
Cryptocurrencies Exchange.
Gemini API is a free Cryptocurrency API that requires no API key, is served over HTTPS and has unconfirmed CORS support.
Build across Spot, Margin, Perpetuals, and Prediction Markets with Gemini APIs, guides, and developer tools.
Details from docs.gemini.com.

Unified API suite · now live
Geocode an address, validate an email, track a flight or pull stock data with one account, one dashboard and one API key.
Exchange rates between 162 currency & 300 crypto currency update each 5 min, accurate, no limits
The Gemini API is provided by Gemini Developer Platform (docs.gemini.com). Build across Spot, Margin, Perpetuals, and Prediction Markets with Gemini APIs, guides, and developer tools.
Yes. The Gemini API is listed in the Cryptocurrency category of the public-apis directory, which only includes APIs that are free or have a free tier. Check its documentation for rate limits and paid plans.
No. The Gemini API requires no authentication, so you can start making requests without signing up.
CORS support for the Gemini API is unknown. Test a request from the browser, and fall back to a server-side call if it is blocked.
Yes. The Gemini API is served over HTTPS, so it's safe to use in production.