limtr

A flexible rate-limiting middleware for Express applications using Redis for storage

Features

• Easy to integrate with Express applications
• Uses Redis for distributed rate limiting
• Customizable rate limits and time windows
• Supports custom key generation for fine-grained control
• Informative rate limit headers

Installation

npm install @muxn4/limtr

Make sure you have Redis installed and running on your system.

Usage

Here's a basic example of how to use limtr in your Express application:

const express = require('express');
const Limiter = require('@muxn4/limtr');

const app = express();

const limiter = new Limiter({
  points: 5, // Allow 5 requests
  duration: 60, // Per 60 seconds
  redisOptions: {
    host: 'localhost',
    port: 6379
  }
});

// Apply the rate limiting middleware globally
app.use(limiter.middleware());

app.get('/', (req, res) => {
  res.send('Hello, World! This route is rate limited.');
});

app.listen(3000, () => {
  console.log('Server is running on port 3000');
});

Configuration

The Limiter constructor accepts the following options:

• points (Number): Maximum number of requests allowed within the duration (default: 10)
• duration (Number): Time window in seconds (default: 1)
• keyPrefix (String): Prefix for Redis keys (default: 'limtr')
• redisOptions (Object): Options for the Redis client (see ioredis documentation)
• keyGenerator (Function): Custom function to generate keys (default: uses IP address)

Headers

limtr sets the following headers on responses:

• X-RateLimit-Limit: The maximum number of requests allowed in the current time window
• X-RateLimit-Remaining: The number of requests remaining in the current time window
• X-RateLimit-Reset: The time at which the current time window resets (in UTC epoch seconds)

When the rate limit is exceeded, it also sets:

• Retry-After: The number of seconds to wait before making another request

Contributing

Contributions are welcome! Please feel free to submit a Pull Request.

License

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