The openAPI uses Python flask but to be frank, it makes sense to use the schema to generate client rather then server. FastAPI and Pydantic can generate openAPI

The openAPI uses Python flask but to be frank, it makes sense to use the schema to generate client rather then server. FastAPI and Pydantic can generate openAPI schema from datamodel which does the type parsing for you, if parsing is the use case. Writing server code with a library that can generate schema is a pro for me rather then keeping up with updates from schema to code.