Koa Rate Limit Middleware

koa-ratelimit is a robust rate limiting middleware designed for Koa web applications. The current stable version is 6.0.0. It provides essential functionality to control and restrict the frequency of client requests to prevent abuse, enhance security, and ensure fair resource usage. Developers can choose between an in-memory driver (using a JavaScript Map) for simple, single-instance deployments or a Redis driver (requiring an ioredis client) for scalable, distributed environments. Key configurable options include the duration of the rate limit window, the maximum number of requests allowed within that duration, custom error messages, and flexible request identification (e.g., by IP address). It also supports advanced features like whitelisting, blacklisting, and custom HTTP headers for communicating rate limit status to clients. Releases follow an evolutionary path, with recent major versions focusing on updated Node.js engine support and feature refinements.