Rate Limiter Proxy API

A flexible API rate limiting proxy service that helps manage and control access to third-party APIs.

Features

• API Key Authentication
• Dynamic App Registration
• Configurable Rate Limiting
• Request Queuing
• Proxy Request Forwarding

Prerequisites

• Node.js (v14 or higher)
• Redis
• MongoDB

Installation

1. Clone the repository
2. Install dependencies:

npm install

3. Copy .env.example to .env and configure your environment variables:

cp .env.example .env

Configuration

Update the .env file with your settings:

PORT=3000
REDIS_URL=redis://localhost:6379
MONGODB_URL=mongodb://localhost:27017/rate-limiter

API Endpoints

Authentication

Register a new user

POST /auth/register
Content-Type: application/json

{
  "email": "[email protected]",
  "password": "your-password"
}

Response:

{
  "message": "User registered successfully",
  "apiKey": "your-api-key"
}

App Management

All app management endpoints require the X-API-Key header.

Register a new app

POST /apps
Content-Type: application/json
X-API-Key: your-api-key

{
  "name": "My API",
  "baseUrl": "https://api.example.com",
  "rateLimitConfig": {
    "strategy": "fixed-window",
    "requestCount": 100,
    "timeWindow": 60000
  }
}

List registered apps

GET /apps
X-API-Key: your-api-key

Update app configuration

PUT /apps/:appId
Content-Type: application/json
X-API-Key: your-api-key

{
  "rateLimitConfig": {
    "requestCount": 200,
    "timeWindow": 60000
  }
}

Delete an app

DELETE /apps/:appId
X-API-Key: your-api-key

Using the Proxy

To make requests through the proxy:

[METHOD] /apis/:appId/*
X-API-Key: your-api-key

The proxy will:

1. Authenticate your request
2. Apply rate limiting
3. Forward your request to the registered API
4. Return the API response

Rate Limiting Strategy

The service implements a fixed-window rate limiting strategy using Redis. When a request is made:

1. The current request count is checked against the configured limit
2. If below the limit, the request is forwarded
3. If at the limit, the request is queued
4. Queued requests are processed when the time window refreshes

Development

# Run in development mode
npm run dev

# Build the project
npm run build

# Run in production mode
npm start

Error Handling

The API uses standard HTTP status codes:

• 200: Success
• 201: Created
• 400: Bad Request
• 401: Unauthorized
• 404: Not Found
• 429: Too Many Requests
• 500: Internal Server Error