feat: add OAuth routes for Google, GitHub, and Apple login

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

packages/server/src/index.ts

@@ -1,6 +1,7 @@
 import express from 'express';
 import cors from 'cors';
 import authRouter from './routes/auth.js';
+import oauthRouter from './routes/oauth.js';
 import projectRouter from './routes/projects.js';
 import importRouter from './routes/import.js';
 import moduleRouter from './routes/modules.js';
@@ -9,12 +10,14 @@ import endpointRouter from './routes/endpoints.js';
 const app = express();
 app.use(cors());
 app.use(express.json({ limit: '10mb' }));
+app.use(express.urlencoded({ extended: true }));
 
 app.get('/api/health', (_req, res) => {
   res.json({ success: true, data: { status: 'ok' } });
 });
 
 app.use('/api/auth', authRouter);
+app.use('/api/auth/oauth', oauthRouter);
 app.use('/api/projects', projectRouter);
 app.use('/api/projects', importRouter);
 app.use('/api/projects', moduleRouter);

packages/server/src/routes/oauth.ts

@@ -0,0 +1,152 @@
+import { Router, type Router as RouterType } from 'express';
+import { prisma } from '@agent-fox/shared';
+import { generateTokenPair } from '../lib/jwt.js';
+import { buildAuthUrl, exchangeCodeForToken, fetchProviderUser, validateState } from '../lib/oauth-providers.js';
+
+const router: RouterType = Router();
+
+const VALID_PROVIDERS = ['google', 'github', 'apple'];
+const FRONTEND_URL = process.env.FRONTEND_URL || 'http://localhost:5173';
+
+// GET /auth/oauth/:provider — redirect to provider's authorization page
+router.get('/:provider', (req, res) => {
+  const { provider } = req.params;
+  if (!VALID_PROVIDERS.includes(provider)) {
+    res.status(400).json({ success: false, error: { code: 'INVALID_PROVIDER', message: `Unknown provider: ${provider}` } });
+    return;
+  }
+
+  try {
+    const url = buildAuthUrl(provider);
+    res.redirect(url);
+  } catch (err) {
+    res.status(500).json({ success: false, error: { code: 'OAUTH_ERROR', message: err instanceof Error ? err.message : 'Failed to build auth URL' } });
+  }
+});
+
+// GET /auth/oauth/:provider/callback — handle provider callback
+router.get('/:provider/callback', async (req, res) => {
+  const { provider } = req.params;
+  const { code, state, error: oauthError } = req.query as Record<string, string>;
+
+  if (oauthError) {
+    res.redirect(`${FRONTEND_URL}/login/callback?error=${encodeURIComponent(oauthError)}`);
+    return;
+  }
+
+  if (!code || !state) {
+    res.redirect(`${FRONTEND_URL}/login/callback?error=${encodeURIComponent('Missing code or state')}`);
+    return;
+  }
+
+  if (!validateState(state, provider)) {
+    res.redirect(`${FRONTEND_URL}/login/callback?error=${encodeURIComponent('Invalid or expired state')}`);
+    return;
+  }
+
+  try {
+    const token = await exchangeCodeForToken(provider, code);
+    const providerUser = await fetchProviderUser(provider, token);
+    if (!providerUser.email) {
+      res.redirect(`${FRONTEND_URL}/login/callback?error=${encodeURIComponent('No email returned from provider')}`);
+      return;
+    }
+
+    const user = await findOrCreateUser(provider, providerUser);
+    const tokens = generateTokenPair({ userId: user.id, email: user.email });
+
+    res.redirect(`${FRONTEND_URL}/login/callback?accessToken=${tokens.accessToken}&refreshToken=${tokens.refreshToken}`);
+  } catch (err) {
+    console.error(`OAuth callback error (${provider}):`, err);
+    res.redirect(`${FRONTEND_URL}/login/callback?error=${encodeURIComponent('Authentication failed')}`);
+  }
+});
+
+// Apple sends callback as POST (form_post response mode)
+router.post('/:provider/callback', async (req, res) => {
+  const { provider } = req.params;
+  const { code, state, error: oauthError } = req.body;
+
+  if (oauthError) {
+    res.redirect(`${FRONTEND_URL}/login/callback?error=${encodeURIComponent(oauthError)}`);
+    return;
+  }
+
+  if (!code || !state) {
+    res.redirect(`${FRONTEND_URL}/login/callback?error=${encodeURIComponent('Missing code or state')}`);
+    return;
+  }
+
+  if (!validateState(state, provider)) {
+    res.redirect(`${FRONTEND_URL}/login/callback?error=${encodeURIComponent('Invalid or expired state')}`);
+    return;
+  }
+
+  try {
+    const token = await exchangeCodeForToken(provider, code);
+    const providerUser = await fetchProviderUser(provider, token);
+    if (!providerUser.email) {
+      res.redirect(`${FRONTEND_URL}/login/callback?error=${encodeURIComponent('No email returned from provider')}`);
+      return;
+    }
+
+    const user = await findOrCreateUser(provider, providerUser);
+    const tokens = generateTokenPair({ userId: user.id, email: user.email });
+
+    res.redirect(`${FRONTEND_URL}/login/callback?accessToken=${tokens.accessToken}&refreshToken=${tokens.refreshToken}`);
+  } catch (err) {
+    console.error(`OAuth POST callback error (${provider}):`, err);
+    res.redirect(`${FRONTEND_URL}/login/callback?error=${encodeURIComponent('Authentication failed')}`);
+  }
+});
+
+async function findOrCreateUser(
+  provider: string,
+  providerUser: { id: string; email: string; name: string; avatarUrl: string | null },
+) {
+  // 1. Check existing OAuthAccount
+  const existingOAuth = await prisma.oAuthAccount.findUnique({
+    where: { provider_providerAccountId: { provider, providerAccountId: providerUser.id } },
+    include: { user: true },
+  });
+  if (existingOAuth) {
+    if (providerUser.avatarUrl && providerUser.avatarUrl !== existingOAuth.user.avatarUrl) {
+      await prisma.user.update({
+        where: { id: existingOAuth.user.id },
+        data: { avatarUrl: providerUser.avatarUrl },
+      });
+    }
+    return existingOAuth.user;
+  }
+
+  // 2. Check existing user by email — link OAuth account
+  const existingUser = await prisma.user.findUnique({ where: { email: providerUser.email } });
+  if (existingUser) {
+    await prisma.oAuthAccount.create({
+      data: { userId: existingUser.id, provider, providerAccountId: providerUser.id },
+    });
+    if (providerUser.avatarUrl && !existingUser.avatarUrl) {
+      await prisma.user.update({
+        where: { id: existingUser.id },
+        data: { avatarUrl: providerUser.avatarUrl },
+      });
+    }
+    return existingUser;
+  }
+
+  // 3. Create new user + OAuth account
+  const newUser = await prisma.user.create({
+    data: {
+      email: providerUser.email,
+      name: providerUser.name,
+      avatarUrl: providerUser.avatarUrl,
+      passwordHash: null,
+      oauthAccounts: {
+        create: { provider, providerAccountId: providerUser.id },
+      },
+    },
+  });
+  return newUser;
+}
+
+export default router;