But what is the OpenAPI Specification?

The OpenAPI Specification (or OAS) is a standard and programming-language agnostic REST API description format. Formerly known as the Swagger Specification, this format has been donated to the Open API Initiative (or OAI) which is a Linux Foundation Collaborative Project.

There are two versions of the OpenAPI Specification:

• Version 2.0 which is basically Swagger 2.0 Specification
• Version 3.0 which is the first evolution after the donation of the Swagger Specification to the Open API Initiative

The OpenAPI Specification is a community driven format, anyone can contribute to it through its github repository.

OpenAPI Specification version 2.0 Tutorial

Learn all OpenAPI Specification 2.0 secrets with this 9 parts tutorial:

OpenAPI Map for version 2.0 & 3.0

If you’re a bit lost in the OpenAPI Specification documentation, take a look at the OpenAPI Map: