Track deliveries, ride fares, payments and loyalty points.
Grab API is a free Transportation API that requires OAuth authentication, is served over HTTPS and has unconfirmed CORS support.
Documentation for Grab Developer
Details from developer.grab.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.
Cruise sailings, day-by-day itineraries, weekly fare history, port traffic and a cruise price index
Yes. The Grab API is listed in the Transportation 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 Grab API uses OAuth authentication, so you need to register for credentials before making requests.
CORS support for the Grab API is unknown. Test a request from the browser, and fall back to a server-side call if it is blocked.
Yes. The Grab API is served over HTTPS, so it's safe to use in production.