diff --git a/tests/api/regression-websocket.test.js b/tests/api/regression-websocket.test.js
new file mode 100644
index 0000000..1150201
--- /dev/null
+++ b/tests/api/regression-websocket.test.js
@@ -0,0 +1,153 @@
+const WebSocket = require('ws');
+const request = require('supertest');
+const { app, server } = require('../../backend/server');
+const { getAuthToken, getAuthHeader, cleanDb, seedGame, seedSession } = require('../helpers/test-utils');
+
+function connectWs() {
+  return new WebSocket(`ws://localhost:${server.address().port}/api/sessions/live`);
+}
+
+function waitForMessage(ws, type, timeoutMs = 3000) {
+  return new Promise((resolve, reject) => {
+    const timeout = setTimeout(() => reject(new Error(`Timeout waiting for ${type}`)), timeoutMs);
+    ws.on('message', function handler(data) {
+      const msg = JSON.parse(data.toString());
+      if (msg.type === type) {
+        clearTimeout(timeout);
+        ws.removeListener('message', handler);
+        resolve(msg);
+      }
+    });
+  });
+}
+
+function authenticateAndSubscribe(ws, sessionId) {
+  return new Promise(async (resolve, reject) => {
+    try {
+      ws.send(JSON.stringify({ type: 'auth', token: getAuthToken() }));
+      await waitForMessage(ws, 'auth_success');
+      ws.send(JSON.stringify({ type: 'subscribe', sessionId }));
+      await waitForMessage(ws, 'subscribed');
+      resolve();
+    } catch (err) {
+      reject(err);
+    }
+  });
+}
+
+beforeAll((done) => {
+  server.listen(0, () => done());
+});
+
+afterAll((done) => {
+  server.close(done);
+});
+
+describe('WebSocket events (regression)', () => {
+  beforeEach(() => {
+    cleanDb();
+  });
+
+  test('auth flow: auth -> auth_success', (done) => {
+    const ws = connectWs();
+    ws.on('open', () => {
+      ws.send(JSON.stringify({ type: 'auth', token: getAuthToken() }));
+    });
+    ws.on('message', (data) => {
+      const msg = JSON.parse(data.toString());
+      if (msg.type === 'auth_success') {
+        ws.close();
+        done();
+      }
+    });
+  });
+
+  test('subscribe/unsubscribe flow', async () => {
+    const session = seedSession({ is_active: 1 });
+    const ws = connectWs();
+    await new Promise((resolve) => ws.on('open', resolve));
+
+    ws.send(JSON.stringify({ type: 'auth', token: getAuthToken() }));
+    await waitForMessage(ws, 'auth_success');
+
+    ws.send(JSON.stringify({ type: 'subscribe', sessionId: session.id }));
+    const subMsg = await waitForMessage(ws, 'subscribed');
+    expect(subMsg.sessionId).toBe(session.id);
+
+    ws.send(JSON.stringify({ type: 'unsubscribe', sessionId: session.id }));
+    const unsubMsg = await waitForMessage(ws, 'unsubscribed');
+    expect(unsubMsg.sessionId).toBe(session.id);
+
+    ws.close();
+  });
+
+  test('session.started broadcasts to all authenticated clients', async () => {
+    const ws = connectWs();
+    await new Promise((resolve) => ws.on('open', resolve));
+
+    ws.send(JSON.stringify({ type: 'auth', token: getAuthToken() }));
+    await waitForMessage(ws, 'auth_success');
+
+    const eventPromise = waitForMessage(ws, 'session.started');
+
+    await request(app)
+      .post('/api/sessions')
+      .set('Authorization', getAuthHeader())
+      .set('Content-Type', 'application/json')
+      .send({ notes: 'Test session' });
+
+    const event = await eventPromise;
+    expect(event.data.session).toEqual(
+      expect.objectContaining({
+        is_active: 1,
+        notes: 'Test session',
+      })
+    );
+
+    ws.close();
+  });
+
+  test('session.ended broadcasts to session subscribers', async () => {
+    const session = seedSession({ is_active: 1 });
+    const ws = connectWs();
+    await new Promise((resolve) => ws.on('open', resolve));
+
+    await authenticateAndSubscribe(ws, session.id);
+
+    const eventPromise = waitForMessage(ws, 'session.ended');
+
+    await request(app)
+      .post(`/api/sessions/${session.id}/close`)
+      .set('Authorization', getAuthHeader())
+      .set('Content-Type', 'application/json');
+
+    const event = await eventPromise;
+    expect(event.data.session.id).toBe(session.id);
+    expect(event.data.session.is_active).toBe(0);
+
+    ws.close();
+  });
+
+  test('game.added broadcasts to session subscribers', async () => {
+    const game = seedGame({ title: 'Quiplash 3', pack_name: 'Party Pack 7' });
+    const session = seedSession({ is_active: 1 });
+    const ws = connectWs();
+    await new Promise((resolve) => ws.on('open', resolve));
+
+    await authenticateAndSubscribe(ws, session.id);
+
+    const eventPromise = waitForMessage(ws, 'game.added');
+
+    await request(app)
+      .post(`/api/sessions/${session.id}/games`)
+      .set('Authorization', getAuthHeader())
+      .set('Content-Type', 'application/json')
+      .send({ game_id: game.id });
+
+    const event = await eventPromise;
+    expect(event.data.game.title).toBe('Quiplash 3');
+    expect(event.data.session.id).toBe(session.id);
+
+    ws.close();
+  });
+});