Topic
Application programming interfaces
An application programming interface, or API, describes how one piece of software can use another.
At a glance
- Abbreviation
- API
- Typical contract
- Inputs, outputs, and operations
Overview
An application programming interface, or API, describes how one piece of software can use another. An API can expose functions within a program or operations over a network. The interface defines the interaction without requiring its caller to reproduce the implementation.
An interface is a boundary
A caller supplies inputs through the documented interface and handles the result. This boundary lets implementation details change while the agreed interaction remains stable, provided compatibility is preserved.
Web APIs
A web API often uses HTTP requests and responses. Methods, paths, payload formats, and error responses form part of its contract; successful network delivery alone does not mean an application operation succeeded.
Sources and review
MOOR's explanatory text is supported by the following source links.
- API glossary — MDN Web Docs
- HTTP overview — MDN Web Docs