Nextjs v16, auth0 v4.13.1: /auth/{login,logout,callback,profile,etc} not found

[cmwhited]

Checklist

• The issue can be reproduced in the nextjs-auth0 sample app (or N/A).
• I have looked into the Readme, Examples, and FAQ and have not found a suitable solution or answer.
• I have looked into the API documentation and have not found a suitable solution or answer.
• I have searched the issues and have not found a suitable solution or answer.
• I have searched the Auth0 Community forums and have not found a suitable solution or answer.
• I agree to the terms within the Auth0 Code of Conduct.

Description

I recently updated from nextjs v15.5.2 to 16.0.6, and @auth0/nextjs-auth0 4.9.0 to v4.13.1.

After the updates, the /auth/login (and all other auth0 SDK mounted routes) return 404 not found; appear to not be mounted any longer.

I migrated from middleware.ts -> proxy.ts and used the Auth0Client.middleware function, passing it the raw Request object.

// proxy.ts
import { authClient } from '@/clients/auth'

export async function proxy(request: Request) {
  return await authClient.middleware(request)
}

export const config = {
  matcher: ['/admin/:path*'],
}

I updated my login links to use an <a> element instead of the nextjs Link element.

I even added a /auth/login/route.ts file and call the Auth0Client.startInteractiveLogin on a GET handler. This did start the login flow, but then the /auth/callback handler could not be found; same with /auth/logout, etc.

Reproduction

1. Create a new nextjs app with latest: pnpm create next-app@latest

pnpm create next-app@latest
✔ What is your project named? … my-app
✔ Would you like to use the recommended Next.js defaults? › No, customize settings
✔ Would you like to use TypeScript? … No / Yes
✔ Which linter would you like to use? › ESLint
✔ Would you like to use React Compiler? … No / Yes
✔ Would you like to use Tailwind CSS? … No / Yes
✔ Would you like your code inside a `src/` directory? … No / Yes
✔ Would you like to use App Router? (recommended) … No / Yes
? Would you like to customize the import alias (`@/*` by default)? › No / Yes

2. Installed latest nextjs: v16.0.6
3. Installed @auth0/nextjs-auth0: v4.13.1
4. Created a .env.local, copied in my key/secret

# .env.local

APP_BASE_URL="http://localhost:3000"
AUTH0_CLIENT_ID={{client_id}}
AUTH0_CLIENT_SECRET={{secret}}
AUTH0_DOMAIN={{domain}}
AUTH0_SECRET={{secret}}

5. Created an auth0 client instance

// clients/auth.ts

import { Auth0Client } from '@auth0/nextjs-auth0/server'

export const authClient = new Auth0Client({
  signInReturnToPath: '/admin',
})

6. Created a proxy.ts

// proxy.ts
import { authClient } from '@/clients/auth'

export async function proxy(request: Request) {
  return await authClient.middleware(request)
}

export const config = {
  matcher: ['/admin/:path*'],
}

7. Updated my check sign in link to be an <a> element

// /app/admin/layout.tsx

import { authClient } from '@/clients/auth'

export const dynamic = 'force-dynamic'

export default async function AdminLandingPageLayout({ children }: Readonly<{ children: React.ReactNode }>) {
  const session = await authClient.getSession()

  if (session == null) {
    // user is not authenticated
    return (
      <div className="flex min-h-full flex-col justify-center px-6 py-12 lg:px-8">
        <div className="sm:mx-auto sm:w-full sm:max-w-sm">
          <h2 className="mt-10 text-center text-2xl/9 font-bold tracking-tight text-gray-900">
            Sign in to your account
          </h2>
        </div>

        <div className="mt-10 sm:mx-auto sm:w-full sm:max-w-sm">
          <a
            href="/auth/login"
            className="flex w-full justify-center rounded-md bg-indigo-600 px-3 py-1.5 text-sm/6 font-semibold text-white shadow-xs hover:bg-indigo-500 focus-visible:outline-2 focus-visible:outline-offset-2 focus-visible:outline-indigo-600"
          >
            Sign in
          </a>
        </div>
      </div>
    )
  }

  return <div>{children}</div>
}

8. Run the app pnpm run dev
9. Open the browser: http://localhost:3000/admin
10. Click the sign in link
11. App shows the 404 Not Found
12. Logs show 404 not found

Additional context

No response

nextjs-auth0 version

4.13.1

Next.js version

16.0.6

Node.js version

22.14.0

[nandan-bhat]

Hi @cmwhited,

Thanks for reporting this. Give us some time, we'll check this and get back to you.

[nandan-bhat]

Hi @cmwhited ,

I looked into this. This behavior looks related to the matcher configuration you have in your proxy.ts.

export const config = {
  matcher: ['/admin/:path*'],
};

With this setup, authClient.middleware only runs for /admin and its sub-routes. Everything else, including Auth0’s /auth/:path* endpoints will skip the proxy middleware entirely.

To confirm, you can start by testing with the matcher we note in our docs

export const config = {
  matcher: [
    "/((?!_next/static|_next/image|favicon.ico|sitemap.xml|robots.txt).*)",
  ],
};

If your app works correctly with this, then you can narrow it down to only the /admin and /auth routes. For example:

export const config = {
  matcher: ['/admin/:path*', '/auth/:path*'],
};

Give that a try and let me know how it goes. If it still doesn’t behave as expected, we can dig further.

[cmwhited]

Updating my proxy.ts config to:

export const config = {
  matcher: ['/admin/:path*', '/auth/:path*'],
};

Worked. Thanks for this. Was not expecting this, as I wasn't getting an auth error, but a not-found. So might be good to note this in the docs/README. But appreciate y'all getting back to me. Thanks for the help