[efitz]

WSDL and OpenAPI/Swagger solve similar problems.

Roughly speaking: WSDL is to XML web services as OpenAPI is to REST

They both model the API and message structure of an API. AFAICT WSDL goes a little farther in that you can declare message sequences (I might be giving short shrift to OpenAPI here).

[flatiron]

Short of “this requires oauth” I think you are right about openapi