Rate Limiter

A highly configurable rate-limiting middleware for Express.js applications.

Overview

The Rate Limiter is an open-source NPM package designed for managing request rates in Express.js applications. It helps prevent abuse and ensures fair usage of server resources through customizable rate-limiting logic.

Features

• Highly configurable and flexible
• Supports in-memory and custom stores
• Automatic cleanup of expired rate data
• Customizable headers and response messages
• Optional logging for requests
• Seamless integration with Express.js

Installation

npm i @radioac7iv/rate-limiter

Usage

Basic Example

import express from "express";
import { expressRateLimiter } from "@radioac7iv/rate-limiter";

const app = express();

const rateLimit = expressRateLimiter({
  key: (req, res) => req.ip as string,
  limitOptions: () => {
    return { max: 5, window: 10 };
  },
  headersType: "draft-7",
  logs: {
    directory: "./logs",
  },
});

app.use(rateLimit);

app.get("/", (request, response) => {
  response.status(200).send({ message: "Hello!" });
});

app.listen(3000, () => {
  console.log("Server started at PORT: 3000");
});

Configuration

The rate limiter can be configured using the following options:

| Option | Type | Description | Default | | ------------------ | --------------------- | ------------------------------------------------------------------------------------------- | ------------------- | | key | function | Unique key to identify each client (e.g., IP address or an API Key). | Client's IP address | | skip | string[] | Keys to skip from rate-limiting. | [] | | skipFailedRequests | boolean | Whether to exclude failed requests from rate limits. | false | | message | string | Custom message when the rate limit is exceeded. | Rate limit exceeded | | statusCode | number | HTTP status code to send when the rate limit is exceeded. | 429 | | headersType | HeadersType | Choose between "legacy", "draft-6", "draft-7" or "draft-8" | legacy | | logs | object | Configuration for logging requests | undefined | | limitOptions | object | Function returning Object defining max (maximum requests) and window (time in seconds). | None (required) | | storeType | StoreType | Choose between "memory", "redis" or "mongodb" | memory | | externalStore | RedisClientType | Db | External store instance for storing rate-limiting data. | undefined |