CoinAPI

Overview

CoinAPI aggregates market data from hundreds of exchanges — real-time and historical prices, order books, trades, and exchange rates — via one REST API. Auth is a free API key (an invalid key returns 401, verified).

Quick Start

Exchange rate (replace YOUR_KEY):

curl "https://rest.coinapi.io/v1/exchangerate/BTC/USD" \
  -H "X-CoinAPI-Key: YOUR_KEY"

{
  "asset_id_base": "BTC",
  "asset_id_quote": "USD",
  "rate": 67234.5,
  "time": "2026-08-22T06:00:00.0000000Z"
}

Current rates across exchanges:

curl "https://rest.coinapi.io/v1/exchangerate/BTC/USD?invert=true" \
  -H "X-CoinAPI-Key: YOUR_KEY"

Historical daily rates:

curl "https://rest.coinapi.io/v1/exchangerate/BTC/USD/history?period_id=1DAY&time_start=2026-08-01" \
  -H "X-CoinAPI-Key: YOUR_KEY"

Authentication

• Register at coinapi.io → free API key (emailed).
• Send it as the X-CoinAPI-Key header (an invalid key returns 401 — verified).

Rate Limits & Notes

• Free tier: 100 requests/day (up to 250 symbols) — small; paid plans scale.
• Covers 600+ assets and 300+ exchanges — a big aggregated universe.
• Symbols use ASSET_BASE/ASSET_QUOTE pairs; metadata endpoints list available symbols.
• Historical data depth depends on the plan.

FAQ

Is CoinAPI free? Free tier: 100 requests/day; more is paid.

How do I get a key? Register at coinapi.io — the key is emailed.

What data is available? Exchange rates, order books, trades, and historical data from 300+ exchanges.