How do I implement JWT in my Express application?

How do I implement JWT in my Express application?

To implement JWT in your Express app, you'll need to install the jsonwebtoken package and set up middleware for authentication.

Can you show me a code example for generating a JWT?

Sure! Here's a simple example:

const jwt = require('jsonwebtoken');

const token = jwt.sign({ userId: 123 }, 'your_secret_key', { expiresIn: '1h' });
console.log(token);

How do I verify the JWT in a protected route?

You can verify the JWT using middleware. Here's an example:

app.use((req, res, next) => {
  const token = req.headers['authorization'];
  jwt.verify(token, 'your_secret_key', (err, decoded) => {
    if (err) return res.sendStatus(403);
    req.user = decoded;
    next();
  });
});

What should I do if the token is expired?

If the token is expired, you should return a 401 Unauthorized response and prompt the user to log in again to obtain a new token.