Coinmarketcap Exchangerate API (TypeScript)

A TypeScript module to fetch cryptocurrency prices from CoinMarketCap API and forex prices from ExchangeRate API.

Features

• Fetch cryptocurrency prices from CoinMarketCap API
• Fetch forex prices from ExchangeRate API
• Automatic detection of cryptocurrency vs forex tickers
• Support for API keys via environment variables or direct assignment
• Easy to use and integrate into your projects
• Written in TypeScript with full type definitions

Installation

npm install coinmarketcap-exchangerate

Usage

Basic Usage

import { PriceFetcher } from '@droonacharyakochelo/coinmarketcap-exchangerate';

// Get API keys from environment variables or .env file
// Or provide them manually here:
const cmcApiKey = process.env.CMC_API_KEY || undefined;
const erApiKey = process.env.ER_API_KEY || undefined;

const fetcher = new PriceFetcher(cmcApiKey, erApiKey);

const tickers = ['BTC', 'ETH', 'EUR', 'JPY', 'DOT'];

const prices = await fetcher.fetchPrices(tickers);

prices.forEach(([ticker, name, price]) => {
  console.log(`${ticker}: ${name}: ${price}`);
});

Running the Example Script via CLI

You can run the example script directly from the command line:

npm run example

npm run example -- BTC ETH EUR JPY

Using API Keys via Environment Variables

Set your API keys as environment variables:

CMC_API_KEY=your_coinmarketcap_api_key
ER_API_KEY=your_exchangerate_api_key

Then run the example:

npm run example

Using API Keys via Direct Assignment - not recommended

import { PriceFetcher } from '@droonacharyakochelo/coinmarketcap-exchangerate';

// Provide API key as variable
const cmcApiKey = 'your_coinmarketcap_api_key';
const erApiKey = 'your_exchangerate_api_key';

const fetcher = new PriceFetcher(cmcApiKey, erApiKey);
const prices = await fetcher.fetchPrices(['BTC', 'EUR']);

Without API Keys (Default)

If no API keys are provided, the module will use:

• CoinMarketCap sandbox API (with limited requests)
• Default ExchangeRate API endpoint

import { PriceFetcher } from 'coinmarketcap-exchangerate';

const fetcher = new PriceFetcher();
const prices = await fetcher.fetchPrices(['BTC', 'EUR']);

Return Format

The fetchPrices() method returns a Promise that resolves to an array of Ticker, Currency Name, Price:

[
  ['EUR', 'Euro', 0.980],
  ['JPY', 'Japanese Yen', 0.005],
  ['BTC', 'Bitcoin', 78000.0],
  ['ETH', 'Ethereum', 3500.0],
  ['DOT', 'Polkadot', 7.5]
]

Each tuple contains the ticker symbol, currency name and its price in USD.

Requirements

• Node.js 20+
• npm or yarn

API Documentation

• CoinMarketCap API Documentation
• ExchangeRate API Documentation

License

MIT License