diff --git a/src/App.tsx b/src/App.tsx
index 4f223e4..48722d5 100644
--- a/src/App.tsx
+++ b/src/App.tsx
@@ -59,7 +59,7 @@ export default function App() {
 
   const handleLogout = useCallback(async () => {
     try {
-      await fetch('/api/auth/dev-logout', { method: 'POST', credentials: 'include' });
+      await fetch('/api/auth/logout', { method: 'POST', credentials: 'include' });
     } catch {
       // Ignore — cookie clear is best-effort
     }
diff --git a/tests/auth-api.test.ts b/tests/auth-api.test.ts
index 95b17b4..9535398 100644
--- a/tests/auth-api.test.ts
+++ b/tests/auth-api.test.ts
@@ -283,6 +283,36 @@ describe('GET /api/auth/me', () => {
     expect(db.firstCalls).toHaveLength(0);
   });
 
+  it('POST /api/auth/logout clears the shared session cookie outside local dev', async () => {
+    const db = new FakeAuthD1();
+    const env = makeEnv(db, {
+      PUBLIC_HOST: 'dev.heygo.cc',
+      PRIVATE_HOST: 'my.dev.heygo.cc',
+      APP_BASE_URL: 'https://dev.heygo.cc',
+      COOKIE_DOMAIN: '.heygo.cc',
+    });
+
+    const response = await fetchWorker('/api/auth/logout', env, { method: 'POST' });
+
+    expect(response.status).toBe(200);
+    expect(await response.json()).toEqual({ ok: true });
+    const setCookie = response.headers.get('set-cookie');
+    expect(setCookie).toContain(`${AUTH_SESSION_COOKIE_NAME}=;`);
+    expect(setCookie).toContain('Expires=Thu, 01 Jan 1970 00:00:00 GMT');
+    expect(setCookie).toContain('Domain=.heygo.cc');
+    expect(setCookie).toContain('HttpOnly');
+    expect(response.headers.get('cache-control')).toBe('no-store');
+  });
+
+  it('rejects GET /api/auth/logout with 405', async () => {
+    const db = new FakeAuthD1();
+    const env = makeEnv(db);
+
+    const response = await fetchWorker('/api/auth/logout', env, { method: 'GET' });
+
+    expect(response.status).toBe(405);
+  });
+
   it('falls through (returns null) for non-matching paths so the worker 404s', async () => {
     const db = new FakeAuthD1();
     const env = makeEnv(db);
diff --git a/worker/routes/api.auth.ts b/worker/routes/api.auth.ts
index 946742e..7e95a4a 100644
--- a/worker/routes/api.auth.ts
+++ b/worker/routes/api.auth.ts
@@ -1,9 +1,28 @@
-import { getCurrentUser } from '../auth';
+import { AUTH_SESSION_COOKIE_NAME, getCurrentUser, getSessionCookieAttributes } from '../auth';
 import type { Env } from '../env';
 
 export async function handleAuthApi(request: Request, env: Env): Promise<Response | null> {
   const url = new URL(request.url);
 
+  if (url.pathname === '/api/auth/logout') {
+    if (request.method !== 'POST') {
+      return Response.json({ error: 'Method not allowed' }, { status: 405 });
+    }
+
+    const cookieAttrs = getSessionCookieAttributes(request.url, env.COOKIE_DOMAIN);
+    const expired = new Date(0).toUTCString();
+    const cookieValue = `${AUTH_SESSION_COOKIE_NAME}=; Expires=${expired}; ${cookieAttrs.join('; ')}`;
+    return Response.json(
+      { ok: true },
+      {
+        headers: {
+          'Set-Cookie': cookieValue,
+          'Cache-Control': 'no-store',
+        },
+      },
+    );
+  }
+
   if (url.pathname !== '/api/auth/me') {
     return null;
   }