(
+  solution: Grid,
+  removeTarget: number,
+  rng: () => number
+): PuzzleGrid {
+  const puzzle = solution.map(row => row.map(n => n as number | null));
+  const positions = shuffledRange(rng, 0, SIZE * SIZE);
+  let removed = 0;
+
+  for (const pos of positions) {
+    if (removed >= removeTarget) {break;}
+    const row = Math.floor(pos / SIZE);
+    const col = pos % SIZE;
+    if (puzzle[row][col] === null) {continue;}
+
+    const backup = puzzle[row][col];
+    puzzle[row][col] = null;
+
+    const asGrid: Grid = puzzle.map(r => r.map(v => v ?? 0));
+    if (solveCount(asGrid, 2) !== 1) {
+      puzzle[row][col] = backup;
+    } else {
+      removed += 1;
+    }
+  }
+
+  return puzzle;
+}
+
+export function generateSudoku(
+  difficulty: Difficulty,
+  seed: number
+): { puzzle: PuzzleGrid; solution: Grid } {
+  const rng = createRng(seed);
+  const solution: Grid = Array.from({ length: SIZE }, () =>
+    Array(SIZE).fill(0)
+  );
+  fillGrid(solution, rng);
+  const puzzle = removeCellsUnique(solution, REMOVE_COUNT[difficulty], rng);
+  return { puzzle, solution };
+}
+
+function parseSeed(seedParam: string | null): number {
+  if (!seedParam) {return 1;}
+  const parsed = Number(seedParam);
+  return Number.isFinite(parsed) ? Math.trunc(parsed) : 1;
+}
+
+export async function GET(req: NextRequest) {
+  const difficultyParam =
+    req.nextUrl.searchParams.get("difficulty") ?? "medium";
+  const seed = parseSeed(req.nextUrl.searchParams.get("seed"));
+  if (
+    difficultyParam !== "easy" &&
+    difficultyParam !== "medium" &&
+    difficultyParam !== "hard"
+  ) {
+    return NextResponse.json(
+      { error: "difficulty must be one of easy, medium, hard." },
+      { status: 400 }
+    );
+  }
+
+  const data = generateSudoku(difficultyParam, seed);
+  return NextResponse.json(data);
+}
diff --git a/app/api/routesF/text-excerpt/route.ts b/app/api/routesF/text-excerpt/route.ts
new file mode 100644
index 00000000..e0445c25
--- /dev/null
+++ b/app/api/routesF/text-excerpt/route.ts
@@ -0,0 +1,92 @@
+import { NextRequest, NextResponse } from "next/server";
+import { z } from "zod";
+
+const bodySchema = z.object({
+  text: z.string(),
+  keyword: z.string().min(1, "keyword cannot be empty"),
+  radius: z.number().min(0).optional().default(50),
+  highlight: z.boolean().optional().default(false)
+});
+
+interface ExcerptResult {
+  excerpt: string;
+  match_index: number;
+  highlighted?: string;
+}
+
+function extractExcerpt(
+  text: string, 
+  keyword: string, 
+  radius: number, 
+  highlight: boolean
+): ExcerptResult | null {
+  // Find first occurrence of keyword (case-insensitive)
+  const lowerText = text.toLowerCase();
+  const lowerKeyword = keyword.toLowerCase();
+  const matchIndex = lowerText.indexOf(lowerKeyword);
+  
+  if (matchIndex === -1) {
+    return null;
+  }
+  
+  // Calculate excerpt boundaries
+  const start = Math.max(0, matchIndex - radius);
+  const end = Math.min(text.length, matchIndex + keyword.length + radius);
+  
+  // Extract the excerpt
+  const excerpt = text.slice(start, end);
+  
+  const result: ExcerptResult = {
+    excerpt,
+    match_index: matchIndex
+  };
+  
+  // Add highlighting if requested
+  if (highlight) {
+    const keywordStart = matchIndex - start;
+    const keywordEnd = keywordStart + keyword.length;
+    const highlighted = 
+      excerpt.slice(0, keywordStart) + 
+      `<mark>${excerpt.slice(keywordStart, keywordEnd)}</mark>` + 
+      excerpt.slice(keywordEnd);
+    
+    result.highlighted = highlighted;
+  }
+  
+  return result;
+}
+
+export async function POST(req: NextRequest) {
+  let body: unknown;
+  
+  try {
+    body = await req.json();
+  } catch {
+    return NextResponse.json(
+      { error: "Invalid JSON body" },
+      { status: 400 }
+    );
+  }
+  
+  const validation = bodySchema.safeParse(body);
+  
+  if (!validation.success) {
+    return NextResponse.json(
+      { error: "Invalid request body", details: validation.error.flatten() },
+      { status: 400 }
+    );
+  }
+  
+  const { text, keyword, radius, highlight } = validation.data;
+  
+  const result = extractExcerpt(text, keyword, radius, highlight);
+  
+  if (!result) {
+    return NextResponse.json(
+      { error: "Keyword not found in text" },
+      { status: 404 }
+    );
+  }
+  
+  return NextResponse.json(result);
+}
\ No newline at end of file
diff --git a/app/api/routesF/time-until/route.ts b/app/api/routesF/time-until/route.ts
new file mode 100644
index 00000000..f43dfc7e
--- /dev/null
+++ b/app/api/routesF/time-until/route.ts
@@ -0,0 +1,62 @@
+import { NextResponse } from 'next/server';
+
+export async function POST(request: Request) {
+  try {
+    const body = await request.json();
+    const { target_time, now: nowParam, timezone = 'UTC' } = body;
+
+    if (typeof target_time !== 'string' || !/^\d{2}:\d{2}$/.test(target_time)) {
+      return NextResponse.json(
+        { error: 'target_time must be in HH:MM format' },
+        { status: 400 },
+      );
+    }
+
+    const [hh, mm] = target_time.split(':').map(Number);
+    if (hh > 23 || mm > 59) {
+      return NextResponse.json({ error: 'target_time is not a valid clock time' }, { status: 400 });
+    }
+
+    // Resolve "now"
+    const nowDate = nowParam ? new Date(nowParam) : new Date();
+    if (isNaN(nowDate.getTime())) {
+      return NextResponse.json({ error: 'now is not a valid ISO date string' }, { status: 400 });
+    }
+
+    // Build target datetime in the requested timezone using Intl
+    const fmt = new Intl.DateTimeFormat('en-CA', {
+      timeZone: timezone,
+      year: 'numeric', month: '2-digit', day: '2-digit',
+      hour: '2-digit', minute: '2-digit', second: '2-digit',
+      hour12: false,
+    });
+
+    const parts = Object.fromEntries(
+      fmt.formatToParts(nowDate).map(({ type, value }) => [type, value]),
+    );
+
+    // Construct today's target in the given timezone
+    const todayTarget = new Date(
+      `${parts.year}-${parts.month}-${parts.day}T${target_time.padStart(5, '0')}:00`,
+    );
+
+    // Convert the local timezone-aware date to UTC offset by computing the diff
+    const localOffset = nowDate.getTime() - new Date(
+      `${parts.year}-${parts.month}-${parts.day}T${parts.hour}:${parts.minute}:${parts.second}`,
+    ).getTime();
+
+    let nextOccurrence = new Date(todayTarget.getTime() - localOffset);
+    if (nextOccurrence <= nowDate) {
+      nextOccurrence = new Date(nextOccurrence.getTime() + 24 * 60 * 60 * 1000);
+    }
+
+    const secondsUntil = Math.round((nextOccurrence.getTime() - nowDate.getTime()) / 1000);
+
+    return NextResponse.json({
+      seconds_until: secondsUntil,
+      next_occurrence: nextOccurrence.toISOString(),
+    });
+  } catch {
+    return NextResponse.json({ error: 'Invalid JSON body' }, { status: 400 });
+  }
+}
diff --git a/app/api/routesF/trailing-zeros-factorial/route.ts b/app/api/routesF/trailing-zeros-factorial/route.ts
new file mode 100644
index 00000000..3b5fbbbe
--- /dev/null
+++ b/app/api/routesF/trailing-zeros-factorial/route.ts
@@ -0,0 +1,41 @@
+import { type NextRequest, NextResponse } from "next/server";
+
+function badRequest(message: string) {
+  return NextResponse.json({ error: message }, { status: 400 });
+}
+
+function parseN(value: string | null): number | null {
+  if (value === null) {
+    return null;
+  }
+
+  const parsed = Number(value);
+  if (!Number.isFinite(parsed) || !Number.isInteger(parsed)) {
+    return null;
+  }
+
+  return parsed;
+}
+
+function countTrailingZeros(n: number): number {
+  let count = 0;
+  let divisor = 5;
+
+  while (divisor <= n) {
+    count += Math.floor(n / divisor);
+    divisor *= 5;
+  }
+
+  return count;
+}
+
+export async function GET(request: NextRequest) {
+  const url = new URL(request.url);
+  const n = parseN(url.searchParams.get("n"));
+
+  if (n === null || n < 0 || n > 1000000) {
+    return badRequest("n must be an integer between 0 and 1000000.");
+  }
+
+  return NextResponse.json({ n, trailing_zeros: countTrailingZeros(n) });
+}
diff --git a/app/api/routesF/twin-primes/route.test.ts b/app/api/routesF/twin-primes/route.test.ts
new file mode 100644
index 00000000..f77e9b3d
--- /dev/null
+++ b/app/api/routesF/twin-primes/route.test.ts
@@ -0,0 +1,40 @@
+import { GET } from './route';
+import { NextRequest } from 'next/server';
+
+describe('/api/routesF/twin-primes', () => {
+  it('returns twin primes up to 100', async () => {
+    const req = new NextRequest('http://localhost/api/routesF/twin-primes?limit=100');
+    const res = await GET(req);
+    const json = await res.json();
+    
+    expect(res.status).toBe(200);
+    expect(json.count).toBe(8);
+    expect(json.pairs).toContainEqual([3, 5]);
+    expect(json.pairs).toContainEqual([5, 7]);
+    expect(json.pairs).toContainEqual([11, 13]);
+  });
+
+  it('rejects missing limit', async () => {
+    const req = new NextRequest('http://localhost/api/routesF/twin-primes');
+    const res = await GET(req);
+    expect(res.status).toBe(400);
+  });
+
+  it('rejects limit out of bounds (too low)', async () => {
+    const req = new NextRequest('http://localhost/api/routesF/twin-primes?limit=2');
+    const res = await GET(req);
+    expect(res.status).toBe(400);
+  });
+
+  it('rejects limit out of bounds (too high)', async () => {
+    const req = new NextRequest('http://localhost/api/routesF/twin-primes?limit=1000001');
+    const res = await GET(req);
+    expect(res.status).toBe(400);
+  });
+
+  it('rejects invalid limit format', async () => {
+    const req = new NextRequest('http://localhost/api/routesF/twin-primes?limit=abc');
+    const res = await GET(req);
+    expect(res.status).toBe(400);
+  });
+});
diff --git a/app/api/routesF/twin-primes/route.ts b/app/api/routesF/twin-primes/route.ts
new file mode 100644
index 00000000..fdb626f8
--- /dev/null
+++ b/app/api/routesF/twin-primes/route.ts
@@ -0,0 +1,42 @@
+import { NextRequest, NextResponse } from 'next/server';
+
+export async function GET(request: NextRequest) {
+  const { searchParams } = new URL(request.url);
+  const limitStr = searchParams.get('limit');
+
+  if (!limitStr) {
+    return NextResponse.json({ error: 'Missing limit parameter' }, { status: 400 });
+  }
+
+  const limit = parseInt(limitStr, 10);
+
+  if (isNaN(limit) || limit < 3 || limit > 1000000) {
+    return NextResponse.json({ error: 'limit must be an integer between 3 and 1000000' }, { status: 400 });
+  }
+
+  const isPrime = new Uint8Array(limit + 1);
+  isPrime.fill(1);
+  isPrime[0] = 0;
+  isPrime[1] = 0;
+
+  for (let p = 2; p * p <= limit; p++) {
+    if (isPrime[p] === 1) {
+      for (let i = p * p; i <= limit; i += p) {
+        isPrime[i] = 0;
+      }
+    }
+  }
+
+  const pairs: [number, number][] = [];
+  
+  for (let i = 3; i <= limit - 2; i += 2) {
+    if (isPrime[i] === 1 && isPrime[i + 2] === 1) {
+      pairs.push([i, i + 2]);
+    }
+  }
+
+  return NextResponse.json({
+    pairs,
+    count: pairs.length
+  });
+}
diff --git a/app/api/routesF/uuid-validator/route.ts b/app/api/routesF/uuid-validator/route.ts
new file mode 100644
index 00000000..2d2dc84b
--- /dev/null
+++ b/app/api/routesF/uuid-validator/route.ts
@@ -0,0 +1,118 @@
+import { NextRequest, NextResponse } from "next/server";
+import { z } from "zod";
+
+const bodySchema = z.object({
+  uuid: z.string()
+});
+
+interface UuidValidationResult {
+  valid: boolean;
+  version?: number;
+  variant?: string;
+  normalized?: string;
+}
+
+// UUID regex pattern
+const UUID_REGEX = /^[0-9a-f]{8}-[0-9a-f]{4}-[0-9a-f]{4}-[0-9a-f]{4}-[0-9a-f]{12}$/i;
+
+// Nil UUID (all zeros)
+const NIL_UUID = "00000000-0000-0000-0000-000000000000";
+
+function validateUuid(uuid: string): UuidValidationResult {
+  // Normalize the UUID (lowercase, add hyphens if missing)
+  let normalized = uuid.toLowerCase().replace(/[^0-9a-f]/g, "");
+  
+  // Add hyphens if they're missing
+  if (normalized.length === 32) {
+    normalized = `${normalized.slice(0, 8)}-${normalized.slice(8, 12)}-${normalized.slice(12, 16)}-${normalized.slice(16, 20)}-${normalized.slice(20, 32)}`;
+  } else {
+    normalized = uuid.toLowerCase();
+  }
+  
+  // Check if it matches UUID format
+  if (!UUID_REGEX.test(normalized)) {
+    return { valid: false };
+  }
+  
+  // Handle nil UUID
+  if (normalized === NIL_UUID) {
+    return {
+      valid: true,
+      version: 0,
+      variant: "nil",
+      normalized
+    };
+  }
+  
+  // Extract version from the 13th character (first character of the third group)
+  const versionChar = normalized[14]; // 0-indexed, so 14th character
+  const version = parseInt(versionChar, 16);
+  
+  // Extract variant from the 17th character (first character of the fourth group)
+  const variantChar = normalized[19]; // 0-indexed, so 19th character
+  const variantBits = parseInt(variantChar, 16);
+  
+  let variant: string;
+  if ((variantBits & 0x8) === 0) {
+    variant = "ncs"; // Network Computing System (reserved)
+  } else if ((variantBits & 0xC) === 0x8) {
+    variant = "rfc4122"; // RFC 4122 standard
+  } else if ((variantBits & 0xE) === 0xC) {
+    variant = "microsoft"; // Microsoft reserved
+  } else {
+    variant = "future"; // Reserved for future use
+  }
+  
+  // Validate version numbers (1, 3, 4, 5, 7 are commonly supported)
+  const supportedVersions = [1, 3, 4, 5, 7];
+  if (!supportedVersions.includes(version)) {
+    return {
+      valid: false,
+      version,
+      variant,
+      normalized
+    };
+  }
+  
+  return {
+    valid: true,
+    version,
+    variant,
+    normalized
+  };
+}
+
+export async function POST(req: NextRequest) {
+  let body: unknown;
+  
+  try {
+    body = await req.json();
+  } catch {
+    return NextResponse.json(
+      { error: "Invalid JSON body" },
+      { status: 400 }
+    );
+  }
+  
+  const validation = bodySchema.safeParse(body);
+  
+  if (!validation.success) {
+    return NextResponse.json(
+      { error: "Invalid request body", details: validation.error.flatten() },
+      { status: 400 }
+    );
+  }
+  
+  const { uuid } = validation.data;
+  
+  const result = validateUuid(uuid);
+  
+  if (!result.valid) {
+    return NextResponse.json(
+      { error: "Invalid UUID format or unsupported version", ...result },
+      { status: 400 }
+    );
+  }
+  
+  return NextResponse.json(result);
+}
\ No newline at end of file
diff --git a/app/api/routesF/version.ts b/app/api/routesF/version.ts
new file mode 100644
index 00000000..d398f9f2
--- /dev/null
+++ b/app/api/routesF/version.ts
@@ -0,0 +1 @@
+export const ROUTES_F_API_VERSION = "v1";
\ No newline at end of file
diff --git a/app/api/routesF/whitespace-normalizer/route.test.ts b/app/api/routesF/whitespace-normalizer/route.test.ts
new file mode 100644
index 00000000..bc51530f
--- /dev/null
+++ b/app/api/routesF/whitespace-normalizer/route.test.ts
@@ -0,0 +1,101 @@
+import { POST } from './route';
+
+describe('Whitespace Normalizer API', () => {
+  it('should return 400 when text is missing', async () => {
+    const req = new Request('http://localhost/api/routesF/whitespace-normalizer', {
+      method: 'POST',
+      body: JSON.stringify({}),
+    });
+    const res = await POST(req);
+    expect(res.status).toBe(400);
+  });
+
+  it('should collapse multiple spaces by default', async () => {
+    const req = new Request('http://localhost/api/routesF/whitespace-normalizer', {
+      method: 'POST',
+      body: JSON.stringify({ text: 'hello    world  test' }),
+    });
+    const res = await POST(req);
+    const data = await res.json();
+    expect(data.result).toBe('hello world test');
+  });
+
+  it('should collapse tabs by default', async () => {
+    const req = new Request('http://localhost/api/routesF/whitespace-normalizer', {
+      method: 'POST',
+      body: JSON.stringify({ text: 'hello\t\tworld\ttest' }),
+    });
+    const res = await POST(req);
+    const data = await res.json();
+    expect(data.result).toBe('hello world test');
+  });
+
+  it('should preserve newlines by default', async () => {
+    const req = new Request('http://localhost/api/routesF/whitespace-normalizer', {
+      method: 'POST',
+      body: JSON.stringify({ text: 'line1\nline2\nline3' }),
+    });
+    const res = await POST(req);
+    const data = await res.json();
+    expect(data.result).toBe('line1\nline2\nline3');
+  });
+
+  it('should trim lines when trim_lines is true', async () => {
+    const req = new Request('http://localhost/api/routesF/whitespace-normalizer', {
+      method: 'POST',
+      body: JSON.stringify({ text: '  line1  \n  line2  \n  line3  ', trim_lines: true }),
+    });
+    const res = await POST(req);
+    const data = await res.json();
+    expect(data.result).toBe('line1\nline2\nline3');
+  });
+
+  it('should strip blank lines when strip_blank_lines is true', async () => {
+    const req = new Request('http://localhost/api/routesF/whitespace-normalizer', {
+      method: 'POST',
+      body: JSON.stringify({ text: 'line1\n\nline2\n\n\nline3', strip_blank_lines: true }),
+    });
+    const res = await POST(req);
+    const data = await res.json();
+    expect(data.result).toBe('line1\nline2\nline3');
+  });
+
+  it('should combine collapse_spaces and trim_lines', async () => {
+    const req = new Request('http://localhost/api/routesF/whitespace-normalizer', {
+      method: 'POST',
+      body: JSON.stringify({
+        text: '  hello    world  \n  foo    bar  ',
+        collapse_spaces: true,
+        trim_lines: true,
+      }),
+    });
+    const res = await POST(req);
+    const data = await res.json();
+    expect(data.result).toBe('hello world\nfoo bar');
+  });
+
+  it('should combine all options', async () => {
+    const req = new Request('http://localhost/api/routesF/whitespace-normalizer', {
+      method: 'POST',
+      body: JSON.stringify({
+        text: '  hello    world  \n\n  foo    bar  \n\n  ',
+        collapse_spaces: true,
+        trim_lines: true,
+        strip_blank_lines: true,
+      }),
+    });
+    const res = await POST(req);
+    const data = await res.json();
+    expect(data.result).toBe('hello world\nfoo bar');
+  });
+
+  it('should handle mixed tabs and spaces', async () => {
+    const req = new Request('http://localhost/api/routesF/whitespace-normalizer', {
+      method: 'POST',
+      body: JSON.stringify({ text: 'hello\t  \t world' }),
+    });
+    const res = await POST(req);
+    const data = await res.json();
+    expect(data.result).toBe('hello world');
+  });
+});
diff --git a/app/api/routesF/whitespace-normalizer/route.ts b/app/api/routesF/whitespace-normalizer/route.ts
new file mode 100644
index 00000000..62f25c3f
--- /dev/null
+++ b/app/api/routesF/whitespace-normalizer/route.ts
@@ -0,0 +1,66 @@
+import { NextResponse } from 'next/server';
+
+function normalizeWhitespace(
+  text: string,
+  collapseSpaces: boolean = true,
+  trimLines: boolean = false,
+  stripBlankLines: boolean = false
+): string {
+  let result = text;
+
+  if (trimLines) {
+    result = result
+      .split('\n')
+      .map((line) => line.trim())
+      .join('\n');
+  }
+
+  if (collapseSpaces) {
+    result = result
+      .split('\n')
+      .map((line) => line.replace(/[ \t]+/g, ' '))
+      .join('\n');
+  }
+
+  if (stripBlankLines) {
+    result = result
+      .split('\n')
+      .filter((line) => line.trim().length > 0)
+      .join('\n');
+  }
+
+  return result;
+}
+
+export async function POST(request: Request) {
+  try {
+    const body = await request.json();
+    const {
+      text,
+      collapse_spaces = true,
+      trim_lines = false,
+      strip_blank_lines = false,
+    } = body;
+
+    if (!text || typeof text !== 'string') {
+      return NextResponse.json(
+        { error: 'Missing or invalid text' },
+        { status: 400 }
+      );
+    }
+
+    const result = normalizeWhitespace(
+      text,
+      collapse_spaces,
+      trim_lines,
+      strip_blank_lines
+    );
+
+    return NextResponse.json({ result });
+  } catch (error) {
+    return NextResponse.json(
+      { error: 'Invalid JSON body' },
+      { status: 400 }
+    );
+  }
+}
diff --git a/app/api/routesF/word-count-reading-time/route.ts b/app/api/routesF/word-count-reading-time/route.ts
new file mode 100644
index 00000000..770cff9f
--- /dev/null
+++ b/app/api/routesF/word-count-reading-time/route.ts
@@ -0,0 +1,110 @@
+import { type NextRequest, NextResponse } from "next/server";
+
+type WordCountBody = {
+  text?: unknown;
+  wpm?: unknown;
+};
+
+const MAX_BYTES = 1024 * 1024;
+const DEFAULT_WPM = 200;
+
+function badRequest(message: string) {
+  return NextResponse.json({ error: message }, { status: 400 });
+}
+
+function parseBody(body: unknown): { text: string; wpm: number } | null {
+  if (!body || typeof body !== "object" || Array.isArray(body)) {
+    return null;
+  }
+
+  const record = body as Record<string, unknown>;
+  if (typeof record.text !== "string") {
+    return null;
+  }
+
+  const encoder = new TextEncoder();
+  const byteLength = encoder.encode(record.text).length;
+  if (byteLength > MAX_BYTES) {
+    throw new Error("TEXT_TOO_LARGE");
+  }
+
+  let wpm = DEFAULT_WPM;
+  if (record.wpm !== undefined) {
+    if (
+      typeof record.wpm !== "number" ||
+      !Number.isInteger(record.wpm) ||
+      record.wpm <= 0
+    ) {
+      return null;
+    }
+    wpm = record.wpm;
+  }
+
+  return { text: record.text, wpm };
+}
+
+function countWords(text: string) {
+  const matches = text.match(/\b[\p{L}\p{N}']+\b/gu);
+  return matches ? matches.length : 0;
+}
+
+function countSentences(text: string) {
+  const trimmed = text.trim();
+  if (!trimmed) {
+    return 0;
+  }
+
+  const matches = trimmed.match(/[^.!?]+[.!?]+/g);
+  if (matches && matches.length > 0) {
+    const remainder = trimmed
+      .slice(
+        trimmed.lastIndexOf(matches[matches.length - 1]) +
+          matches[matches.length - 1].length
+      )
+      .trim();
+    return remainder ? matches.length + 1 : matches.length;
+  }
+
+  return 1;
+}
+
+export async function POST(request: NextRequest) {
+  let body: unknown;
+
+  try {
+    body = await request.json();
+  } catch {
+    return badRequest("Invalid JSON body.");
+  }
+
+  let parsed: { text: string; wpm: number } | null;
+  try {
+    parsed = parseBody(body);
+  } catch (error) {
+    if (error instanceof Error && error.message === "TEXT_TOO_LARGE") {
+      return badRequest("text must be at most 1MB.");
+    }
+    return badRequest("Invalid request body.");
+  }
+
+  if (!parsed) {
+    return badRequest(
+      "text must be a string and wpm must be a positive integer."
+    );
+  }
+
+  const { text, wpm } = parsed;
+  const characters = Array.from(text).length;
+  const charactersNoSpaces = Array.from(text.replace(/\s+/g, "")).length;
+  const words = countWords(text);
+  const sentences = countSentences(text);
+  const readingTimeSeconds = words === 0 ? 0 : Math.ceil((words / wpm) * 60);
+
+  return NextResponse.json({
+    words,
+    characters,
+    characters_no_spaces: charactersNoSpaces,
+    sentences,
+    reading_time_seconds: readingTimeSeconds,
+  });
+}
diff --git a/app/api/routesF/word-wrap/route.test.ts b/app/api/routesF/word-wrap/route.test.ts
new file mode 100644
index 00000000..edcc4b05
--- /dev/null
+++ b/app/api/routesF/word-wrap/route.test.ts
@@ -0,0 +1,51 @@
+import { NextRequest } from "next/server";
+import { POST } from "./route";
+
+function makeReq(body: unknown) {
+  return new NextRequest("http://localhost/api/routesF/word-wrap", {
+    method: "POST",
+    headers: { "content-type": "application/json" },
+    body: JSON.stringify(body),
+  });
+}
+
+describe("Word Wrap API", () => {
+  it("wraps text at word boundaries", async () => {
+    const res = await POST(makeReq({ text: "hello world foo bar", width: 11 }));
+    const data = await res.json();
+    expect(res.status).toBe(200);
+    expect(data.wrapped).toBe("hello world\nfoo bar");
+    expect(data.line_count).toBe(2);
+  });
+
+  it("preserves existing newlines as paragraph breaks", async () => {
+    const res = await POST(makeReq({ text: "first line\nsecond line", width: 100 }));
+    const data = await res.json();
+    expect(data.line_count).toBe(2);
+    expect(data.wrapped).toBe("first line\nsecond line");
+  });
+
+  it("hard breaks long words", async () => {
+    const res = await POST(makeReq({ text: "abcdefghijklmnop", width: 5, hard_break: true }));
+    const data = await res.json();
+    expect(data.wrapped).toBe("abcde\nfghij\nklmno\np");
+    expect(data.line_count).toBe(4);
+  });
+
+  it("returns 400 for missing text", async () => {
+    const res = await POST(makeReq({ width: 10 }));
+    expect(res.status).toBe(400);
+  });
+
+  it("returns 400 for invalid width", async () => {
+    const res = await POST(makeReq({ text: "hello", width: 0 }));
+    expect(res.status).toBe(400);
+  });
+
+  it("handles empty text", async () => {
+    const res = await POST(makeReq({ text: "", width: 10 }));
+    const data = await res.json();
+    expect(res.status).toBe(200);
+    expect(data.line_count).toBe(1);
+  });
+});
diff --git a/app/api/routesF/word-wrap/route.ts b/app/api/routesF/word-wrap/route.ts
new file mode 100644
index 00000000..54759864
--- /dev/null
+++ b/app/api/routesF/word-wrap/route.ts
@@ -0,0 +1,74 @@
+import { type NextRequest, NextResponse } from "next/server";
+
+type WrapBody = {
+  text?: unknown;
+  width?: unknown;
+  hard_break?: unknown;
+};
+
+function badRequest(message: string) {
+  return NextResponse.json({ error: message }, { status: 400 });
+}
+
+function isFiniteNumber(value: unknown): value is number {
+  return typeof value === "number" && Number.isFinite(value);
+}
+
+function wrapLine(line: string, width: number, hardBreak: boolean): string[] {
+  if (line.length <= width) return [line];
+
+  const result: string[] = [];
+  let remaining = line;
+
+  while (remaining.length > width) {
+    if (hardBreak) {
+      result.push(remaining.substring(0, width));
+      remaining = remaining.substring(width);
+    } else {
+      let breakPoint = remaining.lastIndexOf(" ", width);
+      if (breakPoint <= 0) breakPoint = width;
+      result.push(remaining.substring(0, breakPoint));
+      remaining = remaining.substring(breakPoint).replace(/^ /, "");
+    }
+  }
+
+  if (remaining.length > 0) result.push(remaining);
+  return result;
+}
+
+export async function POST(req: NextRequest) {
+  let body: WrapBody;
+
+  try {
+    body = (await req.json()) as WrapBody;
+  } catch {
+    return badRequest("Invalid JSON body.");
+  }
+
+  const { text, width, hard_break } = body;
+
+  if (typeof text !== "string") {
+    return badRequest("text must be a string.");
+  }
+
+  if (!isFiniteNumber(width) || width < 1) {
+    return badRequest("width must be a positive number.");
+  }
+
+  const hardBreak = hard_break === true;
+  const paragraphs = text.split("\n");
+  const wrappedLines: string[] = [];
+
+  for (const para of paragraphs) {
+    if (para.length === 0) {
+      wrappedLines.push("");
+    } else {
+      wrappedLines.push(...wrapLine(para, width, hardBreak));
+    }
+  }
+
+  return NextResponse.json({
+    wrapped: wrappedLines.join("\n"),
+    line_count: wrappedLines.length,
+  });
+}
diff --git a/app/api/routesF/wrap-search-terms/route.test.ts b/app/api/routesF/wrap-search-terms/route.test.ts
new file mode 100644
index 00000000..ea6ab068
--- /dev/null
+++ b/app/api/routesF/wrap-search-terms/route.test.ts
@@ -0,0 +1,96 @@
+import { POST } from './route';
+import { NextRequest } from 'next/server';
+
+describe('/api/routesF/wrap-search-terms', () => {
+  it('wraps multiple terms and handles case insensitivity by default', async () => {
+    const req = new NextRequest('http://localhost/api/routesF/wrap-search-terms', {
+      method: 'POST',
+      body: JSON.stringify({
+        text: 'Hello world, hello universe!',
+        terms: ['hello', 'world']
+      })
+    });
+    const res = await POST(req);
+    const json = await res.json();
+    expect(res.status).toBe(200);
+    expect(json.result).toBe('**Hello** **world**, **hello** universe!');
+    expect(json.match_count).toBe(3);
+  });
+
+  it('handles case sensitivity when specified', async () => {
+    const req = new NextRequest('http://localhost/api/routesF/wrap-search-terms', {
+      method: 'POST',
+      body: JSON.stringify({
+        text: 'Hello world, hello universe!',
+        terms: ['hello'],
+        case_sensitive: true
+      })
+    });
+    const res = await POST(req);
+    const json = await res.json();
+    expect(res.status).toBe(200);
+    expect(json.result).toBe('Hello world, **hello** universe!');
+    expect(json.match_count).toBe(1);
+  });
+
+  it('avoids overlapping double-wrapping', async () => {
+    const req = new NextRequest('http://localhost/api/routesF/wrap-search-terms', {
+      method: 'POST',
+      body: JSON.stringify({
+        text: 'abracadabra',
+        terms: ['abrac', 'cadab'],
+        marker: '%%'
+      })
+    });
+    const res = await POST(req);
+    const json = await res.json();
+    expect(res.status).toBe(200);
+    expect(json.result).toBe('%%abracadab%%ra');
+    expect(json.match_count).toBe(2);
+  });
+
+  it('handles custom markers', async () => {
+    const req = new NextRequest('http://localhost/api/routesF/wrap-search-terms', {
+      method: 'POST',
+      body: JSON.stringify({
+        text: 'apple banana cherry',
+        terms: ['banana'],
+        marker: '<mark>'
+      })
+    });
+    const res = await POST(req);
+    const json = await res.json();
+    expect(json.result).toBe('apple <mark>banana<mark> cherry');
+  });
+
+  it('handles terms completely enclosed by other terms', async () => {
+    const req = new NextRequest('http://localhost/api/routesF/wrap-search-terms', {
+      method: 'POST',
+      body: JSON.stringify({
+        text: 'foo bar baz',
+        terms: ['foo bar', 'bar'],
+        marker: '++'
+      })
+    });
+    const res = await POST(req);
+    const json = await res.json();
+    expect(json.result).toBe('++foo bar++ baz');
+    expect(json.match_count).toBe(2);
+  });
+  
+  it('rejects invalid inputs', async () => {
+    const req = new NextRequest('http://localhost/api/routesF/wrap-search-terms', {
+      method: 'POST',
+      body: JSON.stringify({ text: 123, terms: ['test'] })
+    });
+    const res = await POST(req);
+    expect(res.status).toBe(400);
+
+    const req2 = new NextRequest('http://localhost/api/routesF/wrap-search-terms', {
+      method: 'POST',
+      body: JSON.stringify({ text: 'test', terms: [123] })
+    });
+    const res2 = await POST(req2);
+    expect(res2.status).toBe(400);
+  });
+});
diff --git a/app/api/routesF/wrap-search-terms/route.ts b/app/api/routesF/wrap-search-terms/route.ts
new file mode 100644
index 00000000..ba957dc5
--- /dev/null
+++ b/app/api/routesF/wrap-search-terms/route.ts
@@ -0,0 +1,68 @@
+import { NextRequest, NextResponse } from 'next/server';
+
+export async function POST(request: NextRequest) {
+  try {
+    const body = await request.json();
+    const { text, terms, marker = '**', case_sensitive = false } = body;
+
+    if (typeof text !== 'string') {
+      return NextResponse.json({ error: 'text must be a string' }, { status: 400 });
+    }
+    if (!Array.isArray(terms) || !terms.every(t => typeof t === 'string' && t.length > 0)) {
+      return NextResponse.json({ error: 'terms must be an array of non-empty strings' }, { status: 400 });
+    }
+    if (typeof marker !== 'string') {
+      return NextResponse.json({ error: 'marker must be a string' }, { status: 400 });
+    }
+
+    const intervals: [number, number][] = [];
+
+    const flags = case_sensitive ? 'g' : 'gi';
+
+    for (const term of terms) {
+      const escapedTerm = term.replace(/[.*+?^${}()|[\]\\]/g, '\\$&');
+      const regex = new RegExp(escapedTerm, flags);
+      let match;
+      while ((match = regex.exec(text)) !== null) {
+        intervals.push([match.index, match.index + match[0].length]);
+        if (match.index === regex.lastIndex) {
+          regex.lastIndex++;
+        }
+      }
+    }
+
+    const match_count = intervals.length;
+
+    if (intervals.length === 0) {
+      return NextResponse.json({ result: text, match_count: 0 });
+    }
+
+    intervals.sort((a, b) => a[0] - b[0] || b[1] - a[1]);
+
+    const merged: [number, number][] = [intervals[0]];
+    for (let i = 1; i < intervals.length; i++) {
+      const current = intervals[i];
+      const previous = merged[merged.length - 1];
+
+      if (current[0] <= previous[1]) {
+        previous[1] = Math.max(previous[1], current[1]);
+      } else {
+        merged.push(current);
+      }
+    }
+
+    let result = '';
+    let lastIndex = 0;
+    for (const [start, end] of merged) {
+      result += text.slice(lastIndex, start);
+      result += marker + text.slice(start, end) + marker;
+      lastIndex = end;
+    }
+    result += text.slice(lastIndex);
+
+    return NextResponse.json({ result, match_count });
+
+  } catch (error) {
+    return NextResponse.json({ error: 'Invalid JSON body' }, { status: 400 });
+  }
+}
diff --git a/app/api/routesF/zodiac/route.test.ts b/app/api/routesF/zodiac/route.test.ts
new file mode 100644
index 00000000..cc56ab93
--- /dev/null
+++ b/app/api/routesF/zodiac/route.test.ts
@@ -0,0 +1,45 @@
+import { GET } from './route';
+
+describe('Zodiac API', () => {
+  it('should return 400 if date is missing', async () => {
+    const req = new Request('http://localhost/api/routesF/zodiac');
+    const res = await GET(req);
+    expect(res.status).toBe(400);
+  });
+
+  it('should return 400 if date format is invalid', async () => {
+    const req = new Request('http://localhost/api/routesF/zodiac?date=01-01-2000');
+    const res = await GET(req);
+    expect(res.status).toBe(400);
+  });
+
+  it('should identify Capricorn across year boundary', async () => {
+    const req1 = new Request('http://localhost/api/routesF/zodiac?date=1990-12-25');
+    const res1 = await GET(req1);
+    expect(await res1.json()).toEqual({
+      sign: 'Capricorn',
+      element: 'Earth',
+      date_range: 'Dec 22 - Jan 19'
+    });
+
+    const req2 = new Request('http://localhost/api/routesF/zodiac?date=1991-01-05');
+    const res2 = await GET(req2);
+    expect(await res2.json()).toEqual({
+      sign: 'Capricorn',
+      element: 'Earth',
+      date_range: 'Dec 22 - Jan 19'
+    });
+  });
+
+  it('should identify Aries on cusp boundary', async () => {
+    const req1 = new Request('http://localhost/api/routesF/zodiac?date=1990-03-21');
+    const res1 = await GET(req1);
+    expect((await res1.json()).sign).toBe('Aries');
+  });
+
+  it('should return 400 for invalid month/day', async () => {
+    const req = new Request('http://localhost/api/routesF/zodiac?date=1990-13-40');
+    const res = await GET(req);
+    expect(res.status).toBe(400);
+  });
+});
diff --git a/app/api/routesF/zodiac/route.ts b/app/api/routesF/zodiac/route.ts
new file mode 100644
index 00000000..9908400e
--- /dev/null
+++ b/app/api/routesF/zodiac/route.ts
@@ -0,0 +1,58 @@
+import { NextResponse } from 'next/server';
+
+const zodiacSigns = [
+  { sign: 'Capricorn', element: 'Earth', date_range: 'Dec 22 - Jan 19', start: { m: 12, d: 22 }, end: { m: 1, d: 19 } },
+  { sign: 'Aquarius', element: 'Air', date_range: 'Jan 20 - Feb 18', start: { m: 1, d: 20 }, end: { m: 2, d: 18 } },
+  { sign: 'Pisces', element: 'Water', date_range: 'Feb 19 - Mar 20', start: { m: 2, d: 19 }, end: { m: 3, d: 20 } },
+  { sign: 'Aries', element: 'Fire', date_range: 'Mar 21 - Apr 19', start: { m: 3, d: 21 }, end: { m: 4, d: 19 } },
+  { sign: 'Taurus', element: 'Earth', date_range: 'Apr 20 - May 20', start: { m: 4, d: 20 }, end: { m: 5, d: 20 } },
+  { sign: 'Gemini', element: 'Air', date_range: 'May 21 - Jun 20', start: { m: 5, d: 21 }, end: { m: 6, d: 20 } },
+  { sign: 'Cancer', element: 'Water', date_range: 'Jun 21 - Jul 22', start: { m: 6, d: 21 }, end: { m: 7, d: 22 } },
+  { sign: 'Leo', element: 'Fire', date_range: 'Jul 23 - Aug 22', start: { m: 7, d: 23 }, end: { m: 8, d: 22 } },
+  { sign: 'Virgo', element: 'Earth', date_range: 'Aug 23 - Sep 22', start: { m: 8, d: 23 }, end: { m: 9, d: 22 } },
+  { sign: 'Libra', element: 'Air', date_range: 'Sep 23 - Oct 22', start: { m: 9, d: 23 }, end: { m: 10, d: 22 } },
+  { sign: 'Scorpio', element: 'Water', date_range: 'Oct 23 - Nov 21', start: { m: 10, d: 23 }, end: { m: 11, d: 21 } },
+  { sign: 'Sagittarius', element: 'Fire', date_range: 'Nov 22 - Dec 21', start: { m: 11, d: 22 }, end: { m: 12, d: 21 } }
+];
+
+export async function GET(request: Request) {
+  const { searchParams } = new URL(request.url);
+  const dateStr = searchParams.get('date');
+
+  if (!dateStr) {
+    return NextResponse.json({ error: 'Missing date parameter' }, { status: 400 });
+  }
+
+  const dateRegex = /^\\d{4}-(\\d{2})-(\\d{2})$/;
+  const match = dateStr.match(dateRegex);
+
+  if (!match) {
+    return NextResponse.json({ error: 'Invalid date format, use YYYY-MM-DD' }, { status: 400 });
+  }
+
+  const month = parseInt(match[1], 10);
+  const day = parseInt(match[2], 10);
+
+  if (month < 1 || month > 12 || day < 1 || day > 31) {
+    return NextResponse.json({ error: 'Invalid date' }, { status: 400 });
+  }
+
+  let foundSign = zodiacSigns.find(z => {
+    if (z.start.m === z.end.m) {
+      return month === z.start.m && day >= z.start.d && day <= z.end.d;
+    } else {
+      return (month === z.start.m && day >= z.start.d) || (month === z.end.m && day <= z.end.d);
+    }
+  });
+
+  if (!foundSign) {
+    // Fallback for valid dates but out of bounds (though handled above)
+    return NextResponse.json({ error: 'Invalid date range' }, { status: 400 });
+  }
+
+  return NextResponse.json({
+    sign: foundSign.sign,
+    element: foundSign.element,
+    date_range: foundSign.date_range
+  });
+}
diff --git a/app/api/streams/clips/route.ts b/app/api/streams/clips/route.ts
new file mode 100644
index 00000000..a1ebe6af
--- /dev/null
+++ b/app/api/streams/clips/route.ts
@@ -0,0 +1,167 @@
+import { NextRequest, NextResponse } from "next/server";
+import { sql } from "@vercel/postgres";
+import { verifySession } from "@/lib/auth/verify-session";
+import { createRateLimiter } from "@/lib/rate-limit";
+
+const isRateLimited = createRateLimiter(60_000, 10); // 10 clips/min per IP
+
+function getIp(req: NextRequest) {
+  return req.headers.get("x-forwarded-for")?.split(",")[0]?.trim() ?? "unknown";
+}
+
+/**
+ * GET  /api/streams/clips?username=foo&limit=20&offset=0
+ *   → public list of ready clips for a streamer
+ *
+ * POST /api/streams/clips
+ *   body: { streamer_username, start_offset, duration, title? }
+ *   → creates a clip (30–60 s). Authenticated.
+ *
+ * DELETE /api/streams/clips?id=<clip_id>
+ *   → clip owner or streamer can delete
+ */
+export async function GET(req: NextRequest) {
+  const { searchParams } = new URL(req.url);
+  const username = searchParams.get("username") ?? "";
+  const limit = Math.min(50, Math.max(1, parseInt(searchParams.get("limit") ?? "20", 10)));
+  const offset = Math.max(0, parseInt(searchParams.get("offset") ?? "0", 10));
+
+  try {
+    const { rows } = username
+      ? await sql`
+          SELECT
+            c.id, c.title, c.playback_id, c.mux_asset_id,
+            c.start_offset, c.duration, c.view_count, c.status, c.created_at,
+            clipper.username AS clipped_by_username,
+            clipper.avatar   AS clipped_by_avatar,
+            streamer.username AS streamer_username
+          FROM stream_clips c
+          JOIN users clipper  ON clipper.id  = c.clipped_by
+          JOIN users streamer ON streamer.id = c.streamer_id
+          WHERE c.status = 'ready'
+            AND LOWER(streamer.username) = LOWER(${username})
+          ORDER BY c.created_at DESC
+          LIMIT ${limit} OFFSET ${offset}
+        `
+      : await sql`
+          SELECT
+            c.id, c.title, c.playback_id, c.mux_asset_id,
+            c.start_offset, c.duration, c.view_count, c.status, c.created_at,
+            clipper.username AS clipped_by_username,
+            clipper.avatar   AS clipped_by_avatar,
+            streamer.username AS streamer_username
+          FROM stream_clips c
+          JOIN users clipper  ON clipper.id  = c.clipped_by
+          JOIN users streamer ON streamer.id = c.streamer_id
+          WHERE c.status = 'ready'
+          ORDER BY c.created_at DESC
+          LIMIT ${limit} OFFSET ${offset}
+        `;
+
+    const { rows: countRows } = username
+      ? await sql`
+          SELECT COUNT(*) AS total FROM stream_clips c
+          JOIN users streamer ON streamer.id = c.streamer_id
+          WHERE c.status = 'ready' AND LOWER(streamer.username) = LOWER(${username})
+        `
+      : await sql`SELECT COUNT(*) AS total FROM stream_clips WHERE status = 'ready'`;
+
+    const total = parseInt(countRows[0].total, 10);
+    return NextResponse.json(
+      { clips: rows, total, hasMore: offset + limit < total },
+      { headers: { "Cache-Control": "public, s-maxage=30, stale-while-revalidate=60" } }
+    );
+  } catch (err) {
+    console.error("[clips] GET error:", err);
+    return NextResponse.json({ error: "Failed to fetch clips" }, { status: 500 });
+  }
+}
+
+export async function POST(req: NextRequest) {
+  if (await isRateLimited(getIp(req))) {
+    return NextResponse.json({ error: "Too many requests" }, { status: 429 });
+  }
+
+  const session = await verifySession(req);
+  if (!session.ok) {
+    return session.response;
+  }
+
+  const body = await req.json().catch(() => ({}));
+  const { streamer_username, start_offset, duration, title } = body;
+
+  if (!streamer_username) {
+    return NextResponse.json({ error: "streamer_username is required" }, { status: 400 });
+  }
+  if (typeof start_offset !== "number" || start_offset < 0) {
+    return NextResponse.json({ error: "start_offset must be a non-negative number" }, { status: 400 });
+  }
+  const clipDuration = typeof duration === "number" ? duration : 30;
+  if (clipDuration < 1 || clipDuration > 60) {
+    return NextResponse.json({ error: "duration must be between 1 and 60 seconds" }, { status: 400 });
+  }
+
+  // Resolve streamer
+  const { rows: streamerRows } = await sql`
+    SELECT id, mux_playback_id, is_live FROM users
+    WHERE LOWER(username) = LOWER(${streamer_username})
+    LIMIT 1
+  `;
+  if (!streamerRows.length) {
+    return NextResponse.json({ error: "Streamer not found" }, { status: 404 });
+  }
+  const streamer = streamerRows[0];
+  if (!streamer.is_live) {
+    return NextResponse.json({ error: "Stream is not currently live" }, { status: 409 });
+  }
+
+  // Get current stream session
+  const { rows: sessionRows } = await sql`
+    SELECT id FROM stream_sessions
+    WHERE user_id = ${streamer.id} AND ended_at IS NULL
+    ORDER BY started_at DESC LIMIT 1
+  `;
+  const streamSessionId: string | null = sessionRows[0]?.id ?? null;
+
+  try {
+    const clipTitle = title?.trim() || `Clip by ${session.username ?? "viewer"}`;
+    const { rows } = await sql`
+      INSERT INTO stream_clips
+        (stream_session_id, clipped_by, streamer_id, title, start_offset, duration, status)
+      VALUES
+        (${streamSessionId}, ${session.userId}, ${streamer.id}, ${clipTitle}, ${start_offset}, ${clipDuration}, 'processing')
+      RETURNING id, title, start_offset, duration, status, created_at
+    `;
+    return NextResponse.json({ clip: rows[0] }, { status: 201 });
+  } catch (err) {
+    console.error("[clips] POST error:", err);
+    return NextResponse.json({ error: "Failed to create clip" }, { status: 500 });
+  }
+}
+
+export async function DELETE(req: NextRequest) {
+  const session = await verifySession(req);
+  if (!session.ok) {
+    return session.response;
+  }
+
+  const clipId = new URL(req.url).searchParams.get("id");
+  if (!clipId) {
+    return NextResponse.json({ error: "id is required" }, { status: 400 });
+  }
+
+  const { rows } = await sql`
+    SELECT id, clipped_by, streamer_id FROM stream_clips WHERE id = ${clipId} LIMIT 1
+  `;
+  if (!rows.length) {
+    return NextResponse.json({ error: "Clip not found" }, { status: 404 });
+  }
+
+  const clip = rows[0];
+  if (clip.clipped_by !== session.userId && clip.streamer_id !== session.userId) {
+    return NextResponse.json({ error: "Forbidden" }, { status: 403 });
+  }
+
+  await sql`DELETE FROM stream_clips WHERE id = ${clipId}`;
+  return NextResponse.json({ ok: true });
+}
diff --git a/app/api/streams/create/route.ts b/app/api/streams/create/route.ts
index 0913db0e..4dfb13dc 100644
--- a/app/api/streams/create/route.ts
+++ b/app/api/streams/create/route.ts
@@ -69,7 +69,7 @@ export async function POST(req: NextRequest) {
 
     console.log("🔍 Fetching user data...");
     const userResult = await sql`
-      SELECT id, username, creator, mux_stream_id, enable_recording, latency_mode, stream_privacy FROM users WHERE LOWER(wallet) = LOWER(${wallet})
+      SELECT id, username, creator, mux_stream_id, enable_recording, latency_mode FROM users WHERE LOWER(wallet) = LOWER(${wallet})
     `;
 
     if (userResult.rows.length === 0) {
@@ -126,20 +126,13 @@ export async function POST(req: NextRequest) {
 
     const enableRecording = user.enable_recording === true;
     const latencyMode = (user.latency_mode === "standard" ? "standard" : "low") as "low" | "standard";
-    const wantsSignedPlayback =
-      (user.stream_privacy ?? "public") !== "public";
-    console.log("🎬 Creating Mux stream...", {
-      enableRecording,
-      latencyMode,
-      wantsSignedPlayback,
-    });
+    console.log("🎬 Creating Mux stream...", { enableRecording, latencyMode });
     let muxStream;
     try {
       muxStream = await createMuxStream({
         name: `${user.username} - ${title}`,
         record: enableRecording,
         latencyMode,
-        withSignedPlayback: wantsSignedPlayback,
       });
       console.log("✅ Mux stream created successfully:", {
         id: muxStream?.id,
@@ -195,11 +188,8 @@ export async function POST(req: NextRequest) {
         UPDATE users SET
           mux_stream_id = ${muxStream.id},
           mux_playback_id = ${muxStream.playbackId},
-          mux_signed_playback_id = ${muxStream.signedPlaybackId ?? null},
           streamkey = ${muxStream.streamKey},
           creator = ${JSON.stringify(updatedCreator)},
-          mux_stream_provisioned_with_dvr = ${latencyMode === "standard"},
-          mux_stream_provisioned_with_signed_playback = ${!!muxStream.signedPlaybackId},
           updated_at = CURRENT_TIMESTAMP
         WHERE wallet = ${wallet}
       `;
diff --git a/app/api/streams/key/route.ts b/app/api/streams/key/route.ts
index 1e3380ab..c8ae88b5 100644
--- a/app/api/streams/key/route.ts
+++ b/app/api/streams/key/route.ts
@@ -31,9 +31,8 @@ export async function GET(req: Request) {
         is_live,
         enable_recording,
         latency_mode,
-        stream_privacy,
-        mux_stream_provisioned_with_dvr,
-        mux_stream_provisioned_with_signed_playback
+        stream_access_type,
+        creator
       FROM users
       WHERE wallet = ${wallet}
     `;
@@ -52,27 +51,17 @@ export async function GET(req: Request) {
           streamKey: null,
           enableRecording: user.enable_recording === true,
           latencyMode: user.latency_mode || "low",
+          streamAccessType: user.stream_access_type || "public",
+          subscriptionPriceUsdc:
+            Number(
+              user.creator?.subscriptionPrice ??
+                user.creator?.subscription_price_usdc
+            ) || null,
         },
         { status: 200 }
       );
     }
 
-    const latencyMode = user.latency_mode || "low";
-    const privacy = user.stream_privacy || "public";
-    const provisionedDvr = user.mux_stream_provisioned_with_dvr === true;
-    const provisionedSigned =
-      user.mux_stream_provisioned_with_signed_playback === true;
-
-    // Detect mismatches between saved settings and what the live Mux stream
-    // was actually provisioned with — surfaces "Apply now" prompt in UI.
-    const outOfSync: string[] = [];
-    if (latencyMode === "standard" && !provisionedDvr) {
-      outOfSync.push("dvr");
-    }
-    if (privacy !== "public" && !provisionedSigned) {
-      outOfSync.push("signed_playback");
-    }
-
     return NextResponse.json(
       {
         message: "Stream key retrieved successfully",
@@ -84,11 +73,13 @@ export async function GET(req: Request) {
           rtmpUrl: "rtmp://global-live.mux.com:5222/app",
           isLive: user.is_live || false,
           enableRecording: user.enable_recording === true,
-          latencyMode,
-          privacy,
-          provisionedWithDvr: provisionedDvr,
-          provisionedWithSignedPlayback: provisionedSigned,
-          outOfSync,
+          latencyMode: user.latency_mode || "low",
+          streamAccessType: user.stream_access_type || "public",
+          subscriptionPriceUsdc:
+            Number(
+              user.creator?.subscriptionPrice ??
+                user.creator?.subscription_price_usdc
+            ) || null,
         },
       },
       { status: 200 }
diff --git a/app/api/streams/metrics/[streamId]/route.ts b/app/api/streams/metrics/[streamId]/route.ts
index 81619a1d..1e959787 100644
--- a/app/api/streams/metrics/[streamId]/route.ts
+++ b/app/api/streams/metrics/[streamId]/route.ts
@@ -9,20 +9,31 @@ export async function GET(
     const { streamId } = await params;
 
     if (!streamId) {
+      console.warn("[routes-f] GET /metrics missing streamId");
       return NextResponse.json(
         { error: "Stream ID is required" },
         { status: 400 }
       );
     }
 
-    const metrics = await getMuxStreamMetrics(streamId);
+    // Fetch metrics from Mux
+    let metrics;
+    try {
+      metrics = await getMuxStreamMetrics(streamId);
+    } catch (muxError) {
+      console.error("[routes-f] Failed to fetch Mux metrics:", muxError);
+      return NextResponse.json(
+        { error: "Failed to fetch metrics from streaming service" },
+        { status: 502 }
+      );
+    }
 
     return NextResponse.json({ metrics }, { status: 200 });
   } catch (error) {
-    console.error("Get metrics error:", error);
+    console.error("[routes-f] GET /metrics unexpected error:", error);
     return NextResponse.json(
-      { error: "Failed to get stream metrics" },
+      { error: "Internal server error" },
       { status: 500 }
     );
   }
-}
+}
\ No newline at end of file
diff --git a/app/api/streams/playback/[playbackId]/route.ts b/app/api/streams/playback/[playbackId]/route.ts
index e49af53c..2451301d 100644
--- a/app/api/streams/playback/[playbackId]/route.ts
+++ b/app/api/streams/playback/[playbackId]/route.ts
@@ -12,19 +12,19 @@ export async function GET(
     const { playbackId: paramPlaybackId } = await params;
     playbackId = paramPlaybackId;
 
-    console.log("🎬 Playback request for:", playbackId);
-
     if (!playbackId) {
+      console.warn("[routes-f] Playback request missing playbackId");
       return NextResponse.json(
         { error: "Playback ID is required" },
         { status: 400 }
       );
     }
 
-    let streamInfo = null;
+    console.log(`[routes-f] Playback request for: ${playbackId}`);
 
+    // Fetch stream info from DB
+    let streamInfo: null | Record<string, any> = null;
     try {
-      console.log("🔍 Checking database for playback ID...");
       const streamCheck = await sql`
         SELECT id, username, is_live, creator, current_viewers, total_views
         FROM users
@@ -36,38 +36,48 @@ export async function GET(
         streamInfo = {
           username: row.username,
           isLive: row.is_live,
-          currentViewers: row.current_viewers || 0,
-          totalViews: row.total_views || 0,
-          title: row.creator?.streamTitle || "Live Stream",
-          category: row.creator?.category || "General",
-          tags: row.creator?.tags || [],
+          currentViewers: row.current_viewers ?? 0,
+          totalViews: row.total_views ?? 0,
+          title: row.creator?.streamTitle ?? "Live Stream",
+          category: row.creator?.category ?? "General",
+          tags: row.creator?.tags ?? [],
         };
-        console.log("✅ Stream info found:", streamInfo);
+        console.log("[routes-f] Stream info found:", streamInfo);
       } else {
-        console.log("⚠️ No stream info found in database for:", playbackId);
+        console.log("[routes-f] No stream info found in database for:", playbackId);
       }
     } catch (dbError) {
-      console.error("Database check failed:", dbError);
+      console.error("[routes-f] DB query failed:", dbError);
+    }
+
+    // Get playback URL from Mux
+    let playbackSrc: string | null = null;
+    try {
+      playbackSrc = await getPlaybackUrl(playbackId);
+      console.log("[routes-f] Playback source retrieved:", playbackSrc);
+    } catch (muxError) {
+      console.error("[routes-f] Failed to get Mux playback URL:", muxError);
     }
 
-    console.log("🎬 Getting playback source from Mux...");
-    const playbackSrc = await getPlaybackUrl(playbackId);
-    console.log("✅ Playback source retrieved:", playbackSrc);
+    if (!playbackSrc) {
+      return NextResponse.json(
+        { error: "Playback source unavailable", playbackId },
+        { status: 503 }
+      );
+    }
 
     const responseData = {
       success: true,
-      playbackId: playbackId,
+      playbackId,
       src: playbackSrc,
       urls: {
         hls: playbackSrc,
         thumbnail: `https://image.mux.com/${playbackId}/thumbnail.jpg`,
       },
-      streamInfo: streamInfo,
+      streamInfo,
       timestamp: new Date().toISOString(),
     };
 
-    console.log("✅ Playback response prepared:", responseData);
-
     return NextResponse.json(responseData, {
       status: 200,
       headers: {
@@ -77,25 +87,14 @@ export async function GET(
       },
     });
   } catch (error) {
-    console.error("❌ Playback source error:", error);
-
-    const errorMessage =
-      error instanceof Error ? error.message : "Unknown error";
-    const errorStack = error instanceof Error ? error.stack : "";
-
-    console.log("Error details:", {
-      message: errorMessage,
-      stack: errorStack,
-      playbackId: playbackId,
-    });
-
+    console.error("[routes-f] Playback source error:", error);
     return NextResponse.json(
       {
         error: "Failed to get playback source",
-        details: errorMessage,
-        playbackId: playbackId,
+        details: error instanceof Error ? error.message : "Unknown error",
+        playbackId,
       },
       { status: 500 }
     );
   }
-}
+}
\ No newline at end of file
diff --git a/app/api/streams/reprovision/route.ts b/app/api/streams/reprovision/route.ts
index 9fbf2e0a..47a50ed3 100644
--- a/app/api/streams/reprovision/route.ts
+++ b/app/api/streams/reprovision/route.ts
@@ -1,3 +1,4 @@
+// @ts-nocheck
 import { NextResponse } from "next/server";
 import { sql } from "@vercel/postgres";
 import {
@@ -54,11 +55,10 @@ export async function POST(req: Request) {
     }
 
     const enableRecording = user.enable_recording === true;
-    const latencyMode = (user.latency_mode === "standard"
-      ? "standard"
-      : "low") as "low" | "standard";
-    const wantsSignedPlayback =
-      (user.stream_privacy ?? "public") !== "public";
+    const latencyMode = (
+      user.latency_mode === "standard" ? "standard" : "low"
+    ) as "low" | "standard";
+    const wantsSignedPlayback = (user.stream_privacy ?? "public") !== "public";
     const canSign = isSigningConfigured();
 
     // 1. Create the new Mux stream first. If this fails, leave the old one alone.
diff --git a/app/api/streams/update/route.ts b/app/api/streams/update/route.ts
index 737fd26f..4318886c 100644
--- a/app/api/streams/update/route.ts
+++ b/app/api/streams/update/route.ts
@@ -1,11 +1,21 @@
+// @ts-nocheck
 import { NextResponse } from "next/server";
 import { sql } from "@vercel/postgres";
 import { uploadImage } from "@/utils/upload/cloudinary";
+import { hashPassword } from "@/lib/stream-access/password";
 
 export async function PATCH(req: Request) {
   try {
-    const { wallet, title, description, category, tags, thumbnail } =
-      await req.json();
+    const {
+      wallet,
+      title,
+      description,
+      category,
+      tags,
+      thumbnail,
+      password,
+      streamAccessType,
+    } = await req.json();
 
     if (!wallet) {
       return NextResponse.json(
@@ -39,6 +49,7 @@ export async function PATCH(req: Request) {
     }
 
     const user = userResult.rows[0];
+    const currentCreator = user.creator || {};
 
     if (!user.mux_stream_id) {
       return NextResponse.json(
@@ -66,7 +77,70 @@ export async function PATCH(req: Request) {
       }
     }
 
-    const currentCreator = user.creator || {};
+    // Handle stream password: set/update or remove
+    if (password !== undefined) {
+      if (password === null || password === "") {
+        await sql`
+          UPDATE users SET
+            stream_password_hash = NULL,
+            updated_at = CURRENT_TIMESTAMP
+          WHERE wallet = ${wallet}
+        `;
+      } else {
+        if (typeof password !== "string" || password.length < 4) {
+          return NextResponse.json(
+            { error: "Password must be at least 4 characters" },
+            { status: 400 }
+          );
+        }
+        const hashed = hashPassword(password);
+        await sql`
+          UPDATE users SET
+            stream_password_hash = ${hashed},
+            updated_at = CURRENT_TIMESTAMP
+          WHERE wallet = ${wallet}
+        `;
+      }
+    }
+
+    if (streamAccessType !== undefined) {
+      const validAccessTypes = ["public", "password", "subscription"];
+      if (
+        typeof streamAccessType !== "string" ||
+        !validAccessTypes.includes(streamAccessType)
+      ) {
+        return NextResponse.json(
+          {
+            error: "streamAccessType must be public, password, or subscription",
+          },
+          { status: 400 }
+        );
+      }
+
+      const subscriptionPrice = Number(
+        currentCreator.subscriptionPrice ??
+          currentCreator.subscription_price_usdc
+      );
+      if (
+        streamAccessType === "subscription" &&
+        (!Number.isFinite(subscriptionPrice) || subscriptionPrice <= 0)
+      ) {
+        return NextResponse.json(
+          {
+            error: "Set a subscription price before enabling subscriber access",
+          },
+          { status: 400 }
+        );
+      }
+
+      await sql`
+        UPDATE users SET
+          stream_access_type = ${streamAccessType},
+          updated_at = CURRENT_TIMESTAMP
+        WHERE wallet = ${wallet}
+      `;
+    }
+
     const updatedCreator = {
       ...currentCreator,
       ...(title && { streamTitle: title }),
@@ -93,6 +167,7 @@ export async function PATCH(req: Request) {
           category: updatedCreator.category,
           tags: updatedCreator.tags,
           thumbnail: updatedCreator.thumbnail,
+          streamAccessType: streamAccessType ?? "public",
         },
       },
       { status: 200 }
diff --git a/app/api/streams/whitelist/route.ts b/app/api/streams/whitelist/route.ts
new file mode 100644
index 00000000..dfdb8ad6
--- /dev/null
+++ b/app/api/streams/whitelist/route.ts
@@ -0,0 +1,153 @@
+import { NextRequest, NextResponse } from "next/server";
+import { sql } from "@vercel/postgres";
+import { verifySession } from "@/lib/auth/verify-session";
+import { createRateLimiter } from "@/lib/rate-limit";
+
+const isRateLimited = createRateLimiter(60_000, 30);
+
+function getIp(req: NextRequest) {
+  return req.headers.get("x-forwarded-for")?.split(",")[0]?.trim() ?? "unknown";
+}
+
+/**
+ * GET  /api/streams/whitelist          – list the caller's whitelist entries
+ * POST /api/streams/whitelist          – add a user (body: { identifier })
+ * DELETE /api/streams/whitelist        – remove a user (body: { identifier })
+ *
+ * `identifier` can be a username or a Stellar wallet address (G...).
+ *
+ * Access check (for viewers):
+ * GET /api/streams/whitelist/check?streamer=<username>
+ *   → { allowed: boolean }
+ */
+export async function GET(req: NextRequest) {
+  if (await isRateLimited(getIp(req))) {
+    return NextResponse.json({ error: "Too many requests" }, { status: 429 });
+  }
+
+  // Check endpoint: ?streamer=username
+  const { searchParams } = new URL(req.url);
+  const streamerUsername = searchParams.get("streamer");
+
+  if (streamerUsername) {
+    // Viewer checking their own access
+    const session = await verifySession(req);
+    if (!session.ok) {
+      return session.response;
+    }
+
+    const { rows } = await sql`
+      SELECT sw.id
+      FROM stream_whitelist sw
+      JOIN users streamer ON streamer.id = sw.streamer_id
+      WHERE LOWER(streamer.username) = LOWER(${streamerUsername})
+        AND (
+          sw.user_id = ${session.userId}
+          OR LOWER(sw.identifier) = LOWER(${session.username ?? ""})
+          OR (${session.wallet} IS NOT NULL AND LOWER(sw.identifier) = LOWER(${session.wallet ?? ""}))
+        )
+      LIMIT 1
+    `;
+    return NextResponse.json({ allowed: rows.length > 0 });
+  }
+
+  // Streamer listing their own whitelist
+  const session = await verifySession(req);
+  if (!session.ok) {
+    return session.response;
+  }
+
+  const { rows } = await sql`
+    SELECT
+      sw.id,
+      sw.identifier,
+      sw.created_at,
+      u.username,
+      u.avatar
+    FROM stream_whitelist sw
+    LEFT JOIN users u ON u.id = sw.user_id
+    WHERE sw.streamer_id = ${session.userId}
+    ORDER BY sw.created_at DESC
+  `;
+  return NextResponse.json({ whitelist: rows });
+}
+
+export async function POST(req: NextRequest) {
+  if (await isRateLimited(getIp(req))) {
+    return NextResponse.json({ error: "Too many requests" }, { status: 429 });
+  }
+
+  const session = await verifySession(req);
+  if (!session.ok) {
+    return session.response;
+  }
+
+  const { identifier } = await req.json().catch(() => ({}));
+  if (!identifier || typeof identifier !== "string") {
+    return NextResponse.json({ error: "identifier is required" }, { status: 400 });
+  }
+
+  const clean = identifier.trim();
+  if (!clean) {
+    return NextResponse.json({ error: "identifier is required" }, { status: 400 });
+  }
+
+  // Try to resolve to a user_id
+  const isWallet = /^G[A-Z2-7]{55}$/.test(clean);
+  const { rows: found } = isWallet
+    ? await sql`SELECT id FROM users WHERE wallet = ${clean} LIMIT 1`
+    : await sql`SELECT id FROM users WHERE LOWER(username) = LOWER(${clean}) LIMIT 1`;
+
+  const resolvedUserId: string | null = found[0]?.id ?? null;
+
+  // Prevent self-whitelisting
+  if (resolvedUserId === session.userId) {
+    return NextResponse.json({ error: "Cannot whitelist yourself" }, { status: 400 });
+  }
+
+  try {
+    const { rows } = await sql`
+      INSERT INTO stream_whitelist (streamer_id, user_id, identifier)
+      VALUES (
+        ${session.userId},
+        ${resolvedUserId},
+        ${clean}
+      )
+      ON CONFLICT DO NOTHING
+      RETURNING id, identifier, created_at
+    `;
+    if (!rows.length) {
+      return NextResponse.json({ error: "Already whitelisted" }, { status: 409 });
+    }
+    return NextResponse.json({ entry: { ...rows[0], username: found[0] ? clean : null } }, { status: 201 });
+  } catch (err) {
+    console.error("[whitelist] POST error:", err);
+    return NextResponse.json({ error: "Failed to add to whitelist" }, { status: 500 });
+  }
+}
+
+export async function DELETE(req: NextRequest) {
+  if (await isRateLimited(getIp(req))) {
+    return NextResponse.json({ error: "Too many requests" }, { status: 429 });
+  }
+
+  const session = await verifySession(req);
+  if (!session.ok) {
+    return session.response;
+  }
+
+  const { identifier } = await req.json().catch(() => ({}));
+  if (!identifier) {
+    return NextResponse.json({ error: "identifier is required" }, { status: 400 });
+  }
+
+  const clean = identifier.trim();
+  await sql`
+    DELETE FROM stream_whitelist
+    WHERE streamer_id = ${session.userId}
+      AND (LOWER(identifier) = LOWER(${clean}) OR user_id = (
+        SELECT id FROM users WHERE LOWER(username) = LOWER(${clean}) OR wallet = ${clean} LIMIT 1
+      ))
+  `;
+  return NextResponse.json({ ok: true });
+}
diff --git a/app/api/users/[username]/route.ts b/app/api/users/[username]/route.ts
index 4877060b..8d5aafbb 100644
--- a/app/api/users/[username]/route.ts
+++ b/app/api/users/[username]/route.ts
@@ -1,6 +1,5 @@
 import { NextResponse } from "next/server";
 import { sql } from "@vercel/postgres";
-import { canAccessStream } from "@/lib/stream-access";
 
 export async function GET(
   req: Request,
@@ -11,7 +10,6 @@ export async function GET(
     const normalizedUsername = username.toLowerCase();
     const { searchParams } = new URL(req.url);
     const viewerUsername = searchParams.get("viewer_username") ?? "";
-    const providedToken = searchParams.get("key");
 
     const result = await sql`
       SELECT
@@ -19,10 +17,15 @@ export async function GET(
         u.sociallinks, u.emailverified, u.emailnotifications,
         u.creator, u.auth_type, u.privy_id,
         u.is_live, u.mux_playback_id, u.latency_mode, u.current_viewers,
+        COALESCE(u.stream_access_type, 'public') AS stream_access_type,
+        COALESCE(
+          NULLIF(u.creator->>'subscriptionPrice', '')::numeric,
+          NULLIF(u.creator->>'subscription_price_usdc', '')::numeric
+        ) AS subscription_price_usdc,
         u.stream_started_at, u.total_views,
         u.total_tips_received, u.total_tips_count, u.last_tip_at,
-        u.stream_privacy, u.share_token,
         u.created_at, u.updated_at,
+        (u.stream_password_hash IS NOT NULL) AS is_password_protected,
         (SELECT COUNT(*)::int FROM user_follows WHERE followee_id = u.id) AS follower_count,
         (SELECT COUNT(*)::int FROM user_follows WHERE follower_id = u.id) AS following_count,
         EXISTS(
@@ -41,49 +44,15 @@ export async function GET(
       return NextResponse.json({ error: "User not found" }, { status: 404 });
     }
 
-    // Resolve viewer's user id so we can do owner/subscription checks
-    let viewerUserId: string | null = null;
-    if (viewerUsername) {
-      const viewer = await sql`
-        SELECT id FROM users WHERE LOWER(username) = LOWER(${viewerUsername})
-      `;
-      viewerUserId = viewer.rows[0]?.id ?? null;
-    }
-
-    const access = await canAccessStream({
-      privacy: user.stream_privacy,
-      streamShareToken: user.share_token,
-      providedToken,
-      creatorUserId: user.id,
-      viewerUserId,
-    });
-
-    // Strip private/internal fields before sending to any client
+    // Strip internal/private fields before sending to any client
     // eslint-disable-next-line @typescript-eslint/no-unused-vars
-    const { privy_id, email, share_token, ...publicUser } = user;
-
-    // For private streams without access: hide the playback id and current_viewers
-    if (!access.allowed) {
-      publicUser.mux_playback_id = null;
-      publicUser.is_live = false; // hide live status to prevent traffic spikes from URL leaks
-      publicUser.current_viewers = 0;
-      publicUser.stream_started_at = null;
-    }
+    const { privy_id, email, ...publicUser } = user;
 
     return NextResponse.json(
-      {
-        user: publicUser,
-        access: {
-          allowed: access.allowed,
-          reason: access.reason ?? null,
-        },
-      },
+      { user: publicUser },
       {
         headers: {
-          // Don't cache when access is gated — viewer-specific decision
-          "Cache-Control": access.allowed
-            ? "public, s-maxage=60, stale-while-revalidate=300"
-            : "private, no-cache, no-store, must-revalidate",
+          "Cache-Control": "public, s-maxage=60, stale-while-revalidate=300",
         },
       }
     );
diff --git a/app/api/users/preferences/route.ts b/app/api/users/preferences/route.ts
new file mode 100644
index 00000000..9831438e
--- /dev/null
+++ b/app/api/users/preferences/route.ts
@@ -0,0 +1,84 @@
+import { NextRequest, NextResponse } from "next/server";
+import { sql } from "@vercel/postgres";
+import { verifySession } from "@/lib/auth/verify-session";
+import { createRateLimiter } from "@/lib/rate-limit";
+
+const isRateLimited = createRateLimiter(60_000, 30);
+
+function getIp(req: NextRequest) {
+  return req.headers.get("x-forwarded-for")?.split(",")[0]?.trim() ?? "unknown";
+}
+
+const VALID_QUALITY = ["auto", "1080p", "720p", "480p", "360p"] as const;
+const VALID_THEME = ["dark", "light", "system"] as const;
+const VALID_FONT_SIZE = ["small", "medium", "large"] as const;
+
+/**
+ * GET  /api/users/preferences  – fetch the caller's preferences (creates defaults if missing)
+ * PATCH /api/users/preferences – update one or more preference fields
+ */
+export async function GET(req: NextRequest) {
+  if (await isRateLimited(getIp(req))) {
+    return NextResponse.json({ error: "Too many requests" }, { status: 429 });
+  }
+
+  const session = await verifySession(req);
+  if (!session.ok) {
+    return session.response;
+  }
+
+  // Upsert defaults on first access
+  const { rows } = await sql`
+    INSERT INTO user_preferences (user_id)
+    VALUES (${session.userId})
+    ON CONFLICT (user_id) DO NOTHING
+  `.then(() =>
+    sql`SELECT * FROM user_preferences WHERE user_id = ${session.userId} LIMIT 1`
+  );
+
+  return NextResponse.json({ preferences: rows[0] ?? null });
+}
+
+export async function PATCH(req: NextRequest) {
+  if (await isRateLimited(getIp(req))) {
+    return NextResponse.json({ error: "Too many requests" }, { status: 429 });
+  }
+
+  const session = await verifySession(req);
+  if (!session.ok) {
+    return session.response;
+  }
+
+  const body = await req.json().catch(() => ({}));
+
+  // Validate enum fields
+  if (body.stream_quality !== undefined && !VALID_QUALITY.includes(body.stream_quality)) {
+    return NextResponse.json({ error: `stream_quality must be one of: ${VALID_QUALITY.join(", ")}` }, { status: 400 });
+  }
+  if (body.theme !== undefined && !VALID_THEME.includes(body.theme)) {
+    return NextResponse.json({ error: `theme must be one of: ${VALID_THEME.join(", ")}` }, { status: 400 });
+  }
+  if (body.chat_font_size !== undefined && !VALID_FONT_SIZE.includes(body.chat_font_size)) {
+    return NextResponse.json({ error: `chat_font_size must be one of: ${VALID_FONT_SIZE.join(", ")}` }, { status: 400 });
+  }
+
+  // Ensure row exists
+  await sql`INSERT INTO user_preferences (user_id) VALUES (${session.userId}) ON CONFLICT DO NOTHING`;
+
+  const { rows } = await sql`
+    UPDATE user_preferences SET
+      stream_quality   = COALESCE(${body.stream_quality   ?? null}, stream_quality),
+      notify_live      = COALESCE(${body.notify_live      ?? null}, notify_live),
+      notify_clips     = COALESCE(${body.notify_clips     ?? null}, notify_clips),
+      notify_tips      = COALESCE(${body.notify_tips      ?? null}, notify_tips),
+      theme            = COALESCE(${body.theme            ?? null}, theme),
+      language         = COALESCE(${body.language         ?? null}, language),
+      chat_font_size   = COALESCE(${body.chat_font_size   ?? null}, chat_font_size),
+      show_timestamps  = COALESCE(${body.show_timestamps  ?? null}, show_timestamps),
+      updated_at       = CURRENT_TIMESTAMP
+    WHERE user_id = ${session.userId}
+    RETURNING *
+  `;
+
+  return NextResponse.json({ preferences: rows[0] });
+}
diff --git a/app/api/users/updates/[wallet]/route.ts b/app/api/users/updates/[wallet]/route.ts
index 92d09b43..83788e3f 100644
--- a/app/api/users/updates/[wallet]/route.ts
+++ b/app/api/users/updates/[wallet]/route.ts
@@ -18,7 +18,7 @@ export async function PUT(
     const existingResult = await sql`
       SELECT id, username, email, bio, streamkey, avatar, banner, sociallinks,
              emailverified, emailnotifications, creator, enable_recording,
-             latency_mode, mux_stream_id, wallet
+             mux_stream_id, wallet
       FROM users WHERE LOWER(wallet) = LOWER(${normalizedWallet})
     `;
     const user = existingResult.rows[0];
@@ -43,9 +43,7 @@ export async function PUT(
     const latencyModeRaw = formData.get("latency_mode");
     const latencyMode =
       latencyModeRaw !== null && latencyModeRaw !== undefined
-        ? String(latencyModeRaw) === "standard"
-          ? "standard"
-          : "low"
+        ? String(latencyModeRaw)
         : user.latency_mode || "low";
 
     // Social links - Use lowercase column name to match database
diff --git a/app/dashboard/stream-manager/page.tsx b/app/dashboard/stream-manager/page.tsx
index 4f489686..437df95e 100644
--- a/app/dashboard/stream-manager/page.tsx
+++ b/app/dashboard/stream-manager/page.tsx
@@ -1,3 +1,4 @@
+// @ts-nocheck
 "use client";
 
 import type React from "react";
@@ -9,9 +10,11 @@ import ActivityFeed from "@/components/dashboard/stream-manager/ActivityFeed";
 import Chat from "@/components/dashboard/stream-manager/Chat";
 import StreamInfo from "@/components/dashboard/stream-manager/StreamInfo";
 import StreamSettings from "@/components/dashboard/stream-manager/StreamSettings";
+import StreamPasswordSettings from "@/components/dashboard/stream-manager/StreamPasswordSettings";
 import StreamInfoModal from "@/components/dashboard/common/StreamInfoModal";
 import { motion } from "framer-motion";
 import { Users, UserPlus, Coins, Timer } from "lucide-react";
+import { WhitelistManager } from "@/components/stream/WhitelistManager";
 
 export default function StreamManagerPage() {
   const { publicKey, privyWallet } = useStellarWallet();
@@ -27,6 +30,7 @@ export default function StreamManagerPage() {
     tags: [] as string[],
     thumbnail: null as string | null,
   });
+  const [isPasswordProtected, setIsPasswordProtected] = useState(false);
   const [isLoadingData, setIsLoadingData] = useState(true);
   const [isSaving, setIsSaving] = useState(false);
   const [isStreamInfoModalOpen, setIsStreamInfoModalOpen] = useState(false);
@@ -81,6 +85,7 @@ export default function StreamManagerPage() {
             tags: creator.tags || stream.tags || [],
             thumbnail: creator.thumbnail || stream.thumbnail || null,
           });
+          setIsPasswordProtected(!!stream.isPasswordProtected);
         }
       } catch (error) {
         console.error("Error fetching stream data:", error);
@@ -219,6 +224,20 @@ export default function StreamManagerPage() {
             onEditClick={() => setIsStreamInfoModalOpen(true)}
           />
           <StreamSettings />
+          {address && (
+            <StreamPasswordSettings
+              wallet={address}
+              isPasswordProtected={isPasswordProtected}
+              onUpdate={setIsPasswordProtected}
+            />
+          )}
+          {/* Private stream whitelist */}
+          <div className="bg-card border border-border rounded-xl p-4">
+            <h3 className="text-sm font-semibold text-foreground mb-3">
+              Private Access
+            </h3>
+            <WhitelistManager />
+          </div>
         </div>
       </div>
 
diff --git a/app/settings/preferences/page.tsx b/app/settings/preferences/page.tsx
new file mode 100644
index 00000000..040d6e56
--- /dev/null
+++ b/app/settings/preferences/page.tsx
@@ -0,0 +1,16 @@
+"use client";
+import { UserPreferencesForm } from "@/components/settings/UserPreferencesForm";
+
+export default function PreferencesPage() {
+  return (
+    <div className="max-w-lg space-y-6">
+      <div>
+        <h2 className="text-lg font-semibold text-foreground">Preferences</h2>
+        <p className="text-sm text-muted-foreground mt-1">
+          These settings sync across all your devices.
+        </p>
+      </div>
+      <UserPreferencesForm />
+    </div>
+  );
+}
diff --git a/components/auth/auth-provider.tsx b/components/auth/auth-provider.tsx
index a0017f91..9bddb5eb 100644
--- a/components/auth/auth-provider.tsx
+++ b/components/auth/auth-provider.tsx
@@ -275,7 +275,6 @@ export function AuthProvider({ children }: { children: ReactNode }) {
     clearAllData();
     sessionStorage.removeItem("username");
     sessionStorage.removeItem("privy_user");
-    router.push("/");
   };
 
   useEffect(() => {
diff --git a/components/dashboard/stream-manager/StreamPasswordSettings.tsx b/components/dashboard/stream-manager/StreamPasswordSettings.tsx
new file mode 100644
index 00000000..409523bd
--- /dev/null
+++ b/components/dashboard/stream-manager/StreamPasswordSettings.tsx
@@ -0,0 +1,97 @@
+"use client";
+
+import { useState } from "react";
+
+interface StreamPasswordSettingsProps {
+  wallet: string;
+  isPasswordProtected: boolean;
+  onUpdate: (nextValue: boolean) => void;
+}
+
+export default function StreamPasswordSettings({
+  wallet,
+  isPasswordProtected,
+  onUpdate,
+}: StreamPasswordSettingsProps) {
+  const [enabled, setEnabled] = useState(isPasswordProtected);
+  const [password, setPassword] = useState("");
+  const [isSaving, setIsSaving] = useState(false);
+  const [message, setMessage] = useState<string | null>(null);
+
+  const handleSave = async () => {
+    setIsSaving(true);
+    setMessage(null);
+
+    try {
+      const response = await fetch("/api/streams/update", {
+        method: "PATCH",
+        headers: { "Content-Type": "application/json" },
+        body: JSON.stringify({
+          wallet,
+          streamAccessType: enabled ? "password" : "public",
+          password: enabled ? password : "",
+        }),
+      });
+
+      const data = await response.json();
+      if (!response.ok) {
+        setMessage(data.error || "Failed to update stream access.");
+        return;
+      }
+
+      onUpdate(enabled);
+      setPassword("");
+      setMessage("Stream access settings updated.");
+    } catch {
+      setMessage("Failed to update stream access.");
+    } finally {
+      setIsSaving(false);
+    }
+  };
+
+  return (
+    <div className="bg-card border border-border rounded-xl p-4">
+      <div className="flex items-center justify-between gap-4 mb-3">
+        <div>
+          <h3 className="text-sm font-semibold text-foreground">
+            Password Protection
+          </h3>
+          <p className="text-xs text-muted-foreground">
+            Require a password before viewers can enter the stream.
+          </p>
+        </div>
+        <label className="inline-flex items-center gap-2 text-sm text-foreground">
+          <input
+            type="checkbox"
+            checked={enabled}
+            onChange={event => setEnabled(event.target.checked)}
+          />
+          Enabled
+        </label>
+      </div>
+
+      {enabled && (
+        <input
+          type="password"
+          value={password}
+          onChange={event => setPassword(event.target.value)}
+          className="w-full rounded-lg border border-border bg-background px-3 py-2 text-sm mb-3"
+          placeholder="Set stream password"
+        />
+      )}
+
+      {message && (
+        <p className="text-xs text-muted-foreground mb-3">{message}</p>
+      )}
+
+      <button
+        type="button"
+        onClick={handleSave}
+        disabled={isSaving || (enabled && password.trim().length === 0)}
+        className="rounded-lg bg-highlight px-4 py-2 text-sm font-medium text-primary-foreground disabled:opacity-60"
+      >
+        {isSaving ? "Saving..." : "Save access settings"}
+      </button>
+    </div>
+  );
+}
diff --git a/components/explore/Navbar.tsx b/components/explore/Navbar.tsx
index b36327ce..83d194e3 100644
--- a/components/explore/Navbar.tsx
+++ b/components/explore/Navbar.tsx
@@ -447,7 +447,7 @@ export default function Navbar({}: NavbarProps) {
               </button>
               <button
                 onClick={handleConnectWallet}
-                className="hidden md:inline-flex bg-highlight hover:bg-highlight/80 text-background px-4 py-2.5 rounded-md text-sm font-medium transition-all"
+                className="bg-highlight hover:bg-highlight/80 text-background px-4 py-2.5 rounded-md text-sm font-medium transition-all"
               >
                 Connect Wallet
               </button>
diff --git a/components/settings/SettingsNavigation.tsx b/components/settings/SettingsNavigation.tsx
index eeb34dbc..9b1d928b 100644
--- a/components/settings/SettingsNavigation.tsx
+++ b/components/settings/SettingsNavigation.tsx
@@ -11,6 +11,7 @@ const URL_MAPPING = {
   "Stream & Channel Preferences": "/settings/stream-preference",
   Appearance: "/settings/appearance",
   "Connected Accounts": "/settings/connected-accounts",
+  Preferences: "/settings/preferences",
 };
 
 export default function SettingsNavigation() {
diff --git a/components/settings/UserPreferencesForm.tsx b/components/settings/UserPreferencesForm.tsx
new file mode 100644
index 00000000..7f8dec28
--- /dev/null
+++ b/components/settings/UserPreferencesForm.tsx
@@ -0,0 +1,136 @@
+"use client";
+
+import { useUserPreferences } from "@/hooks/useUserPreferences";
+import { toast } from "sonner";
+
+/**
+ * Cross-device user preferences form.
+ * Covers stream quality, notifications, UI theme, language, and chat settings.
+ */
+export function UserPreferencesForm() {
+  const { preferences, isLoading, update } = useUserPreferences();
+
+  if (isLoading) {
+    return <div className="text-sm text-muted-foreground">Loading preferences…</div>;
+  }
+  if (!preferences) {
+    return <div className="text-sm text-muted-foreground">Could not load preferences.</div>;
+  }
+
+  const handleChange = async (patch: Parameters<typeof update>[0]) => {
+    try {
+      await update(patch);
+      toast.success("Preference saved");
+    } catch {
+      toast.error("Failed to save preference");
+    }
+  };
+
+  return (
+    <div className="space-y-8 text-foreground">
+      {/* Playback */}
+      <section className="space-y-3">
+        <h3 className="text-sm font-semibold text-muted-foreground uppercase tracking-wide">Playback</h3>
+        <div className="flex items-center justify-between">
+          <label htmlFor="stream_quality" className="text-sm">Default stream quality</label>
+          <select
+            id="stream_quality"
+            value={preferences.stream_quality}
+            onChange={e => handleChange({ stream_quality: e.target.value as typeof preferences.stream_quality })}
+            className="bg-muted text-foreground text-sm px-3 py-1.5 rounded-lg border border-border focus:outline-none"
+          >
+            {(["auto", "1080p", "720p", "480p", "360p"] as const).map(q => (
+              <option key={q} value={q}>{q}</option>
+            ))}
+          </select>
+        </div>
+      </section>
+
+      {/* Notifications */}
+      <section className="space-y-3">
+        <h3 className="text-sm font-semibold text-muted-foreground uppercase tracking-wide">Notifications</h3>
+        {(
+          [
+            { key: "notify_live",  label: "Notify when a followed streamer goes live" },
+            { key: "notify_clips", label: "Notify when someone clips your stream" },
+            { key: "notify_tips",  label: "Notify when you receive a tip" },
+          ] as const
+        ).map(({ key, label }) => (
+          <div key={key} className="flex items-center justify-between">
+            <label htmlFor={key} className="text-sm">{label}</label>
+            <input
+              id={key}
+              type="checkbox"
+              checked={preferences[key]}
+              onChange={e => handleChange({ [key]: e.target.checked })}
+              className="w-4 h-4 accent-highlight"
+            />
+          </div>
+        ))}
+      </section>
+
+      {/* Appearance */}
+      <section className="space-y-3">
+        <h3 className="text-sm font-semibold text-muted-foreground uppercase tracking-wide">Appearance</h3>
+        <div className="flex items-center justify-between">
+          <label htmlFor="theme" className="text-sm">Theme</label>
+          <select
+            id="theme"
+            value={preferences.theme}
+            onChange={e => handleChange({ theme: e.target.value as typeof preferences.theme })}
+            className="bg-muted text-foreground text-sm px-3 py-1.5 rounded-lg border border-border focus:outline-none"
+          >
+            {(["dark", "light", "system"] as const).map(t => (
+              <option key={t} value={t}>{t.charAt(0).toUpperCase() + t.slice(1)}</option>
+            ))}
+          </select>
+        </div>
+        <div className="flex items-center justify-between">
+          <label htmlFor="language" className="text-sm">Language</label>
+          <select
+            id="language"
+            value={preferences.language}
+            onChange={e => handleChange({ language: e.target.value })}
+            className="bg-muted text-foreground text-sm px-3 py-1.5 rounded-lg border border-border focus:outline-none"
+          >
+            <option value="en">English</option>
+            <option value="es">Español</option>
+            <option value="fr">Français</option>
+            <option value="de">Deutsch</option>
+            <option value="pt">Português</option>
+            <option value="zh">中文</option>
+            <option value="ja">日本語</option>
+          </select>
+        </div>
+      </section>
+
+      {/* Chat */}
+      <section className="space-y-3">
+        <h3 className="text-sm font-semibold text-muted-foreground uppercase tracking-wide">Chat</h3>
+        <div className="flex items-center justify-between">
+          <label htmlFor="chat_font_size" className="text-sm">Font size</label>
+          <select
+            id="chat_font_size"
+            value={preferences.chat_font_size}
+            onChange={e => handleChange({ chat_font_size: e.target.value as typeof preferences.chat_font_size })}
+            className="bg-muted text-foreground text-sm px-3 py-1.5 rounded-lg border border-border focus:outline-none"
+          >
+            {(["small", "medium", "large"] as const).map(s => (
+              <option key={s} value={s}>{s.charAt(0).toUpperCase() + s.slice(1)}</option>
+            ))}
+          </select>
+        </div>
+        <div className="flex items-center justify-between">
+          <label htmlFor="show_timestamps" className="text-sm">Show message timestamps</label>
+          <input
+            id="show_timestamps"
+            type="checkbox"
+            checked={preferences.show_timestamps}
+            onChange={e => handleChange({ show_timestamps: e.target.checked })}
+            className="w-4 h-4 accent-highlight"
+          />
+        </div>
+      </section>
+    </div>
+  );
+}
diff --git a/components/settings/stream-channel-preferences/stream-preference.tsx b/components/settings/stream-channel-preferences/stream-preference.tsx
index 3ed5f8fe..11ad3597 100644
--- a/components/settings/stream-channel-preferences/stream-preference.tsx
+++ b/components/settings/stream-channel-preferences/stream-preference.tsx
@@ -1,14 +1,12 @@
 "use client";
 import type React from "react";
 import { useState, useRef, useEffect } from "react";
-import { Copy, Eye, Globe, Lock, RefreshCw, Users, Zap } from "lucide-react";
+import { Eye, Zap } from "lucide-react";
 import { toast } from "sonner";
 import StreamKeyModal from "@/components/ui/streamkeyModal";
 import StreamKeyConfirmationModal from "@/components/ui/streamKeyConfirmationModal";
 import { useStellarWallet } from "@/contexts/stellar-wallet-context";
 
-type StreamPrivacy = "public" | "unlisted" | "subscribers_only";
-
 interface ToggleSwitchProps {
   enabled: boolean;
   onChange: () => void;
@@ -142,13 +140,13 @@ const StreamPreferencesPage: React.FC = () => {
   const [recordingToggleSaving, setRecordingToggleSaving] = useState(false);
   const [latencyMode, setLatencyMode] = useState<"low" | "standard">("low");
   const [latencyToggleSaving, setLatencyToggleSaving] = useState(false);
-
-  const [privacy, setPrivacy] = useState<StreamPrivacy>("public");
-  const [shareToken, setShareToken] = useState<string | null>(null);
-  const [privacySaving, setPrivacySaving] = useState(false);
-  const [tokenRotating, setTokenRotating] = useState(false);
-  const [outOfSync, setOutOfSync] = useState<string[]>([]);
-  const [reprovisioning, setReprovisioning] = useState(false);
+  const [streamAccessType, setStreamAccessType] = useState<
+    "public" | "password" | "subscription"
+  >("public");
+  const [subscriptionPriceUsdc, setSubscriptionPriceUsdc] = useState<
+    number | null
+  >(null);
+  const [accessTypeSaving, setAccessTypeSaving] = useState(false);
   const [loading, setLoading] = useState(true);
 
   // State for the modals
@@ -176,7 +174,20 @@ const StreamPreferencesPage: React.FC = () => {
         );
         const mode = data.latencyMode || data.streamData?.latencyMode || "low";
         setLatencyMode(mode === "standard" ? "standard" : "low");
-        setOutOfSync(data.streamData?.outOfSync ?? []);
+        const accessType =
+          data.streamAccessType ||
+          data.streamData?.streamAccessType ||
+          "public";
+        setStreamAccessType(
+          accessType === "password" || accessType === "subscription"
+            ? accessType
+            : "public"
+        );
+        setSubscriptionPriceUsdc(
+          data.subscriptionPriceUsdc ??
+            data.streamData?.subscriptionPriceUsdc ??
+            null
+        );
         if (data.hasStream && data.streamData) {
           setStreamData(data.streamData);
         } else {
@@ -192,161 +203,6 @@ const StreamPreferencesPage: React.FC = () => {
     fetchStreamKey();
   }, [address]);
 
-  // Load privacy settings
-  useEffect(() => {
-    if (!address) {
-      return;
-    }
-    fetch(`/api/streams/privacy?wallet=${address}`)
-      .then(r => (r.ok ? r.json() : null))
-      .then(data => {
-        if (!data) {
-          return;
-        }
-        if (data.privacy) {
-          setPrivacy(data.privacy as StreamPrivacy);
-        }
-        setShareToken(data.shareToken ?? null);
-      })
-      .catch(() => {});
-  }, [address]);
-
-  const handlePrivacyChange = async (next: StreamPrivacy) => {
-    if (!address || privacySaving || next === privacy) {
-      return;
-    }
-    setPrivacySaving(true);
-    try {
-      const res = await fetch("/api/streams/privacy", {
-        method: "POST",
-        headers: { "Content-Type": "application/json" },
-        body: JSON.stringify({ wallet: address, privacy: next }),
-      });
-      if (!res.ok) {
-        throw new Error("Failed");
-      }
-      const data = await res.json();
-      setPrivacy(data.privacy);
-      setShareToken(data.shareToken ?? null);
-      // Privacy change may require reprovisioning for signed playback
-      try {
-        const refresh = await fetch(`/api/streams/key?wallet=${address}`);
-        if (refresh.ok) {
-          const refreshData = await refresh.json();
-          setOutOfSync(refreshData.streamData?.outOfSync ?? []);
-        }
-      } catch {
-        /* non-fatal */
-      }
-      toast.success(
-        next === "public"
-          ? "Stream is now public — visible on Explore."
-          : next === "unlisted"
-            ? "Stream is now unlisted. Share the invite link with viewers."
-            : "Stream is now subscribers-only. Share the invite link with viewers."
-      );
-    } catch {
-      toast.error("Failed to update privacy");
-    } finally {
-      setPrivacySaving(false);
-    }
-  };
-
-  const handleRotateShareToken = async () => {
-    if (!address || tokenRotating) {
-      return;
-    }
-    setTokenRotating(true);
-    try {
-      const res = await fetch("/api/streams/privacy", {
-        method: "POST",
-        headers: { "Content-Type": "application/json" },
-        body: JSON.stringify({ wallet: address, rotate_token: true }),
-      });
-      if (!res.ok) {
-        throw new Error("Failed");
-      }
-      const data = await res.json();
-      setShareToken(data.shareToken ?? null);
-      toast.success("Invite link rotated. Old links no longer work.");
-    } catch {
-      toast.error("Failed to rotate invite link");
-    } finally {
-      setTokenRotating(false);
-    }
-  };
-
-  const buildShareUrl = () => {
-    if (!username || !shareToken) {
-      return "";
-    }
-    const origin =
-      typeof window !== "undefined" ? window.location.origin : "";
-    return `${origin}/${username}/watch?key=${shareToken}`;
-  };
-
-  const handleReprovision = async () => {
-    if (!address || reprovisioning) {
-      return;
-    }
-    if (streamData?.isLive) {
-      toast.error("End your current stream before applying changes.");
-      return;
-    }
-    const confirmed = window.confirm(
-      "This will rotate your stream key. You'll need to update OBS with the new key before your next stream. Continue?"
-    );
-    if (!confirmed) {
-      return;
-    }
-    setReprovisioning(true);
-    try {
-      const res = await fetch("/api/streams/reprovision", {
-        method: "POST",
-        headers: { "Content-Type": "application/json" },
-        body: JSON.stringify({ wallet: address }),
-      });
-      const data = await res.json();
-      if (!res.ok) {
-        throw new Error(data?.detail || data?.error || "Failed");
-      }
-      // Refresh the displayed stream data + clear out-of-sync state
-      const refreshRes = await fetch(`/api/streams/key?wallet=${address}`);
-      if (refreshRes.ok) {
-        const refresh = await refreshRes.json();
-        if (refresh.hasStream && refresh.streamData) {
-          setStreamData(refresh.streamData);
-          setOutOfSync(refresh.streamData.outOfSync ?? []);
-        }
-      } else {
-        setOutOfSync([]);
-      }
-      toast.success(
-        "Stream key rotated. Update OBS with the new key before going live."
-      );
-      if (data.warnings?.length) {
-        data.warnings.forEach((w: string) => toast.message(w));
-      }
-    } catch (e: any) {
-      toast.error(e?.message || "Failed to reprovision stream");
-    } finally {
-      setReprovisioning(false);
-    }
-  };
-
-  const handleCopyShareLink = async () => {
-    const url = buildShareUrl();
-    if (!url) {
-      return;
-    }
-    try {
-      await navigator.clipboard.writeText(url);
-      toast.success("Invite link copied to clipboard");
-    } catch {
-      toast.error("Couldn't copy link");
-    }
-  };
-
   // Cleanup timer on unmount
   useEffect(() => {
     return () => {
@@ -463,20 +319,10 @@ const StreamPreferencesPage: React.FC = () => {
         throw new Error("Failed to update");
       }
       setLatencyMode(newValue);
-      // Re-check out-of-sync state since latency change requires reprovisioning
-      try {
-        const refresh = await fetch(`/api/streams/key?wallet=${address}`);
-        if (refresh.ok) {
-          const data = await refresh.json();
-          setOutOfSync(data.streamData?.outOfSync ?? []);
-        }
-      } catch {
-        /* non-fatal */
-      }
       toast.success(
         newValue === "standard"
-          ? "DVR enabled. Apply the change above to make it live."
-          : "Low latency enabled. Apply the change above to make it live."
+          ? "DVR enabled — viewers can rewind your stream. Takes effect on next stream."
+          : "Low latency enabled — minimal delay. Takes effect on next stream."
       );
     } catch (e) {
       console.error("Failed to update latency mode:", e);
@@ -510,6 +356,49 @@ const StreamPreferencesPage: React.FC = () => {
     }
   };
 
+  const handleAccessTypeChange = async (
+    nextValue: "public" | "password" | "subscription"
+  ) => {
+    if (!address || accessTypeSaving) {
+      return;
+    }
+    if (
+      nextValue === "subscription" &&
+      (!subscriptionPriceUsdc || subscriptionPriceUsdc <= 0)
+    ) {
+      toast.error("Set a subscription price before enabling subscriber access");
+      return;
+    }
+
+    const previous = streamAccessType;
+    setStreamAccessType(nextValue);
+    setAccessTypeSaving(true);
+    try {
+      const res = await fetch("/api/streams/update", {
+        method: "PATCH",
+        headers: { "Content-Type": "application/json" },
+        body: JSON.stringify({
+          wallet: address,
+          streamAccessType: nextValue,
+        }),
+      });
+      const data = await res.json();
+      if (!res.ok) {
+        throw new Error(data.error || "Failed to update stream access");
+      }
+      toast.success("Stream access updated");
+    } catch (error) {
+      setStreamAccessType(previous);
+      toast.error(
+        error instanceof Error
+          ? error.message
+          : "Failed to update stream access"
+      );
+    } finally {
+      setAccessTypeSaving(false);
+    }
+  };
+
   const handleReset = () => {
     console.log("Reset clicked");
     // Clear any existing timers
@@ -618,53 +507,6 @@ const StreamPreferencesPage: React.FC = () => {
               actions={streamKeyActions}
             />
 
-            {/* Out-of-sync banner — DVR or signed-playback settings need re-provisioning */}
-            {outOfSync.length > 0 && (
-              <div className="bg-blue-500/10 border border-blue-500/40 rounded-lg p-4 mt-4">
-                <p className="text-blue-600 dark:text-blue-400 font-semibold mb-2">
-                  Settings need to be applied to your stream
-                </p>
-                <p className="text-sm text-muted-foreground mb-2">
-                  These changes are saved but won&rsquo;t take effect until your
-                  Mux stream is rebuilt:
-                </p>
-                <ul className="text-sm text-muted-foreground list-disc list-inside mb-3 space-y-0.5">
-                  {outOfSync.includes("dvr") && (
-                    <li>
-                      <span className="font-medium text-foreground">
-                        DVR / Rewind
-                      </span>{" "}
-                      — viewers can&rsquo;t scrub back yet
-                    </li>
-                  )}
-                  {outOfSync.includes("signed_playback") && (
-                    <li>
-                      <span className="font-medium text-foreground">
-                        Privacy: {privacy === "unlisted" ? "Unlisted" : "Subscribers only"}
-                      </span>{" "}
-                      — using app-layer protection only, no CDN-level signed
-                      playback yet
-                    </li>
-                  )}
-                </ul>
-                <p className="text-xs text-muted-foreground italic mb-3">
-                  Applying will rotate your stream key. Update OBS with the new
-                  key afterwards. You must not be live.
-                </p>
-                <button
-                  onClick={handleReprovision}
-                  disabled={reprovisioning || streamData?.isLive}
-                  className="bg-blue-600 hover:bg-blue-700 disabled:opacity-50 disabled:cursor-not-allowed text-white px-4 py-2 rounded-md text-sm font-medium"
-                >
-                  {reprovisioning
-                    ? "Applying..."
-                    : streamData?.isLive
-                      ? "End stream first to apply"
-                      : "Apply changes & rotate key"}
-                </button>
-              </div>
-            )}
-
             {/* Warning */}
             <div className="bg-yellow-500/10 border border-yellow-500/50 rounded-lg p-4 mt-4">
               <p className="text-yellow-600 dark:text-yellow-400 font-semibold mb-2">
@@ -727,126 +569,49 @@ const StreamPreferencesPage: React.FC = () => {
           </div>
         </SectionCard>
 
-        {/* Privacy */}
         <SectionCard>
-          <h2 className="text-highlight text-xl font-medium mb-2">
-            Stream Privacy
-          </h2>
-          <p className="text-muted-foreground text-sm italic mb-4">
-            Control who can watch your stream. Private streams won&rsquo;t appear on
-            Explore.
-          </p>
-
-          <div className="space-y-2">
-            {(
-              [
-                {
-                  value: "public" as const,
-                  icon: Globe,
-                  title: "Public",
-                  desc: "Anyone can find and watch — your stream appears on Explore.",
-                },
-                {
-                  value: "unlisted" as const,
-                  icon: Lock,
-                  title: "Unlisted",
-                  desc: "Only people with the invite link can watch. Hidden from Explore.",
-                },
-                {
-                  value: "subscribers_only" as const,
-                  icon: Users,
-                  title: "Subscribers only",
-                  desc: "Only people with the invite link can watch for now. Paid subscriptions are coming soon.",
-                },
-              ]
-            ).map(opt => {
-              const Icon = opt.icon;
-              const selected = privacy === opt.value;
-              return (
-                <button
-                  key={opt.value}
-                  type="button"
-                  onClick={() => handlePrivacyChange(opt.value)}
-                  disabled={privacySaving}
-                  className={`w-full text-left flex items-start gap-3 p-3 rounded-lg border transition-colors ${
-                    selected
-                      ? "border-highlight bg-highlight/5"
-                      : "border-border bg-transparent hover:bg-accent/40"
-                  }`}
-                >
-                  <div className="mt-0.5">
-                    <Icon
-                      size={18}
-                      className={
-                        selected ? "text-highlight" : "text-muted-foreground"
-                      }
-                    />
-                  </div>
-                  <div className="flex-1 min-w-0">
-                    <div className="text-sm font-medium text-foreground">
-                      {opt.title}
-                    </div>
-                    <div className="text-xs text-muted-foreground mt-0.5">
-                      {opt.desc}
-                    </div>
-                  </div>
-                  <div
-                    className={`w-4 h-4 rounded-full border flex items-center justify-center mt-1 ${
-                      selected
-                        ? "border-highlight bg-highlight"
-                        : "border-muted-foreground"
-                    }`}
-                  >
-                    {selected && (
-                      <div className="w-1.5 h-1.5 rounded-full bg-white" />
-                    )}
-                  </div>
-                </button>
-              );
-            })}
-          </div>
-
-          {privacy !== "public" && shareToken && (
-            <div className="mt-4 p-4 bg-input rounded-lg">
-              <div className="flex items-center justify-between mb-2">
-                <h3 className="text-sm font-medium text-foreground">
-                  Invite link
-                </h3>
-                <button
-                  type="button"
-                  onClick={handleRotateShareToken}
-                  disabled={tokenRotating}
-                  className="flex items-center gap-1.5 text-xs text-muted-foreground hover:text-foreground disabled:opacity-50"
-                >
-                  <RefreshCw
-                    size={12}
-                    className={tokenRotating ? "animate-spin" : ""}
-                  />
-                  {tokenRotating ? "Rotating..." : "Rotate"}
-                </button>
-              </div>
-              <div className="flex gap-2">
-                <input
-                  readOnly
-                  value={buildShareUrl()}
-                  className="flex-1 bg-background text-foreground text-xs font-mono rounded-md px-3 py-2 outline-none"
-                  onFocus={e => e.target.select()}
-                />
-                <button
-                  type="button"
-                  onClick={handleCopyShareLink}
-                  className="bg-secondary hover:bg-secondary/80 text-secondary-foreground px-3 rounded-md flex items-center gap-1.5 text-xs"
-                >
-                  <Copy size={12} />
-                  Copy
-                </button>
-              </div>
-              <p className="text-xs text-muted-foreground mt-2">
-                Anyone with this link can watch. Rotate to invalidate previously
-                shared links.
+          <div className="flex flex-col gap-4 md:flex-row md:items-start md:justify-between">
+            <div className="flex-1">
+              <h2 className="text-highlight text-xl font-medium mb-2">
+                Stream Access
+              </h2>
+              <p className="text-muted-foreground text-sm italic">
+                Choose who can watch this stream. Subscriber access uses your
+                monthly subscription price.
               </p>
             </div>
-          )}
+            <div className="flex flex-col gap-2 md:min-w-64">
+              <select
+                value={streamAccessType}
+                onChange={e =>
+                  handleAccessTypeChange(
+                    e.target.value as "public" | "password" | "subscription"
+                  )
+                }
+                disabled={accessTypeSaving || !streamData}
+                className="w-full bg-input text-foreground rounded-lg p-3 border border-border focus:outline-none focus:ring-2 focus:ring-highlight"
+                title={
+                  !subscriptionPriceUsdc || subscriptionPriceUsdc <= 0
+                    ? "Set a subscription price to enable subscriber-only streams"
+                    : undefined
+                }
+              >
+                <option value="public">Public</option>
+                <option value="password">Password protected</option>
+                <option
+                  value="subscription"
+                  disabled={
+                    !subscriptionPriceUsdc || subscriptionPriceUsdc <= 0
+                  }
+                >
+                  Subscribers only
+                </option>
+              </select>
+              {accessTypeSaving && (
+                <span className="text-sm text-muted-foreground">Saving...</span>
+              )}
+            </div>
+          </div>
         </SectionCard>
 
         {/* Latency Mode / DVR */}
@@ -862,8 +627,8 @@ const StreamPreferencesPage: React.FC = () => {
                   : "Low latency mode is active. Minimal delay (~3–5 seconds), but viewers cannot rewind the stream."}
               </p>
               <p className="text-muted-foreground text-xs mt-2">
-                Changes take effect on your next stream. Existing streams are not
-                affected.
+                Changes take effect on your next stream. Existing streams are
+                not affected.
               </p>
             </div>
             <div className="flex items-center shrink-0">
diff --git a/components/stream/AccessGate.tsx b/components/stream/AccessGate.tsx
new file mode 100644
index 00000000..e56690c2
--- /dev/null
+++ b/components/stream/AccessGate.tsx
@@ -0,0 +1,106 @@
+"use client";
+
+import { useMemo, useState } from "react";
+import { Lock, ShieldCheck } from "lucide-react";
+
+type AccessType = "password" | "subscription";
+
+interface AccessGateProps {
+  playbackId: string;
+  username: string;
+  onAccessGranted: () => void;
+  accessType: AccessType;
+  monthlyPrice?: number | null;
+  viewerPublicKey?: string | null;
+}
+
+export default function AccessGate({
+  username,
+  onAccessGranted,
+  accessType,
+  monthlyPrice,
+  viewerPublicKey,
+}: AccessGateProps) {
+  const [password, setPassword] = useState("");
+  const [error, setError] = useState<string | null>(null);
+
+  const subtitle = useMemo(() => {
+    if (accessType === "subscription") {
+      return monthlyPrice
+        ? `This stream is for supporters. A subscription of ${monthlyPrice} USDC is required.`
+        : "This stream is for supporters only.";
+    }
+
+    return "This stream is password protected.";
+  }, [accessType, monthlyPrice]);
+
+  const handleSubmit = () => {
+    if (accessType === "subscription") {
+      setError(
+        viewerPublicKey
+          ? "Subscription validation is not available on this branch yet."
+          : "Connect a wallet to continue when subscription validation is available."
+      );
+      return;
+    }
+
+    if (!password.trim()) {
+      setError("Enter the stream password to continue.");
+      return;
+    }
+
+    setError(null);
+    onAccessGranted();
+  };
+
+  return (
+    <div className="min-h-[70vh] flex items-center justify-center px-4 py-16">
+      <div className="max-w-md w-full bg-card border border-border rounded-2xl p-8 shadow-sm">
+        <div className="flex items-center gap-3 mb-4">
+          <div className="w-12 h-12 rounded-full bg-muted flex items-center justify-center">
+            {accessType === "subscription" ? (
+              <ShieldCheck className="w-6 h-6 text-muted-foreground" />
+            ) : (
+              <Lock className="w-6 h-6 text-muted-foreground" />
+            )}
+          </div>
+          <div>
+            <h1 className="text-xl font-semibold text-foreground">
+              {accessType === "subscription"
+                ? "Supporter-only stream"
+                : "Password-protected stream"}
+            </h1>
+            <p className="text-sm text-muted-foreground">Creator: {username}</p>
+          </div>
+        </div>
+
+        <p className="text-sm text-muted-foreground mb-5">{subtitle}</p>
+
+        {accessType === "password" && (
+          <div className="mb-4">
+            <label className="block text-sm font-medium text-foreground mb-2">
+              Stream password
+            </label>
+            <input
+              type="password"
+              value={password}
+              onChange={event => setPassword(event.target.value)}
+              className="w-full rounded-lg border border-border bg-background px-3 py-2 text-sm"
+              placeholder="Enter password"
+            />
+          </div>
+        )}
+
+        {error && <p className="text-sm text-destructive mb-4">{error}</p>}
+
+        <button
+          type="button"
+          onClick={handleSubmit}
+          className="w-full rounded-lg bg-highlight px-4 py-2.5 text-sm font-medium text-primary-foreground"
+        >
+          {accessType === "subscription" ? "Check access" : "Unlock stream"}
+        </button>
+      </div>
+    </div>
+  );
+}
diff --git a/components/stream/ClipButton.tsx b/components/stream/ClipButton.tsx
new file mode 100644
index 00000000..7f77379c
--- /dev/null
+++ b/components/stream/ClipButton.tsx
@@ -0,0 +1,80 @@
+"use client";
+
+import { useState } from "react";
+import { Scissors } from "lucide-react";
+import { toast } from "sonner";
+
+interface ClipButtonProps {
+  streamerUsername: string;
+  /** Approximate seconds elapsed since stream started (for start_offset) */
+  streamElapsedSeconds?: number;
+  className?: string;
+}
+
+/**
+ * ✂️ Clip button — lets any authenticated viewer create a 30-second clip
+ * from the current live stream position.
+ */
+export function ClipButton({ streamerUsername, streamElapsedSeconds = 0, className = "" }: ClipButtonProps) {
+  const [loading, setLoading] = useState(false);
+  const [justClipped, setJustClipped] = useState(false);
+
+  const handleClip = async () => {
+    if (loading || justClipped) {
+      return;
+    }
+    setLoading(true);
+    try {
+      // Clip the last 30 seconds
+      const duration = 30;
+      const start_offset = Math.max(0, streamElapsedSeconds - duration);
+
+      const res = await fetch("/api/streams/clips", {
+        method: "POST",
+        headers: { "Content-Type": "application/json" },
+        credentials: "include",
+        body: JSON.stringify({
+          streamer_username: streamerUsername,
+          start_offset,
+          duration,
+        }),
+      });
+
+      if (res.status === 401) {
+        toast.error("Sign in to create clips");
+        return;
+      }
+      if (!res.ok) {
+        const { error } = await res.json().catch(() => ({}));
+        toast.error(error ?? "Failed to create clip");
+        return;
+      }
+
+      toast.success("Clip created! It'll be ready in a moment.");
+      setJustClipped(true);
+      // Reset after 10 s so they can clip again
+      setTimeout(() => setJustClipped(false), 10_000);
+    } catch {
+      toast.error("Failed to create clip");
+    } finally {
+      setLoading(false);
+    }
+  };
+
+  return (
+    <button
+      onClick={handleClip}
+      disabled={loading || justClipped}
+      title="Create a 30-second clip"
+      aria-label="Create clip"
+      className={`flex items-center gap-1.5 px-3 py-1.5 rounded-lg text-sm font-medium transition-colors
+        ${justClipped
+          ? "bg-green-600/20 text-green-400 cursor-default"
+          : "bg-muted hover:bg-accent text-foreground disabled:opacity-50 disabled:cursor-not-allowed"
+        } ${className}`}
+    >
+      <Scissors className="w-4 h-4" />
+      {loading ? "Clipping…" : justClipped ? "Clipped!" : "Clip"}
+    </button>
+  );
+}
diff --git a/components/stream/WhitelistManager.tsx b/components/stream/WhitelistManager.tsx
new file mode 100644
index 00000000..d4b6a224
--- /dev/null
+++ b/components/stream/WhitelistManager.tsx
@@ -0,0 +1,106 @@
+"use client";
+
+import { useState } from "react";
+import { X, UserPlus, Lock } from "lucide-react";
+import Image from "next/image";
+import { toast } from "sonner";
+import { useStreamWhitelist } from "@/hooks/useStreamWhitelist";
+import { getDefaultAvatar } from "@/lib/profile-icons";
+
+/**
+ * Streamer-side whitelist manager.
+ * Lets the streamer add/remove users by username or wallet address.
+ */
+export function WhitelistManager() {
+  const { whitelist, isLoading, add, remove, adding, removing } = useStreamWhitelist();
+  const [input, setInput] = useState("");
+
+  const handleAdd = async () => {
+    const val = input.trim();
+    if (!val) {
+      return;
+    }
+    try {
+      await add(val);
+      setInput("");
+      toast.success(`Added ${val} to whitelist`);
+    } catch (err: unknown) {
+      toast.error(err instanceof Error ? err.message : "Failed to add user");
+    }
+  };
+
+  const handleRemove = async (identifier: string) => {
+    try {
+      await remove(identifier);
+      toast.success("Removed from whitelist");
+    } catch {
+      toast.error("Failed to remove user");
+    }
+  };
+
+  return (
+    <div className="space-y-4">
+      <div className="flex items-center gap-2 text-sm text-muted-foreground">
+        <Lock className="w-4 h-4" />
+        <span>Only whitelisted users can watch this stream</span>
+      </div>
+
+      {/* Add input */}
+      <div className="flex gap-2">
+        <input
+          type="text"
+          value={input}
+          onChange={e => setInput(e.target.value)}
+          onKeyDown={e => e.key === "Enter" && handleAdd()}
+          placeholder="Username or wallet address"
+          className="flex-1 bg-muted text-foreground text-sm px-3 py-2 rounded-lg border border-border focus:outline-none focus:border-highlight"
+        />
+        <button
+          onClick={handleAdd}
+          disabled={adding || !input.trim()}
+          className="flex items-center gap-1.5 px-3 py-2 rounded-lg bg-highlight text-white text-sm font-medium hover:bg-highlight/90 disabled:opacity-50 disabled:cursor-not-allowed transition-colors"
+        >
+          <UserPlus className="w-4 h-4" />
+          {adding ? "Adding…" : "Add"}
+        </button>
+      </div>
+
+      {/* List */}
+      {isLoading ? (
+        <p className="text-sm text-muted-foreground">Loading…</p>
+      ) : whitelist.length === 0 ? (
+        <p className="text-sm text-muted-foreground">No users whitelisted yet.</p>
+      ) : (
+        <ul className="space-y-2">
+          {whitelist.map(entry => (
+            <li
+              key={entry.id}
+              className="flex items-center justify-between gap-3 bg-muted rounded-lg px-3 py-2"
+            >
+              <div className="flex items-center gap-2 min-w-0">
+                <Image
+                  src={entry.avatar ?? getDefaultAvatar(entry.identifier)}
+                  alt={entry.identifier}
+                  width={28}
+                  height={28}
+                  className="rounded-full flex-shrink-0"
+                />
+                <span className="text-sm text-foreground truncate">
+                  {entry.username ?? entry.identifier}
+                </span>
+              </div>
+              <button
+                onClick={() => handleRemove(entry.identifier)}
+                disabled={removing === entry.identifier}
+                aria-label={`Remove ${entry.identifier}`}
+                className="text-muted-foreground hover:text-destructive transition-colors flex-shrink-0 disabled:opacity-50"
+              >
+                <X className="w-4 h-4" />
+              </button>
+            </li>
+          ))}
+        </ul>
+      )}
+    </div>
+  );
+}
diff --git a/components/stream/view-stream.tsx b/components/stream/view-stream.tsx
index a932ce68..91089b9d 100644
--- a/components/stream/view-stream.tsx
+++ b/components/stream/view-stream.tsx
@@ -43,6 +43,7 @@ import { useChat } from "@/hooks/useChat";
 import { TipButton, TipModalContainer } from "@/components/tipping";
 import { useTipModal } from "@/hooks/useTipModal";
 import { toast } from "sonner";
+import { ClipButton } from "@/components/stream/ClipButton";
 
 const socialIcons: Record<string, JSX.Element> = {
   twitter: <Twitter className="h-4 w-4" />,
@@ -275,11 +276,6 @@ const ViewStream = ({
   const [showReportModal, setShowReportModal] = useState(false);
   const [isSavingStreamInfo, setIsSavingStreamInfo] = useState(false);
   const [recordings, setRecordings] = useState<PastRecording[]>([]);
-  // For private streams: signed playback id + JWT (overrides userData.playbackId)
-  const [playbackOverride, setPlaybackOverride] = useState<{
-    playbackId: string;
-    token?: string;
-  } | null>(null);
 
   // Use custom hooks for Stellar wallet and tip modal state
   const { publicKey, privyWallet } = useStellarWallet();
@@ -355,46 +351,6 @@ const ViewStream = ({
     getStreamData();
   }, [username, onStatusChange, userData, initialIsLive]);
 
-  // Private streams: fetch signed playback token after access has been verified.
-  // Skips for public streams (uses userData.playbackId directly).
-  useEffect(() => {
-    const privacy = userData?.privacy;
-    if (!privacy || privacy === "public") {
-      setPlaybackOverride(null);
-      return;
-    }
-    if (!isLive) {
-      return;
-    }
-
-    const qs = new URLSearchParams();
-    qs.set("username", username);
-    if (userData?.shareKey) {
-      qs.set("key", userData.shareKey);
-    }
-    if (address) {
-      qs.set("viewer_wallet", address);
-    }
-
-    fetch(`/api/streams/playback-token?${qs.toString()}`)
-      .then(r => (r.ok ? r.json() : null))
-      .then(data => {
-        if (data?.playbackId) {
-          setPlaybackOverride({
-            playbackId: data.playbackId,
-            token: data.signed ? data.token : undefined,
-          });
-        }
-      })
-      .catch(() => {});
-  }, [
-    username,
-    isLive,
-    userData?.privacy,
-    userData?.shareKey,
-    address,
-  ]);
-
   // Fetch past recordings for this streamer
   useEffect(() => {
     fetch(
@@ -589,59 +545,33 @@ const ViewStream = ({
                     : undefined
                 }
               >
-                {(() => {
-                  // For private streams, use the signed playback id+token from /playback-token.
-                  // For public streams, use userData.playbackId directly.
-                  const isPrivate =
-                    userData?.privacy && userData.privacy !== "public";
-                  const effectivePlaybackId = isPrivate
-                    ? playbackOverride?.playbackId
-                    : userData?.playbackId;
-                  const effectiveToken = isPrivate
-                    ? playbackOverride?.token
-                    : undefined;
-                  const playerReady =
-                    !isPrivate || !!playbackOverride?.playbackId;
-
-                  return isLive && effectivePlaybackId && playerReady ? (
-                    <MuxPlayer
-                      playbackId={effectivePlaybackId}
-                      streamType={
-                        userData.latencyMode === "standard" ? "live:dvr" : "live"
-                      }
-                      autoPlay="muted"
-                      tokens={
-                        effectiveToken
-                          ? {
-                              playback: effectiveToken,
-                              thumbnail: effectiveToken,
-                              storyboard: effectiveToken,
-                            }
-                          : undefined
-                      }
-                      metadata={{
-                        video_id: effectivePlaybackId,
-                        video_title: streamData.title || `${username}'s Stream`,
-                        viewer_user_id: "anonymous",
-                      }}
-                      primaryColor="#ac39f2"
-                      className="w-full h-full"
-                    />
-                  ) : (
-                    <div className="absolute inset-0 flex items-center justify-center bg-card">
-                      <div className="text-foreground text-center">
-                        <p className="text-lg mb-2">
-                          {isLive ? "Loading stream..." : "Stream is offline"}
-                        </p>
-                        <p className="text-sm text-muted-foreground">
-                          {isLive
-                            ? "Please wait while we load the stream"
-                            : "Check back later or browse past streams below"}
-                        </p>
-                      </div>
+                {isLive && userData?.playbackId ? (
+                  <MuxPlayer
+                    playbackId={userData.playbackId}
+                    streamType={userData.latencyMode === "standard" ? "live:dvr" : "live"}
+                    autoPlay="muted"
+                    metadata={{
+                      video_id: userData.playbackId,
+                      video_title: streamData.title || `${username}'s Stream`,
+                      viewer_user_id: "anonymous",
+                    }}
+                    primaryColor="#ac39f2"
+                    className="w-full h-full"
+                  />
+                ) : (
+                  <div className="absolute inset-0 flex items-center justify-center bg-card">
+                    <div className="text-foreground text-center">
+                      <p className="text-lg mb-2">
+                        {isLive ? "Loading stream..." : "Stream is offline"}
+                      </p>
+                      <p className="text-sm text-muted-foreground">
+                        {isLive
+                          ? "Please wait while we load the stream"
+                          : "Check back later or browse past streams below"}
+                      </p>
                     </div>
-                  );
-                })()}
+                  </div>
+                )}
 
                 {/* Stream info overlay in fullscreen (visible on hover) */}
                 {isFullscreen && (
@@ -956,6 +886,16 @@ const ViewStream = ({
                             >
                               <Share2 className="w-4 h-4" />
                             </Button>
+                            {isLive && (
+                              <ClipButton
+                                streamerUsername={username}
+                                streamElapsedSeconds={
+                                  userData?.startedAt
+                                    ? Math.floor((Date.now() - new Date(userData.startedAt).getTime()) / 1000)
+                                    : 0
+                                }
+                              />
+                            )}
                             <button
                               className="hidden lg:flex p-2 rounded-md border border-border bg-transparent hover:bg-accent text-foreground transition-colors"
                               onClick={toggleChat}
diff --git a/components/wallet/AddFundsButton.tsx b/components/wallet/AddFundsButton.tsx
index 26910fb0..15914b58 100644
--- a/components/wallet/AddFundsButton.tsx
+++ b/components/wallet/AddFundsButton.tsx
@@ -1,61 +1,61 @@
-"use client";
-
-import { PlusCircle } from "lucide-react";
-import { toast } from "sonner";
-
-import { Button } from "@/components/ui/button";
-import { useTransak } from "@/hooks/useTransak";
-import type { TransakOrderData, TransakWidgetParams } from "@/types/transak";
-
-interface AddFundsButtonProps {
-  walletAddress: string | null;
-  variant?: "default" | "outline" | "ghost" | "secondary";
-  size?: "default" | "sm" | "lg" | "icon";
-  className?: string;
-  /** Called after a successful on-ramp order is confirmed by Transak */
-  onSuccess?: (order: TransakOrderData) => void;
-  /** Optional widget URL param overrides (e.g. cryptoCurrencyCode: "USDC") */
-  paramOverrides?: Partial<TransakWidgetParams>;
-}
-
-/**
- * AddFundsButton — opens the Transak on-ramp widget for the given
- * Stellar wallet address.  Returns null when no wallet is connected
- * so callers don't need to guard against it.
- */
-export function AddFundsButton({
-  walletAddress,
-  variant = "default",
-  size = "default",
-  className,
-  onSuccess,
-  paramOverrides,
-}: AddFundsButtonProps) {
-  const { openTransak, isOpen } = useTransak({
-    walletAddress,
-    paramOverrides,
-    onSuccess: order => {
-      toast.success(
-        `Successfully purchased ${order.cryptoAmount} ${order.cryptoCurrency}`
-      );
-      onSuccess?.(order);
-    },
-  });
-
-  if (!walletAddress) {
-    return null;
-  }
-
-  return (
-    <Button
-      variant={variant}
-      size={size}
-      onClick={openTransak}
-      disabled={isOpen}
-      className={className}
-    >
-      <PlusCircle className="w-4 h-4 mr-2" />
-      {isOpen ? "Opening..." : "Add Funds"}
-    </Button>
-  );
-}
+"use client";
+
+import { PlusCircle } from "lucide-react";
+import { toast } from "sonner";
+
+import { Button } from "@/components/ui/button";
+import { useTransak } from "@/hooks/useTransak";
+import type { TransakOrderData, TransakWidgetParams } from "@/types/transak";
+
+interface AddFundsButtonProps {
+  walletAddress: string | null;
+  variant?: "default" | "outline" | "ghost" | "secondary";
+  size?: "default" | "sm" | "lg" | "icon";
+  className?: string;
+  /** Called after a successful on-ramp order is confirmed by Transak */
+  onSuccess?: (order: TransakOrderData) => void;
+  /** Optional widget URL param overrides (e.g. cryptoCurrencyCode: "USDC") */
+  paramOverrides?: Partial<TransakWidgetParams>;
+}
+
+/**
+ * AddFundsButton — opens the Transak on-ramp widget for the given
+ * Stellar wallet address.  Returns null when no wallet is connected
+ * so callers don't need to guard against it.
+ */
+export function AddFundsButton({
+  walletAddress,
+  variant = "default",
+  size = "default",
+  className,
+  onSuccess,
+  paramOverrides,
+}: AddFundsButtonProps) {
+  const { openTransak, isOpen } = useTransak({
+    walletAddress,
+    paramOverrides,
+    onSuccess: order => {
+      toast.success(
+        `Successfully purchased ${order.cryptoAmount} ${order.cryptoCurrency}`
+      );
+      onSuccess?.(order);
+    },
+  });
+
+  if (!walletAddress) {
+    return null;
+  }
+
+  return (
+    <Button
+      variant={variant}
+      size={size}
+      onClick={openTransak}
+      disabled={isOpen}
+      className={className}
+    >
+      <PlusCircle className="w-4 h-4 mr-2" />
+      {isOpen ? "Opening..." : "Add Funds"}
+    </Button>
+  );
+}
diff --git a/data/settings/index.ts b/data/settings/index.ts
index ce91ba7c..1eef7d3d 100644
--- a/data/settings/index.ts
+++ b/data/settings/index.ts
@@ -5,4 +5,5 @@ export const tabs = [
   { id: "Stream & Channel Preferences", route: "/settings/stream-Preference" },
   { id: "Appearance", route: "/settings/Appearance" },
   { id: "Connected Accounts", route: "/settings/connected-accounts" },
+  { id: "Preferences", route: "/settings/preferences" },
 ];
diff --git a/db/migrations/20260427_backend_enhancements.sql b/db/migrations/20260427_backend_enhancements.sql
new file mode 100644
index 00000000..1358ef74
--- /dev/null
+++ b/db/migrations/20260427_backend_enhancements.sql
@@ -0,0 +1,80 @@
+-- 20260427_backend_enhancements.sql
+
+-- 1. Stream Extensions (#535)
+CREATE TABLE IF NOT EXISTS extension_catalog (
+    id UUID PRIMARY KEY DEFAULT gen_random_uuid(),
+    name VARCHAR(255) NOT NULL,
+    description TEXT,
+    json_schema JSONB NOT NULL,
+    icon_url VARCHAR(255),
+    is_active BOOLEAN DEFAULT TRUE,
+    created_at TIMESTAMP WITH TIME ZONE DEFAULT CURRENT_TIMESTAMP
+);
+
+CREATE TABLE IF NOT EXISTS stream_extensions (
+    id UUID PRIMARY KEY DEFAULT gen_random_uuid(),
+    user_id UUID REFERENCES users(id) ON DELETE CASCADE,
+    extension_id UUID REFERENCES extension_catalog(id) ON DELETE CASCADE,
+    position VARCHAR(20) CHECK (position IN ('overlay', 'panel')),
+    config JSONB DEFAULT '{}',
+    is_enabled BOOLEAN DEFAULT TRUE,
+    created_at TIMESTAMP WITH TIME ZONE DEFAULT CURRENT_TIMESTAMP,
+    updated_at TIMESTAMP WITH TIME ZONE DEFAULT CURRENT_TIMESTAMP
+);
+
+-- 2. OBS Overlay Config (#459)
+CREATE TABLE IF NOT EXISTS user_overlay_config (
+    user_id UUID PRIMARY KEY REFERENCES users(id) ON DELETE CASCADE,
+    theme VARCHAR(50) DEFAULT 'default',
+    position VARCHAR(50) DEFAULT 'bottom-right',
+    font_size INTEGER DEFAULT 16,
+    opacity NUMERIC(3, 2) DEFAULT 1.0,
+    token TEXT UNIQUE,
+    created_at TIMESTAMP WITH TIME ZONE DEFAULT CURRENT_TIMESTAMP,
+    updated_at TIMESTAMP WITH TIME ZONE DEFAULT CURRENT_TIMESTAMP
+);
+
+-- 3. Co-streamer Squads (#465)
+CREATE TABLE IF NOT EXISTS co_stream_invites (
+    id UUID PRIMARY KEY DEFAULT gen_random_uuid(),
+    creator_id UUID REFERENCES users(id) ON DELETE CASCADE,
+    invitee_id UUID REFERENCES users(id) ON DELETE CASCADE,
+    expires_at TIMESTAMP WITH TIME ZONE NOT NULL,
+    status VARCHAR(20) DEFAULT 'pending' CHECK (status IN ('pending', 'accepted', 'rejected', 'expired')),
+    created_at TIMESTAMP WITH TIME ZONE DEFAULT CURRENT_TIMESTAMP
+);
+
+CREATE TABLE IF NOT EXISTS squad_members (
+    id UUID PRIMARY KEY DEFAULT gen_random_uuid(),
+    creator_id UUID REFERENCES users(id) ON DELETE CASCADE,
+    user_id UUID REFERENCES users(id) ON DELETE CASCADE,
+    joined_at TIMESTAMP WITH TIME ZONE DEFAULT CURRENT_TIMESTAMP,
+    UNIQUE(creator_id, user_id)
+);
+
+-- 4. Raid Functionality (#463)
+CREATE TABLE IF NOT EXISTS raids (
+    id UUID PRIMARY KEY DEFAULT gen_random_uuid(),
+    raider_id UUID REFERENCES users(id) ON DELETE CASCADE,
+    target_id UUID REFERENCES users(id) ON DELETE CASCADE,
+    viewer_count INTEGER NOT NULL,
+    raided_at TIMESTAMP WITH TIME ZONE DEFAULT CURRENT_TIMESTAMP,
+    is_acknowledged BOOLEAN DEFAULT FALSE
+);
+
+-- Indices
+CREATE INDEX IF NOT EXISTS idx_stream_extensions_user ON stream_extensions(user_id);
+CREATE INDEX IF NOT EXISTS idx_stream_extensions_enabled ON stream_extensions(is_enabled);
+CREATE INDEX IF NOT EXISTS idx_co_stream_invites_creator ON co_stream_invites(creator_id);
+CREATE INDEX IF NOT EXISTS idx_co_stream_invites_invitee ON co_stream_invites(invitee_id);
+CREATE INDEX IF NOT EXISTS idx_co_stream_invites_status ON co_stream_invites(status);
+CREATE INDEX IF NOT EXISTS idx_raids_target ON raids(target_id);
+CREATE INDEX IF NOT EXISTS idx_raids_raider ON raids(raider_id);
+CREATE INDEX IF NOT EXISTS idx_raids_acknowledged ON raids(is_acknowledged);
+
+-- Default Extensions for catalog
+INSERT INTO extension_catalog (name, description, json_schema, icon_url) VALUES
+('Tip Alert', 'Shows a popup notification when someone tips', '{"type": "object", "properties": {"duration": {"type": "number", "default": 5}, "sound": {"type": "boolean", "default": true}}}', '/icons/tip-alert.png'),
+('Poll Widget', 'Interactive polls for your audience', '{"type": "object", "properties": {"theme": {"type": "string", "default": "dark"}}}', '/icons/poll-widget.png'),
+('Chat Box', 'Display chat messages on screen', '{"type": "object", "properties": {"font": {"type": "string", "default": "Inter"}, "opacity": {"type": "number", "default": 0.8}}}', '/icons/chat-box.png')
+ON CONFLICT DO NOTHING;
diff --git a/db/migrations/add-feature-flags-clips-whitelist-preferences.sql b/db/migrations/add-feature-flags-clips-whitelist-preferences.sql
new file mode 100644
index 00000000..854d00af
--- /dev/null
+++ b/db/migrations/add-feature-flags-clips-whitelist-preferences.sql
@@ -0,0 +1,81 @@
+-- ─── Feature Flags ────────────────────────────────────────────────────────────
+CREATE TABLE IF NOT EXISTS feature_flags (
+    id UUID PRIMARY KEY DEFAULT gen_random_uuid(),
+    key VARCHAR(100) UNIQUE NOT NULL,          -- e.g. 'clips', 'gifts', 'subscriptions'
+    description TEXT,
+    enabled BOOLEAN DEFAULT FALSE,             -- global on/off
+    rollout_percentage INTEGER DEFAULT 0       -- 0-100; used when enabled=true
+        CHECK (rollout_percentage BETWEEN 0 AND 100),
+    allowed_user_ids UUID[] DEFAULT '{}',      -- explicit per-user overrides
+    created_at TIMESTAMP WITH TIME ZONE DEFAULT CURRENT_TIMESTAMP,
+    updated_at TIMESTAMP WITH TIME ZONE DEFAULT CURRENT_TIMESTAMP
+);
+
+-- ─── Stream Whitelist ──────────────────────────────────────────────────────────
+CREATE TABLE IF NOT EXISTS stream_whitelist (
+    id UUID PRIMARY KEY DEFAULT gen_random_uuid(),
+    streamer_id UUID NOT NULL REFERENCES users(id) ON DELETE CASCADE,
+    -- Either user_id (registered user) or raw identifier (username/wallet) for pending invites
+    user_id UUID REFERENCES users(id) ON DELETE CASCADE,
+    identifier VARCHAR(255),                   -- username or wallet address
+    created_at TIMESTAMP WITH TIME ZONE DEFAULT CURRENT_TIMESTAMP,
+    UNIQUE (streamer_id, user_id),
+    UNIQUE (streamer_id, identifier)
+);
+
+-- ─── Stream Clips ─────────────────────────────────────────────────────────────
+CREATE TABLE IF NOT EXISTS stream_clips (
+    id UUID PRIMARY KEY DEFAULT gen_random_uuid(),
+    stream_session_id UUID REFERENCES stream_sessions(id) ON DELETE SET NULL,
+    clipped_by UUID NOT NULL REFERENCES users(id) ON DELETE CASCADE,
+    streamer_id UUID NOT NULL REFERENCES users(id) ON DELETE CASCADE,
+    title VARCHAR(255),
+    playback_id VARCHAR(255),                  -- Mux clip playback id
+    mux_asset_id VARCHAR(255),                 -- Mux asset id for the clip
+    start_offset INTEGER NOT NULL,             -- seconds from stream start
+    duration INTEGER NOT NULL                  -- 30-60 seconds
+        CHECK (duration BETWEEN 1 AND 60),
+    status VARCHAR(20) DEFAULT 'processing'    -- processing | ready | failed
+        CHECK (status IN ('processing', 'ready', 'failed')),
+    view_count INTEGER DEFAULT 0,
+    created_at TIMESTAMP WITH TIME ZONE DEFAULT CURRENT_TIMESTAMP
+);
+
+-- ─── User Preferences ─────────────────────────────────────────────────────────
+CREATE TABLE IF NOT EXISTS user_preferences (
+    user_id UUID PRIMARY KEY REFERENCES users(id) ON DELETE CASCADE,
+    -- Playback
+    stream_quality VARCHAR(20) DEFAULT 'auto'  -- auto | 1080p | 720p | 480p | 360p
+        CHECK (stream_quality IN ('auto', '1080p', '720p', '480p', '360p')),
+    -- Notifications
+    notify_live BOOLEAN DEFAULT TRUE,
+    notify_clips BOOLEAN DEFAULT TRUE,
+    notify_tips BOOLEAN DEFAULT TRUE,
+    -- UI
+    theme VARCHAR(20) DEFAULT 'dark'
+        CHECK (theme IN ('dark', 'light', 'system')),
+    language VARCHAR(10) DEFAULT 'en',
+    -- Chat
+    chat_font_size VARCHAR(10) DEFAULT 'medium'
+        CHECK (chat_font_size IN ('small', 'medium', 'large')),
+    show_timestamps BOOLEAN DEFAULT FALSE,
+    updated_at TIMESTAMP WITH TIME ZONE DEFAULT CURRENT_TIMESTAMP
+);
+
+-- ─── Indexes ──────────────────────────────────────────────────────────────────
+CREATE INDEX IF NOT EXISTS idx_feature_flags_key ON feature_flags(key);
+CREATE INDEX IF NOT EXISTS idx_stream_whitelist_streamer ON stream_whitelist(streamer_id);
+CREATE INDEX IF NOT EXISTS idx_stream_whitelist_user ON stream_whitelist(user_id);
+CREATE INDEX IF NOT EXISTS idx_stream_clips_streamer ON stream_clips(streamer_id);
+CREATE INDEX IF NOT EXISTS idx_stream_clips_clipped_by ON stream_clips(clipped_by);
+CREATE INDEX IF NOT EXISTS idx_stream_clips_status ON stream_clips(status);
+CREATE INDEX IF NOT EXISTS idx_stream_clips_session ON stream_clips(stream_session_id);
+
+-- ─── Seed default feature flags ───────────────────────────────────────────────
+INSERT INTO feature_flags (key, description, enabled, rollout_percentage) VALUES
+  ('clips',              'Allow viewers to create short clips from live streams', TRUE,  100),
+  ('gifts',              'Virtual gift sending during streams',                   FALSE, 0),
+  ('subscriptions',      'Paid channel subscriptions',                            FALSE, 0),
+  ('token_gated_streams','Token-gated stream access',                             FALSE, 0),
+  ('private_streams',    'Whitelist-based private stream access',                 TRUE,  100)
+ON CONFLICT (key) DO NOTHING;
diff --git a/db/migrations/add-latency-mode.sql b/db/migrations/add-latency-mode.sql
new file mode 100644
index 00000000..104acaec
--- /dev/null
+++ b/db/migrations/add-latency-mode.sql
@@ -0,0 +1,6 @@
+-- Add latency_mode column to users table
+-- 'low' = low-latency (3-5s delay, no DVR/rewind)
+-- 'standard' = standard latency (10-15s delay, DVR/rewind enabled)
+-- Default to 'low' to preserve existing behavior
+ALTER TABLE users
+ADD COLUMN IF NOT EXISTS latency_mode VARCHAR(10) DEFAULT 'low';
diff --git a/db/migrations/add-transcription-jobs.sql b/db/migrations/add-transcription-jobs.sql
new file mode 100644
index 00000000..049fd00d
--- /dev/null
+++ b/db/migrations/add-transcription-jobs.sql
@@ -0,0 +1,22 @@
+-- Transcription jobs for VOD auto-generated captions
+-- Run after add-stream-recording.sql
+
+CREATE TABLE IF NOT EXISTS transcription_jobs (
+    id UUID PRIMARY KEY DEFAULT gen_random_uuid(),
+    recording_id UUID NOT NULL REFERENCES stream_recordings(id) ON DELETE CASCADE,
+    user_id UUID NOT NULL REFERENCES users(id) ON DELETE CASCADE,
+    status VARCHAR(20) NOT NULL DEFAULT 'pending'
+        CHECK (status IN ('pending', 'processing', 'ready', 'failed')),
+    content TEXT,                        -- WebVTT text once ready
+    error_reason TEXT,                   -- populated on failure
+    created_at TIMESTAMP WITH TIME ZONE DEFAULT CURRENT_TIMESTAMP,
+    updated_at TIMESTAMP WITH TIME ZONE DEFAULT CURRENT_TIMESTAMP,
+    UNIQUE(recording_id)                 -- one active job per recording
+);
+
+CREATE INDEX IF NOT EXISTS idx_transcription_jobs_recording_id
+    ON transcription_jobs(recording_id);
+CREATE INDEX IF NOT EXISTS idx_transcription_jobs_user_id
+    ON transcription_jobs(user_id);
+CREATE INDEX IF NOT EXISTS idx_transcription_jobs_status
+    ON transcription_jobs(status);
diff --git a/db/migrations/add-user-sessions.sql b/db/migrations/add-user-sessions.sql
new file mode 100644
index 00000000..861c50be
--- /dev/null
+++ b/db/migrations/add-user-sessions.sql
@@ -0,0 +1,24 @@
+-- Migration: add user_sessions table for active session tracking & revocation
+-- Run once against your Vercel Postgres / Neon database.
+
+CREATE TABLE IF NOT EXISTS user_sessions (
+  id           UUID        PRIMARY KEY DEFAULT gen_random_uuid(),
+  user_id      UUID        NOT NULL REFERENCES users(id) ON DELETE CASCADE,
+  token_hash   TEXT        NOT NULL UNIQUE,   -- SHA-256 hex of the raw session token
+  ip_address   INET,
+  user_agent   TEXT,
+  device_hint  TEXT,                          -- e.g. "Chrome on macOS"
+  last_seen_at TIMESTAMPTZ NOT NULL DEFAULT now(),
+  created_at   TIMESTAMPTZ NOT NULL DEFAULT now(),
+  expires_at   TIMESTAMPTZ NOT NULL,
+  revoked      BOOLEAN     NOT NULL DEFAULT false
+);
+
+-- Composite index used by every auth check and the list-sessions query
+CREATE INDEX IF NOT EXISTS user_sessions_user
+  ON user_sessions(user_id, revoked, expires_at);
+
+-- Unique index on token_hash already implied by UNIQUE constraint above,
+-- but an explicit index name makes it easier to reference in EXPLAIN plans.
+CREATE UNIQUE INDEX IF NOT EXISTS user_sessions_token_hash
+  ON user_sessions(token_hash);
diff --git a/db/schema.sql b/db/schema.sql
index f1469aca..34bcb4d3 100644
--- a/db/schema.sql
+++ b/db/schema.sql
@@ -34,7 +34,8 @@ CREATE TABLE IF NOT EXISTS users (
     creator JSONB DEFAULT '{}',
     total_tips_received NUMERIC(20, 7) DEFAULT 0,
     total_tips_count INTEGER DEFAULT 0,
-    last_tip_at TIMESTAMP
+    last_tip_at TIMESTAMP,
+    enable_recording BOOLEAN DEFAULT false
 );
 
 ALTER TABLE users
@@ -43,10 +44,30 @@ ADD COLUMN IF NOT EXISTS followers UUID[];
 ALTER TABLE users
 ADD COLUMN IF NOT EXISTS following UUID[];
 
+ALTER TABLE users
+ADD COLUMN IF NOT EXISTS stream_password_hash VARCHAR(255);
+
+ALTER TABLE users
+ADD COLUMN IF NOT EXISTS stream_access_type TEXT DEFAULT 'public'
+CHECK (stream_access_type IN ('public', 'password', 'subscription'));
+
+CREATE TABLE IF NOT EXISTS subscriptions (
+  id UUID PRIMARY KEY DEFAULT gen_random_uuid(),
+  subscriber_id UUID REFERENCES users(id),
+  streamer_id UUID REFERENCES users(id),
+  price_usdc NUMERIC(10,2) NOT NULL,
+  status TEXT NOT NULL,
+  current_period_end TIMESTAMPTZ NOT NULL,
+  tx_hash TEXT,
+  created_at TIMESTAMPTZ DEFAULT now()
+);
+
 CREATE TABLE IF NOT EXISTS stream_sessions (
     id UUID PRIMARY KEY DEFAULT gen_random_uuid(),
     user_id UUID REFERENCES users(id) ON DELETE CASCADE,
     mux_session_id VARCHAR(255),
+    title VARCHAR(255),
+    playback_id VARCHAR(255),
 
     started_at TIMESTAMP WITH TIME ZONE DEFAULT CURRENT_TIMESTAMP,
     ended_at TIMESTAMP WITH TIME ZONE,
@@ -81,6 +102,20 @@ CREATE TABLE IF NOT EXISTS chat_messages (
     created_at TIMESTAMP WITH TIME ZONE DEFAULT CURRENT_TIMESTAMP
 );
 
+CREATE TABLE IF NOT EXISTS watch_history (
+  id              UUID PRIMARY KEY DEFAULT gen_random_uuid(),
+  viewer_id       UUID REFERENCES users(id) ON DELETE CASCADE,
+  streamer_id     UUID REFERENCES users(id),
+  stream_type     TEXT NOT NULL,   -- 'live' | 'vod' | 'clip'
+  stream_id       TEXT,            -- recording ID if VOD/clip, null if live
+  stream_title    TEXT,            -- title of the stream at the time
+  started_at      TIMESTAMPTZ DEFAULT now(),
+  last_seen_at    TIMESTAMPTZ DEFAULT now(),
+  watch_seconds   INT DEFAULT 0,
+  completed       BOOLEAN DEFAULT false,
+  UNIQUE(viewer_id, streamer_id, stream_id, stream_type)
+);
+
 CREATE TABLE IF NOT EXISTS stream_viewers (
     id UUID PRIMARY KEY DEFAULT gen_random_uuid(),
     stream_session_id UUID REFERENCES stream_sessions(id) ON DELETE CASCADE,
@@ -95,6 +130,21 @@ CREATE TABLE IF NOT EXISTS stream_viewers (
     created_at TIMESTAMP WITH TIME ZONE DEFAULT CURRENT_TIMESTAMP
 );
 
+CREATE TABLE IF NOT EXISTS stream_recordings (
+    id UUID PRIMARY KEY DEFAULT gen_random_uuid(),
+    user_id UUID NOT NULL REFERENCES users(id) ON DELETE CASCADE,
+    stream_session_id UUID REFERENCES stream_sessions(id) ON DELETE SET NULL,
+    mux_asset_id VARCHAR(255) NOT NULL,
+    playback_id VARCHAR(255) NOT NULL,
+    title VARCHAR(255),
+    duration INTEGER,
+    created_at TIMESTAMP WITH TIME ZONE DEFAULT CURRENT_TIMESTAMP,
+    status VARCHAR(50) DEFAULT 'processing',
+    UNIQUE(mux_asset_id)
+);
+
+
+
 CREATE TABLE IF NOT EXISTS verification_tokens (
     email VARCHAR(255),
     token VARCHAR(6),                            
@@ -147,6 +197,12 @@ CREATE INDEX IF NOT EXISTS idx_stream_categories_title ON stream_categories(titl
 CREATE INDEX IF NOT EXISTS idx_stream_categories_active ON stream_categories(is_active);
 CREATE INDEX IF NOT EXISTS idx_tags_title ON tags(title);
 CREATE INDEX IF NOT EXISTS idx_tags_title_lower ON tags(LOWER(title));
+CREATE INDEX IF NOT EXISTS idx_watch_history_viewer ON watch_history(viewer_id, last_seen_at DESC);
+CREATE INDEX IF NOT EXISTS idx_watch_history_streamer ON watch_history(streamer_id, started_at DESC);
+CREATE INDEX IF NOT EXISTS idx_stream_recordings_user_id ON stream_recordings(user_id);
+CREATE INDEX IF NOT EXISTS idx_stream_recordings_playback_id ON stream_recordings(playback_id);
+CREATE INDEX IF NOT EXISTS idx_stream_recordings_created_at ON stream_recordings(created_at DESC);
+
 
 INSERT INTO stream_categories (title, description, tags) VALUES
 ('Gaming', 'Video game streaming and gameplay', ARRAY['gaming', 'esports', 'gameplay']),
@@ -203,7 +259,8 @@ SELECT
     CASE 
         WHEN table_name IN (
             'users', 'waitlist', 'stream_sessions', 'chat_messages', 
-            'stream_viewers', 'verification_tokens', 'stream_categories'
+            'stream_viewers', 'verification_tokens', 'stream_categories',
+            'watch_history', 'stream_recordings'
         ) THEN '✅ Created'
         ELSE '❌ Missing'
     END as status
@@ -211,7 +268,8 @@ FROM information_schema.tables
 WHERE table_schema = 'public' 
 AND table_name IN (
     'users', 'waitlist', 'stream_sessions', 'chat_messages', 
-    'stream_viewers', 'verification_tokens', 'stream_categories'
+    'stream_viewers', 'verification_tokens', 'stream_categories',
+    'watch_history', 'stream_recordings'
 )
 ORDER BY table_name;
 
@@ -250,4 +308,10 @@ SELECT
     'verification_tokens' as table_name, COUNT(*) as record_count FROM verification_tokens
 UNION ALL
 SELECT 
-    'stream_categories' as table_name, COUNT(*) as record_count FROM stream_categories;
+    'stream_categories' as table_name, COUNT(*) as record_count FROM stream_categories
+UNION ALL
+SELECT 
+    'watch_history' as table_name, COUNT(*) as record_count FROM watch_history
+UNION ALL
+SELECT 
+    'stream_recordings' as table_name, COUNT(*) as record_count FROM stream_recordings;
diff --git a/documentation/IMPLEMENTATION_SUMMARY.md b/documentation/IMPLEMENTATION_SUMMARY.md
deleted file mode 100644
index f4289bdd..00000000
--- a/documentation/IMPLEMENTATION_SUMMARY.md
+++ /dev/null
@@ -1,382 +0,0 @@
-# StreamFi - Persistent Stream Key Implementation Summary
-
-## ✅ Implementation Complete!
-
-Based on research from [Twitch](https://www.streamscheme.com/how-to-find-your-twitch-stream-key/) and [Kick](https://viewerboss.com/blog/how-to-stream-on-kick-complete-beginners-guide-2026) streaming platforms, here's what was implemented:
-
----
-
-## 🔑 Persistent Stream Key Flow (Like Twitch/Kick)
-
-### How It Works:
-
-1. **User Signs Up** → Automatic Mux stream creation (implement in signup flow)
-2. **User Gets Permanent Stream Key** → Never changes unless manually reset
-3. **User Views Key in Settings** → `/settings/stream-preference`
-4. **User Starts OBS** → Uses same key every time
-5. **Stream Goes Live** → Automatically detected
-
----
-
-## 📁 Files Modified:
-
-### 1. Stream Preference Page
-
-**File:** `/components/settings/stream-channel-preferences/stream-preference.tsx`
-
-**Changes:**
-
-- ✅ Fetches real stream key from `/api/streams/key`
-- ✅ Shows RTMP URL: `rtmp://global-live.mux.com:5222/app`
-- ✅ Shows/hides stream key with security modal
-- ✅ Copy to clipboard functionality
-- ✅ Reset button (for compromised keys)
-- ✅ Security warning (never share key)
-- ✅ Auto-hides key after 10 minutes
-- ✅ Polls for updates
-
-**Features:**
-
-```typescript
-- Real-time key fetching
-- Show/Hide toggle with confirmation
-- Copy key to clipboard
-- Reset key functionality
-- Security warnings
-- Auto-hide after inactivity
-```
-
-### 2. Stream Manager Dashboard
-
-**File:** `/components/dashboard/stream-manager/StreamPreview.tsx`
-
-**Changes:**
-
-- ✅ Integrated Mux Player for live preview
-- ✅ Real-time live/offline status
-- ✅ Polls every 10 seconds for status updates
-- ✅ Low-latency streaming (`ll-live` mode)
-- ✅ Shows LIVE indicator when broadcasting
-- ✅ Muted autoplay for preview
-
-**Features:**
-
-```typescript
-- Mux Player integration
-- Real-time status polling
-- Live indicator with pulse animation
-- Fullscreen support
-- Low-latency preview (1.5-4 seconds)
-```
-
----
-
-## 🎯 How It Compares to Twitch/Kick:
-
-| Feature                   | Twitch/Kick | StreamFi                      |
-| ------------------------- | ----------- | ----------------------------- |
-| **Persistent Stream Key** | ✅          | ✅                            |
-| **Show/Hide Key**         | ✅          | ✅                            |
-| **Copy Key**              | ✅          | ✅                            |
-| **Reset Key**             | ✅          | ✅ (Ready for implementation) |
-| **Security Warning**      | ✅          | ✅                            |
-| **Live Preview**          | ✅          | ✅                            |
-| **Real-time Status**      | ✅          | ✅                            |
-| **Low Latency**           | ✅          | ✅ (1.5-4s)                   |
-
----
-
-## 🚀 User Flow:
-
-### Step 1: Get Stream Key (One Time)
-
-1. User goes to `/settings/stream-preference`
-2. Sees RTMP URL and Stream Key
-3. Clicks "Show" → Security confirmation modal
-4. Copies stream key
-
-### Step 2: Configure OBS (One Time)
-
-```
-Settings → Stream
-├── Service: Custom
-├── Server: rtmp://global-live.mux.com:5222/app
-└── Stream Key: [Your persistent key]
-```
-
-### Step 3: Go Live (Every Time)
-
-1. Open OBS
-2. Click "Start Streaming"
-3. Stream appears in Stream Manager dashboard
-4. LIVE indicator shows automatically
-
-### Step 4: View Dashboard
-
-1. Go to `/dashboard/stream-manager`
-2. See live preview with Mux Player
-3. Monitor viewers, followers, donations
-4. Chat with viewers
-
----
-
-## 🔐 Security Features (Like Twitch/Kick):
-
-### 1. Stream Key Protection
-
-```typescript
-- Never shown by default (password field)
-- Requires confirmation modal to reveal
-- Auto-hides after 10 minutes
-- Hides when tab loses focus
-- Prominent "never share" warning
-```
-
-### 2. Key Reset
-
-```typescript
-// Future implementation
-const resetStreamKey = async () => {
-  // 1. Delete old Mux stream
-  // 2. Create new Mux stream
-  // 3. Update database
-  // 4. Show new key
-};
-```
-
----
-
-## 📊 API Endpoints Used:
-
-### 1. Get Stream Key
-
-```typescript
-GET /api/streams/key?wallet={wallet}
-
-Response:
-{
-  "hasStream": true,
-  "streamData": {
-    "streamKey": "abc123...",
-    "streamId": "mux_stream_id",
-    "playbackId": "playback_id",
-    "rtmpUrl": "rtmp://global-live.mux.com:5222/app",
-    "isLive": false
-  }
-}
-```
-
-### 2. Create/Get Stream
-
-```typescript
-POST /api/streams/create
-{
-  "wallet": "0x...",
-  "title": "Stream Title"
-}
-
-Response:
-{
-  "message": "Stream already exists",
-  "streamData": {
-    "streamId": "...",
-    "playbackId": "...",
-    "streamKey": "...",
-    "rtmpUrl": "...",
-    "persistent": true
-  }
-}
-```
-
-### 3. Start Stream
-
-```typescript
-POST /api/streams/start
-{ "wallet": "0x..." }
-
-// Marks stream as live in database
-```
-
-### 4. Stop Stream
-
-```typescript
-DELETE /api/streams/start
-{ "wallet": "0x..." }
-
-// Marks stream as offline in database
-```
-
----
-
-## 🎨 UI Components:
-
-### Settings Page (`/settings/stream-preference`)
-
-```
-┌─────────────────────────────────────┐
-│  Stream URL (RTMP Server)           │
-│  ├── rtmp://global-live.mux...      │
-│  └── [👁 Show/Hide]                  │
-├─────────────────────────────────────┤
-│  Stream Key (Keep Secret!)          │
-│  ├── •••••••••••••••                │
-│  ├── [👁 Show] [Copy] [Reset]       │
-│  └── ⚠️ Security Warning             │
-└─────────────────────────────────────┘
-```
-
-### Stream Manager (`/dashboard/stream-manager`)
-
-```
-┌────────────────────────────────────────┐
-│  Viewers: 0  Followers: 0  Donations: 0│
-├────────────────────────────────────────┤
-│  ┌──────────────┬─────────┬──────────┐ │
-│  │              │  Chat   │  Info    │ │
-│  │ [LIVE] 🔴    │         │          │ │
-│  │  Mux Player  │         │          │ │
-│  │              │         │          │ │
-│  └──────────────┴─────────┴──────────┘ │
-└────────────────────────────────────────┘
-```
-
----
-
-## ⚡ Low-Latency Configuration:
-
-```typescript
-// Mux Player Settings
-streamType="ll-live"          // Low-Latency Live
-targetLiveWindow={1.5}        // 1.5 seconds from live edge
-preferPlayback="mse"          // Media Source Extensions
-startTime={-10}               // Start 10s from live edge
-preload="auto"                // Preload immediately
-
-// Expected Latency: 1.5-4 seconds
-```
-
----
-
-## 🔄 Real-Time Updates:
-
-### Stream Status Polling
-
-```typescript
-// Polls every 10 seconds for:
-- Stream live/offline status
-- Playback ID
-- Stream health
-```
-
-### Auto-Hide Stream Key
-
-```typescript
-// Security feature:
-- Shows key after confirmation
-- Auto-hides after 10 minutes
-- Hides when tab loses focus
-- Hides on page unload
-```
-
----
-
-## 🛠️ Next Steps (To Complete Full Implementation):
-
-### 1. Auto-Create Stream on Signup
-
-```typescript
-// In signup API route:
-const newUser = await createUser(userData);
-
-// Auto-create Mux stream
-const muxStream = await createMuxStream({
-  name: `${newUser.username}'s Stream`,
-  record: true,
-});
-
-// Save to database
-await updateUser(newUser.id, {
-  mux_stream_id: muxStream.id,
-  mux_playback_id: muxStream.playbackId,
-  streamkey: muxStream.streamKey,
-});
-```
-
-### 2. Implement Stream Key Reset
-
-```typescript
-// POST /api/streams/reset
-async function resetStreamKey(wallet: string) {
-  // 1. Get user's old stream
-  const user = await getUserByWallet(wallet);
-
-  // 2. Delete old Mux stream
-  await deleteMuxStream(user.mux_stream_id);
-
-  // 3. Create new Mux stream
-  const newStream = await createMuxStream({
-    name: `${user.username}'s Stream`,
-    record: true,
-  });
-
-  // 4. Update database
-  await updateUser(user.id, {
-    mux_stream_id: newStream.id,
-    mux_playback_id: newStream.playbackId,
-    streamkey: newStream.streamKey,
-  });
-
-  return newStream;
-}
-```
-
-### 3. Add Viewer Count
-
-```typescript
-// Use Mux Data API
-const viewerCount = await mux.data.metrics.breakdown({
-  metric: "current-viewers",
-  filters: [`playback_id:${playbackId}`],
-});
-```
-
-### 4. Add Stream Notifications
-
-```typescript
-// When stream goes live:
-- Send email to followers
-- Push notification to mobile app
-- Discord/Telegram webhook
-```
-
----
-
-## 📚 Sources & Research:
-
-- [Kick Stream Key Management](https://viewerboss.com/blog/how-to-stream-on-kick-complete-beginners-guide-2026)
-- [Twitch Stream Key Guide](https://www.streamscheme.com/how-to-find-your-twitch-stream-key/)
-- [How to Stream on Kick](https://help.kick.com/en/articles/7066931-how-to-stream-on-kick-com)
-- [Mux Player React Documentation](https://www.mux.com/docs/guides/player-api-reference/react)
-
----
-
-## ✅ Summary:
-
-StreamFi now implements persistent stream keys exactly like Twitch and Kick:
-
-1. ✅ **One stream key per user** - Never changes unless reset
-2. ✅ **Security first** - Show/hide, auto-hide, warnings
-3. ✅ **Easy to use** - Copy key, configure OBS once
-4. ✅ **Live preview** - Mux Player in dashboard
-5. ✅ **Low latency** - 1.5-4 second delay
-6. ✅ **Real-time status** - Auto-detects live/offline
-
-Users can now:
-
-- View their stream key in `/settings/stream-preference`
-- Copy it to OBS one time
-- Start streaming anytime with same key
-- See live preview in `/dashboard/stream-manager`
-- Monitor viewers, chat, etc.
-
-**This is production-ready for streaming!** 🎉
diff --git a/eslint.config.mjs b/eslint.config.mjs
index 8eca63e1..9dc99c45 100644
--- a/eslint.config.mjs
+++ b/eslint.config.mjs
@@ -38,8 +38,15 @@ const eslintConfig = [
       "react/jsx-no-duplicate-props": "error", // No duplicate props
 
       // TypeScript specific rules
-      "@typescript-eslint/no-unused-vars": "error", // TypeScript unused vars
+      "@typescript-eslint/no-unused-vars": [
+        "error",
+        { argsIgnorePattern: "^_", varsIgnorePattern: "^_", caughtErrorsIgnorePattern: "^_" },
+      ],
       "@typescript-eslint/no-explicit-any": "warn", // Warn about any usage
+      "@typescript-eslint/ban-ts-comment": [
+        "error",
+        { "ts-nocheck": false, "ts-ignore": true, "ts-expect-error": "allow-with-description" },
+      ],
 
       // Best practices
       eqeqeq: "error", // Require === and !==
diff --git a/hooks/useFeatureFlags.ts b/hooks/useFeatureFlags.ts
new file mode 100644
index 00000000..eddb46e6
--- /dev/null
+++ b/hooks/useFeatureFlags.ts
@@ -0,0 +1,26 @@
+import useSWR from "swr";
+
+const fetcher = (url: string) => fetch(url, { credentials: "include" }).then(r => r.json());
+
+/**
+ * Returns resolved feature flag states for the current user.
+ * Pass specific keys to avoid fetching all flags.
+ *
+ * @example
+ * const { flags } = useFeatureFlags(["clips", "gifts"]);
+ * if (flags.clips) { ... }
+ */
+export function useFeatureFlags(keys?: string[]) {
+  const query = keys?.length ? `?keys=${keys.join(",")}` : "";
+  const { data, error, isLoading } = useSWR<{ flags: Record<string, boolean> }>(
+    `/api/feature-flags${query}`,
+    fetcher,
+    { revalidateOnFocus: false, dedupingInterval: 60_000 }
+  );
+
+  return {
+    flags: data?.flags ?? {},
+    isLoading,
+    error,
+  };
+}
diff --git a/hooks/useStreamWhitelist.ts b/hooks/useStreamWhitelist.ts
new file mode 100644
index 00000000..a534326e
--- /dev/null
+++ b/hooks/useStreamWhitelist.ts
@@ -0,0 +1,92 @@
+import useSWR from "swr";
+import { useCallback, useState } from "react";
+
+export interface WhitelistEntry {
+  id: string;
+  identifier: string;
+  username: string | null;
+  avatar: string | null;
+  created_at: string;
+}
+
+const fetcher = (url: string) => fetch(url, { credentials: "include" }).then(r => r.json());
+
+/** Streamer-side: manage their whitelist */
+export function useStreamWhitelist() {
+  const { data, error, isLoading, mutate } = useSWR<{ whitelist: WhitelistEntry[] }>(
+    "/api/streams/whitelist",
+    fetcher,
+    { revalidateOnFocus: false }
+  );
+
+  const [adding, setAdding] = useState(false);
+  const [removing, setRemoving] = useState<string | null>(null);
+
+  const add = useCallback(
+    async (identifier: string) => {
+      setAdding(true);
+      try {
+        const res = await fetch("/api/streams/whitelist", {
+          method: "POST",
+          headers: { "Content-Type": "application/json" },
+          credentials: "include",
+          body: JSON.stringify({ identifier }),
+        });
+        if (!res.ok) {
+          const { error: msg } = await res.json();
+          throw new Error(msg ?? "Failed to add");
+        }
+        await mutate();
+      } finally {
+        setAdding(false);
+      }
+    },
+    [mutate]
+  );
+
+  const remove = useCallback(
+    async (identifier: string) => {
+      setRemoving(identifier);
+      try {
+        const res = await fetch("/api/streams/whitelist", {
+          method: "DELETE",
+          headers: { "Content-Type": "application/json" },
+          credentials: "include",
+          body: JSON.stringify({ identifier }),
+        });
+        if (!res.ok) {
+          throw new Error("Failed to remove");
+        }
+        mutate(
+          prev => prev
+            ? { whitelist: prev.whitelist.filter(e => e.identifier !== identifier) }
+            : prev,
+          false
+        );
+      } finally {
+        setRemoving(null);
+      }
+    },
+    [mutate]
+  );
+
+  return {
+    whitelist: data?.whitelist ?? [],
+    isLoading,
+    error,
+    add,
+    remove,
+    adding,
+    removing,
+  };
+}
+
+/** Viewer-side: check if they have access to a private stream */
+export function useWhitelistAccess(streamerUsername: string | null) {
+  const { data, isLoading } = useSWR<{ allowed: boolean }>(
+    streamerUsername ? `/api/streams/whitelist?streamer=${encodeURIComponent(streamerUsername)}` : null,
+    fetcher,
+    { revalidateOnFocus: false }
+  );
+  return { allowed: data?.allowed ?? false, isLoading };
+}
diff --git a/hooks/useUserPreferences.ts b/hooks/useUserPreferences.ts
new file mode 100644
index 00000000..008df8ff
--- /dev/null
+++ b/hooks/useUserPreferences.ts
@@ -0,0 +1,55 @@
+import useSWR from "swr";
+import { useCallback } from "react";
+
+export interface UserPreferences {
+  user_id: string;
+  stream_quality: "auto" | "1080p" | "720p" | "480p" | "360p";
+  notify_live: boolean;
+  notify_clips: boolean;
+  notify_tips: boolean;
+  theme: "dark" | "light" | "system";
+  language: string;
+  chat_font_size: "small" | "medium" | "large";
+  show_timestamps: boolean;
+  updated_at: string;
+}
+
+const fetcher = (url: string) => fetch(url, { credentials: "include" }).then(r => r.json());
+
+export function useUserPreferences() {
+  const { data, error, isLoading, mutate } = useSWR<{ preferences: UserPreferences }>(
+    "/api/users/preferences",
+    fetcher,
+    { revalidateOnFocus: false }
+  );
+
+  const update = useCallback(
+    async (patch: Partial<Omit<UserPreferences, "user_id" | "updated_at">>) => {
+      // Optimistic update
+      if (data?.preferences) {
+        mutate({ preferences: { ...data.preferences, ...patch } }, false);
+      }
+      const res = await fetch("/api/users/preferences", {
+        method: "PATCH",
+        headers: { "Content-Type": "application/json" },
+        credentials: "include",
+        body: JSON.stringify(patch),
+      });
+      if (!res.ok) {
+        mutate(); // revert on failure
+        throw new Error("Failed to update preferences");
+      }
+      const updated = await res.json();
+      mutate({ preferences: updated.preferences }, false);
+      return updated.preferences as UserPreferences;
+    },
+    [data, mutate]
+  );
+
+  return {
+    preferences: data?.preferences ?? null,
+    isLoading,
+    error,
+    update,
+  };
+}
diff --git a/jest.setup.ts b/jest.setup.ts
index 6738769e..e06d7490 100644
--- a/jest.setup.ts
+++ b/jest.setup.ts
@@ -1,8 +1,32 @@
-import "whatwg-fetch";
-
 import "@testing-library/jest-dom";
 
 // Polyfill TextEncoder / TextDecoder — required by @stellar/stellar-sdk and
 // other crypto libs when running in Jest's jsdom environment.
 import { TextEncoder, TextDecoder } from "util";
 Object.assign(global, { TextEncoder, TextDecoder });
+
+// jsdom 26 does not include the Fetch API (Request/Response/Headers/fetch).
+// node-fetch v2 is used as a polyfill; it avoids the this.url= conflict that
+// whatwg-fetch has with NextRequest's read-only url getter.
+if (typeof global.Request === "undefined") {
+  // eslint-disable-next-line @typescript-eslint/no-require-imports
+  const { fetch: nodeFetch, Request, Response, Headers, FormData } = require("node-fetch");
+
+  // node-fetch v2 lacks Response.json() static method (added in the Web API later).
+  // NextResponse.json() delegates to Response.json(), so we need to add it.
+  if (!("json" in Response)) {
+    (Response as { json?: unknown }).json = function (
+      data: unknown,
+      init?: ResponseInit
+    ): Response {
+      const body = JSON.stringify(data);
+      const headers = new Headers(init?.headers);
+      if (!headers.has("content-type")) {
+        headers.set("content-type", "application/json");
+      }
+      return new Response(body, { ...init, headers });
+    };
+  }
+
+  Object.assign(global, { fetch: nodeFetch, Request, Response, Headers, FormData });
+}
diff --git a/lib/admin-auth.ts b/lib/admin-auth.ts
index a15286fc..f40ef5bb 100644
--- a/lib/admin-auth.ts
+++ b/lib/admin-auth.ts
@@ -27,6 +27,13 @@ export async function verifyAdminSession(): Promise<boolean> {
   return false;
 }
 
+/** Returns true when userId is in the ADMIN_PRIVY_IDS or ADMIN_WALLET_ADDRESSES env lists. */
+export function isAdmin(userId: string): boolean {
+  const ids = (process.env.ADMIN_PRIVY_IDS ?? "").split(",").map(s => s.trim()).filter(Boolean);
+  const wallets = (process.env.ADMIN_WALLET_ADDRESSES ?? "").split(",").map(s => s.trim()).filter(Boolean);
+  return ids.includes(userId) || wallets.includes(userId);
+}
+
 /** Convenience helper — returns a 401 JSON response. */
 export function adminUnauthorized(): Response {
   return Response.json({ error: "Unauthorized" }, { status: 401 });
diff --git a/lib/auth.ts b/lib/auth.ts
new file mode 100644
index 00000000..523138ce
--- /dev/null
+++ b/lib/auth.ts
@@ -0,0 +1,5 @@
+// Stub — routes that import this module are pending a real auth integration.
+import { NextRequest } from "next/server";
+export async function getAuthUser(_req: NextRequest): Promise<null> {
+  return null;
+}
diff --git a/lib/auth/verify-session.ts b/lib/auth/verify-session.ts
index 658458cd..d2d81648 100644
--- a/lib/auth/verify-session.ts
+++ b/lib/auth/verify-session.ts
@@ -22,6 +22,10 @@
 import { NextRequest, NextResponse } from "next/server";
 import { sql } from "@vercel/postgres";
 import { verifyToken } from "@/lib/auth/sign-token";
+import {
+  findActiveSession,
+  touchSession,
+} from "@/lib/sessions/user-sessions";
 
 export type VerifiedSession =
   | {
@@ -58,6 +62,31 @@ export async function verifySession(
     }
 
     try {
+      // Check user_sessions table first — catches revoked sessions immediately.
+      // Falls back gracefully if the table doesn't exist yet (pre-migration).
+      let sessionRow: { id: string; last_seen_at: Date } | null = null;
+      try {
+        sessionRow = await findActiveSession(privySessionId);
+        if (!sessionRow) {
+          // Session was revoked or expired — reject even if the cookie is valid
+          return {
+            ok: false,
+            response: NextResponse.json(
+              { error: "Session revoked or expired" },
+              { status: 401 }
+            ),
+          };
+        }
+      } catch (sessionErr) {
+        // user_sessions table may not exist yet (pre-migration environment).
+        // Log and continue with the legacy DB-only check so existing deployments
+        // aren't broken during the rollout window.
+        console.warn(
+          "[verifySession] user_sessions check failed (table may not exist yet):",
+          sessionErr
+        );
+      }
+
       const { rows } = await sql`
         SELECT id, privy_id, wallet, username, email
         FROM users
@@ -75,6 +104,13 @@ export async function verifySession(
         };
       }
 
+      // Touch last_seen_at (debounced — at most once per minute)
+      if (sessionRow) {
+        touchSession(sessionRow.id).catch(() => {
+          // Non-critical — ignore errors
+        });
+      }
+
       const u = rows[0];
       return {
         ok: true,
@@ -126,6 +162,26 @@ export async function verifySession(
     }
 
     try {
+      // Check user_sessions table for revocation (graceful fallback pre-migration)
+      let sessionRow: { id: string; last_seen_at: Date } | null = null;
+      try {
+        sessionRow = await findActiveSession(walletSessionToken);
+        if (!sessionRow) {
+          return {
+            ok: false,
+            response: NextResponse.json(
+              { error: "Session revoked or expired" },
+              { status: 401 }
+            ),
+          };
+        }
+      } catch (sessionErr) {
+        console.warn(
+          "[verifySession] user_sessions check failed (table may not exist yet):",
+          sessionErr
+        );
+      }
+
       // Cross-check both userId AND wallet against DB — forged tokens with
       // valid signatures but mismatched fields are rejected here.
       const { rows } = await sql`
@@ -145,6 +201,13 @@ export async function verifySession(
         };
       }
 
+      // Touch last_seen_at (debounced)
+      if (sessionRow) {
+        touchSession(sessionRow.id).catch(() => {
+          // Non-critical — ignore errors
+        });
+      }
+
       const u = rows[0];
       return {
         ok: true,
diff --git a/lib/db.ts b/lib/db.ts
new file mode 100644
index 00000000..1ea3e690
--- /dev/null
+++ b/lib/db.ts
@@ -0,0 +1,2 @@
+// Stub — routes that import this module are pending a real database integration.
+export const db = {} as Record<string, unknown>;
diff --git a/lib/mux/server.ts b/lib/mux/server.ts
index f988b267..091fbcf9 100644
--- a/lib/mux/server.ts
+++ b/lib/mux/server.ts
@@ -29,24 +29,18 @@ export async function createMuxStream(streamData?: {
   name: string;
   record?: boolean;
   latencyMode?: "low" | "standard";
-  /** When true, also provision a signed playback ID for private streams. */
   withSignedPlayback?: boolean;
 }) {
   try {
     const record = streamData?.record === true;
     const latencyMode = streamData?.latencyMode ?? "low";
-    const withSigned = streamData?.withSignedPlayback === true;
-
-    const playbackPolicy: ("public" | "signed")[] = withSigned
-      ? ["public", "signed"]
-      : ["public"];
 
     const liveStream = await Promise.race([
       mux.video.liveStreams.create({
-        playback_policy: playbackPolicy,
+        playback_policy: ["public"],
         ...(record && {
           new_asset_settings: {
-            playback_policy: playbackPolicy,
+            playback_policy: ["public"],
           },
         }),
         reconnect_window: 60,
@@ -61,20 +55,14 @@ export async function createMuxStream(streamData?: {
       ),
     ]);
 
-    // Find public and signed playback IDs (Mux returns multiple when multiple policies are requested)
-    const publicId =
-      liveStream.playback_ids?.find(p => p.policy === "public")?.id ||
-      liveStream.playback_ids?.[0]?.id ||
-      "";
-    const signedId = liveStream.playback_ids?.find(
-      p => p.policy === "signed"
-    )?.id;
+    // Get the playback ID from the created stream
+    const playbackId = liveStream.playback_ids?.[0]?.id || "";
 
     return {
       id: liveStream.id,
       streamKey: liveStream.stream_key || "",
-      playbackId: publicId,
-      signedPlaybackId: signedId,
+      playbackId,
+      signedPlaybackId: undefined,
       status: liveStream.status || "idle",
       rtmpUrl: "rtmp://global-live.mux.com:5222/app",
       isActive: liveStream.status === "active",
@@ -98,6 +86,7 @@ export async function getMuxStream(streamId: string) {
       id: liveStream.id,
       streamKey: liveStream.stream_key || "",
       playbackId: liveStream.playback_ids?.[0]?.id || "",
+      signedPlaybackId: undefined,
       status: liveStream.status || "idle",
       rtmpUrl: "rtmp://global-live.mux.com:5222/app",
       isActive: liveStream.status === "active",
diff --git a/lib/redis.ts b/lib/redis.ts
new file mode 100644
index 00000000..2114c674
--- /dev/null
+++ b/lib/redis.ts
@@ -0,0 +1,2 @@
+// Stub — routes that import this module are pending a real Redis integration.
+export const redis = {} as Record<string, unknown>;
diff --git a/lib/sessions/extract-raw-token.ts b/lib/sessions/extract-raw-token.ts
new file mode 100644
index 00000000..494a7ec9
--- /dev/null
+++ b/lib/sessions/extract-raw-token.ts
@@ -0,0 +1,21 @@
+/**
+ * Extracts the raw session token string from a Next.js request.
+ *
+ * Priority order matches verifySession:
+ *  1. privy_session cookie  (value IS the raw token — the privy_id string)
+ *  2. wallet_session cookie (value IS the raw signed JWT)
+ *  3. legacy wallet cookie  (value IS the raw wallet address)
+ *
+ * Returns null if no session cookie is present.
+ */
+
+import { NextRequest } from "next/server";
+
+export function extractRawToken(req: NextRequest): string | null {
+  return (
+    req.cookies.get("privy_session")?.value ??
+    req.cookies.get("wallet_session")?.value ??
+    req.cookies.get("wallet")?.value ??
+    null
+  );
+}
diff --git a/lib/sessions/user-sessions.ts b/lib/sessions/user-sessions.ts
new file mode 100644
index 00000000..6974aabd
--- /dev/null
+++ b/lib/sessions/user-sessions.ts
@@ -0,0 +1,273 @@
+/**
+ * Shared helpers for the user_sessions table.
+ *
+ * Responsibilities:
+ *  - Hash raw session tokens (SHA-256) so we never store them in plaintext
+ *  - Parse a User-Agent string into a human-readable device hint
+ *  - Insert a new session row on login
+ *  - Validate a session token on every request (revoked / expired check)
+ *  - Touch last_seen_at at most once per minute (write-amplification guard)
+ *  - Mask the last octet of an IP address for privacy
+ */
+
+import { createHash } from "crypto";
+import { sql } from "@vercel/postgres";
+
+// ─── Token hashing ────────────────────────────────────────────────────────────
+
+/**
+ * Returns the SHA-256 hex digest of a raw session token.
+ * This is what we store in the DB — never the raw token.
+ */
+export function hashToken(rawToken: string): string {
+  return createHash("sha256").update(rawToken).digest("hex");
+}
+
+// ─── User-Agent parsing ───────────────────────────────────────────────────────
+
+/**
+ * Produces a short, human-readable device hint from a User-Agent string.
+ * Examples: "Chrome on macOS", "Safari on iPhone", "Firefox on Windows"
+ */
+export function parseDeviceHint(userAgent: string | null): string {
+  if (!userAgent) return "Unknown device";
+
+  const ua = userAgent;
+
+  let browser = "Unknown browser";
+  if (/Edg\//i.test(ua)) {
+    browser = "Edge";
+  } else if (/OPR\//i.test(ua) || /Opera/i.test(ua)) {
+    browser = "Opera";
+  } else if (/Chrome\//i.test(ua) && !/Chromium/i.test(ua)) {
+    browser = "Chrome";
+  } else if (/Firefox\//i.test(ua)) {
+    browser = "Firefox";
+  } else if (/Safari\//i.test(ua) && !/Chrome/i.test(ua)) {
+    browser = "Safari";
+  } else if (/MSIE|Trident/i.test(ua)) {
+    browser = "Internet Explorer";
+  }
+
+  let os = "Unknown OS";
+  if (/iPhone/i.test(ua)) {
+    os = "iPhone";
+  } else if (/iPad/i.test(ua)) {
+    os = "iPad";
+  } else if (/Android/i.test(ua)) {
+    os = "Android";
+  } else if (/Windows NT/i.test(ua)) {
+    os = "Windows";
+  } else if (/Macintosh|Mac OS X/i.test(ua)) {
+    os = "macOS";
+  } else if (/Linux/i.test(ua)) {
+    os = "Linux";
+  } else if (/CrOS/i.test(ua)) {
+    os = "ChromeOS";
+  }
+
+  return `${browser} on ${os}`;
+}
+
+// ─── IP masking ───────────────────────────────────────────────────────────────
+
+/**
+ * Masks the last octet of an IPv4 address (e.g. "1.2.3.4" → "1.2.3.x").
+ * IPv6 addresses have their last group replaced with "xxxx".
+ */
+export function maskIp(ip: string | null): string | null {
+  if (!ip) return null;
+  const v4 = ip.match(/^(\d{1,3}\.\d{1,3}\.\d{1,3})\.\d{1,3}$/);
+  if (v4) return `${v4[1]}.x`;
+  const v6parts = ip.split(":");
+  if (v6parts.length > 1) {
+    v6parts[v6parts.length - 1] = "xxxx";
+    return v6parts.join(":");
+  }
+  return ip;
+}
+
+/**
+ * Returns the value only if it looks like a valid IP address, otherwise null.
+ * Prevents passing "unknown" or empty strings to a PostgreSQL INET column.
+ */
+function safeIp(ip: string | null): string | null {
+  if (!ip) return null;
+  // Matches IPv4 (e.g. 1.2.3.4) and IPv6 (hex digits + colons)
+  return /^[\d.:a-fA-F]+$/.test(ip) ? ip : null;
+}
+
+// ─── Session row shape ────────────────────────────────────────────────────────
+
+export interface SessionRow {
+  id: string;
+  device_hint: string | null;
+  ip_address: string | null;
+  last_seen_at: string;
+  created_at: string;
+  /** Not stored in DB — computed by the caller based on token_hash match. */
+  is_current: boolean;
+}
+
+// ─── Create session ───────────────────────────────────────────────────────────
+
+export interface CreateSessionOptions {
+  userId: string;
+  rawToken: string;
+  ipAddress: string | null;
+  userAgent: string | null;
+  /** Seconds from now until the session expires. */
+  ttlSeconds: number;
+}
+
+/**
+ * Inserts a new row into user_sessions.
+ * Call this immediately after setting the session cookie on login.
+ */
+export async function createSession(opts: CreateSessionOptions): Promise<void> {
+  const tokenHash = hashToken(opts.rawToken);
+  const deviceHint = parseDeviceHint(opts.userAgent);
+  const ip = safeIp(opts.ipAddress); // null-safe — never passes "unknown" to INET
+
+  // expires_at: build the interval string in JS so we don't mix a parameterized
+  // number with an INTERVAL literal inside the SQL template.
+  const expiresInterval = `${opts.ttlSeconds} seconds`;
+
+  await sql`
+    INSERT INTO user_sessions
+      (user_id, token_hash, ip_address, user_agent, device_hint, expires_at)
+    VALUES (
+      ${opts.userId},
+      ${tokenHash},
+      ${ip}::INET,
+      ${opts.userAgent},
+      ${deviceHint},
+      NOW() + ${expiresInterval}::INTERVAL
+    )
+    ON CONFLICT (token_hash) DO NOTHING
+  `;
+}
+
+// ─── Validate session ─────────────────────────────────────────────────────────
+
+export interface ValidSessionRow {
+  id: string;
+  user_id: string;
+  last_seen_at: Date;
+}
+
+/**
+ * Looks up a session by its raw token hash.
+ * Returns the row if it exists, is not revoked, and has not expired.
+ * Returns null otherwise.
+ */
+export async function findActiveSession(
+  rawToken: string
+): Promise<ValidSessionRow | null> {
+  const tokenHash = hashToken(rawToken);
+
+  const { rows } = await sql<ValidSessionRow>`
+    SELECT id, user_id, last_seen_at
+    FROM user_sessions
+    WHERE token_hash = ${tokenHash}
+      AND revoked    = false
+      AND expires_at > NOW()
+    LIMIT 1
+  `;
+
+  return rows[0] ?? null;
+}
+
+// ─── Touch last_seen_at (debounced) ───────────────────────────────────────────
+
+/**
+ * Updates last_seen_at for a session, but only if it hasn't been updated
+ * within the last minute. Prevents a DB write on every single request.
+ *
+ * Fire-and-forget — callers should not await this unless they need the result.
+ */
+export async function touchSession(sessionId: string): Promise<void> {
+  await sql`
+    UPDATE user_sessions
+    SET    last_seen_at = NOW()
+    WHERE  id           = ${sessionId}
+      AND  last_seen_at < NOW() - INTERVAL '1 minute'
+  `;
+}
+
+// ─── Revoke helpers ───────────────────────────────────────────────────────────
+
+/**
+ * Revokes a single session by its UUID.
+ * Returns true if a row was actually updated (i.e. it existed and wasn't already revoked).
+ */
+export async function revokeSession(
+  sessionId: string,
+  userId: string
+): Promise<boolean> {
+  const { rowCount } = await sql`
+    UPDATE user_sessions
+    SET    revoked = true
+    WHERE  id      = ${sessionId}
+      AND  user_id = ${userId}
+      AND  revoked = false
+  `;
+  return (rowCount ?? 0) > 0;
+}
+
+/**
+ * Revokes all sessions for a user except the one identified by currentRawToken.
+ * Returns the number of sessions revoked.
+ */
+export async function revokeAllOtherSessions(
+  userId: string,
+  currentRawToken: string
+): Promise<number> {
+  const currentHash = hashToken(currentRawToken);
+
+  const { rowCount } = await sql`
+    UPDATE user_sessions
+    SET    revoked = true
+    WHERE  user_id    = ${userId}
+      AND  token_hash != ${currentHash}
+      AND  revoked    = false
+  `;
+  return rowCount ?? 0;
+}
+
+// ─── List sessions ────────────────────────────────────────────────────────────
+
+/**
+ * Returns all active (non-revoked, non-expired) sessions for a user.
+ * The caller passes the current raw token so we can mark is_current.
+ */
+export async function listActiveSessions(
+  userId: string,
+  currentRawToken: string
+): Promise<SessionRow[]> {
+  const currentHash = hashToken(currentRawToken);
+
+  const { rows } = await sql`
+    SELECT
+      id,
+      device_hint,
+      ip_address::TEXT AS ip_address,
+      last_seen_at,
+      created_at,
+      token_hash
+    FROM user_sessions
+    WHERE  user_id    = ${userId}
+      AND  revoked    = false
+      AND  expires_at > NOW()
+    ORDER BY last_seen_at DESC
+  `;
+
+  return rows.map((r) => ({
+    id: r.id as string,
+    device_hint: (r.device_hint as string | null) ?? null,
+    ip_address: maskIp(r.ip_address as string | null),
+    last_seen_at: (r.last_seen_at as Date).toISOString(),
+    created_at: (r.created_at as Date).toISOString(),
+    is_current: r.token_hash === currentHash,
+  }));
+}
diff --git a/lib/stream-access/password.ts b/lib/stream-access/password.ts
new file mode 100644
index 00000000..d8fdcd6c
--- /dev/null
+++ b/lib/stream-access/password.ts
@@ -0,0 +1,21 @@
+import crypto from "crypto";
+
+function sha256(value: string) {
+  return crypto.createHash("sha256").update(value).digest("hex");
+}
+
+export function hashPassword(password: string) {
+  return sha256(password);
+}
+
+export function verifyPassword(password: string, hashedPassword: string) {
+  const expected = sha256(password);
+  const left = Buffer.from(expected, "hex");
+  const right = Buffer.from(hashedPassword, "hex");
+
+  if (left.length !== right.length) {
+    return false;
+  }
+
+  return crypto.timingSafeEqual(left, right);
+}
diff --git a/lib/stream/access.ts b/lib/stream/access.ts
new file mode 100644
index 00000000..1d9ea03b
--- /dev/null
+++ b/lib/stream/access.ts
@@ -0,0 +1,31 @@
+import { sql } from "@vercel/postgres";
+
+export type StreamAccessReason = "password" | "subscription";
+
+export type AccessResult =
+  | { allowed: true }
+  | { allowed: false; reason: StreamAccessReason };
+
+export async function checkSubscriptionAccess(
+  streamerId: string,
+  viewerPublicKey: string | null
+): Promise<AccessResult> {
+  if (!viewerPublicKey) {
+    return { allowed: false, reason: "subscription" };
+  }
+
+  const { rows } = await sql`
+    SELECT id FROM subscriptions
+    WHERE streamer_id = ${streamerId}
+      AND subscriber_id = (
+        SELECT id FROM users WHERE LOWER(wallet) = LOWER(${viewerPublicKey})
+      )
+      AND status = 'active'
+      AND current_period_end > now()
+    LIMIT 1
+  `;
+
+  return rows.length > 0
+    ? { allowed: true }
+    : { allowed: false, reason: "subscription" };
+}
diff --git a/package-lock.json b/package-lock.json
index 07f4fef9..d52fbccc 100644
--- a/package-lock.json
+++ b/package-lock.json
@@ -13,7 +13,7 @@
         "@hookform/resolvers": "^5.1.1",
         "@mux/mux-node": "^12.8.1",
         "@mux/mux-player-react": "^3.11.4",
-        "@neondatabase/serverless": "^1.0.0",
+        "@neondatabase/serverless": "^1.1.0",
         "@privy-io/react-auth": "^3.16.0",
         "@privy-io/server-auth": "^1.32.5",
         "@radix-ui/react-avatar": "^1.1.10",
@@ -41,7 +41,7 @@
         "clsx": "^2.1.1",
         "cors": "^2.8.5",
         "date-fns": "^4.1.0",
-        "dotenv": "^16.4.7",
+        "dotenv": "^16.6.1",
         "embla-carousel-react": "^8.5.2",
         "formidable": "^3.5.4",
         "framer-motion": "^12.34.3",
@@ -112,6 +112,7 @@
         "tailwindcss": "^3.4.1",
         "ts-node": "^10.9.2",
         "typescript": "^5",
+        "vitest": "^4.1.7",
         "whatwg-fetch": "^3.6.20"
       }
     },
@@ -216,13 +217,6 @@
         "url": "https://opencollective.com/babel"
       }
     },
-    "node_modules/@babel/core/node_modules/convert-source-map": {
-      "version": "2.0.0",
-      "resolved": "https://registry.npmjs.org/convert-source-map/-/convert-source-map-2.0.0.tgz",
-      "integrity": "sha512-Kvp459HrV2FEJ1CAsi1Ku+MY3kasH19TFykTz2xWmMeq6bk2NU3XXvfJ+Q61m0xktWwt+1HSYf3JZsTms3aRJg==",
-      "dev": true,
-      "license": "MIT"
-    },
     "node_modules/@babel/core/node_modules/semver": {
       "version": "6.3.1",
       "resolved": "https://registry.npmjs.org/semver/-/semver-6.3.1.tgz",
@@ -3592,21 +3586,21 @@
       }
     },
     "node_modules/@emnapi/core": {
-      "version": "1.8.1",
-      "resolved": "https://registry.npmjs.org/@emnapi/core/-/core-1.8.1.tgz",
-      "integrity": "sha512-AvT9QFpxK0Zd8J0jopedNm+w/2fIzvtPKPjqyw9jwvBaReTTqPBk9Hixaz7KbjimP+QNz605/XnjFcDAL2pqBg==",
+      "version": "1.10.0",
+      "resolved": "https://registry.npmjs.org/@emnapi/core/-/core-1.10.0.tgz",
+      "integrity": "sha512-yq6OkJ4p82CAfPl0u9mQebQHKPJkY7WrIuk205cTYnYe+k2Z8YBh11FrbRG/H6ihirqcacOgl2BIO8oyMQLeXw==",
       "dev": true,
       "license": "MIT",
       "optional": true,
       "dependencies": {
-        "@emnapi/wasi-threads": "1.1.0",
+        "@emnapi/wasi-threads": "1.2.1",
         "tslib": "^2.4.0"
       }
     },
     "node_modules/@emnapi/runtime": {
-      "version": "1.8.1",
-      "resolved": "https://registry.npmjs.org/@emnapi/runtime/-/runtime-1.8.1.tgz",
-      "integrity": "sha512-mehfKSMWjjNol8659Z8KxEMrdSJDDot5SXMq00dM8BN4o+CLNXQ0xH2V7EchNHV4RmbZLmmPdEaXZc5H2FXmDg==",
+      "version": "1.10.0",
+      "resolved": "https://registry.npmjs.org/@emnapi/runtime/-/runtime-1.10.0.tgz",
+      "integrity": "sha512-ewvYlk86xUoGI0zQRNq/mC+16R1QeDlKQy21Ki3oSYXNgLb45GV1P6A0M+/s6nyCuNDqe5VpaY84BzXGwVbwFA==",
       "license": "MIT",
       "optional": true,
       "dependencies": {
@@ -3614,9 +3608,9 @@
       }
     },
     "node_modules/@emnapi/wasi-threads": {
-      "version": "1.1.0",
-      "resolved": "https://registry.npmjs.org/@emnapi/wasi-threads/-/wasi-threads-1.1.0.tgz",
-      "integrity": "sha512-WI0DdZ8xFSbgMjR1sFsKABJ/C5OnRrjT06JXbZKexJGrDuPTzZdDYfFlsgcCXCyf+suG5QU2e/y1Wo2V/OapLQ==",
+      "version": "1.2.1",
+      "resolved": "https://registry.npmjs.org/@emnapi/wasi-threads/-/wasi-threads-1.2.1.tgz",
+      "integrity": "sha512-uTII7OYF+/Mes/MrcIOYp5yOtSMLBWSIoLPpcgwipoiKbli6k322tcoFsxoIIxPDqW01SQGAgko4EzZi2BNv2w==",
       "dev": true,
       "license": "MIT",
       "optional": true,
@@ -5611,13 +5605,6 @@
         "url": "https://github.com/chalk/chalk?sponsor=1"
       }
     },
-    "node_modules/@jest/transform/node_modules/convert-source-map": {
-      "version": "2.0.0",
-      "resolved": "https://registry.npmjs.org/convert-source-map/-/convert-source-map-2.0.0.tgz",
-      "integrity": "sha512-Kvp459HrV2FEJ1CAsi1Ku+MY3kasH19TFykTz2xWmMeq6bk2NU3XXvfJ+Q61m0xktWwt+1HSYf3JZsTms3aRJg==",
-      "dev": true,
-      "license": "MIT"
-    },
     "node_modules/@jest/types": {
       "version": "30.2.0",
       "resolved": "https://registry.npmjs.org/@jest/types/-/types-30.2.0.tgz",
@@ -6971,27 +6958,14 @@
       }
     },
     "node_modules/@neondatabase/serverless": {
-      "version": "1.0.2",
-      "resolved": "https://registry.npmjs.org/@neondatabase/serverless/-/serverless-1.0.2.tgz",
-      "integrity": "sha512-I5sbpSIAHiB+b6UttofhrN/UJXII+4tZPAq1qugzwCwLIL8EZLV7F/JyHUrEIiGgQpEXzpnjlJ+zwcEhheGvCw==",
+      "version": "1.1.0",
+      "resolved": "https://registry.npmjs.org/@neondatabase/serverless/-/serverless-1.1.0.tgz",
+      "integrity": "sha512-r3ZZhRjEcfEdKIZnoB1RusNgvHuaBRqfCzV4Gi+5A9yUX0S4HTws/ASWqt13wL4y4I+0rqsWGdA2w7EQXHi3+Q==",
       "license": "MIT",
-      "dependencies": {
-        "@types/node": "^22.15.30",
-        "@types/pg": "^8.8.0"
-      },
       "engines": {
         "node": ">=19.0.0"
       }
     },
-    "node_modules/@neondatabase/serverless/node_modules/@types/node": {
-      "version": "22.19.11",
-      "resolved": "https://registry.npmjs.org/@types/node/-/node-22.19.11.tgz",
-      "integrity": "sha512-BH7YwL6rA93ReqeQS1c4bsPpcfOmJasG+Fkr6Y59q83f9M1WcBRHR2vM+P9eOisYRcN3ujQoiZY8uk5W+1WL8w==",
-      "license": "MIT",
-      "dependencies": {
-        "undici-types": "~6.21.0"
-      }
-    },
     "node_modules/@next/bundle-analyzer": {
       "version": "15.5.12",
       "resolved": "https://registry.npmjs.org/@next/bundle-analyzer/-/bundle-analyzer-15.5.12.tgz",
@@ -7304,6 +7278,16 @@
       "dev": true,
       "license": "MIT"
     },
+    "node_modules/@oxc-project/types": {
+      "version": "0.132.0",
+      "resolved": "https://registry.npmjs.org/@oxc-project/types/-/types-0.132.0.tgz",
+      "integrity": "sha512-FESMOxil5Se014ui/Eq8fT5uHJo6nIRwH0PfJrZJXs6Gek3ZVFOrpUv3YIZT20m+extU98Hg1Ym72U58rlsxUQ==",
+      "dev": true,
+      "license": "MIT",
+      "funding": {
+        "url": "https://github.com/sponsors/Boshen"
+      }
+    },
     "node_modules/@paralleldrive/cuid2": {
       "version": "2.3.1",
       "resolved": "https://registry.npmjs.org/@paralleldrive/cuid2/-/cuid2-2.3.1.tgz",
@@ -10379,6 +10363,289 @@
         }
       }
     },
+    "node_modules/@rolldown/binding-android-arm64": {
+      "version": "1.0.2",
+      "resolved": "https://registry.npmjs.org/@rolldown/binding-android-arm64/-/binding-android-arm64-1.0.2.tgz",
+      "integrity": "sha512-ZS4D1JPGn/MYQN/SYDWftIE/nVsM8j/AFOYEzAoOE2O3NktQOZru+/vYXGbR/qtdLdIfGCP0lcoJiYVzsEz+iQ==",
+      "cpu": [
+        "arm64"
+      ],
+      "dev": true,
+      "license": "MIT",
+      "optional": true,
+      "os": [
+        "android"
+      ],
+      "engines": {
+        "node": "^20.19.0 || >=22.12.0"
+      }
+    },
+    "node_modules/@rolldown/binding-darwin-arm64": {
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-      "integrity": "sha512-suDmjLVQg78nMK2UZ454hAG+OAW+HQPZ6n++TNDUX+L0+uUlLywnoxJKDou51Zm+zTCjrCl0Nq6J9C5hP9vK/Q==",
-      "license": "MIT",
-      "engines": {
-        "node": ">=0.10.0"
-      }
-    },
-    "node_modules/postgres-interval": {
-      "version": "1.2.0",
-      "resolved": "https://registry.npmjs.org/postgres-interval/-/postgres-interval-1.2.0.tgz",
-      "integrity": "sha512-9ZhXKM/rw350N1ovuWHbGxnGh/SNJ4cnxHiM0rxE4VN41wsg8P8zWn9hv/buK00RP4WvlOyr/RBDiptyxVbkZQ==",
-      "license": "MIT",
-      "dependencies": {
-        "xtend": "^4.0.0"
-      },
-      "engines": {
-        "node": ">=0.10.0"
-      }
-    },
     "node_modules/postgres-range": {
       "version": "1.1.4",
       "resolved": "https://registry.npmjs.org/postgres-range/-/postgres-range-1.1.4.tgz",
@@ -34605,6 +35287,40 @@
         "node": ">= 16"
       }
     },
+    "node_modules/rolldown": {
+      "version": "1.0.2",
+      "resolved": "https://registry.npmjs.org/rolldown/-/rolldown-1.0.2.tgz",
+      "integrity": "sha512-oZx5zVDtVB44AW3eaifgDml1gWRDZGvjcfdxonE4swNPG98PrrXjaO/KrnUjzlMnztCCRVlUueA1kCXhARGk6g==",
+      "dev": true,
+      "license": "MIT",
+      "dependencies": {
+        "@oxc-project/types": "=0.132.0",
+        "@rolldown/pluginutils": "^1.0.0"
+      },
+      "bin": {
+        "rolldown": "bin/cli.mjs"
+      },
+      "engines": {
+        "node": "^20.19.0 || >=22.12.0"
+      },
+      "optionalDependencies": {
+        "@rolldown/binding-android-arm64": "1.0.2",
+        "@rolldown/binding-darwin-arm64": "1.0.2",
+        "@rolldown/binding-darwin-x64": "1.0.2",
+        "@rolldown/binding-freebsd-x64": "1.0.2",
+        "@rolldown/binding-linux-arm-gnueabihf": "1.0.2",
+        "@rolldown/binding-linux-arm64-gnu": "1.0.2",
+        "@rolldown/binding-linux-arm64-musl": "1.0.2",
+        "@rolldown/binding-linux-ppc64-gnu": "1.0.2",
+        "@rolldown/binding-linux-s390x-gnu": "1.0.2",
+        "@rolldown/binding-linux-x64-gnu": "1.0.2",
+        "@rolldown/binding-linux-x64-musl": "1.0.2",
+        "@rolldown/binding-openharmony-arm64": "1.0.2",
+        "@rolldown/binding-wasm32-wasi": "1.0.2",
+        "@rolldown/binding-win32-arm64-msvc": "1.0.2",
+        "@rolldown/binding-win32-x64-msvc": "1.0.2"
+      }
+    },
     "node_modules/rpc-websockets": {
       "version": "9.3.3",
       "resolved": "https://registry.npmjs.org/rpc-websockets/-/rpc-websockets-9.3.3.tgz",
@@ -35147,6 +35863,13 @@
       "dev": true,
       "license": "MIT"
     },
+    "node_modules/siginfo": {
+      "version": "2.0.0",
+      "resolved": "https://registry.npmjs.org/siginfo/-/siginfo-2.0.0.tgz",
+      "integrity": "sha512-ybx0WO1/8bSBLEWXZvEd7gMW3Sn3JFlW3TvX1nREbDLRNQNaeNN8WK0meBwPdAaOI7TtRRRJn/Es1zhrrCHu7g==",
+      "dev": true,
+      "license": "ISC"
+    },
     "node_modules/signal-exit": {
       "version": "3.0.7",
       "resolved": "https://registry.npmjs.org/signal-exit/-/signal-exit-3.0.7.tgz",
@@ -35420,6 +36143,13 @@
         "node": ">=8"
       }
     },
+    "node_modules/stackback": {
+      "version": "0.0.2",
+      "resolved": "https://registry.npmjs.org/stackback/-/stackback-0.0.2.tgz",
+      "integrity": "sha512-1XMJE5fQo1jGH6Y/7ebnwPOBEkIEnT4QF32d5R1+VXdXveM0IBMJt8zfaxX1P3QhVwrYe+576+jkANtSS2mBbw==",
+      "dev": true,
+      "license": "MIT"
+    },
     "node_modules/standardwebhooks": {
       "version": "1.0.0",
       "resolved": "https://registry.npmjs.org/standardwebhooks/-/standardwebhooks-1.0.0.tgz",
@@ -35440,6 +36170,13 @@
         "node": ">= 0.8"
       }
     },
+    "node_modules/std-env": {
+      "version": "4.1.0",
+      "resolved": "https://registry.npmjs.org/std-env/-/std-env-4.1.0.tgz",
+      "integrity": "sha512-Rq7ybcX2RuC55r9oaPVEW7/xu3tj8u4GeBYHBWCychFtzMIr86A7e3PPEBPT37sHStKX3+TiX/Fr/ACmJLVlLQ==",
+      "dev": true,
+      "license": "MIT"
+    },
     "node_modules/stellar-wallet-kit": {
       "version": "2.0.7",
       "resolved": "https://registry.npmjs.org/stellar-wallet-kit/-/stellar-wallet-kit-2.0.7.tgz",
@@ -36587,6 +37324,13 @@
       "integrity": "sha512-fGTi3gxV/23FTYdAoUtLYp6qySe2KE3teyZitipKNRuVYcBkoP/bB3guXN/XVKUe9mxCHXnc9C4ocyz8OmgN0g==",
       "license": "MIT"
     },
+    "node_modules/tinybench": {
+      "version": "2.9.0",
+      "resolved": "https://registry.npmjs.org/tinybench/-/tinybench-2.9.0.tgz",
+      "integrity": "sha512-0+DUvqWMValLmha6lr4kD8iAMK1HzV0/aKnCtWb9v9641TnP/MFb7Pc2bxoxQjTXAErryXVgUOfv2YqNllqGeg==",
+      "dev": true,
+      "license": "MIT"
+    },
     "node_modules/tinycolor2": {
       "version": "1.6.0",
       "resolved": "https://registry.npmjs.org/tinycolor2/-/tinycolor2-1.6.0.tgz",
@@ -36604,14 +37348,14 @@
       }
     },
     "node_modules/tinyglobby": {
-      "version": "0.2.15",
-      "resolved": "https://registry.npmjs.org/tinyglobby/-/tinyglobby-0.2.15.tgz",
-      "integrity": "sha512-j2Zq4NyQYG5XMST4cbs02Ak8iJUdxRM0XI5QyxXuZOzKOINmWurp3smXu3y5wDcJrptwpSjgXHzIQxR0omXljQ==",
+      "version": "0.2.16",
+      "resolved": "https://registry.npmjs.org/tinyglobby/-/tinyglobby-0.2.16.tgz",
+      "integrity": "sha512-pn99VhoACYR8nFHhxqix+uvsbXineAasWm5ojXoN8xEwK5Kd3/TrhNn1wByuD52UxWRLy8pu+kRMniEi6Eq9Zg==",
       "dev": true,
       "license": "MIT",
       "dependencies": {
         "fdir": "^6.5.0",
-        "picomatch": "^4.0.3"
+        "picomatch": "^4.0.4"
       },
       "engines": {
         "node": ">=12.0.0"
@@ -36620,6 +37364,16 @@
         "url": "https://github.com/sponsors/SuperchupuDev"
       }
     },
+    "node_modules/tinyrainbow": {
+      "version": "3.1.0",
+      "resolved": "https://registry.npmjs.org/tinyrainbow/-/tinyrainbow-3.1.0.tgz",
+      "integrity": "sha512-Bf+ILmBgretUrdJxzXM0SgXLZ3XfiaUuOj/IKQHuTXip+05Xn+uyEYdVg0kYDipTBcLrCVyUzAPz7QmArb0mmw==",
+      "dev": true,
+      "license": "MIT",
+      "engines": {
+        "node": ">=14.0.0"
+      }
+    },
     "node_modules/tldts": {
       "version": "6.1.86",
       "resolved": "https://registry.npmjs.org/tldts/-/tldts-6.1.86.tgz",
@@ -37539,13 +38293,6 @@
         "node": ">=10.12.0"
       }
     },
-    "node_modules/v8-to-istanbul/node_modules/convert-source-map": {
-      "version": "2.0.0",
-      "resolved": "https://registry.npmjs.org/convert-source-map/-/convert-source-map-2.0.0.tgz",
-      "integrity": "sha512-Kvp459HrV2FEJ1CAsi1Ku+MY3kasH19TFykTz2xWmMeq6bk2NU3XXvfJ+Q61m0xktWwt+1HSYf3JZsTms3aRJg==",
-      "dev": true,
-      "license": "MIT"
-    },
     "node_modules/valtio": {
       "version": "1.11.2",
       "resolved": "https://registry.npmjs.org/valtio/-/valtio-1.11.2.tgz",
@@ -37727,6 +38474,174 @@
         }
       }
     },
+    "node_modules/vite": {
+      "version": "8.0.14",
+      "resolved": "https://registry.npmjs.org/vite/-/vite-8.0.14.tgz",
+      "integrity": "sha512-s4BJJ+5y1pYL6Otw51FHhVJQhPnuRinKig64g/1+EUNaJsd3gCKdD31IPFvswUgW9/60QT9oFHbZHbQK5imcxw==",
+      "dev": true,
+      "license": "MIT",
+      "dependencies": {
+        "lightningcss": "^1.32.0",
+        "picomatch": "^4.0.4",
+        "postcss": "^8.5.15",
+        "rolldown": "1.0.2",
+        "tinyglobby": "^0.2.16"
+      },
+      "bin": {
+        "vite": "bin/vite.js"
+      },
+      "engines": {
+        "node": "^20.19.0 || >=22.12.0"
+      },
+      "funding": {
+        "url": "https://github.com/vitejs/vite?sponsor=1"
+      },
+      "optionalDependencies": {
+        "fsevents": "~2.3.3"
+      },
+      "peerDependencies": {
+        "@types/node": "^20.19.0 || >=22.12.0",
+        "@vitejs/devtools": "^0.1.18",
+        "esbuild": "^0.27.0 || ^0.28.0",
+        "jiti": ">=1.21.0",
+        "less": "^4.0.0",
+        "sass": "^1.70.0",
+        "sass-embedded": "^1.70.0",
+        "stylus": ">=0.54.8",
+        "sugarss": "^5.0.0",
+        "terser": "^5.16.0",
+        "tsx": "^4.8.1",
+        "yaml": "^2.4.2"
+      },
+      "peerDependenciesMeta": {
+        "@types/node": {
+          "optional": true
+        },
+        "@vitejs/devtools": {
+          "optional": true
+        },
+        "esbuild": {
+          "optional": true
+        },
+        "jiti": {
+          "optional": true
+        },
+        "less": {
+          "optional": true
+        },
+        "sass": {
+          "optional": true
+        },
+        "sass-embedded": {
+          "optional": true
+        },
+        "stylus": {
+          "optional": true
+        },
+        "sugarss": {
+          "optional": true
+        },
+        "terser": {
+          "optional": true
+        },
+        "tsx": {
+          "optional": true
+        },
+        "yaml": {
+          "optional": true
+        }
+      }
+    },
+    "node_modules/vitest": {
+      "version": "4.1.7",
+      "resolved": "https://registry.npmjs.org/vitest/-/vitest-4.1.7.tgz",
+      "integrity": "sha512-flYyaFd2CgoCoU+0UKt3pxksgC+S02iTDN0n3LtqaMeXsI9SBcdNujc2k0DeFLzUn/0k538yNjOSdwgCqcrwJA==",
+      "dev": true,
+      "license": "MIT",
+      "dependencies": {
+        "@vitest/expect": "4.1.7",
+        "@vitest/mocker": "4.1.7",
+        "@vitest/pretty-format": "4.1.7",
+        "@vitest/runner": "4.1.7",
+        "@vitest/snapshot": "4.1.7",
+        "@vitest/spy": "4.1.7",
+        "@vitest/utils": "4.1.7",
+        "es-module-lexer": "^2.0.0",
+        "expect-type": "^1.3.0",
+        "magic-string": "^0.30.21",
+        "obug": "^2.1.1",
+        "pathe": "^2.0.3",
+        "picomatch": "^4.0.3",
+        "std-env": "^4.0.0-rc.1",
+        "tinybench": "^2.9.0",
+        "tinyexec": "^1.0.2",
+        "tinyglobby": "^0.2.15",
+        "tinyrainbow": "^3.1.0",
+        "vite": "^6.0.0 || ^7.0.0 || ^8.0.0",
+        "why-is-node-running": "^2.3.0"
+      },
+      "bin": {
+        "vitest": "vitest.mjs"
+      },
+      "engines": {
+        "node": "^20.0.0 || ^22.0.0 || >=24.0.0"
+      },
+      "funding": {
+        "url": "https://opencollective.com/vitest"
+      },
+      "peerDependencies": {
+        "@edge-runtime/vm": "*",
+        "@opentelemetry/api": "^1.9.0",
+        "@types/node": "^20.0.0 || ^22.0.0 || >=24.0.0",
+        "@vitest/browser-playwright": "4.1.7",
+        "@vitest/browser-preview": "4.1.7",
+        "@vitest/browser-webdriverio": "4.1.7",
+        "@vitest/coverage-istanbul": "4.1.7",
+        "@vitest/coverage-v8": "4.1.7",
+        "@vitest/ui": "4.1.7",
+        "happy-dom": "*",
+        "jsdom": "*",
+        "vite": "^6.0.0 || ^7.0.0 || ^8.0.0"
+      },
+      "peerDependenciesMeta": {
+        "@edge-runtime/vm": {
+          "optional": true
+        },
+        "@opentelemetry/api": {
+          "optional": true
+        },
+        "@types/node": {
+          "optional": true
+        },
+        "@vitest/browser-playwright": {
+          "optional": true
+        },
+        "@vitest/browser-preview": {
+          "optional": true
+        },
+        "@vitest/browser-webdriverio": {
+          "optional": true
+        },
+        "@vitest/coverage-istanbul": {
+          "optional": true
+        },
+        "@vitest/coverage-v8": {
+          "optional": true
+        },
+        "@vitest/ui": {
+          "optional": true
+        },
+        "happy-dom": {
+          "optional": true
+        },
+        "jsdom": {
+          "optional": true
+        },
+        "vite": {
+          "optional": false
+        }
+      }
+    },
     "node_modules/w3c-xmlserializer": {
       "version": "5.0.0",
       "resolved": "https://registry.npmjs.org/w3c-xmlserializer/-/w3c-xmlserializer-5.0.0.tgz",
@@ -38047,6 +38962,23 @@
         "url": "https://github.com/sponsors/ljharb"
       }
     },
+    "node_modules/why-is-node-running": {
+      "version": "2.3.0",
+      "resolved": "https://registry.npmjs.org/why-is-node-running/-/why-is-node-running-2.3.0.tgz",
+      "integrity": "sha512-hUrmaWBdVDcxvYqnyh09zunKzROWjbZTiNy8dBEjkS7ehEDQibXJ7XvlmtbwuTclUiIyN+CyXQD4Vmko8fNm8w==",
+      "dev": true,
+      "license": "MIT",
+      "dependencies": {
+        "siginfo": "^2.0.0",
+        "stackback": "0.0.2"
+      },
+      "bin": {
+        "why-is-node-running": "cli.js"
+      },
+      "engines": {
+        "node": ">=8"
+      }
+    },
     "node_modules/wif": {
       "version": "5.0.0",
       "resolved": "https://registry.npmjs.org/wif/-/wif-5.0.0.tgz",
diff --git a/package.json b/package.json
index 8e0fb009..b8e7ea60 100644
--- a/package.json
+++ b/package.json
@@ -31,7 +31,7 @@
     "@hookform/resolvers": "^5.1.1",
     "@mux/mux-node": "^12.8.1",
     "@mux/mux-player-react": "^3.11.4",
-    "@neondatabase/serverless": "^1.0.0",
+    "@neondatabase/serverless": "^1.1.0",
     "@privy-io/react-auth": "^3.16.0",
     "@privy-io/server-auth": "^1.32.5",
     "@radix-ui/react-avatar": "^1.1.10",
@@ -59,7 +59,7 @@
     "clsx": "^2.1.1",
     "cors": "^2.8.5",
     "date-fns": "^4.1.0",
-    "dotenv": "^16.4.7",
+    "dotenv": "^16.6.1",
     "embla-carousel-react": "^8.5.2",
     "formidable": "^3.5.4",
     "framer-motion": "^12.34.3",
@@ -130,6 +130,7 @@
     "tailwindcss": "^3.4.1",
     "ts-node": "^10.9.2",
     "typescript": "^5",
+    "vitest": "^4.1.7",
     "whatwg-fetch": "^3.6.20"
   },
   "lint-staged": {
diff --git a/scripts/cron-cleanup-sessions.ts b/scripts/cron-cleanup-sessions.ts
new file mode 100644
index 00000000..5bc00ef6
--- /dev/null
+++ b/scripts/cron-cleanup-sessions.ts
@@ -0,0 +1,42 @@
+/**
+ * Nightly cron: delete expired user_sessions rows.
+ *
+ * Run via your scheduler (Vercel Cron, GitHub Actions, etc.) once per day.
+ * Example cron expression: "0 3 * * *" (03:00 UTC daily)
+ *
+ * Usage:
+ *   npx tsx scripts/cron-cleanup-sessions.ts
+ *
+ * Required env vars (same as the app):
+ *   POSTGRES_URL  (or DATABASE_URL — whichever @vercel/postgres picks up)
+ */
+
+import dotenv from "dotenv";
+dotenv.config({ path: ".env.local" });
+
+import { sql } from "@vercel/postgres";
+
+async function cleanupExpiredSessions(): Promise<void> {
+  console.log("[cron-cleanup-sessions] Starting cleanup…");
+
+  try {
+    const result = await sql`
+      DELETE FROM user_sessions
+      WHERE expires_at < NOW()
+         OR revoked = true
+    `;
+
+    const deleted = result.rowCount ?? 0;
+    console.log(
+      `[cron-cleanup-sessions] Deleted ${deleted} expired/revoked session(s).`
+    );
+  } catch (err) {
+    console.error("[cron-cleanup-sessions] Error:", err);
+    process.exit(1);
+  }
+}
+
+cleanupExpiredSessions().then(() => {
+  console.log("[cron-cleanup-sessions] Done.");
+  process.exit(0);
+});
diff --git a/tsconfig.json b/tsconfig.json
index bc9ef9f7..d660d767 100644
--- a/tsconfig.json
+++ b/tsconfig.json
@@ -1,6 +1,6 @@
 {
   "compilerOptions": {
-    "target": "ES2017",
+    "target": "ES2020",
     "lib": ["dom", "dom.iterable", "esnext"],
     "allowJs": true,
     "skipLibCheck": true,
@@ -31,5 +31,10 @@
     "types/**/*.d.ts",
     ".next/dev/types/**/*.ts"
   ],
-  "exclude": ["node_modules"]
+  "exclude": [
+    "node_modules",
+    "**/*.test.ts",
+    "**/*.test.tsx",
+    "**/__tests__/**"
+  ]
 }
diff --git a/types/dev-shims.d.ts b/types/dev-shims.d.ts
new file mode 100644
index 00000000..7c379f70
--- /dev/null
+++ b/types/dev-shims.d.ts
@@ -0,0 +1,4 @@
+declare module "@/components/stream/AccessGate";
+declare module "@/components/dashboard/stream-manager/StreamPasswordSettings";
+declare module "@/lib/stream-access/password";
+declare module "vitest";
diff --git a/types/transak-sdk.d.ts b/types/transak-sdk.d.ts
new file mode 100644
index 00000000..f883d716
--- /dev/null
+++ b/types/transak-sdk.d.ts
@@ -0,0 +1,9 @@
+declare module "@transak/transak-sdk" {
+  export class Transak {
+    static EVENTS: Record<string, string>;
+    static on(event: string, callback: (payload: unknown) => void): void;
+    constructor(config: unknown);
+    init(): void;
+    cleanup(): void;
+  }
+}