The original title is: "The Token Bucket Algorithm: Build Server-Side API Rate Limiting in ~40 Lines"

Short summary

The token bucket algorithm provides fair API rate limiting: requests consume tokens from a refillable bucket, sustaining an average rate while allowing bursts. This tutorial implements it in 40 lines of JavaScript with no dependencies, then scales it to Redis for distributed systems. Production-ready details include structured error responses, Retry-After headers, and strategies for key eviction and endpoint-specific costs.

• •Token bucket algorithm balances sustained rate limits with burst capacity
• •40-line JavaScript implementation with lazy-computed refill and no dependencies
• •Scale to Redis for distributed systems using atomic Lua scripts

Generated with AI, which can make mistakes.