What problem does it solve? APIs and serverless endpoints need protection against abuse, traffic spikes, and runaway clients, but building distributed rate limiting from scratch is error-prone. This Skill provides guidance for configuring the Upstash Ratelimit TypeScript SDK so requests can be throttled consistently across regions with Redis as the backing store. ## Core Features & Use Cases - Multiple Algorithms: Choose between Fixed Window, Sliding Window, and Token Bucket limiters with documented trade-offs for accuracy, burst handling, and Redis command cost. - Protection & Analytics: Enable deny lists, automatic IP blocking from abuse feeds, and per-request analytics with dashboard visibility. - Cost & Operations Guidance: Understand exact Redis command counts per algorithm and feature to control latency and Upstash billing. - Use Case: A Next.js API route limits each user to 10 requests per 10 seconds using a sliding window limiter, blocks known abusive IPs automatically, and returns 429 responses with retry-after information when limits are exceeded. ## Quick Start Set up an Upstash Redis rate limiter in my TypeScript app that allows 10 requests per 10 seconds per user and rejects requests once the limit is exceeded.
