Rate Limiter Middleware
ELI5 — The Vibe Check
Rate limiter middleware is the bouncer that stops users from hammering your API too fast. '100 requests per minute, buddy. Come back in 30 seconds.' Without it, one aggressive user or bot can DOS your entire server.
Real Talk
Rate limiter middleware enforces request frequency limits per client, typically identified by IP address or API key. It uses algorithms like token bucket, sliding window, or fixed window to track request counts. When limits are exceeded, it returns 429 Too Many Requests. It's essential for API protection, fair usage, and cost control.
Show Me The Code
const rateLimit = require('express-rate-limit');
app.use(rateLimit({
windowMs: 15 * 60 * 1000, // 15 minutes
max: 100,
message: 'Too many requests, slow down'
}));
When You'll Hear This
"Add rate limiting before someone scripts 10,000 requests to our signup endpoint." / "The rate limiter returns 429 after 100 requests per minute per IP."
Related Terms
Middleware
Middleware is like a security checkpoint at an airport.
Rate Limiting
Rate limiting is like a bouncer who says 'you can come in 100 times per hour, then you wait.
Sliding Window
Sliding window rate limiting counts requests in a moving time window.
Token Bucket
A token bucket is a rate limiting algorithm. Imagine a bucket that fills with tokens at a steady rate. Each request costs one token.