What problem does it solve?
Protects APIs and backend services from abuse, excessive requests, and quota exhaustion by defining, enforcing, and monitoring rate limits so legitimate traffic remains unaffected and costly spikes are controlled.
Core Features & Use Cases
- Strategy design: Guidance on choosing fixed window, sliding window, token bucket, and leaky bucket approaches based on traffic patterns and burst tolerance.
- Implementation patterns: Examples and best practices for Express middleware, Redis-backed distributed counters, token-bucket libraries, Nginx limit_req, and per-API-key throttling.
- Operational controls: Configuring RateLimit headers, Retry-After responses, logging, monitoring, progressive penalties, and automated bans for abusive actors.
- Use Case: Protect public and authenticated endpoints, throttle expensive AI generation calls, limit login attempts, and enforce tiered quotas for free/pro/enterprise clients.
Quick Start
Add an express-rate-limit middleware with a Redis store to limit /api/ to a safe per-user quota, return RateLimit headers, and log violations for alerting.
