Project: Cryptocurrency Stats API

This project is a server-side application built with Node.js and MongoDB that fetches cryptocurrency data (Bitcoin, Ethereum, Matic) from the CoinGecko API and provides various statistics through a set of API routes. The background service runs every 2 hours to update the cryptocurrency prices in the MongoDB database.

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Hosted Site

The API is hosted at: https://koinx-assignment-4cav.onrender.com

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Requirements

• Node.js
• MongoDB
• npm (Node Package Manager)

Setup Instructions

1. Clone the repository:

   git clone <repository-url>

2. Install dependencies:

   npm install

3. Create a .env file with the following content:

   MONGO_URI=<Your MongoDB URI>
   

4. Start the server:

   npm start

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API Endpoints

1. Get Latest Cryptocurrency Stats

   • Route: /api/stats
   • Method: GET
   • Query Params:
     • coin: Must be one of bitcoin, ethereum, matic
   • Hosted Endpoint: https://koinx-assignment-4cav.onrender.com/api/stats?coin=bitcoin
   • Sample Request:

     GET /api/stats?coin=bitcoin

   • Sample Response:

     {
       "price": 40000,
       "marketCap": 800000000,
       "24hChange": 3.4
     }

2. Get Price Standard Deviation

   • Route: /api/deviation
   • Method: GET
   • Query Params:
     • coin: Must be one of bitcoin, ethereum, matic
   • Hosted Endpoint: https://koinx-assignment-4cav.onrender.com/api/deviation?coin=bitcoin
   • Sample Request:

     GET /api/deviation?coin=bitcoin

   • Sample Response:

     {
       "deviation": 4082.48
     }

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Background Job

• The application runs a background job every 2 hours using node-cron that fetches the current price, market cap, and 24-hour price change for Bitcoin, Ethereum, and Matic from the CoinGecko API, and stores it in the MongoDB database.

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Folder Structure

crypto-app/
│
├── .env                # Environment variables
├── package.json        # Project dependencies
├── index.js            # Main application entry point
├── models/
│   └── cryptoModel.js  # Mongoose schema for storing crypto data
├── services/
│   └── fetchCryptoData.js  # Service to fetch crypto data from CoinGecko
│   └── saveCryptoData.js   # Service to save the fetched data to MongoDB
└── node_modules/

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Dependencies

• Express: For creating API routes
• Mongoose: For interacting with MongoDB
• Node-Cron: For scheduling background tasks
• Axios: For making HTTP requests to the CoinGecko API