In today\'s web development world, REST APIs have become a standard for enabling communication between different applications. Node.js, thanks to its robustness and flexibility, is one of the most widely used platforms for creating efficient and scalable APIs. In this tutorial, we\'ll focus on creating a REST API in Node.js that includes authentication using JSON Web Tokens (JWT), a secure method for transmitting information between parties as a JSON object. Why use JWT for authentication? The use of JWT for authentication and session management is popular because it is self-contained, meaning it contains all the necessary information about the user. Furthermore, it is secure because it is digitally signed. This reduces the need to store information on the server, making them ideal for scalable APIs.

Setting up our Node.js project

First, we\'ll create a new Node.js project using npm:

$ mkdir myapi && cd myapi
$ npm init -y

Next, we\'ll install the necessary libraries:

$ npm install express jsonwebtoken bcryptjs

These include Express, a popular Node.js framework; jsonwebtoken, for handling JWTs; and bcryptjs, to encrypt passwords.

Creating the Basic Server

We open our file index.js and implement a basic server:

const express = require(express);
const app = express();
app.use(express.json());
app.listen(3000, () => console.log(Server running on port 3000));

This code starts a server on port 3000 and enables handling of JSON requests.

User Management and Security

We will add basic endpoints to register users and manage their authentication. We will create a simple controller for it:

// Database simulation
let users = [];

app.post(/register, async (req, res) => {
 const { username, password } = req.body;
 const hashedPassword = await bcrypt.hash(password, 10);
 users.push({ username, password: hashedPassword });
 res.status(201).send(Registered user successfully);
});

app.post(/login, async (req, res) => {
 const { username, password } = req.body;
 const user = users.find(user => user.username === username);

 if (!user || )) {
 return res.status(401).send(Bad credentials);
 }

 const token = jwt.sign({ username: user.username }, secretkey);
 res.json({ token });
});

Securing our Routes with JWT

To protect our routes you will require a middleware function that validates the tokens:

const authenticateJWT = (req, res, next) => {
 const token = req.header(Authorization);

 if (!token) return res.sendStatus(403); 

 jwt.verify(token.split( )[1], secretkey, (err, user) => {
 if (err) return res.sendStatus(403);

 req.user = user;
 next();
 });
};

Then we can use this function on any route we want to protect.

Putting it all together

You can see how these combined features allow you to create robust applications. By using JWTs, we not only secure our VPN routes and secure encryption, but we also improve the user experience by eliminating the constant need to log in.

More on developing with Mox here.