@lucid-softworks/rate-limit

Wrap a synchronous or asynchronous function so only a fixed number of calls start during each time window. Calls beyond the limit wait in FIFO order.

import { rateLimit } from "@lucid-softworks/rate-limit";

const fetchUser = rateLimit(
  async (id: string) =>
    fetch(`/api/users/${id}`).then((response) => response.json()),
  { limit: 5, intervalMs: 1_000 },
);

const user = await fetchUser("42");

pending reports how many calls are queued. clear(reason?) rejects queued calls without affecting work that has already started. Without a custom reason, queued calls reject with RateLimitClearedError.

limit must be a positive integer and intervalMs must be a finite, non-negative number. An interval of zero disables waiting while preserving the same promise-based interface.