Server-Side API Rate Limiting with `express-rate-limit`

const express = require('express');
const rateLimit = require('express-rate-limit');
const app = express();

// Apply to all requests
const apiLimiter = rateLimit({
  windowMs: 15 * 60 * 1000, // 15 minutes
  max: 100, // Limit each IP to 100 requests per windowMs
  message: 'Too many requests from this IP, please try again after 15 minutes',
  standardHeaders: true, // Return rate limit info in the `RateLimit-*` headers
  legacyHeaders: false, // Disable the `X-RateLimit-*` headers
});

// Apply to specific routes, e.g., authentication
const authLimiter = rateLimit({
  windowMs: 60 * 60 * 1000, // 1 hour
  max: 5, // Limit each IP to 5 requests per hour for auth
  message: 'Too many authentication attempts from this IP, please try again after an hour',
  standardHeaders: true,
  legacyHeaders: false,
});

app.use('/api/', apiLimiter); // Apply to all API routes
app.post('/login', authLimiter, (req, res) => {
  // Handle login logic
  res.send('Login attempt processed.');
});

app.get('/', (req, res) => {
  res.send('Welcome!');
});

// Example API route
app.get('/api/data', (req, res) => {
  res.json({ message: 'Here is your data!' });
});

const PORT = process.env.PORT || 3000;
app.listen(PORT, () => {
  console.log(`Server running on port ${PORT}`);
});