Introduction

When you call an API that limits how many requests you can make (e.g. 100 per minute), or when you don’t want to flood a service with too many parallel calls, you need something to queue and pace your work.

rate-queue does that: you give it async jobs, and it runs them according to rules you set.

Production = multiple Node instances. In production, Node usually runs on more than one process (containers, PM2 cluster, several servers). Each process has its own memory, so a limit that lives only in one process doesn’t apply to the others. For a single shared limit across all instances, use the Redis-backed limiter (DistributedRateLimiter). The in-memory limiter (RateLimiter) is for a single process (e.g. local dev or one instance).

• Concurrency — e.g. “at most 5 requests at a time” (across all instances with Redis).
• Rate — e.g. “start at most one every 100ms” or “max 60 per minute”.
• Token bucket — e.g. “10 tokens, refill 10 every minute”.

Next: Installation → Quick start.