Rate Limiter

A customizable rate-limiting and throttling middleware for Node.js applications. It allows you to limit the number of requests a client can make to your server within a specified time window.

Features

• Flexible request limiting based on time windows.
• Easily configurable for IP-based or user-based rate limiting.
• Simple integration as middleware in Node.js apps (e.g., with Express).
• Supports both rate limiting and throttling.

Installation

You can install the package via npm:

npm install digi-rate-limiter

Usage

Basic Usage

The package can be used as middleware in your Node.js/Express applications to limit requests. Here's an example to allow 10 requests per second.

import express from 'express';
import rateLimiter from 'digi-rate-limiter';

const app = express();

// Apply rate limiter middleware
app.use(rateLimiter({
  windowMs: 1000,   // 1 second
  maxRequests: 10   // Limit each client to 10 requests per windowMs
}));

app.get('/', (req, res) => {
  res.send('Hello, world!');
});

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

Options

The rateLimiter function accepts an options object to configure the behavior:

• windowMs: The time frame (in milliseconds) to allow maxRequests. For example, 1000 will enforce the limit per second.
• maxRequests: The maximum number of requests allowed during the windowMs period.

Example: 100 Requests per 15 Minutes

app.use(rateLimiter({
  windowMs: 15 * 60 * 1000,  // 15 minutes
  maxRequests: 100           // Limit each client to 100 requests per windowMs
}));

Advanced Features

IP-Based Limiting

By default, the middleware identifies clients by their IP address (req.ip in Express). This ensures that requests from each client IP are tracked separately.

User-Based Limiting

You can also implement user-based rate limiting by passing a user identifier (such as an API key or user ID) to the rate limiter.

app.use((req, res, next) => {
  const clientId = req.user.id; // Assuming you have user authentication
  rateLimiter({
    windowMs: 60000,   // 1 minute
    maxRequests: 30    // Limit to 30 requests per minute per user
  })(req, res, next);
});

Development

If you'd like to contribute or modify the package, you can clone the repository and run it locally:

git clone https://git.digimantra.com/abad_dml/rate-limiter
cd rate-limiter
npm install

Testing Locally

To run the Express example:

1. Create a file app.js as shown in the example above.
2. Run the server:

node app.js

Contributing

Contributions are welcome! Please open issues and submit pull requests on GitHub if you'd like to improve the package.

Issues

If you encounter any problems or have any questions, feel free to open an issue on GitHub.

Links

• GitHub: https://git.digimantra.com/abad_dml/rate-limiter
• NPM: https://www.npmjs.com/package/digi-rate-limiter

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