Guide
CryptoETF API
Free REST API for US spot crypto ETF data: daily net flows for 16 assets and for every fund behind them (IBIT, FBTC, ETHA, …), a fund directory with net assets (AUM), the CEFI — Crypto ETF Flow Index, spot prices of the coins and weekly totals. These are the numbers behind cryptoetf.today. Overview, FAQ and the MCP setup: cryptoetf.today/api.
REST · /v18 endpoints16 assetsJSONMCP
Get a keyFree, no card. It is created in your profile on cryptoetf.today.Open profile →Make a requestSend the key as a Bearer token or in the X-API-Key header.Authentication →Connect an agentClaude, Cursor and other agents read the same data. No key needed.MCP server →
Endpoints
| GET | /flows/summary | Latest net flow for every asset |
| GET | /flows/{asset} | Daily net flows of one asset |
| GET | /flows/{asset}/funds | Daily net flows of one asset, fund by fund |
| GET | /funds | Fund directory with assets under management |
| GET | /index/cefi | CEFI — Crypto ETF Flow Index |
| GET | /tickers | List tracked assets |
| GET | /prices | Spot prices of the coins |
| GET | /analytics/weekly | Seven-day flow totals |
Guides
- AuthenticationEvery /v1 request needs a free API key — no card, no plan.
- Rate limits120 requests per minute per key , counted in fixed 60 second windows.
- Data window30 days.
- CEFI indexEvery trading day CEFI adds up the net flows of all spot ETFs on the 16 tracked assets, in dollars.
- ConventionsDates are UTC, YYYY MM DD ; timestamps are ISO 8601.
- ErrorsErrors are JSON: { "statusCode": 401, "error": "Unauthorized", "message": "…" } .
- Changelog2026 10 16 — Per fund flows ( /v1/flows/{asset}/funds , MCP get_fund_flows ) and the fund directory with net assets ( /v1/funds , MCP get_funds ).
- TermsUse of the API is covered by the Terms of Service.