diff --git a/src/commands/mine-local.ts b/src/commands/mine-local.ts
index 5bc9c1bb..b1113bbd 100644
--- a/src/commands/mine-local.ts
+++ b/src/commands/mine-local.ts
@@ -121,6 +121,10 @@ function runGateViaStdin(opts: {
     const child = spawn(opts.bin, args, {
       stdio: ["pipe", "pipe", "pipe"],
       env: { ...process.env, HIVEMIND_WIKI_WORKER: "1", HIVEMIND_CAPTURE: "false" },
+      // CREATE_NO_WINDOW: this runs inside the detached, console-less mine-local
+      // worker, so without it Windows pops a visible console window for the
+      // summarizer CLI child. No-op on POSIX.
+      windowsHide: true,
     });
 
     let stdout = "";
diff --git a/src/hooks/commit-kpi-extract.ts b/src/hooks/commit-kpi-extract.ts
index a09199b5..8d81770b 100644
--- a/src/hooks/commit-kpi-extract.ts
+++ b/src/hooks/commit-kpi-extract.ts
@@ -122,6 +122,9 @@ export async function tryCommitKpiExtract(
       cwd,
       detached: true,
       stdio: "ignore",
+      // CREATE_NO_WINDOW: detached summarizer CLI spawn — without it Windows
+      // pops a visible console window for the claude/codex child. No-op on POSIX.
+      windowsHide: true,
       env: process.env,
     });
     child.unref();
diff --git a/src/hooks/hermes/wiki-worker.ts b/src/hooks/hermes/wiki-worker.ts
index d1d04d5c..2953b8bc 100644
--- a/src/hooks/hermes/wiki-worker.ts
+++ b/src/hooks/hermes/wiki-worker.ts
@@ -269,6 +269,9 @@ async function main(): Promise<void> {
         "--ignore-user-config",
       ], {
         stdio: ["ignore", "pipe", "pipe"],
+        // Suppress the visible console window Windows would otherwise pop for
+        // a child of this console-less detached worker. No-op on POSIX.
+        windowsHide: true,
         timeout: 120_000,
         // hermes streams to stdout, which execFileSync buffers. The Node
         // default (1 MB) overflows to ENOBUFS on a verbose run, killing the
diff --git a/src/hooks/wiki-worker-spawn.ts b/src/hooks/wiki-worker-spawn.ts
index 4a62571c..7d5a6f20 100644
--- a/src/hooks/wiki-worker-spawn.ts
+++ b/src/hooks/wiki-worker-spawn.ts
@@ -35,13 +35,16 @@ export function buildClaudeInvocation(claudeBin: string, prompt: string): Claude
     return {
       file: claudeBin,
       args: ["-p", ...CLAUDE_FLAGS],
-      options: { input: prompt, stdio: ["pipe", "pipe", "pipe"], shell: true },
+      // windowsHide: the wiki worker is a detached, console-less process, so
+      // without CREATE_NO_WINDOW Windows allocates a visible console window
+      // (titled after the CLI exe) for the child. No-op on POSIX.
+      options: { input: prompt, stdio: ["pipe", "pipe", "pipe"], shell: true, windowsHide: true },
     };
   }
   return {
     file: claudeBin,
     args: ["-p", prompt, ...CLAUDE_FLAGS],
-    options: { stdio: ["ignore", "pipe", "pipe"] },
+    options: { stdio: ["ignore", "pipe", "pipe"], windowsHide: true },
   };
 }
 
@@ -63,13 +66,15 @@ export function buildTrailingPromptInvocation(bin: string, flags: string[], prom
     return {
       file: bin,
       args: [...flags],
-      options: { input: prompt, stdio: ["pipe", "pipe", "pipe"], shell: true },
+      // windowsHide: see buildClaudeInvocation — suppress the visible console
+      // window Windows would pop for a child of the console-less worker.
+      options: { input: prompt, stdio: ["pipe", "pipe", "pipe"], shell: true, windowsHide: true },
     };
   }
   return {
     file: bin,
     args: [...flags, prompt],
-    options: { stdio: ["ignore", "pipe", "pipe"] },
+    options: { stdio: ["ignore", "pipe", "pipe"], windowsHide: true },
   };
 }
 
@@ -87,6 +92,10 @@ export function buildStdinPromptInvocation(bin: string, flags: string[], prompt:
     options: {
       input: prompt,
       stdio: ["pipe", "pipe", "pipe"],
+      // windowsHide: see buildClaudeInvocation — the doc/wiki worker is a
+      // detached, console-less process, so without CREATE_NO_WINDOW Windows
+      // pops a visible console window for the summarizer CLI. No-op on POSIX.
+      windowsHide: true,
       ...(binNeedsShell(bin) ? { shell: true } : {}),
     },
   };
diff --git a/src/skillify/advisor.ts b/src/skillify/advisor.ts
index 942b2943..48057898 100644
--- a/src/skillify/advisor.ts
+++ b/src/skillify/advisor.ts
@@ -131,6 +131,10 @@ function runAdvisorGate(prompt: string, claudeBin: string): Promise<string> {
     ], {
       stdio: ["pipe", "pipe", "pipe"],
       env: { ...process.env, HIVEMIND_WIKI_WORKER: "1", HIVEMIND_CAPTURE: "false" },
+      // CREATE_NO_WINDOW: this runs inside the detached, console-less mine-local
+      // worker, so without it Windows pops a visible console window for the
+      // claude child. No-op on POSIX.
+      windowsHide: true,
     });
     let stdout = "";
     let stderr = "";
diff --git a/src/skillify/agent-model.ts b/src/skillify/agent-model.ts
index ac6209d1..da640dd5 100644
--- a/src/skillify/agent-model.ts
+++ b/src/skillify/agent-model.ts
@@ -146,6 +146,7 @@ export function agentModel(opts: {
     const child = spawnFn(bin, args, {
       stdio: ["ignore", "pipe", "pipe"],
       env: { ...env, HIVEMIND_CAPTURE: "false", HIVEMIND_WIKI_WORKER: "1" },
+      windowsHide: true,
     });
     let out = "";
     let err = "";
diff --git a/src/skillify/claude-model.ts b/src/skillify/claude-model.ts
index 34ea08e6..1cab05b3 100644
--- a/src/skillify/claude-model.ts
+++ b/src/skillify/claude-model.ts
@@ -36,6 +36,10 @@ export function claudeModel(model: string, opts: { timeoutMs?: number } = {}): M
     const child = spawn(findAgentBin("claude_code"), args, {
       stdio: ["ignore", "pipe", "pipe"],
       env: { ...process.env, HIVEMIND_CAPTURE: "false", HIVEMIND_WIKI_WORKER: "1" },
+      // CREATE_NO_WINDOW: the skillopt engine's judge/proposer steps run inside
+      // the detached, console-less skillopt/mine-local worker, so without it
+      // Windows pops a visible console window for the claude child. No-op on POSIX.
+      windowsHide: true,
     });
     let out = "";
     let err = "";
diff --git a/src/skillify/gate-runner.ts b/src/skillify/gate-runner.ts
index be2c462a..8c60726c 100644
--- a/src/skillify/gate-runner.ts
+++ b/src/skillify/gate-runner.ts
@@ -200,6 +200,9 @@ export function runGate(opts: GateRunOptions): GateRunResult {
   try {
     const result = runChildProcess(bin, args, {
       stdio: ["ignore", "pipe", "pipe"],
+      // Suppress the visible console window Windows would otherwise pop for
+      // a child of the console-less detached skillify worker. No-op on POSIX.
+      windowsHide: true,
       timeout: opts.timeoutMs ?? 120_000,
       maxBuffer: 8 * 1024 * 1024,
       env: { ...inheritedEnv.env, HIVEMIND_WIKI_WORKER: "1", HIVEMIND_CAPTURE: "false" },
diff --git a/src/skillify/stage-memory.ts b/src/skillify/stage-memory.ts
index 7efd1c8b..5b3013de 100644
--- a/src/skillify/stage-memory.ts
+++ b/src/skillify/stage-memory.ts
@@ -95,6 +95,11 @@ export interface ClaudeSpawnPlan {
   shell: boolean;
   /** Prompt to write to stdin, or null when it's passed as a positional arg. */
   stdinInput: string | null;
+  /**
+   * CREATE_NO_WINDOW: this worker is detached and console-less, so without it
+   * Windows pops a visible console window for the claude child. No-op on POSIX.
+   */
+  windowsHide: boolean;
 }
 
 /**
@@ -115,6 +120,7 @@ export function planClaudeSpawn(inv: ReturnType<typeof buildClaudeInvocation>):
     stdio: [stdinInput !== null ? "pipe" : "ignore", "ignore", "ignore"],
     shell,
     stdinInput,
+    windowsHide: inv.options.windowsHide === true,
   };
 }
 
@@ -132,6 +138,7 @@ function runClaude(claudeBin: string, prompt: string, timeoutMs: number): Promis
       env: { ...process.env, HIVEMIND_WIKI_WORKER: "1", HIVEMIND_CAPTURE: "false" },
       timeout: timeoutMs,
       shell: plan.shell,
+      windowsHide: plan.windowsHide,
     });
     child.on("error", () => resolve(false));
     if (plan.stdinInput !== null) child.stdin?.end(plan.stdinInput);
diff --git a/tests/claude-code/inner-cli-spawn-windowshide-source.test.ts b/tests/claude-code/inner-cli-spawn-windowshide-source.test.ts
new file mode 100644
index 00000000..3159c3c9
--- /dev/null
+++ b/tests/claude-code/inner-cli-spawn-windowshide-source.test.ts
@@ -0,0 +1,47 @@
+import { describe, expect, it } from "vitest";
+import { readFileSync } from "node:fs";
+import { join } from "node:path";
+
+/**
+ * Source-level guards for the inner summarizer-CLI spawns that do NOT go
+ * through the wiki-worker-spawn builders (those are unit-asserted in
+ * wiki-worker-windows.test.ts). Every one of these runs inside a detached,
+ * console-less worker, so without `windowsHide: true` Windows pops a visible
+ * console window for the claude/codex child. These call sites `spawn`/
+ * `execFileSync` a real binary, so a unit test cannot observe the options
+ * object — hence the scoped source guard (same approach as the hermes
+ * wiki-worker and skillify gate-runner guards).
+ *
+ * Each regex ties `windowsHide: true` to the specific spawn/exec call
+ * ([^)]* = no closing paren between the call open and the option) so the guard
+ * fails if the option ever drifts out of that spawn.
+ */
+function src(rel: string): string {
+  return readFileSync(join(process.cwd(), rel), "utf-8");
+}
+
+describe("inner CLI spawn windowsHide — source guards", () => {
+  it("mine-local worker spawns the summarizer claude -p with windowsHide", () => {
+    expect(src("src/commands/mine-local.ts")).toMatch(/spawn\(\s*opts\.bin[^)]*windowsHide:\s*true/);
+  });
+
+  it("advisor gate spawns claude with windowsHide", () => {
+    expect(src("src/skillify/advisor.ts")).toMatch(/spawn\(\s*claudeBin[^)]*windowsHide:\s*true/);
+  });
+
+  it("claude-model judge/proposer spawn passes windowsHide", () => {
+    expect(src("src/skillify/claude-model.ts")).toMatch(/spawn\(\s*findAgentBin\([^;]*windowsHide:\s*true/);
+  });
+
+  it("commit-kpi-extract detached CLI spawn passes windowsHide", () => {
+    expect(src("src/hooks/commit-kpi-extract.ts")).toMatch(/spawn\(\s*cli\.bin[^)]*windowsHide:\s*true/);
+  });
+
+  it("stage-memory threads windowsHide from the invocation into the spawn plan and spawn call", () => {
+    const s = src("src/skillify/stage-memory.ts");
+    // plan carries it through from the builder's options...
+    expect(s).toMatch(/windowsHide:\s*inv\.options\.windowsHide\s*===\s*true/);
+    // ...and the spawn call applies it.
+    expect(s).toMatch(/spawn\(\s*plan\.file[^)]*windowsHide:\s*plan\.windowsHide/);
+  });
+});
diff --git a/tests/claude-code/skillify-gate-runner.test.ts b/tests/claude-code/skillify-gate-runner.test.ts
index 9a477d85..e0b7984f 100644
--- a/tests/claude-code/skillify-gate-runner.test.ts
+++ b/tests/claude-code/skillify-gate-runner.test.ts
@@ -1,5 +1,5 @@
 import { describe, expect, it, beforeEach, afterEach } from "vitest";
-import { mkdtempSync, writeFileSync, chmodSync, rmSync } from "node:fs";
+import { mkdtempSync, writeFileSync, chmodSync, rmSync, readFileSync } from "node:fs";
 import { tmpdir } from "node:os";
 import { join } from "node:path";
 import { runGate, buildArgs, findAgentBin, type Agent } from "../../src/skillify/gate-runner.js";
@@ -33,6 +33,19 @@ describe.skipIf(process.platform === "win32")("runGate spawn (POSIX)", () => {
   });
 });
 
+describe("gate-runner spawn options", () => {
+  it("passes windowsHide so the gate CLI never pops a console window on Windows", () => {
+    // The skillify worker is detached and console-less; without windowsHide
+    // on the inner CLI spawn, Windows allocates a visible console window.
+    // Source-level guard because the dispatch tests exec a real /usr/bin/echo
+    // and can't observe the options object.
+    // Scoped to the runChildProcess call ([^)]* = no closing paren in
+    // between) so the guard fails if the option drifts out of the spawn.
+    const src = readFileSync(join(process.cwd(), "src/skillify/gate-runner.ts"), "utf-8");
+    expect(src).toMatch(/runChildProcess\([^)]*windowsHide:\s*true/);
+  });
+});
+
 describe("findAgentBin", () => {
   it("returns a path for each known agent (PATH lookup or fallback)", () => {
     for (const agent of ["claude_code", "codex", "cursor", "hermes", "pi"] as Agent[]) {
diff --git a/tests/claude-code/wiki-worker-windows.test.ts b/tests/claude-code/wiki-worker-windows.test.ts
index e35ee39e..90219e53 100644
--- a/tests/claude-code/wiki-worker-windows.test.ts
+++ b/tests/claude-code/wiki-worker-windows.test.ts
@@ -184,3 +184,49 @@ describe("buildTrailingPromptInvocation (codex / cursor / pi)", () => {
     expect(inv.args).toEqual([...FLAGS, "PROMPT-TEXT"]);
   });
 });
+
+describe("windowsHide — no visible console window for the summarizer CLI", () => {
+  // The wiki worker is spawned detached and console-less (spawn-detached.ts
+  // sets windowsHide on the worker itself). Without CREATE_NO_WINDOW on the
+  // INNER spawn too, Windows allocates a fresh visible console window titled
+  // after the CLI exe (users reported a bare "claude.exe" window popping up).
+  it("buildClaudeInvocation sets windowsHide on every branch", () => {
+    setPlatform("win32");
+    expect(buildClaudeInvocation("C:\\npm\\claude.cmd", "P").options.windowsHide).toBe(true);
+    expect(buildClaudeInvocation("C:\\pf\\claude.exe", "P").options.windowsHide).toBe(true);
+    setPlatform("linux");
+    expect(buildClaudeInvocation("/usr/local/bin/claude", "P").options.windowsHide).toBe(true);
+  });
+
+  it("buildTrailingPromptInvocation sets windowsHide on every branch", () => {
+    const FLAGS = ["exec"];
+    setPlatform("win32");
+    expect(buildTrailingPromptInvocation("C:\\npm\\codex.cmd", FLAGS, "P").options.windowsHide).toBe(true);
+    expect(buildTrailingPromptInvocation("C:\\pf\\codex.exe", FLAGS, "P").options.windowsHide).toBe(true);
+    setPlatform("linux");
+    expect(buildTrailingPromptInvocation("/usr/local/bin/codex", FLAGS, "P").options.windowsHide).toBe(true);
+  });
+
+  // buildStdinPromptInvocation feeds whole-file prompts over stdin for the doc
+  // REFRESH/GENERATE path (refresh-llm.ts runHostPrompt execFileSyncs it), so
+  // it is another inner summarizer-CLI spawn that must not pop a console window.
+  it("buildStdinPromptInvocation sets windowsHide on the .cmd (shell) branch", () => {
+    setPlatform("win32");
+    expect(buildStdinPromptInvocation("C:\\npm\\codex.cmd", ["-"], "P").options.windowsHide).toBe(true);
+    expect(buildStdinPromptInvocation("C:\\npm\\codex.cmd", ["-"], "P").options.shell).toBe(true);
+  });
+
+  it("buildStdinPromptInvocation sets windowsHide on the .exe / Unix branch", () => {
+    setPlatform("win32");
+    expect(buildStdinPromptInvocation("C:\\pf\\codex.exe", ["-"], "P").options.windowsHide).toBe(true);
+    setPlatform("linux");
+    expect(buildStdinPromptInvocation("/usr/local/bin/codex", ["-"], "P").options.windowsHide).toBe(true);
+  });
+
+  it("buildClaudeStdinInvocation inherits windowsHide from the stdin builder", () => {
+    setPlatform("win32");
+    expect(buildClaudeStdinInvocation("C:\\npm\\claude.cmd", "P").options.windowsHide).toBe(true);
+    setPlatform("linux");
+    expect(buildClaudeStdinInvocation("/usr/local/bin/claude", "P").options.windowsHide).toBe(true);
+  });
+});
diff --git a/tests/hermes/hermes-wiki-worker-source.test.ts b/tests/hermes/hermes-wiki-worker-source.test.ts
index c36b82f1..68151f30 100644
--- a/tests/hermes/hermes-wiki-worker-source.test.ts
+++ b/tests/hermes/hermes-wiki-worker-source.test.ts
@@ -26,6 +26,14 @@ describe("hermes wiki-worker source", () => {
     expect(WORKER_SRC).not.toMatch(/"--dangerously-bypass-approvals-and-sandbox"/);
   });
 
+  it("hermes spawn passes windowsHide (no visible console window on Windows)", () => {
+    // hermes is the only worker that calls execFileSync directly instead of
+    // going through the wiki-worker-spawn builders, so it needs its own guard.
+    // Scoped to the hermesBin call ([^)]* = no closing paren in between) so
+    // the guard fails if the option drifts out of the spawn.
+    expect(WORKER_SRC).toMatch(/execFileSync\(\s*cfg\.hermesBin[^)]*windowsHide:\s*true/);
+  });
+
   it("config carries hermesBin + hermesProvider + hermesModel (not codexBin)", () => {
     expect(WORKER_SRC).toContain("hermesBin: string");
     expect(WORKER_SRC).toContain("hermesProvider: string");
diff --git a/tests/shared/agent-model.test.ts b/tests/shared/agent-model.test.ts
index 7995d2ea..5dc4409f 100644
--- a/tests/shared/agent-model.test.ts
+++ b/tests/shared/agent-model.test.ts
@@ -4,9 +4,9 @@ import { agentModel, detectScorerAgent } from "../../src/skillify/agent-model.js
 
 /** A fake child process that emits `stdout` then closes with `code`, and records argv. */
 function fakeSpawn(stdout: string, code = 0) {
-  const calls: Array<{ bin: string; args: string[]; env: Record<string, unknown> }> = [];
+  const calls: Array<{ bin: string; args: string[]; env: Record<string, unknown>; opts: Record<string, unknown> }> = [];
   const spawnImpl = (bin: string, args: string[], opts: Record<string, unknown>) => {
-    calls.push({ bin, args, env: (opts.env as Record<string, unknown>) ?? {} });
+    calls.push({ bin, args, env: (opts.env as Record<string, unknown>) ?? {}, opts });
     const child = new EventEmitter() as EventEmitter & { stdout: EventEmitter; stderr: EventEmitter; kill: () => void };
     child.stdout = new EventEmitter();
     child.stderr = new EventEmitter();
@@ -32,6 +32,8 @@ describe("agentModel — per-agent no-tools dispatch", () => {
     // isolation env always set
     expect(calls[0].env.HIVEMIND_CAPTURE).toBe("false");
     expect(calls[0].env.HIVEMIND_WIKI_WORKER).toBe("1");
+    // no console window on Windows: the scorer runs inside a detached worker
+    expect(calls[0].opts.windowsHide).toBe(true);
   });
 
   it("claude_code proposer defaults to a capable model (sonnet)", async () => {