diff --git a/CHANGELOG.md b/CHANGELOG.md
index defd9a24..2bce40e1 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -7,6 +7,10 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 ## [Unreleased]
 
+### Added
+
+- **Personal memory now has an always-on retention schedule.** Previously, personal-memory decay and cleanup ran only via manual REST calls or user-enabled triggers — there was no default daily enforcement (unlike the autonomous Claw runtime, which already trims its own tables daily). A new daily scheduler runs importance decay + dead-memory cleanup automatically. It is pure hygiene — no LLM calls, no conversation extraction, no semantic consolidation — and only removes already-dead entries (importance below 0.1, older than 90 days, and untouched for 90 days), so it runs by default while the LLM-driven `memory_extract` / `memory_consolidate` triggers stay opt-in. Cleanup (an idempotent delete) runs on startup and daily; the compounding decay step runs only on the daily tick, so it stays independent of how often the process restarts.
+
 ### Fixed
 
 - **UI shipped unstyled when the Tailwind native scanner fell back to WASM.** Tailwind v4 scans sources with the native `@tailwindcss/oxide` addon; when its platform binary fails to load (a corrupt `@tailwindcss/oxide-win32-x64-msvc` install — missing `package.json` — on Windows), oxide silently falls back to its WASM build, which scans nothing and emits a utility-less ~13 KB stylesheet instead of ~250 KB, with no error. A new build-only `css-size-guard` Vite plugin now **fails the build** if total emitted CSS is under 80 KB, so this can never silently ship (including in Docker images) again.
diff --git a/packages/gateway/src/server.ts b/packages/gateway/src/server.ts
index dd71ac47..6dba8574 100644
--- a/packages/gateway/src/server.ts
+++ b/packages/gateway/src/server.ts
@@ -878,6 +878,16 @@ async function main() {
     log.warn('Autonomy Engine failed to start', { error: String(error) });
   }
 
+  // Start always-on personal-memory retention (daily decay + cleanup). Pure
+  // hygiene — no LLM, no conversation extraction — so it runs by default,
+  // unlike the opt-in memory_extract / memory_consolidate triggers.
+  try {
+    const { startMemoryRetention } = await import('./services/memory/retention.js');
+    startMemoryRetention('default');
+  } catch (error) {
+    log.warn('Memory retention scheduler failed to start', { error: String(error) });
+  }
+
   // Seed example plans (only creates if not already present)
   try {
     const planSeed = await seedExamplePlans('default');
@@ -1098,6 +1108,14 @@ async function main() {
       log.warn('Heartbeat service reset error', { error: String(e) });
     }
 
+    // 5.6c-mem. Stop the personal-memory retention scheduler
+    try {
+      const { stopMemoryRetention } = await import('./services/memory/retention.js');
+      stopMemoryRetention();
+    } catch (e) {
+      log.warn('Memory retention stop error', { error: String(e) });
+    }
+
     // 5.6d. Reset memory service
     try {
       const { resetMemoryService } = await import('./services/memory-service.js');
diff --git a/packages/gateway/src/services/memory/retention.test.ts b/packages/gateway/src/services/memory/retention.test.ts
new file mode 100644
index 00000000..0f05e9e6
--- /dev/null
+++ b/packages/gateway/src/services/memory/retention.test.ts
@@ -0,0 +1,120 @@
+/**
+ * Memory retention scheduler tests — mocks the MemoryService and the logger,
+ * uses fake timers to assert the boot pass vs. daily-tick cadence.
+ */
+
+import { describe, it, expect, vi, beforeEach, afterEach } from 'vitest';
+
+const { mockService } = vi.hoisted(() => {
+  const mockService = {
+    decayMemories: vi.fn(async () => 0),
+    cleanupMemories: vi.fn(async () => 0),
+  };
+  return { mockService };
+});
+
+vi.mock('../memory-service.js', () => ({
+  getMemoryService: () => mockService,
+}));
+
+vi.mock('../log.js', () => ({
+  getLog: () => ({ info: vi.fn(), warn: vi.fn(), debug: vi.fn(), error: vi.fn() }),
+}));
+
+vi.mock('@ownpilot/core', () => ({
+  getErrorMessage: (e: unknown) => (e instanceof Error ? e.message : String(e)),
+}));
+
+const { runMemoryRetentionCleanup, startMemoryRetention, stopMemoryRetention } =
+  await import('./retention.js');
+
+const DAY_MS = 24 * 60 * 60 * 1000;
+
+beforeEach(() => {
+  vi.clearAllMocks();
+});
+
+afterEach(() => {
+  stopMemoryRetention();
+  vi.useRealTimers();
+});
+
+describe('runMemoryRetentionCleanup', () => {
+  it('runs decay then cleanup by default', async () => {
+    await runMemoryRetentionCleanup('default');
+    expect(mockService.decayMemories).toHaveBeenCalledWith('default');
+    expect(mockService.cleanupMemories).toHaveBeenCalledWith('default');
+  });
+
+  it('skips decay when { decay: false }', async () => {
+    await runMemoryRetentionCleanup('default', { decay: false });
+    expect(mockService.decayMemories).not.toHaveBeenCalled();
+    expect(mockService.cleanupMemories).toHaveBeenCalledTimes(1);
+  });
+
+  it('still runs cleanup when decay throws', async () => {
+    mockService.decayMemories.mockRejectedValueOnce(new Error('boom'));
+    await runMemoryRetentionCleanup('default');
+    expect(mockService.cleanupMemories).toHaveBeenCalledTimes(1);
+  });
+
+  it('never throws when cleanup throws', async () => {
+    mockService.cleanupMemories.mockRejectedValueOnce(new Error('boom'));
+    await expect(runMemoryRetentionCleanup('default')).resolves.toBeUndefined();
+  });
+});
+
+describe('startMemoryRetention', () => {
+  it('runs a cleanup-only boot pass immediately (no decay)', async () => {
+    vi.useFakeTimers();
+    startMemoryRetention('default');
+    // Flush the microtask from the fire-and-forget boot pass.
+    await vi.advanceTimersByTimeAsync(0);
+    expect(mockService.cleanupMemories).toHaveBeenCalledTimes(1);
+    expect(mockService.decayMemories).not.toHaveBeenCalled();
+  });
+
+  it('runs a full decay + cleanup pass on the daily tick', async () => {
+    vi.useFakeTimers();
+    startMemoryRetention('default');
+    await vi.advanceTimersByTimeAsync(0); // boot pass
+    expect(mockService.decayMemories).not.toHaveBeenCalled();
+
+    await vi.advanceTimersByTimeAsync(DAY_MS);
+    expect(mockService.decayMemories).toHaveBeenCalledTimes(1);
+    // boot cleanup + daily cleanup
+    expect(mockService.cleanupMemories).toHaveBeenCalledTimes(2);
+  });
+
+  it('is idempotent — a second start does not schedule a second timer', async () => {
+    vi.useFakeTimers();
+    startMemoryRetention('default');
+    startMemoryRetention('default');
+    await vi.advanceTimersByTimeAsync(0);
+    // Only one boot pass despite two start calls.
+    expect(mockService.cleanupMemories).toHaveBeenCalledTimes(1);
+
+    await vi.advanceTimersByTimeAsync(DAY_MS);
+    // Only one daily decay despite two start calls.
+    expect(mockService.decayMemories).toHaveBeenCalledTimes(1);
+  });
+});
+
+describe('stopMemoryRetention', () => {
+  it('stops the timer so no further passes run', async () => {
+    vi.useFakeTimers();
+    startMemoryRetention('default');
+    await vi.advanceTimersByTimeAsync(0);
+    stopMemoryRetention();
+
+    await vi.advanceTimersByTimeAsync(DAY_MS * 3);
+    expect(mockService.decayMemories).not.toHaveBeenCalled();
+  });
+
+  it('is idempotent', () => {
+    expect(() => {
+      stopMemoryRetention();
+      stopMemoryRetention();
+    }).not.toThrow();
+  });
+});
diff --git a/packages/gateway/src/services/memory/retention.ts b/packages/gateway/src/services/memory/retention.ts
new file mode 100644
index 00000000..1b54b15f
--- /dev/null
+++ b/packages/gateway/src/services/memory/retention.ts
@@ -0,0 +1,93 @@
+/**
+ * Personal Memory Retention
+ *
+ * Always-on daily hygiene for personal memories, mirroring the Claw manager's
+ * retention timer for its system tables (services/claw/manager-helpers.ts).
+ *
+ * A full pass runs importance *decay* (ages out stale, unaccessed memories)
+ * followed by *cleanup* (deletes already-dead entries: importance < 0.1 AND
+ * older than the cutoff AND not accessed within it). This is pure retention —
+ * no LLM calls, no conversation extraction, no semantic consolidation — so it
+ * is safe to run by default without the privacy/cost concerns that keep the
+ * `memory_extract` / `memory_consolidate` triggers opt-in.
+ *
+ * Cadence note: `cleanup` is an idempotent DELETE (re-running deletes the same
+ * dead set once), so it runs on boot AND on the daily tick — short-lived /
+ * frequently-restarted processes still get their storage bounded. `decay` is a
+ * *compounding* UPDATE (importance *= 0.9), so it runs ONLY on the daily
+ * interval tick, never on the boot pass: this bounds decay to at most once per
+ * 24h of continuous uptime and keeps it independent of restart frequency (a
+ * dev process that restarts 20×/day must not decay a memory 20×).
+ */
+
+import { getErrorMessage } from '@ownpilot/core';
+import { getMemoryService } from '../memory-service.js';
+import { getLog } from '../log.js';
+
+const log = getLog('MemoryRetention');
+
+const CLEANUP_INTERVAL_MS = 24 * 60 * 60 * 1000; // once per day
+
+/** Owner whose memories are maintained in single-tenant mode. */
+const RETENTION_OWNER_ID = 'default';
+
+let retentionTimer: ReturnType<typeof setInterval> | null = null;
+
+/**
+ * Run one retention pass for the given owner. Never throws — each step is
+ * isolated so a decay failure still lets cleanup run, and so the daily timer
+ * keeps firing. Pass `{ decay: false }` for the boot pass to skip the
+ * compounding decay step (see cadence note above).
+ */
+export async function runMemoryRetentionCleanup(
+  userId: string = RETENTION_OWNER_ID,
+  options: { decay?: boolean } = {}
+): Promise<void> {
+  const { decay = true } = options;
+  const service = getMemoryService();
+
+  if (decay) {
+    try {
+      const decayed = await service.decayMemories(userId);
+      if (decayed > 0) log.info(`Decayed ${decayed} stale memories`);
+    } catch (err) {
+      log.warn(`Memory decay failed: ${getErrorMessage(err)}`);
+    }
+  }
+
+  try {
+    const cleaned = await service.cleanupMemories(userId);
+    if (cleaned > 0) log.info(`Cleaned up ${cleaned} dead memories`);
+  } catch (err) {
+    log.warn(`Memory cleanup failed: ${getErrorMessage(err)}`);
+  }
+}
+
+/**
+ * Start the always-on daily retention timer. Runs an immediate cleanup-only
+ * pass, then a full decay + cleanup pass once per day. Idempotent — a second
+ * call while already running is a no-op.
+ */
+export function startMemoryRetention(userId: string = RETENTION_OWNER_ID): void {
+  if (retentionTimer) return;
+
+  // Boot pass: cleanup only (idempotent), no compounding decay.
+  void runMemoryRetentionCleanup(userId, { decay: false });
+
+  retentionTimer = setInterval(() => {
+    void runMemoryRetentionCleanup(userId, { decay: true });
+  }, CLEANUP_INTERVAL_MS);
+  // Don't hold the process open just for this cleanup — Node should be free to
+  // exit when nothing else keeps the event loop alive (matches ClawManager).
+  retentionTimer.unref?.();
+
+  log.info('Memory retention scheduler started (daily decay + cleanup)');
+}
+
+/** Stop the retention timer (graceful shutdown / test teardown). Idempotent. */
+export function stopMemoryRetention(): void {
+  if (retentionTimer) {
+    clearInterval(retentionTimer);
+    retentionTimer = null;
+  }
+}