diff --git a/src/cli/cli.ts b/src/cli/cli.ts
index 1ece740..c8ab251 100644
--- a/src/cli/cli.ts
+++ b/src/cli/cli.ts
@@ -8,7 +8,8 @@ import { fileURLToPath } from 'node:url';
 import { readVersion } from './version.js';
 import { initBrain } from '../core/init.js';
 import { resolveBrainPath, brainExists } from '../core/config.js';
-import { MykbStore } from '../core/knowledge-store.js';
+import type { KnowledgeStore } from '../core/types.js';
+import { selectKnowledgeStore } from '../daemon/store-selection.js';
 import {
   createArea,
   listAreas,
@@ -50,13 +51,17 @@ function requireBrain(): string {
   return bp;
 }
 
-function withStore<T>(fn: (store: MykbStore) => T): T {
+function withStore<T>(fn: (store: KnowledgeStore) => T): T {
   const bp = requireBrain();
-  const store = MykbStore.open(bp);
+  // Contract §2.4: when the daemon is running the operator CLI must use
+  // the RPC store (else two writers race ~/.mykb); when it is not,
+  // LocalMykbStore is the direct-disk operator path. selectKnowledgeStore
+  // encodes exactly that policy.
+  const { store, close } = selectKnowledgeStore(bp);
   try {
     return fn(store);
   } finally {
-    store.close();
+    close();
   }
 }
 
@@ -824,7 +829,7 @@ workCmd
 
     // Build addKnowledge callback using the store
     const bp = requireBrain();
-    const store = MykbStore.open(bp);
+    const { store, close: closeStore } = selectKnowledgeStore(bp);
     const addKnowledge = (
       type: string,
       area: string,
@@ -846,7 +851,7 @@ workCmd
     };
 
     const result = storage.checkpoint(activeId, input, addKnowledge);
-    store.close();
+    closeStore();
 
     // Report
     const parts: string[] = [];
diff --git a/src/daemon/store-selection.ts b/src/daemon/store-selection.ts
index 80d98fc..2e5e347 100644
--- a/src/daemon/store-selection.ts
+++ b/src/daemon/store-selection.ts
@@ -30,6 +30,13 @@ export interface SelectedStore {
   store: KnowledgeStore;
   mode: StoreMode;
   socketPath?: string;
+  /**
+   * Release the underlying resource (local DB handle / RPC worker).
+   * `close()` is a lifecycle concern, deliberately NOT on the
+   * `KnowledgeStore` domain interface — the selection wrapper owns it so
+   * callers stay interface-pure.
+   */
+  close(): void;
 }
 
 function socketPathFor(brainPath: string): string {
@@ -40,15 +47,12 @@ export function selectKnowledgeStore(brainPath: string): SelectedStore {
   const forced = process.env.MYKB_STORE;
   const sock = socketPathFor(brainPath);
 
-  if (forced === 'local') {
-    return { store: MykbStore.open(brainPath), mode: 'local' };
-  }
-  if (forced === 'rpc') {
-    return { store: new RpcKnowledgeStore(sock), mode: 'rpc', socketPath: sock };
-  }
-  // Auto-detect: presence of the socket is the signal (§2.4).
-  if (fs.existsSync(sock)) {
-    return { store: new RpcKnowledgeStore(sock), mode: 'rpc', socketPath: sock };
+  const useRpc = forced === 'rpc' || (forced !== 'local' && fs.existsSync(sock));
+
+  if (useRpc) {
+    const store = new RpcKnowledgeStore(sock);
+    return { store, mode: 'rpc', socketPath: sock, close: () => store.close() };
   }
-  return { store: MykbStore.open(brainPath), mode: 'local' };
+  const store = MykbStore.open(brainPath);
+  return { store, mode: 'local', close: () => store.close() };
 }
diff --git a/tests/daemon/cli-over-daemon.scenario.test.ts b/tests/daemon/cli-over-daemon.scenario.test.ts
new file mode 100644
index 0000000..4ed411a
--- /dev/null
+++ b/tests/daemon/cli-over-daemon.scenario.test.ts
@@ -0,0 +1,96 @@
+import { describe, it, expect, beforeAll, afterEach } from 'vitest';
+import { spawn, spawnSync, execFileSync, type ChildProcess } from 'node:child_process';
+import { fileURLToPath } from 'node:url';
+import * as os from 'node:os';
+import * as path from 'node:path';
+import * as fs from 'node:fs';
+import { initBrain } from '../../src/core/init.js';
+
+// Phase 5 scenario — the genuinely new behaviour: the OPERATOR `kb` CLI,
+// when a daemon socket is present, routes its writes through the daemon
+// (contract §2.4: "when the daemon is running the operator CLI must use
+// RpcMykbStore", else two writers race ~/.mykb). The full CLI suite
+// already proves the local-fallback path (645/645 unchanged); this proves
+// the daemon path end-to-end through the real CLI binary.
+
+const repoRoot = path.resolve(fileURLToPath(import.meta.url), '../../..');
+const cliPath = path.join(repoRoot, 'dist', 'cli', 'cli.js');
+const daemonMain = path.join(repoRoot, 'dist', 'daemon', 'main.js');
+
+beforeAll(() => {
+  if (!fs.existsSync(cliPath) || !fs.existsSync(daemonMain)) {
+    execFileSync('npm', ['run', 'build'], { cwd: repoRoot, stdio: 'inherit' });
+  }
+}, 120_000);
+
+const procs: ChildProcess[] = [];
+afterEach(() => {
+  for (const p of procs.splice(0)) p.kill('SIGTERM');
+});
+
+function kb(
+  args: string[],
+  env: NodeJS.ProcessEnv,
+): { stdout: string; stderr: string; code: number } {
+  const r = spawnSync(process.execPath, [cliPath, ...args], {
+    env: { ...process.env, ...env },
+    encoding: 'utf-8',
+    timeout: 15000,
+  });
+  return {
+    stdout: r.stdout ?? '',
+    stderr: r.stderr ?? '',
+    code: r.status ?? 1,
+  };
+}
+
+describe('kb CLI over the daemon (§2.4 operator-CLI-uses-RPC)', () => {
+  it('a `kb add fact` write lands in the brain via the separate daemon process', async () => {
+    const dir = fs.mkdtempSync(path.join(os.tmpdir(), 'mykb-cli-daemon-'));
+    const brainPath = path.join(dir, 'brain');
+    fs.mkdirSync(brainPath);
+    initBrain(brainPath);
+    const socketPath = path.join(dir, 'd.sock');
+
+    // Daemon owns the brain on disk (separate process — real topology).
+    const daemon = spawn(process.execPath, [daemonMain], {
+      env: { ...process.env, MYKB_DIR: brainPath, MYKB_SOCKET: socketPath },
+      stdio: ['ignore', 'ignore', 'pipe'],
+    });
+    procs.push(daemon);
+    await new Promise<void>((resolve, reject) => {
+      const t = setTimeout(() => reject(new Error('daemon did not start')), 20_000);
+      const tick = setInterval(() => {
+        if (fs.existsSync(socketPath)) {
+          clearInterval(tick);
+          clearTimeout(t);
+          resolve();
+        }
+      }, 50);
+      daemon.on('error', reject);
+    });
+
+    const env = { MYKB_DIR: brainPath, MYKB_SOCKET: socketPath };
+    delete (env as NodeJS.ProcessEnv).KB_SESSION_ID;
+
+    // init area is the operator direct-disk path (fine — same brain dir).
+    const init = kb(['init', 'area', 'docker', 'Docker', 'containers'], env);
+    expect(init.code).toBe(0);
+
+    // The socket is present → selectKnowledgeStore picks RpcKnowledgeStore;
+    // this write necessarily travels CLI → socket → daemon → disk.
+    const add = kb(['add', 'fact', 'docker', 'cgroups isolate processes'], env);
+    expect(add.code).toBe(0);
+
+    // Prove persistence by reading the JSONL the DAEMON wrote (the CLI
+    // process never touched the file — it only spoke to the socket).
+    const factsFile = path.join(brainPath, 'areas', 'docker', 'facts.jsonl');
+    const facts = fs.readFileSync(factsFile, 'utf-8');
+    expect(facts).toContain('cgroups isolate processes');
+
+    // And a read-path verb round-trips through the daemon too.
+    const load = kb(['load', 'docker'], env);
+    expect(load.code).toBe(0);
+    expect(load.stdout).toContain('cgroups isolate processes');
+  });
+});