Learn how to use Middleware in Next.js with Nextauth to login and to protect private routes

Middleware is a key concept in web development, providing a way to extend the functionality of a web application with reusable code. In the context of Next.js, middleware can be used to add authentication and authorization logic to a Next.js application, and Nextauth is a popular library for handling authentication in Next.js applications.

In this article, we’ll explore how to use middleware in a Next.js application with Nextauth to implement user authentication and protect private routes.

Setting up Nextauth

The first step in using middleware with Nextauth is to set up Nextauth in a Next.js application. To do this, we need to install the necessary packages:

$ npm install next-auth

Once Nextauth is installed, we can set up a Nextauth provider in our Next.js application by creating a file called [...nextauth].js in the pages/api/auth directory. This file will contain the configuration for Nextauth, including the authentication providers and any other options we want to specify.

Implementing middleware in Next.js

With Nextauth set up, we can now implement middleware in our Next.js application to protect private routes and handle user authentication. Next.js provides a powerful middleware API that allows us to define custom middleware functions to perform actions before handling a request, making it the perfect tool for implementing authentication and authorization logic.

Here’s an example of how we can implement middleware in Next.js to protect a private route:

// pages/profile.js

import { useSession } from 'next-auth/client';
import { useRouter } from 'next/router';

const Profile = () => {
  const [session, loading] = useSession();
  const router = useRouter();

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

  if (!session) {
    router.push('/login');
  }

  return <div>
    <h1>Profile Page</h1>
    <p>Welcome, {session.user.name}!</p>
  </div>;
};

export default Profile;

In this example, we’re using the useSession hook from Nextauth to check if the user is authenticated. If the user is not authenticated, we redirect them to the login page using the useRouter hook from Next.js.

Conclusion

Middleware is a powerful concept in web development, and using it in a Next.js application with Nextauth can greatly simplify the process of implementing user authentication and protecting private routes. By setting up Nextauth and using the middleware API in Next.js, we can easily add authentication and authorization logic to our Next.js applications, making them more secure and user-friendly.