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auth0-nextjs

Use when adding authentication to Next.js applications with both server and client-side auth - supports App Router and Pages Router with @auth0/nextjs-auth0 SDK

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npx tessl i github:auth0/agent-skills --skill auth0-nextjs
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Auth0 Next.js Integration

Add authentication to Next.js applications using @auth0/nextjs-auth0. Supports both App Router and Pages Router.


Prerequisites

  • Next.js 13+ application (App Router or Pages Router)
  • Auth0 account and application configured
  • If you don't have Auth0 set up yet, use the auth0-quickstart skill first

When NOT to Use

  • Client-side only React apps - Use auth0-react for Vite/CRA SPAs
  • React Native mobile apps - Use auth0-react-native for iOS/Android
  • Non-Next.js frameworks - Use framework-specific SDKs (Express, Vue, Angular, etc.)
  • Stateless APIs only - Use JWT validation middleware if you don't need session management

Quick Start Workflow

1. Install SDK

npm install @auth0/nextjs-auth0

2. Configure Environment

For automated setup with Auth0 CLI, see Setup Guide for complete scripts.

For manual setup:

Create .env.local:

AUTH0_SECRET=<generate-a-32-character-secret>
APP_BASE_URL=http://localhost:3000
AUTH0_DOMAIN=your-tenant.auth0.com
AUTH0_CLIENT_ID=your-client-id
AUTH0_CLIENT_SECRET=your-client-secret

Generate secret: openssl rand -hex 32

Important: Add .env.local to .gitignore

3. Create Auth0 Client and Middleware

Create lib/auth0.ts:

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

export const auth0 = new Auth0Client({
  domain: process.env.AUTH0_DOMAIN!,
  clientId: process.env.AUTH0_CLIENT_ID!,
  clientSecret: process.env.AUTH0_CLIENT_SECRET!,
  secret: process.env.AUTH0_SECRET!,
  appBaseUrl: process.env.APP_BASE_URL!,
});

Middleware Configuration (Next.js 15 vs 16):

Next.js 15 - Create middleware.ts at project root:

import { NextRequest } from 'next/server';
import { auth0 } from './lib/auth0';

export async function middleware(request: NextRequest) {
  return await auth0.middleware(request);
}

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

Next.js 16 - You have two options:

Option 1: Use middleware.ts (same as Next.js 15):

import { NextRequest } from 'next/server';
import { auth0 } from './lib/auth0';

export async function middleware(request: NextRequest) {
  return await auth0.middleware(request);
}

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

Option 2: Use proxy.ts at project root:

import { NextRequest } from 'next/server';
import { auth0 } from './lib/auth0';

export async function proxy(request: NextRequest) {
  return await auth0.middleware(request);
}

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

This automatically creates endpoints:

  • /auth/login - Login
  • /auth/logout - Logout
  • /auth/callback - OAuth callback
  • /auth/profile - User profile

4. Add User Context (Optional)

Note: In v4, wrapping with <Auth0Provider> is optional. Only needed if you want to pass an initial user during server rendering to useUser().

App Router - Optionally wrap app in app/layout.tsx:

import { Auth0Provider } from '@auth0/nextjs-auth0/client';
import { auth0 } from './lib/auth0';

export default async function RootLayout({ children }: { children: React.ReactNode }) {
  const session = await auth0.getSession();

  return (
    <html>
      <body>
        <Auth0Provider user={session?.user}>{children}</Auth0Provider>
      </body>
    </html>
  );
}

Pages Router - Optionally wrap app in pages/_app.tsx:

import { Auth0Provider } from '@auth0/nextjs-auth0/client';
import type { AppProps } from 'next/app';

export default function App({ Component, pageProps }: AppProps) {
  return (
    <Auth0Provider user={pageProps.user}>
      <Component {...pageProps} />
    </Auth0Provider>
  );
}

5. Add Authentication UI

Client Component (works in both routers):

'use client'; // Only needed for App Router

import { useUser } from '@auth0/nextjs-auth0/client';

export default function Profile() {
  const { user, isLoading } = useUser();

  if (isLoading) return <div>Loading...</div>;

  if (user) {
    return (
      <div>
        <img src={user.picture} alt={user.name} />
        <h2>Welcome, {user.name}!</h2>
        <a href="/auth/logout">Logout</a>
      </div>
    );
  }

  return <a href="/auth/login">Login</a>;
}

6. Test Authentication

Start your dev server:

npm run dev

Visit http://localhost:3000 and test the login flow.


Detailed Documentation

  • Setup Guide - Automated setup scripts, environment configuration, Auth0 CLI usage
  • Integration Guide - Server-side auth, protected routes, API routes, middleware
  • API Reference - Complete SDK API, hooks, helpers, session management

Common Mistakes

MistakeFix
Using v3 environment variablesv4 uses APP_BASE_URL and AUTH0_DOMAIN (not AUTH0_BASE_URL or AUTH0_ISSUER_BASE_URL)
Forgot to add callback URL in Auth0 DashboardAdd /auth/callback to Allowed Callback URLs (e.g., http://localhost:3000/auth/callback)
Missing middleware configurationv4 requires middleware to mount auth routes - create middleware.ts (Next.js 15+16) or proxy.ts (Next.js 16 only) with auth0.middleware()
Wrong route pathsv4 uses /auth/login not /api/auth/login - routes drop the /api prefix
Missing or weak AUTH0_SECRETGenerate secure secret with openssl rand -hex 32 and store in .env.local
Using .env instead of .env.localNext.js requires .env.local for local secrets, and .env.local should be in .gitignore
App created as SPA type in Auth0Must be Regular Web Application type for Next.js
Using removed v3 helpersv4 removed withPageAuthRequired and withApiAuthRequired - use getSession() instead
Using useUser in Server ComponentuseUser is client-only, use auth0.getSession() for Server Components
AUTH0_DOMAIN includes https://v4 AUTH0_DOMAIN should be just the domain (e.g., example.auth0.com), no scheme

Related Skills

  • auth0-quickstart - Basic Auth0 setup
  • auth0-migration - Migrate from another auth provider
  • auth0-mfa - Add Multi-Factor Authentication

Quick Reference

V4 Setup:

  • Create lib/auth0.ts with Auth0Client instance
  • Create middleware configuration (required):
    • Next.js 15: middleware.ts with middleware() function
    • Next.js 16: middleware.ts with middleware() OR proxy.ts with proxy() function
  • Optional: Wrap with <Auth0Provider> for SSR user

Client-Side Hooks:

  • useUser() - Get user in client components
  • user - User profile object
  • isLoading - Loading state

Server-Side Methods:

  • auth0.getSession() - Get session in Server Components/API routes/middleware
  • auth0.getAccessToken() - Get access token for calling APIs

Common Use Cases:


References

Repository
auth0/agent-skills
Last updated
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