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 install rate-limiter

Usage

Basic Example

import express from "express";
import { rateLimiter } from "rate-limiter";

const app = express();

const rateLimit = rateLimiter({
  key: (req, res) => req.ip as string,
  limitOptions: () => {
    return { max: 5, window: 10 };
  },
  standardHeaders: "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	string	Unique key to identify each client (e.g., IP address).	None (required)
limitOptions	Array	List of objects defining limit (maximum requests) and window (time in seconds).	None (required)
skip	Array	Keys to skip from rate-limiting.	[]
skipFailedRequests	boolean	Whether to exclude failed requests from rate limits.	false
cleanUpInterval	number	Interval (in seconds) for cleaning up expired rate data.	30
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
legacyHeaders	boolean	Whether to include legacy headers (e.g., X-RateLimit-Limit).	true
standardHeaders	boolean	Whether to include standard headers (e.g., RateLimit-Limit).	false
logs	object	Configuration for logging requests (e.g., directory).	undefined

Contributing

Contributions are welcome! If you'd like to contribute:

• Fork the repository.
• Create a feature branch: git checkout -b feature-name.
• Commit your changes: git commit -m "Add feature-name".
• Push to the branch: git push origin feature-name.
• Submit a pull request.

License

This project is licensed under the MIT License. See the LICENSE file for details.