Next.js Callback 404 Not Found Error

Knowledge Articles
1

Overview

This article explains why a 404 Not Found error may be seen on the /api/auth/callback route when utilizing the nextjs-auth0 library.

Applies To

  • NextJS-Auth0

Cause

If the callback looks similar to the following error, with being the domain associated with the Auth0 tenant, this error is happening because of the misuse of the Auth0 domain.

https://<AUTH0-DOMAIN>/api/auth/callback

  • The Auth0 domain should only be utilized to complete calls towards one of the Auth0-managed APIs
  • The error occurs because the /api/auth/callback is not an Auth0 API endpoint, but rather a route in the application.

Solution

  1. Verify that the environment variable AUTH0_BASE_URL exists within the .env configuration file for applications built with the NextJS-Auth0 SDK.
  2. Set the AUTH0_BASE_URL variable to the base URL where the Next.js application is hosted.
    • For local development, this value is typically similar to the following example: http://localhost:3000.
  3. Confirm the AUTH0_BASE_URL variable contains the application’s hosting URL, not the Auth0 tenant domain.
    • Example of an incorrect value (tenant domain): https://<tenant_name>.<region>.auth0.com/
  4. If issues continue, check the configured AUTH0_BASE_URL domain for correct spelling and validity.