Cmc Api Crypto

CoinMarketCap Cryptocurrency API

This skill covers the CoinMarketCap Cryptocurrency API endpoints for retrieving price data, market listings, historical quotes, trending coins, and token metadata.

Authentication

All requests require an API key in the header.

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curl -X GET "https://pro-api.coinmarketcap.com/v3/cryptocurrency/listings/latest" \
  -H "X-CMC_PRO_API_KEY: your-api-key"

Get your API key at: https://pro.coinmarketcap.com/login

Base URL

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https://pro-api.coinmarketcap.com

Common Use Cases

See use-cases.md for goal-based guidance on which endpoint to use:

1. Get current price of a token
2. Find a token's CMC ID from symbol or name
3. Get a token by contract address
4. Get top 100 coins by market cap
5. Find coins in a price range
6. Get historical price at a specific date
7. Build a price chart (OHLCV data)
8. Find where a coin trades
9. Get all-time high and distance from ATH
10. Find today's biggest gainers
11. Discover newly listed coins
12. Get all tokens in a category (e.g., DeFi)

API Overview

Common Workflows

Get Token Price by Symbol

1. First, map the symbol to a CMC ID using /v1/cryptocurrency/map
2. Then fetch the price using /v3/cryptocurrency/quotes/latest

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# Step 1: Get CMC ID for ETH
curl -X GET "https://pro-api.coinmarketcap.com/v1/cryptocurrency/map?symbol=ETH" \
  -H "X-CMC_PRO_API_KEY: your-api-key"

# Step 2: Get price quote (using id=1027 for ETH)
curl -X GET "https://pro-api.coinmarketcap.com/v3/cryptocurrency/quotes/latest?id=1027" \
  -H "X-CMC_PRO_API_KEY: your-api-key"

The v3 response returns data as an array sorted by ID, and quote as an array with one object per convert currency, each carrying that currency's id and symbol. Read the price from the quote entry whose symbol is USD (the default). See quotes.md.

Get Top 100 Coins by Market Cap

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curl -X GET "https://pro-api.coinmarketcap.com/v3/cryptocurrency/listings/latest?limit=100&sort=market_cap" \
  -H "X-CMC_PRO_API_KEY: your-api-key"

Get Historical Price Data

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curl -X GET "https://pro-api.coinmarketcap.com/v3/cryptocurrency/quotes/historical?id=1&time_start=2024-01-01&time_end=2024-01-31&interval=daily" \
  -H "X-CMC_PRO_API_KEY: your-api-key"

Get Token Metadata

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curl -X GET "https://pro-api.coinmarketcap.com/v2/cryptocurrency/info?id=1,1027" \
  -H "X-CMC_PRO_API_KEY: your-api-key"

Error Handling

HTTP Status Codes

Rate Limits

Rate limits depend on your subscription plan. The response headers include:

1. X-CMC_PRO_API_KEY_CREDITS_USED - Credits used this call
2. X-CMC_PRO_API_KEY_CREDITS_LEFT - Credits remaining

Common Errors

Invalid ID: Ensure you use valid CMC IDs from the /map endpoint. Symbol lookups may return multiple matches.

Missing Required Parameter: Some endpoints require at least one identifier (id, slug, or symbol).

Plan Restrictions: Historical endpoints and some features require paid plans. Check your plan limits.

Error Response Format

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{
  "status": {
    "timestamp": "2024-01-15T12:00:00.000Z",
    "error_code": 400,
    "error_message": "Invalid value for 'id'",
    "credit_count": 0
  }
}

Response Format

All responses follow this structure:

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{
  "status": {
    "timestamp": "2024-01-15T12:00:00.000Z",
    "error_code": 0,
    "error_message": null,
    "credit_count": 1
  },
  "data": { ... }
}

/v3/cryptocurrency/listings/latest and /v3/cryptocurrency/quotes/latest return error_code as a string ("0" on success) and error_message as an empty string, so compare error_code as a string or convert it first.

Reference Files

See the references/ directory for complete parameter and response documentation for each endpoint.