feat: support guest session (#919)

app/(auth)/api/auth/guest/route.ts

@@ -0,0 +1,21 @@
+import { signIn } from '@/app/(auth)/auth';
+import { isDevelopmentEnvironment } from '@/lib/constants';
+import { getToken } from 'next-auth/jwt';
+import { NextResponse } from 'next/server';
+
+export async function GET(request: Request) {
+  const { searchParams } = new URL(request.url);
+  const redirectUrl = searchParams.get('redirectUrl') || '/';
+
+  const token = await getToken({
+    req: request,
+    secret: process.env.AUTH_SECRET,
+    secureCookie: !isDevelopmentEnvironment,
+  });
+
+  if (token) {
+    return NextResponse.redirect(new URL('/', request.url));
+  }
+
+  return signIn('guest', { redirect: true, redirectTo: redirectUrl });
+}

app/(auth)/auth.config.ts

@@ -9,31 +9,5 @@ export const authConfig = {
     // added later in auth.ts since it requires bcrypt which is only compatible with Node.js
     // while this file is also used in non-Node.js environments
   ],
-  callbacks: {
-    authorized({ auth, request: { nextUrl } }) {
-      const isLoggedIn = !!auth?.user;
-      const isOnChat = nextUrl.pathname.startsWith('/');
-      const isOnRegister = nextUrl.pathname.startsWith('/register');
-      const isOnLogin = nextUrl.pathname.startsWith('/login');
-
-      if (isLoggedIn && (isOnLogin || isOnRegister)) {
-        return Response.redirect(new URL('/', nextUrl as unknown as URL));
-      }
-
-      if (isOnRegister || isOnLogin) {
-        return true; // Always allow access to register and login pages
-      }
-
-      if (isOnChat) {
-        if (isLoggedIn) return true;
-        return false; // Redirect unauthenticated users to login page
-      }
-
-      if (isLoggedIn) {
-        return Response.redirect(new URL('/', nextUrl as unknown as URL));
-      }
-
-      return true;
-    },
-  },
+  callbacks: {},
 } satisfies NextAuthConfig;

app/(auth)/auth.ts

@@ -1,14 +1,33 @@
 import { compare } from 'bcrypt-ts';
-import NextAuth, { type User, type Session } from 'next-auth';
+import NextAuth, { type DefaultSession } from 'next-auth';
 import Credentials from 'next-auth/providers/credentials';
-
-import { getUser } from '@/lib/db/queries';
-
+import { createGuestUser, getUser } from '@/lib/db/queries';
 import { authConfig } from './auth.config';
 import { DUMMY_PASSWORD } from '@/lib/constants';
+import type { DefaultJWT } from 'next-auth/jwt';
 
-interface ExtendedSession extends Session {
-  user: User;
+export type UserType = 'guest' | 'regular';
+
+declare module 'next-auth' {
+  interface Session extends DefaultSession {
+    user: {
+      id: string;
+      type: UserType;
+    } & DefaultSession['user'];
+  }
+
+  interface User {
+    id?: string;
+    email?: string | null;
+    type: UserType;
+  }
+}
+
+declare module 'next-auth/jwt' {
+  interface JWT extends DefaultJWT {
+    id: string;
+    type: UserType;
+  }
 }
 
 export const {
@@ -40,27 +59,31 @@ export const {
 
         if (!passwordsMatch) return null;
 
-        return user as any;
+        return { ...user, type: 'regular' };
+      },
+    }),
+    Credentials({
+      id: 'guest',
+      credentials: {},
+      async authorize() {
+        const [guestUser] = await createGuestUser();
+        return { ...guestUser, type: 'guest' };
       },
     }),
   ],
   callbacks: {
     async jwt({ token, user }) {
       if (user) {
-        token.id = user.id;
+        token.id = user.id as string;
+        token.type = user.type;
       }
 
       return token;
     },
-    async session({
-      session,
-      token,
-    }: {
-      session: ExtendedSession;
-      token: any;
-    }) {
+    async session({ session, token }) {
       if (session.user) {
-        session.user.id = token.id as string;
+        session.user.id = token.id;
+        session.user.type = token.type;
       }
 
       return session;

app/(auth)/login/page.tsx

@@ -9,6 +9,7 @@ import { AuthForm } from '@/components/auth-form';
 import { SubmitButton } from '@/components/submit-button';
 
 import { login, type LoginActionState } from '../actions';
+import { useSession } from 'next-auth/react';
 
 export default function Page() {
   const router = useRouter();
@@ -23,6 +24,8 @@ export default function Page() {
     },
   );
 
+  const { update: updateSession } = useSession();
+
   useEffect(() => {
     if (state.status === 'failed') {
       toast({
@@ -36,6 +39,7 @@ export default function Page() {
       });
     } else if (state.status === 'success') {
       setIsSuccessful(true);
+      updateSession();
       router.refresh();
     }
   }, [state.status]);

app/(auth)/register/page.tsx

@@ -9,6 +9,7 @@ import { SubmitButton } from '@/components/submit-button';
 
 import { register, type RegisterActionState } from '../actions';
 import { toast } from '@/components/toast';
+import { useSession } from 'next-auth/react';
 
 export default function Page() {
   const router = useRouter();
@@ -23,6 +24,8 @@ export default function Page() {
     },
   );
 
+  const { update: updateSession } = useSession();
+
   useEffect(() => {
     if (state.status === 'user_exists') {
       toast({ type: 'error', description: 'Account already exists!' });
@@ -37,6 +40,7 @@ export default function Page() {
       toast({ type: 'success', description: 'Account created successfully!' });
 
       setIsSuccessful(true);
+      updateSession();
       router.refresh();
     }
   }, [state]);

app/(chat)/api/chat/route.ts

@@ -5,11 +5,12 @@ import {
   smoothStream,
   streamText,
 } from 'ai';
-import { auth } from '@/app/(auth)/auth';
+import { auth, type UserType } from '@/app/(auth)/auth';
 import { systemPrompt } from '@/lib/ai/prompts';
 import {
   deleteChatById,
   getChatById,
+  getMessageCountByUserId,
   saveChat,
   saveMessages,
 } from '@/lib/db/queries';
@@ -25,6 +26,7 @@ import { requestSuggestions } from '@/lib/ai/tools/request-suggestions';
 import { getWeather } from '@/lib/ai/tools/get-weather';
 import { isProductionEnvironment } from '@/lib/constants';
 import { myProvider } from '@/lib/ai/providers';
+import { entitlementsByUserType } from '@/lib/ai/entitlements';
 
 export const maxDuration = 60;
 
@@ -46,6 +48,22 @@ export async function POST(request: Request) {
       return new Response('Unauthorized', { status: 401 });
     }
 
+    const userType: UserType = session.user.type;
+
+    const messageCount = await getMessageCountByUserId({
+      id: session.user.id,
+      differenceInHours: 24,
+    });
+
+    if (messageCount > entitlementsByUserType[userType].maxMessagesPerDay) {
+      return new Response(
+        'You have exceeded your maximum number of messages for the day! Please try again later.',
+        {
+          status: 429,
+        },
+      );
+    }
+
     const userMessage = getMostRecentUserMessage(messages);
 
     if (!userMessage) {

app/(chat)/chat/[id]/page.tsx

@@ -1,13 +1,13 @@
 import { cookies } from 'next/headers';
-import { notFound } from 'next/navigation';
+import { notFound, redirect } from 'next/navigation';
 
 import { auth } from '@/app/(auth)/auth';
 import { Chat } from '@/components/chat';
 import { getChatById, getMessagesByChatId } from '@/lib/db/queries';
 import { DataStreamHandler } from '@/components/data-stream-handler';
 import { DEFAULT_CHAT_MODEL } from '@/lib/ai/models';
-import { DBMessage } from '@/lib/db/schema';
-import { Attachment, UIMessage } from 'ai';
+import type { DBMessage } from '@/lib/db/schema';
+import type { Attachment, UIMessage } from 'ai';
 
 export default async function Page(props: { params: Promise<{ id: string }> }) {
   const params = await props.params;
@@ -20,8 +20,12 @@ export default async function Page(props: { params: Promise<{ id: string }> }) {
 
   const session = await auth();
 
+  if (!session) {
+    redirect('/api/auth/guest');
+  }
+
   if (chat.visibility === 'private') {
-    if (!session || !session.user) {
+    if (!session.user) {
       return notFound();
     }
 
@@ -59,6 +63,7 @@ export default async function Page(props: { params: Promise<{ id: string }> }) {
           selectedChatModel={DEFAULT_CHAT_MODEL}
           selectedVisibilityType={chat.visibility}
           isReadonly={session?.user?.id !== chat.userId}
+          session={session}
         />
         <DataStreamHandler id={id} />
       </>
@@ -73,6 +78,7 @@ export default async function Page(props: { params: Promise<{ id: string }> }) {
         selectedChatModel={chatModelFromCookie.value}
         selectedVisibilityType={chat.visibility}
         isReadonly={session?.user?.id !== chat.userId}
+        session={session}
       />
       <DataStreamHandler id={id} />
     </>

app/(chat)/page.tsx

@@ -4,8 +4,16 @@ import { Chat } from '@/components/chat';
 import { DEFAULT_CHAT_MODEL } from '@/lib/ai/models';
 import { generateUUID } from '@/lib/utils';
 import { DataStreamHandler } from '@/components/data-stream-handler';
+import { auth } from '../(auth)/auth';
+import { redirect } from 'next/navigation';
 
 export default async function Page() {
+  const session = await auth();
+
+  if (!session) {
+    redirect('/api/auth/guest');
+  }
+
   const id = generateUUID();
 
   const cookieStore = await cookies();
@@ -21,6 +29,7 @@ export default async function Page() {
           selectedChatModel={DEFAULT_CHAT_MODEL}
           selectedVisibilityType="private"
           isReadonly={false}
+          session={session}
         />
         <DataStreamHandler id={id} />
       </>
@@ -36,6 +45,7 @@ export default async function Page() {
         selectedChatModel={modelIdFromCookie.value}
         selectedVisibilityType="private"
         isReadonly={false}
+        session={session}
       />
       <DataStreamHandler id={id} />
     </>

app/layout.tsx

@@ -4,6 +4,7 @@ import { Geist, Geist_Mono } from 'next/font/google';
 import { ThemeProvider } from '@/components/theme-provider';
 
 import './globals.css';
+import { SessionProvider } from 'next-auth/react';
 
 export const metadata: Metadata = {
   metadataBase: new URL('https://chat.vercel.ai'),
@@ -77,7 +78,7 @@ export default async function RootLayout({
           disableTransitionOnChange
         >
           <Toaster position="top-center" />
-          {children}
+          <SessionProvider>{children}</SessionProvider>
         </ThemeProvider>
       </body>
     </html>