🌐 Node API Proxy Server

A secure, production-ready proxy server for hiding API keys, implementing rate limiting, and caching responses. Built with Node.js and Express.

🎯 Features

• 🔐 API Key Protection - Keep your API keys secure on the server side
• ⚡ Rate Limiting - Prevent abuse with configurable request limits
• 💾 Response Caching - Improve performance and reduce API calls
• 🌤️ Weather App Demo - Includes a beautiful weather application UI
• 🔄 Flexible Configuration - Easy to adapt for any public API
• 🎨 Modern UI - Responsive design with glassmorphism effects

🚀 Why Use an API Proxy?

When working with third-party APIs (OpenWeather, GitHub, Twitter, etc.), you typically need to include your API key in client-side requests. This exposes your credentials to anyone who inspects your code.

The Problem:

// ❌ API key exposed in client-side code
fetch(
  `https://api.openweathermap.org/data/2.5/weather?q=London&appid=YOUR_API_KEY`
);

The Solution:

// ✅ API key hidden on server
fetch(`/api?q=London`);

This proxy server acts as a secure middleman, handling API authentication on the server while your client makes simple requests to your own endpoints.

📋 Prerequisites

• Node.js (v14 or higher)
• npm or yarn
• An API key from OpenWeather API (free tier available)

⚙️ Installation

1. Clone the repository

git clone https://github.com/SaketKothari/api-proxy-server.git
cd api-proxy-server

2. Install dependencies

npm install

3. Configure environment variables

Rename .env.example to .env and add your API credentials:

API_BASE_URL=https://api.openweathermap.org/data/2.5/weather
API_KEY_NAME=appid
API_KEY_VALUE=your_openweather_api_key_here

4. Start the development server

npm run dev

5. Open your browser

Navigate to http://localhost:5000

🔧 Configuration

Environment Variables

The .env file structure is designed to work with any public API:

# Base URL of the API (without query parameters)
API_BASE_URL=https://api.example.com/endpoint

# The query parameter name for the API key
API_KEY_NAME=apiKey

# Your actual API key value
API_KEY_VALUE=your_secret_key

Rate Limiting

Customize rate limits in your server configuration:

• Default: 100 requests per 15 minutes per IP
• Adjust as needed based on your API's limits

Caching

Configure cache duration to reduce redundant API calls:

• Responses are cached to improve performance
• Configurable TTL (Time To Live)

🎨 Usage Examples

Basic Weather Query

// Client-side request
fetch("/api?q=London")
  .then((res) => res.json())
  .then((data) => console.log(data));

With Additional Parameters

// Add any query parameters your API supports
fetch("/api?q=NewYork&units=metric")
  .then((res) => res.json())
  .then((data) => console.log(data));

📁 Project Structure

api-proxy-server/
├── index.js              # Main server file
├── package.json          # Dependencies and scripts
├── .env                  # Environment variables (create from .env.example)
├── middleware/
│   └── error.js         # Error handling middleware
├── routes/
│   └── index.js         # API routes
└── public/              # Client-side files
   ├── index.html       # Main HTML file
   ├── style.css        # Styles with modern design
   └── main.js          # Client-side JavaScript

🔌 Adapting for Other APIs

This proxy server is designed to be flexible. To use it with different APIs:

1. Update the .env file with your API's base URL and key format
2. Modify the routes in routes/index.js if needed
3. Adjust the client-side code in public/main.js to handle your API's response format

Example: GitHub API

API_BASE_URL=https://api.github.com/users
API_KEY_NAME=Authorization
API_KEY_VALUE=token your_github_token

🛡️ Security Features

• ✅ API keys stored securely in environment variables
• ✅ Rate limiting to prevent abuse
• ✅ CORS configuration
• ✅ Error handling middleware
• ✅ Input validation

🚀 Deployment

This server can be deployed to various platforms:

• Heroku: git push heroku main
• Vercel: Deploy with Vercel CLI
• Railway: Connect GitHub repository
• DigitalOcean: Deploy on App Platform

Remember to set environment variables in your deployment platform!

📝 License

This project is open source and available under the MIT License.

🤝 Contributing

Contributions, issues, and feature requests are welcome! Feel free to check the issues page.

📧 Contact

For questions or support, please open an issue in the GitHub repository.

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Made with ❤️ using Node.js and Express