OpenAPI Specification

The OpenAPI Specification, previously known as the Swagger Specification, is a specification for a machine-readable interface definition language for describing, producing, consuming and visualizing web services. Originally developed to support the Swagger framework, it became a separate project in 2015, overseen by the OpenAPI Initiative, an open-source collaboration project of the Linux Foundation.

An OpenAPI Description (OAD) represents a formal description of an API that tools can use to generate code, documentation, test cases, and more.