We already have swagger API specification enabled but not tested.
https://swagger.io/specification/
Swagger is a Web API specification document that helps developers design, build, document, and consume RESTfulweb services. Swagger tools support automated documentation, code generation, and test-case generation.
The Swagger specification should provide information about APIs like,
All the operations that API supports
API’s parameters and return type
API objects structure
API authorization
License to use the API etc.
These should enable users to create an API Client using any swagger-supported REST API Client tool example autorest