SKILL.md
API Authentication
Table of Contents
- [Overview](#overview)
- [When to Use](#when-to-use)
- [Quick Start](#quick-start)
- [Reference Guides](#reference-guides)
- [Best Practices](#best-practices)
Overview
Implement comprehensive authentication strategies for APIs including JWT tokens, OAuth 2.0, API keys, and session management with proper security practices.
When to Use
- Securing API endpoints
- Implementing user login/logout flows
- Managing access tokens and refresh tokens
- Integrating OAuth 2.0 providers
- Protecting sensitive data
- Implementing API key authentication
Quick Start
Minimal working example:
// Node.js JWT Implementation
const express = require('express');
const jwt = require('jsonwebtoken');
const bcrypt = require('bcrypt');
const app = express();
const SECRET_KEY = process.env.JWT_SECRET || 'your-secret-key';
const REFRESH_SECRET = process.env.REFRESH_SECRET || 'your-refresh-secret';
// User login endpoint
app.post('/api/auth/login', async (req, res) => {
try {
const { email, password } = req.body;
// Find user in database
const user = await User.findOne({ email });
if (!user) {
return res.status(401).json({ error: 'Invalid credentials' });
}
// Verify password
const isValid = await bcrypt.compare(password, user.password);
if (!isValid) {
return res.status(401).json({ error: 'Invalid credentials' });
}
// ... (see reference guides for full implementation)Reference Guides
Detailed implementations in the references/ directory:
Guide
Contents
JWT Authentication
OAuth 2.0 Implementation
API Key Authentication
Python Authentication Implementation
Python Authentication Implementation
Best Practices
✅ DO
- Use HTTPS for all authentication
- Store tokens securely (HttpOnly cookies)
- Implement token refresh mechanism
- Set appropriate token expiration times
- Hash and salt passwords
- Use strong secret keys
- Validate tokens on every request
- Implement rate limiting on auth endpoints
- Log authentication attempts
- Rotate secrets regularly
❌ DON'T
- Store passwords in plain text
- Send tokens in URL parameters
- Use weak secret keys
- Store sensitive data in JWT payload
- Ignore token expiration
- Disable HTTPS in production
- Log sensitive tokens
- Reuse API keys across services
- Store credentials in code