Realtime & Historical Stock and Market Data.
IEX Cloud API is a free Finance API that requires apiKey authentication, is served over HTTPS and supports CORS, so it can be called from the browser.

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.
Get complete history of India Mutual Funds Data
Yes. The IEX Cloud API is listed in the Finance 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 IEX Cloud API uses apiKey authentication, so you need to register for credentials before making requests.
Yes. The IEX Cloud API supports CORS, so front-end JavaScript can call it directly.
Yes. The IEX Cloud API is served over HTTPS, so it's safe to use in production.