@chirag127/rate-limit

Edge-ready rate limiter for Cloudflare Workers and Astro API endpoints.

Supports CF KV as store or falls back to in-memory Map with TTL.

Install

npm i @chirag127/rate-limit

Usage

Core

import { rateLimit } from '@chirag127/rate-limit';

const limiter = rateLimit({ limit: 10, window: 60, keyPrefix: 'api' });

// CF Worker — pass env.MY_KV as store
const { allowed, remaining, resetAt } = await limiter.check(clientIp, env.MY_KV);

// In-memory fallback (no store arg)
const result = await limiter.check(clientIp);

Astro middleware

// src/middleware.js
import { rateLimitMiddleware } from '@chirag127/rate-limit/middleware';

export const onRequest = rateLimitMiddleware({
  limit: 20,
  window: 60,
  keyPrefix: 'web',
  // optional: provide CF KV binding via Astro locals / runtime
  // store: runtime.env.RATE_LIMIT_KV,
  // optional: custom key function
  // keyFn: (req) => req.headers.get('cf-connecting-ip') ?? 'anon',
});

API

rateLimit(opts)

| Option | Type | Default | Description | |---|---|---|---| | limit | number | 10 | Max requests per window | | window | number | 60 | Window duration in seconds | | keyPrefix | string | 'rl' | KV/memory key prefix |

Returns a limiter object.

limiter.check(key, store?)

| Param | Type | Description | |---|---|---| | key | string | Client identifier (IP, user ID, etc.) | | store | CF KV namespace | Optional; falls back to in-memory |

Returns Promise<{ allowed: boolean, remaining: number, resetAt: Date }>.

rateLimitMiddleware(opts)

Same opts as rateLimit plus:

| Option | Type | Description | |---|---|---| | store | CF KV namespace | Optional KV binding | | keyFn | (req: Request) => string | Custom key extractor |

Returns an Astro onRequest middleware function. Sends 429 with Retry-After header when limit exceeded. Adds X-RateLimit-* headers to every response.

License

MIT