This guide demonstrates how to integrate Auth0 with any new or existing Next.js application using the Auth0 Next.js v4 SDK. We recommend that you log in to follow this quickstart with examples configured for your account.
1

Configure Auth0

To use Auth0 services, you’ll need to have an application set up in the Auth0 Dashboard. The Auth0 application is where you will configure how you want authentication to work for the project you are developing.

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Configure an application

Use the interactive selector to create a new Auth0 application or select an existing application that represents the project you want to integrate with. Every application in Auth0 is assigned an alphanumeric, unique client ID that your application code will use to call Auth0 APIs through the SDK.Any settings you configure using this quickstart will automatically update for your Application in the Dashboard, which is where you can manage your Applications in the future.If you would rather explore a complete configuration, you can view a sample application instead.

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Configure Callback URLs

A callback URL is a URL in your application that you would like Auth0 to redirect users to after they have authenticated. If not set, users will not be returned to your application after they log in.
If you are following along with our sample project, set this to http://localhost:3000/auth/callback.

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Configure Logout URLs

A logout URL is a URL in your application that you would like Auth0 to redirect users to after they have logged out. If not set, users will not be able to log out from your application and will receive an error.
If you are following along with our sample project, set this to http://localhost:3000.
2

Install the Auth0 Next.js v4 SDK

Install the Auth0 Next.js SDK using npm or yarn.Run the following command within your project directory to install the Auth0 Next.js SDK:
npm i @auth0/nextjs-auth0
The SDK exposes methods and variables that help you integrate Auth0 with your Next.js application using Route Handlers on the backend and React Context with React Hooks on the frontend.
3

Configure the SDK

In the root directory of your project, add the file .env.local with the following environment variables:
  • AUTH0_SECRET: A long secret value used to encrypt the session cookie. You can generate a suitable string using openssl rand -hex 32 on the command line.
  • APP_BASE_URL: The base URL of your application.
  • AUTH0_DOMAIN: The URL of your Auth0 tenant domain. If you are using a Custom Domain with Auth0, set this to the value of your Custom Domain instead of the value reflected in the “Settings” tab.
  • AUTH0_CLIENT_ID: Your Auth0 application’s Client ID.
  • AUTH0_CLIENT_SECRET: Your Auth0 application’s Client Secret.
The SDK will read these values from the Node.js process environment and automatically configure itself.
4

Create the Auth0 SDK Client

Create a file at src/lib/auth0.ts. This file provides methods for handling authentication, sessions and user data.Then, import the Auth0Client class from the SDK to create an instance and export it as auth0. This instance is used in your app to interact with Auth0.
5

Create a Login Page

The Next.js Middleware allows you to run code before a request is completed.
Create a file at src/middleware.ts. This file is used to enforce authentication on specific routes.The middleware function intercepts incoming requests and applies Auth0’s authentication logic. The matcher configuration ensures that the middleware runs on all routes except for static files and metadata.
6

Add the Landing Page Content

The Landing page src/app/page.tsx is where users interact with your app. It displays different content based on whether the users is logged in or not.Edit the file src/app/page.tsx to add the auth0.getSession() method to determine if the user is logged in by retrieving the user session.If there is no user session, the method returns null and the app displays the Sign up or Log in buttons. If a user sessions exists, the app displays a welcome message with the user’s name and a Log out button.
The Logout functionality is already included in the file src/app/page.tsx. When the user selects the Log out button, they are redirected to the Auth0 logout endpoint, which clears their session and redirects back to your app.
7

Run Your Application

Run this command to start your Next.js development server:
npm run dev
Visit the url http://localhost:3000 in your browser.You will see:
  • A Sign up and Log in button if the user is not authenticated.
  • A welcome message and a Log out button if the user is authenticated.

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Next Steps

Excellent work! If you made it this far, you should now have login, logout, and user profile information running in your application.This concludes our quickstart tutorial, but there is so much more to explore. To learn more about what you can do with Auth0, check out:
  • Auth0 Dashboard - Learn how to configure and manage your Auth0 tenant and applications
  • nextjs-auth0 SDK - Explore the SDK used in this tutorial more fully
  • Auth0 Marketplace - Discover integrations you can enable to extend Auth0’s functionality