JWT Authentication Skill

Implement secure, scalable authentication in Node.js applications using JSON Web Tokens.

Quick Start

JWT authentication in 4 steps:

1. Install - npm install jsonwebtoken bcryptjs
2. Register - Hash password, create user, generate token
3. Login - Verify password, generate token
4. Protect - Verify token in middleware

Core Concepts

Generate JWT

const jwt = require('jsonwebtoken');

function generateToken(userId) {