How do I implement JWT authentication in an Express.js app?

How do I implement JWT authentication in an Express.js app?

To implement JWT authentication in an Express.js app, you need to install the necessary packages like jsonwebtoken and express-jwt.

What are the steps to create a JWT token?

First, you need to create a user model, then generate a token using jsonwebtoken when the user logs in.

How do I protect my routes using JWT?

You can use middleware to verify the token on protected routes. Use express-jwt to handle this easily.

Can you show me a code example?

Sure! Here's a simple example:

const jwt = require('jsonwebtoken');
const express = require('express');
const app = express();

app.post('/login', (req, res) => {
    const user = { id: 1 }; // Example user
    const token = jwt.sign({ user }, 'your_secret_key');
    res.json({ token });
});

app.get('/protected', expressJwt({ secret: 'your_secret_key', algorithms: ['HS256'] }), (req, res) => {
    res.send('This is a protected route');
});

Make sure to replace 'your_secret_key' with a strong secret.