Building a Zero-Dependency Rate Limiter for Express: Inside api-rate-guard

Building a Zero-Dependency Rate Limiter for Express: Inside api-rate-guard Rate limiting is one of those things every production Node.js API needs, and most teams implement it too late — after the first abuse incident, the first DDoS attempt, or the first credit card bill from a runaway scraper. I just published api-rate-guard — a zero-dependency sliding window rate limiter middleware for Express. This post explains why we built it, how the algorithm works under the hood, and the patterns that make it useful for real production APIs. Why Another Rate Limiter? express-rate-limit is excellent and widely used. So why build something new? A few reasons came up while writing the Node.js API Rate Limiting guide : Learning value — understanding how a rate limiter works makes you much better at configuring one. The express-rate-limit source is solid but spread across multiple files with plugin abstractions. Zero dependencies — express-rate-limit pulls in a handful of small deps. Someti