I really liked this detailed guide to consuming APIs through Javascript. No matter if you are using ReactJS or Angular or any other frontend framework, this is basic knowledge that you have to deal with at some point. Rahul leads by example here. A must read in my opinion.
Further reading
- HTTP/2 and gRPC — protocol choices for modern APIs.
- APIs for Authentication — OAuth, JWT and modern auth for the requests you make.
- Scrape a Webpage using Python 2.7 — fetching data from the web, Python edition.
