Authentication with Next.js and Passport.js: A Comprehensive Guide

In today's digital landscape, ensuring secure user authentication is paramount for web applications. Next.js, a popular React framework, combined with Passport.js, a versatile authentication middleware for Node.js, provides a robust solution for implementing user authentication.

In this guide, we'll explore how to integrate Passport.js with Next.js to create a secure authentication system.

Why Next.js and Passport.js?

Next.js offers server-side rendering, routing, and other powerful features out of the box, making it an excellent choice for building modern web applications.

Passport.js, on the other hand, simplifies the authentication process by providing a flexible and modular framework with support for various authentication strategies such as local, OAuth, and OpenID.

Getting Started

Before diving into the code, make sure you have Node.js and npm installed on your machine. Start by creating a new Next.js project:

npx create-next-app@latest my-auth-app
cd my-auth-app  
  

Next, install Passport.js and its dependencies:

npm install passport passport-local express-session  
  

Setting Up Passport.js

Create a new file named `passport-config.js` in the root directory of your project. This file will contain the configuration for Passport.js:

// passport-config.js
const passport = require('passport');
const LocalStrategy = require('passport-local').Strategy;

passport.use(new LocalStrategy(
  (username, password, done) => {
    // Add your authentication logic here
  }
));

passport.serializeUser((user, done) => {
  done(null, user.id);
});

passport.deserializeUser((id, done) => {
  // Fetch user from the database using id
});
  

Integrating Passport.js with Next.js

Next, integrate Passport.js with your Next.js application. Create a custom server using `next.config.js`:

// next.config.js
const express = require('express');
const next = require('next');
const passport = require('passport');
const session = require('express-session');
const bodyParser = require('body-parser');
require('./passport-config'); // Import passport configuration

const dev = process.env.NODE_ENV !== 'production';
const app = next({ dev });
const handle = app.getRequestHandler();

app.prepare().then(() => {
  const server = express();

  server.use(bodyParser.urlencoded({ extended: true }));
  server.use(session({ secret: 'secret', resave: false, saveUninitialized: false }));
  server.use(passport.initialize());
  server.use(passport.session());

  // Define your authentication routes here

  server.get('*', (req, res) => {
    return handle(req, res);
  });

  server.listen(3000, (err) => {
    if (err) throw err;
    console.log('> Ready on http://localhost:3000');
  });
});  
  

Implementing Authentication Routes

Now, you can define authentication routes in your custom server:

// Inside your custom server
server.post('/login', passport.authenticate('local', {
  successRedirect: '/',
  failureRedirect: '/login',
  failureFlash: true,
}));

server.get('/logout', (req, res) => {
  req.logout();
  res.redirect('/');
});

// Add more routes for registration, forgot password, etc.  
  

Conclusion

By integrating Passport.js with Next.js, you can create a secure and flexible authentication system for your web application. This combination provides the foundation for implementing various authentication strategies while leveraging the power and simplicity of Next.js.

Start building your authentication system today and ensure the safety of your users' data. Happy coding!