Application Programming Interface

What is Application Programming Interface?

A defined set of rules, functions or endpoints that lets one piece of software request services or data from another without needing to know how the other side implements them internally. That separation is the whole point — the implementation behind an API can be rewritten entirely, and as long as the interface itself stays the same, nothing on the other side needs to notice.

The five clues

Engineerdle #20 described Application Programming Interface with five clues, revealed one at a time from hardest to most direct. Each clue points at a different property of the concept.

1. 01A contract that lets two pieces of software talk without knowing each other's internals.
2. 02It defines what you can ask for, not how the answer gets computed.
3. 03Change what's behind it and, ideally, nothing on the other side even notices.
4. 04A web version of it typically speaks over HTTP, often exchanging JSON.
5. 05A defined set of rules and endpoints that lets separate software components communicate without exposing internal implementation.

More Software Engineering concepts

• Object-Oriented ProgrammingPuzzle #25