Quick Tutorial: Setting Up NextAuth.js

NextAuth.js is a powerful authentication library for Next.js applications. It provides a simple and secure way to handle authentication.

NextAuth.js Features

1. Built-in Providers:
   • Support for popular providers like Google, Facebook, Twitter, GitHub, and more.
   • Custom provider options for flexibility.
2. JWT (JSON Web Tokens):
   • Secure token-based authentication.
   • Optional database sessions.
3. Secure by Default:
   • CSRF protection.
   • Secure cookies.
   • HTTPS support.
4. Database Support:
   • Compatible with multiple databases (e.g., MySQL, PostgreSQL, MongoDB, etc.).
   • Prisma adapter for database management.
5. Session Management:
   • Server-side and client-side session management.
   • Configurable session lifetimes.
6. Callbacks:
   • Customizable callback functions for control over sign-in, session, and JWT behavior.
7. Theming:
   • Customizable sign-in pages and styles.
8. Multi-Factor Authentication (MFA):
   • Support for MFA implementations.
9. Internationalization (i18n):
   • Support for multiple languages and custom translations.
10. Flexible Configuration:
    • Granular control over authentication and session behavior.
    • Environment variable support for secure configuration.
11. API Routes:
    • Built-in API routes for authentication actions.
    • Extensible API endpoints.
12. Community and Documentation:
    • Comprehensive documentation.
    • Active community support.

NextAuth.js offers a powerful and flexible authentication solution for Next.js applications, catering to a wide range of use cases and security requirements.

Here's a straightforward guide to get you started.

Setting Up NextAuth.js for Beginners

NextAuth.js simplifies authentication for Next.js apps. Here’s how to set it up quickly.

Step 1: Install Dependencies

Run the following command to install NextAuth.js and its dependencies:

npm install next-auth @next-auth/prisma-adapter

Step 2: Configure NextAuth.js

Create [...nextauth].js in pages/api/auth and add your configuration:

// pages/api/auth/[...nextauth].js
import NextAuth from 'next-auth';
import Providers from 'next-auth/providers';

export default NextAuth({
  providers: [
    Providers.Google({
      clientId: process.env.GOOGLE_CLIENT_ID,
      clientSecret: process.env.GOOGLE_CLIENT_SECRET,
    }),
  ],
  database: process.env.DATABASE_URL,
});

Step 3: Set Environment Variables

Create a .env file in your project's root directory and add:

GOOGLE_CLIENT_ID=your-google-client-id
GOOGLE_CLIENT_SECRET=your-google-client-secret
DATABASE_URL=your-database-url

Step 4: Protect Pages

Use the useSession hook to protect your pages:

// pages/protected.js
import { useSession, signIn, signOut } from 'next-auth/client';

export default function ProtectedPage() {
  const [session, loading] = useSession();

  if (loading) return <p>Loading...</p>;

  if (!session) {
    return (
      <>
        <p>You are not signed in</p>
        <button onClick={signIn}>Sign in</button>
      </>
    );
  }

  return (
    <>
      <p>Welcome, {session.user.name}</p>
      <button onClick={signOut}>Sign out</button>
    </>
  );
}

Step 5: Wrap Your App

In _app.js, wrap your app with the Provider:

// pages/_app.js
import { Provider } from 'next-auth/client';

export default function App({ Component, pageProps }) {
  return (
    <Provider session={pageProps.session}>
      <Component {...pageProps} />
    </Provider>
  );
}

Final Step: Start Your App

Run your app:

npm run dev

Your Next.js app now has basic authentication with NextAuth.js. For more details, check out the NextAuth.js documentation.