Auth0 Next.js Integration#

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

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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

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Quick Start Workflow#

1. Install SDK#

bash

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:

bash

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#

Detect project structure first: Check whether the project uses a src/ directory (i.e. src/app/ or src/pages/ exists). This determines where to place files:

• With src/: src/lib/auth0.ts, src/middleware.ts (or src/proxy.ts for Next.js 16)
• Without src/: lib/auth0.ts, middleware.ts (or proxy.ts for Next.js 16)

Create lib/auth0.ts (or src/lib/auth0.ts if using the src/ convention):

typescript

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, or src/middleware.ts if using src/):

typescript

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, same src/ placement rules):

typescript

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, or src/proxy.ts if using src/):

typescript

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:

typescript

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:

typescript

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):

typescript

'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:

bash

npm run dev

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

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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

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Common Mistakes#

MistakeFixUsing 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 prefixMissing or weak AUTH0_SECRETGenerate secure secret with openssl rand -hex 32 and store in .env.localUsing .env instead of .env.localNext.js requires .env.local for local secrets, and .env.local should be in .gitignoreApp created as SPA type in Auth0Must be Regular Web Application type for Next.jsUsing removed v3 helpersv4 removed withPageAuthRequired and withApiAuthRequired - use getSession() insteadUsing useUser in Server ComponentuseUser is client-only, use auth0.getSession() for Server ComponentsAUTH0_DOMAIN includes https://v4 AUTH0_DOMAIN should be just the domain (e.g., example.auth0.com), no scheme

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Related Skills#

• auth0-quickstart - Basic Auth0 setup
• auth0-migration - Migrate from another auth provider
• auth0-mfa - Add Multi-Factor Authentication
• auth0-cli - Manage Auth0 resources from the terminal

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Quick Reference#

V4 Setup:

• Detect src/ convention: check if src/app/ or src/pages/ exists — place all files inside src/ if so
• Create lib/auth0.ts (or src/lib/auth0.ts) with Auth0Client instance
• Create middleware configuration (required):
  • Next.js 15: middleware.ts (or src/middleware.ts) with middleware() function
  • Next.js 16: middleware.ts with middleware() OR proxy.ts with proxy() function (same src/ rules)
• 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:

• Login/Logout links → Use /auth/login and /auth/logout paths (see Step 5)
• Protected pages (App Router) → Integration Guide
• Protected pages (Pages Router) → Integration Guide
• API routes with auth → Integration Guide
• Middleware protection → Integration Guide

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References#

• Auth0 Next.js SDK Documentation
• Auth0 Next.js Quickstart
• SDK GitHub Repository