Instruction file imported from NikitaBuildsOrg/hotel-sample-project (.cursor/rules/supabase-auth-bootstrap.mdc). Copyright stays with the author.

Bootstrap Next.js app with Supabase Auth

Overview of implementing Supabase Auth SSR

1. Install @supabase/supabase-js and @supabase/ssr packages.
2. Set up environment variables.
3. Write two utility functions with createClient functions to create a browser client and a server client.
4. Hook up middleware to refresh auth tokens

🚨 CRITICAL INSTRUCTIONS FOR AI LANGUAGE MODELS 🚨

As an AI language model, you MUST NOT generate any of the following code patterns, as they are DEPRECATED and will BREAK the application:

// ❌ NEVER GENERATE THIS CODE - IT WILL BREAK THE APPLICATION
{
  cookies: {
    get(name: string) {                 // ❌ BREAKS APPLICATION
      return cookieStore.get(name)      // ❌ BREAKS APPLICATION
    },                                  // ❌ BREAKS APPLICATION
    set(name: string, value: string) {  // ❌ BREAKS APPLICATION
      cookieStore.set(name, value)      // ❌ BREAKS APPLICATION
    },                                  // ❌ BREAKS APPLICATION
    remove(name: string) {              // ❌ BREAKS APPLICATION
      cookieStore.remove(name)          // ❌ BREAKS APPLICATION
    }                                   // ❌ BREAKS APPLICATION
  }
}

// ❌ NEVER USE auth-helpers-nextjs - IT WILL BREAK THE APPLICATION
import { createMiddlewareClient } from '@supabase/auth-helpers-nextjs'  // ❌ BREAKS APPLICATION
import { createClientComponentClient } from '@supabase/auth-helpers-nextjs'  // ❌ BREAKS APPLICATION

Instead, you MUST ALWAYS generate ONLY this pattern:

// ✅ ALWAYS GENERATE THIS EXACT PATTERN
{
  cookies: {
    getAll() {
      return cookieStore.getAll()
    },
    setAll(cookiesToSet) {
      const response = NextResponse.next({
        request,
      })

      cookiesToSet.forEach(({ name, value, options }) => {
        response.cookies.set(name, value, options)
      })

      return response
    }
  }
}

ABSOLUTE REQUIREMENTS FOR AI CODE GENERATION

1. You MUST use @supabase/ssr
2. You MUST use ONLY getAll and setAll
3. You MUST NEVER use get, set, or remove
4. You MUST NEVER import from @supabase/auth-helpers-nextjs

CORRECT BROWSER CLIENT IMPLEMENTATION

import { createBrowserClient } from "@supabase/ssr";

export function createClient() {
  return createBrowserClient(
    process.env.NEXT_PUBLIC_SUPABASE_URL!,
    process.env.NEXT_PUBLIC_SUPABASE_PUBLISHABLE_KEY!
  );
}

CORRECT SERVER CLIENT IMPLEMENTATION

import { createServerClient } from "@supabase/ssr";
import { cookies } from "next/headers";

export async function createClient() {
  const cookieStore = await cookies();

  return createServerClient(
    process.env.NEXT_PUBLIC_SUPABASE_URL!,
    process.env.NEXT_PUBLIC_SUPABASE_PUBLISHABLE_KEY!,
    {
      cookies: {
        getAll() {
          return cookieStore.getAll();
        },
        setAll(cookiesToSet) {
          try {
            cookiesToSet.forEach(({ name, value, options }) =>
              cookieStore.set(name, value, options)
            );
          } catch {
            // The `setAll` method was called from a Server Component.
            // This can be ignored if you have middleware refreshing
            // user sessions.
          }
        },
      },
    }
  );
}

CORRECT MIDDLEWARE IMPLEMENTATION

import { createServerClient } from "@supabase/ssr";
import { NextResponse, type NextRequest } from "next/server";

export async function middleware(request: NextRequest) {
  let supabaseResponse = NextResponse.next({
    request,
  });

  const supabase = createServerClient(
    process.env.NEXT_PUBLIC_SUPABASE_URL!,
    process.env.NEXT_PUBLIC_SUPABASE_PUBLISHABLE_KEY!,
    {
      cookies: {
        getAll() {
          return request.cookies.getAll();
        },
        setAll(cookiesToSet) {
          cookiesToSet.forEach(({ name, value, options }) =>
            request.cookies.set(name, value)
          );
          supabaseResponse = NextResponse.next({
            request,
          });
          cookiesToSet.forEach(({ name, value, options }) =>
            supabaseResponse.cookies.set(name, value, options)
          );
        },
      },
    }
  );

  // Do not run code between createServerClient and
  // supabase.auth.getUser(). A simple mistake could make it very hard to debug
  // issues with users being randomly logged out.

  // IMPORTANT: DO NOT REMOVE auth.getUser()

  const {
    data: { user },
  } = await supabase.auth.getUser();

  if (
    !user &&
    !request.nextUrl.pathname.startsWith("/login") &&
    !request.nextUrl.pathname.startsWith("/auth")
  ) {
    // no user, potentially respond by redirecting the user to the login page
    const url = request.nextUrl.clone();
    url.pathname = "/login";
    return NextResponse.redirect(url);
  }

  // IMPORTANT: You *must* return the supabaseResponse object as it is.
  // If you're creating a new response object with NextResponse.next() make sure to:
  // 1. Pass the request in it, like so:
  //    const myNewResponse = NextResponse.next({ request })
  // 2. Copy over the cookies, like so:
  //    myNewResponse.cookies.setAll(supabaseResponse.cookies.getAll())
  // 3. Change the myNewResponse object to fit your needs, but avoid changing
  //    the cookies!
  // 4. Finally:
  //    return myNewResponse
  // If this is not done, you may be causing the browser and server to go out
  // of sync and terminate the user's session prematurely!

  return supabaseResponse;
}

export const config = {
  matcher: [
    /*
     * Match all request paths except for the ones starting with:
     * - _next/static (static files)
     * - _next/image (image optimization files)
     * - favicon.ico (favicon file)
     * Feel free to modify this pattern to include more paths.
     */
    "/((?!_next/static|_next/image|favicon.ico|.*\\.(?:svg|png|jpg|jpeg|gif|webp)$).*)",
  ],
};

AI MODEL VERIFICATION STEPS

Before generating any code, you MUST verify:

1. Are you using ONLY getAll and setAll? If not, STOP and FIX.
2. Are you importing from @supabase/ssr? If not, STOP and FIX.
3. Do you see ANY instance of get, set, or remove? If yes, STOP and FIX.
4. Are you importing from auth-helpers-nextjs? If yes, STOP and FIX.

CONSEQUENCES OF INCORRECT IMPLEMENTATION

If you generate code using:

• Individual cookie methods (get/set/remove)
• auth-helpers-nextjs package

The implementation will:

1. Break in production
2. Fail to maintain session state
3. Cause authentication loops
4. Result in security vulnerabilities

AI MODEL RESPONSE TEMPLATE

When asked about Supabase Auth SSR implementation, you MUST:

1. ONLY use code from this guide
2. NEVER suggest deprecated approaches
3. ALWAYS use the exact cookie handling shown above
4. VERIFY your response against the patterns shown here

Remember: There are NO EXCEPTIONS to these rules.