# Authentication with JWT

## Authentication with JWT

```javascript
const jwt = require("jsonwebtoken");
const bcrypt = require("bcrypt");

const generateToken = (userId) => {
  return jwt.sign(
    { userId, iat: Math.floor(Date.now() / 1000) },
    process.env.JWT_SECRET,
    { expiresIn: "24h" },
  );
};

app.post(
  "/login",
  asyncHandler(async (req, res) => {
    const { email, password } = req.body;
    const user = await User.findOne({ where: { email } });

    if (!user) return res.status(404).json({ error: "User not found" });

    const validPassword = await bcrypt.compare(password, user.password);
    if (!validPassword)
      return res.status(401).json({ error: "Invalid password" });

    const token = generateToken(user.id);
    res.json({ token, user: { id: user.id, email: user.email } });
  }),
);
```