Now that we understand the basics of YAML, we're ready to write our specification.
There are a few versions of the OpenAPI Specification available. At the time of writing this book, the OpenAPI Specification is at version 3.0.0 and was officially released on 26 July 2017. You may also find many OpenAPI 2.0 specifications in the wild as tooling support for 3.0.0 is lacking in many areas.
We will use OAS 3.0.0 as it is the latest version. Here, you'll find an overview of all the possible root properties in OAS 3.0.0. Not all fields are covered, and required fields are marked with an asterisk (*):
- openapi* (string): This specifies the OpenAPI specification version in use. We should specify the semver version; ...