diff --git a/cloudflare/packages/core/src/account-store.ts b/cloudflare/packages/core/src/account-store.ts
new file mode 100644
index 00000000..a1f5b521
--- /dev/null
+++ b/cloudflare/packages/core/src/account-store.ts
@@ -0,0 +1,162 @@
+import { Context, Effect, Layer } from "effect"
+
+/**
+ * SubrouterActor — multi-tenant rewrite of the Go subrouter, hosted on Rivet
+ * actors. v1 = functional parity with Go subrouter (sticky session → account
+ * routing). Aurora-backed account store, not local JSON.
+ *
+ * This file is the *interface and sticky-routing core*. The actual Rivet
+ * actor wrapper lives in packages/actors and forwards into here. The HTTP
+ * transport (the thing that *replaces* what Go subrouter listens for at
+ * 0.0.0.0:31415) lives in packages/proxy/src/gateway.ts since the AI
+ * integrations go through the same proxy as gh/registries/etc.
+ *
+ * Why: Go subrouter today requires a long-lived VM (Mac Mini or systemd box).
+ * Rivet actors let us host it with zero VM ops, multi-tenant from the start.
+ */
+
+export interface Account {
+  readonly id: string
+  readonly orgId: string
+  readonly kind: "codex_oauth" | "anthropic_oauth" | "openai_apikey" | "anthropic_apikey"
+  readonly label: string
+  readonly enabled: boolean
+  readonly rateLimitRemaining?: number
+  readonly modelQuotas?: AccountModelQuotas
+  readonly lastUsedAt?: number
+}
+
+export interface AccountModelQuota {
+  readonly remainingPercent: number
+  readonly resetsAt?: number
+  readonly protectedBelowPercent?: number
+}
+
+export type AccountModelQuotas = Readonly<Record<string, AccountModelQuota>>
+
+// Named model-family quota pools. A request whose model name contains one of
+// these keywords draws from that pool instead of the account-wide "default":
+// Codex Spark ("spark") and Claude Opus/Sonnet weekly limits ("opus"/"sonnet").
+// Keep this in sync with what the quota populator writes into Account.modelQuotas:
+// a model keyed to a pool no account carries is ineligible everywhere (see
+// accountHasQuotaForModel), which is also what isolates providers (a Claude
+// "opus" model only matches accounts that carry an "opus" pool). Anthropic's
+// opus/sonnet caps are sub-limits of the account-wide window, so the populator
+// must set each to min(account-wide remaining, family remaining); the Codex
+// Spark pool is independent of the account-wide window.
+const MODEL_QUOTA_POOLS = ["spark", "opus", "sonnet"] as const
+
+export const quotaKeyForModel = (model: string | undefined): string => {
+  const normalized = model?.trim().toLowerCase()
+  if (!normalized) return "default"
+  for (const pool of MODEL_QUOTA_POOLS) {
+    if (normalized.includes(pool)) return pool
+  }
+  return "default"
+}
+
+export const accountHasQuotaForModel = (
+  account: Account,
+  quotaKey: string
+): boolean => {
+  const quota = account.modelQuotas?.[quotaKey]
+  if (!quota) return quotaKey === "default"
+  return quota.remainingPercent > 0
+}
+
+export interface AccountStore {
+  readonly list: (orgId: string) => Effect.Effect<ReadonlyArray<Account>>
+  readonly pick: (input: {
+    readonly orgId: string
+    readonly sessionId: string
+    readonly preferAccountId?: string
+    readonly model?: string
+    readonly quotaKey?: string
+  }) => Effect.Effect<Account | null>
+  readonly recordUse: (accountId: string) => Effect.Effect<void>
+}
+
+export class AccountStoreTag extends Context.Tag("AccountStore")<
+  AccountStoreTag,
+  AccountStore
+>() {}
+
+/**
+ * Sticky session table. In production: a Postgres row per (orgId, sessionId).
+ * Here: in-memory Map. Stickiness ensures cached agent context stays useful
+ * (matches Go subrouter's `X-Subrouter-Session` semantics).
+ */
+export const makeInMemoryStickyStore = () => {
+  const map = new Map<string, string>() // `${orgId}:${sessionId}` -> accountId
+  return {
+    get: (orgId: string, sessionId: string, quotaKey = "default"): string | null =>
+      map.get(`${orgId}:${quotaKey}:${sessionId}`) ?? null,
+    set: (
+      orgId: string,
+      sessionId: string,
+      accountId: string,
+      quotaKey = "default"
+    ): void => {
+      map.set(`${orgId}:${quotaKey}:${sessionId}`, accountId)
+    },
+    clear: (): void => {
+      map.clear()
+    },
+  }
+}
+
+/**
+ * Reference in-memory AccountStore impl that round-robins enabled accounts and
+ * respects sticky sessions. Production swaps in a Postgres-backed implementation
+ * that reads from `accounts` and `subrouter_session_assignments`.
+ */
+export const makeInMemoryAccountStoreLayer = (initial: ReadonlyArray<Account>) => {
+  const accounts = [...initial]
+  const sticky = makeInMemoryStickyStore()
+  let cursor = 0
+
+  return Layer.succeed(AccountStoreTag, {
+    list: (orgId) =>
+      Effect.succeed(accounts.filter((a) => a.orgId === orgId && a.enabled)),
+
+    pick: ({ orgId, sessionId, preferAccountId, model, quotaKey }) => {
+      const resolvedQuotaKey = quotaKey ?? quotaKeyForModel(model)
+      const isEligible = (account: Account): boolean =>
+        account.orgId === orgId &&
+        account.enabled &&
+        accountHasQuotaForModel(account, resolvedQuotaKey)
+
+      // 1. sticky table first
+      const stickyId = sticky.get(orgId, sessionId, resolvedQuotaKey)
+      if (stickyId) {
+        const found = accounts.find((a) => a.id === stickyId && isEligible(a))
+        if (found) return Effect.succeed(found)
+      }
+      // 2. explicit pin
+      if (preferAccountId) {
+        const found = accounts.find(
+          (a) => a.id === preferAccountId && isEligible(a)
+        )
+        if (found) {
+          sticky.set(orgId, sessionId, found.id, resolvedQuotaKey)
+          return Effect.succeed(found)
+        }
+      }
+      // 3. round-robin over enabled accounts for the org
+      const eligible = accounts.filter(isEligible)
+      if (eligible.length === 0) return Effect.succeed(null)
+      const pick = eligible[cursor % eligible.length]!
+      cursor += 1
+      sticky.set(orgId, sessionId, pick.id, resolvedQuotaKey)
+      return Effect.succeed(pick)
+    },
+
+    recordUse: (accountId) =>
+      Effect.sync(() => {
+        const i = accounts.findIndex((a) => a.id === accountId)
+        if (i >= 0) {
+          accounts[i] = { ...accounts[i]!, lastUsedAt: Date.now() }
+        }
+      }),
+  } satisfies AccountStore)
+}
diff --git a/cloudflare/packages/core/src/index.ts b/cloudflare/packages/core/src/index.ts
index 138bf977..4b7c8369 100644
--- a/cloudflare/packages/core/src/index.ts
+++ b/cloudflare/packages/core/src/index.ts
@@ -1,163 +1,19 @@
-import { Context, Effect, Layer } from "effect"
-export * from "./service.ts"
-
-/**
- * SubrouterActor — multi-tenant rewrite of the Go subrouter, hosted on Rivet
- * actors. v1 = functional parity with Go subrouter (sticky session → account
- * routing). Aurora-backed account store, not local JSON.
- *
- * This file is the *interface and sticky-routing core*. The actual Rivet
- * actor wrapper lives in packages/actors and forwards into here. The HTTP
- * transport (the thing that *replaces* what Go subrouter listens for at
- * 0.0.0.0:31415) lives in packages/proxy/src/gateway.ts since the AI
- * integrations go through the same proxy as gh/registries/etc.
- *
- * Why: Go subrouter today requires a long-lived VM (Mac Mini or systemd box).
- * Rivet actors let us host it with zero VM ops, multi-tenant from the start.
- */
-
-export interface Account {
-  readonly id: string
-  readonly orgId: string
-  readonly kind: "codex_oauth" | "anthropic_oauth" | "openai_apikey" | "anthropic_apikey"
-  readonly label: string
-  readonly enabled: boolean
-  readonly rateLimitRemaining?: number
-  readonly modelQuotas?: AccountModelQuotas
-  readonly lastUsedAt?: number
-}
-
-export interface AccountModelQuota {
-  readonly remainingPercent: number
-  readonly resetsAt?: number
-  readonly protectedBelowPercent?: number
-}
-
-export type AccountModelQuotas = Readonly<Record<string, AccountModelQuota>>
-
-// Named model-family quota pools. A request whose model name contains one of
-// these keywords draws from that pool instead of the account-wide "default":
-// Codex Spark ("spark") and Claude Opus/Sonnet weekly limits ("opus"/"sonnet").
-// Keep this in sync with what the quota populator writes into Account.modelQuotas:
-// a model keyed to a pool no account carries is ineligible everywhere (see
-// accountHasQuotaForModel), which is also what isolates providers (a Claude
-// "opus" model only matches accounts that carry an "opus" pool). Anthropic's
-// opus/sonnet caps are sub-limits of the account-wide window, so the populator
-// must set each to min(account-wide remaining, family remaining); the Codex
-// Spark pool is independent of the account-wide window.
-const MODEL_QUOTA_POOLS = ["spark", "opus", "sonnet"] as const
-
-export const quotaKeyForModel = (model: string | undefined): string => {
-  const normalized = model?.trim().toLowerCase()
-  if (!normalized) return "default"
-  for (const pool of MODEL_QUOTA_POOLS) {
-    if (normalized.includes(pool)) return pool
-  }
-  return "default"
-}
-
-export const accountHasQuotaForModel = (
-  account: Account,
-  quotaKey: string
-): boolean => {
-  const quota = account.modelQuotas?.[quotaKey]
-  if (!quota) return quotaKey === "default"
-  return quota.remainingPercent > 0
-}
-
-export interface AccountStore {
-  readonly list: (orgId: string) => Effect.Effect<ReadonlyArray<Account>>
-  readonly pick: (input: {
-    readonly orgId: string
-    readonly sessionId: string
-    readonly preferAccountId?: string
-    readonly model?: string
-    readonly quotaKey?: string
-  }) => Effect.Effect<Account | null>
-  readonly recordUse: (accountId: string) => Effect.Effect<void>
-}
-
-export class AccountStoreTag extends Context.Tag("AccountStore")<
+export {
   AccountStoreTag,
-  AccountStore
->() {}
-
-/**
- * Sticky session table. In production: a Postgres row per (orgId, sessionId).
- * Here: in-memory Map. Stickiness ensures cached agent context stays useful
- * (matches Go subrouter's `X-Subrouter-Session` semantics).
- */
-export const makeInMemoryStickyStore = () => {
-  const map = new Map<string, string>() // `${orgId}:${sessionId}` -> accountId
-  return {
-    get: (orgId: string, sessionId: string, quotaKey = "default"): string | null =>
-      map.get(`${orgId}:${quotaKey}:${sessionId}`) ?? null,
-    set: (
-      orgId: string,
-      sessionId: string,
-      accountId: string,
-      quotaKey = "default"
-    ): void => {
-      map.set(`${orgId}:${quotaKey}:${sessionId}`, accountId)
-    },
-    clear: (): void => {
-      map.clear()
-    },
-  }
-}
-
-/**
- * Reference in-memory AccountStore impl that round-robins enabled accounts and
- * respects sticky sessions. Production swaps in a Postgres-backed implementation
- * that reads from `accounts` and `subrouter_session_assignments`.
- */
-export const makeInMemoryAccountStoreLayer = (initial: ReadonlyArray<Account>) => {
-  const accounts = [...initial]
-  const sticky = makeInMemoryStickyStore()
-  let cursor = 0
-
-  return Layer.succeed(AccountStoreTag, {
-    list: (orgId) =>
-      Effect.succeed(accounts.filter((a) => a.orgId === orgId && a.enabled)),
-
-    pick: ({ orgId, sessionId, preferAccountId, model, quotaKey }) => {
-      const resolvedQuotaKey = quotaKey ?? quotaKeyForModel(model)
-      const isEligible = (account: Account): boolean =>
-        account.orgId === orgId &&
-        account.enabled &&
-        accountHasQuotaForModel(account, resolvedQuotaKey)
-
-      // 1. sticky table first
-      const stickyId = sticky.get(orgId, sessionId, resolvedQuotaKey)
-      if (stickyId) {
-        const found = accounts.find((a) => a.id === stickyId && isEligible(a))
-        if (found) return Effect.succeed(found)
-      }
-      // 2. explicit pin
-      if (preferAccountId) {
-        const found = accounts.find(
-          (a) => a.id === preferAccountId && isEligible(a)
-        )
-        if (found) {
-          sticky.set(orgId, sessionId, found.id, resolvedQuotaKey)
-          return Effect.succeed(found)
-        }
-      }
-      // 3. round-robin over enabled accounts for the org
-      const eligible = accounts.filter(isEligible)
-      if (eligible.length === 0) return Effect.succeed(null)
-      const pick = eligible[cursor % eligible.length]!
-      cursor += 1
-      sticky.set(orgId, sessionId, pick.id, resolvedQuotaKey)
-      return Effect.succeed(pick)
-    },
-
-    recordUse: (accountId) =>
-      Effect.sync(() => {
-        const i = accounts.findIndex((a) => a.id === accountId)
-        if (i >= 0) {
-          accounts[i] = { ...accounts[i]!, lastUsedAt: Date.now() }
-        }
-      }),
-  } satisfies AccountStore)
-}
+  accountHasQuotaForModel,
+  makeInMemoryAccountStoreLayer,
+  makeInMemoryStickyStore,
+  quotaKeyForModel,
+} from "./account-store.ts"
+export type {
+  Account,
+  AccountModelQuota,
+  AccountModelQuotas,
+  AccountStore,
+} from "./account-store.ts"
+export {
+  NoEligibleAccount,
+  SubrouterService,
+  makeSubrouterServiceLayer,
+} from "./service.ts"
+export type { PickedRoute } from "./service.ts"
diff --git a/cloudflare/packages/core/src/service.ts b/cloudflare/packages/core/src/service.ts
index 4f2ae220..b3fe0e1f 100644
--- a/cloudflare/packages/core/src/service.ts
+++ b/cloudflare/packages/core/src/service.ts
@@ -14,7 +14,7 @@ import { Context, Effect, Layer } from "effect"
 import {
   AccountStoreTag,
   type Account,
-} from "./index.ts"
+} from "./account-store.ts"
 
 export class NoEligibleAccount extends Error {
   readonly _tag = "NoEligibleAccount"
diff --git a/cloudflare/packages/core/test/public-api.test.ts b/cloudflare/packages/core/test/public-api.test.ts
new file mode 100644
index 00000000..916855eb
--- /dev/null
+++ b/cloudflare/packages/core/test/public-api.test.ts
@@ -0,0 +1,29 @@
+import { expect, test } from "bun:test"
+import { Effect, Layer } from "effect"
+import * as core from "../src/index.ts"
+import * as service from "../src/service.ts"
+
+test("the core barrel exposes one coherent service and account-store API", async () => {
+  expect(core.SubrouterService).toBe(service.SubrouterService)
+  expect(core.NoEligibleAccount).toBe(service.NoEligibleAccount)
+  expect(typeof core.makeInMemoryAccountStoreLayer).toBe("function")
+
+  const layer = core.makeInMemoryAccountStoreLayer([
+    {
+      id: "account-1",
+      orgId: "org-1",
+      kind: "codex_oauth",
+      label: "primary",
+      enabled: true,
+    },
+  ])
+  const program = Effect.gen(function* () {
+    const subrouter = yield* core.SubrouterService
+    return yield* subrouter.route({ orgId: "org-1", sessionId: "session-1" })
+  }).pipe(Effect.provide(core.makeSubrouterServiceLayer().pipe(
+    Layer.provideMerge(layer)
+  )))
+
+  const result = await Effect.runPromise(program)
+  expect(result.account.id).toBe("account-1")
+})
diff --git a/cloudflare/packages/worker/src/core-routing.ts b/cloudflare/packages/worker/src/core-routing.ts
new file mode 100644
index 00000000..58ebfe4f
--- /dev/null
+++ b/cloudflare/packages/worker/src/core-routing.ts
@@ -0,0 +1,4 @@
+export {
+  accountHasQuotaForModel,
+  quotaKeyForModel,
+} from "@subrouter/core"
diff --git a/cloudflare/packages/worker/src/index.ts b/cloudflare/packages/worker/src/index.ts
index c7148d4c..7bcae948 100644
--- a/cloudflare/packages/worker/src/index.ts
+++ b/cloudflare/packages/worker/src/index.ts
@@ -1,10 +1,6 @@
 import { DurableObject } from "cloudflare:workers"
-import {
-  accountHasQuotaForModel,
-  quotaKeyForModel,
-  type Account,
-  type AccountModelQuotas,
-} from "@subrouter/core"
+import type { Account, AccountModelQuotas } from "@subrouter/core"
+import { accountHasQuotaForModel, quotaKeyForModel } from "./core-routing.ts"
 import {
   authModeForAccount,
   blockingRefreshFailure,
diff --git a/cloudflare/packages/worker/test/proxy-streaming.test.ts b/cloudflare/packages/worker/test/proxy-streaming.test.ts
index 7b5684c5..e84129a3 100644
--- a/cloudflare/packages/worker/test/proxy-streaming.test.ts
+++ b/cloudflare/packages/worker/test/proxy-streaming.test.ts
@@ -2,7 +2,7 @@ import { afterEach, describe, expect, mock, test } from "bun:test"
 import { Buffer } from "node:buffer"
 
 mock.module("cloudflare:workers", () => ({ DurableObject: class {} }))
-mock.module("@subrouter/core", () => ({
+mock.module("../src/core-routing.ts", () => ({
   accountHasQuotaForModel: () => true,
   quotaKeyForModel: (model: string | undefined) => model ?? "default",
 }))