fastify-rate-limiter

Simple rate limiter plugin based on memory and token bucket algorithm.

Installation

yarn add fastify-rate-limiter

Usage

import fastify, { FastifyReply } from 'fastify';
import ratelimiter from 'fastify-rate-limiter';

const app = fastify({ logger: true });

app.register(ratelimiter, {
  max: 5,
  timeWindow: 10,
});

app.get('/', (_, reply: FastifyReply) => {
  reply.send('hello world');
});

app.listen(3000);

Options

max: Maximum number of requests allowed in a time window, default is 100.

timeWindow: Time window value in seconds, default is 60

keyGenerator: A function to generate a unique identifier for each incoming request, default unique identifier is request.ip.

errorHandler: A handler function to customize response when limit reached: (req, request) => void

Response headers

request accepted

Rate limiting related headers will be added automatically.

X-RateLimit-Limit: Your max param, indicate the token bucket capacity.

X-RateLimit-Remaining: The number of remaining requests that can currently be accepted.

request rejected

Retry-After: Minimum wait time before next request can be sent. You can use errorHandler to customize your response header or do something else.