Find Local Business.
Yelp API is a free Open Data API that requires OAuth authentication, is served over HTTPS and has unconfirmed CORS support.

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.
Composite travel-safety scores for 180 countries (FCDO + US State + GPI + WGI + live incident wire), OpenAPI 3.1 spec, CC BY 4.0
Brazilian company profiles by CNPJ, CNAE establishment counts and municipality coordinates
Yes. The Yelp API is listed in the Open Data 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.
Yes. The Yelp API uses OAuth authentication, so you need to register for credentials before making requests.
CORS support for the Yelp API is unknown. Test a request from the browser, and fall back to a server-side call if it is blocked.
Yes. The Yelp API is served over HTTPS, so it's safe to use in production.