Don't see much of a reason to use it, its also important to mention that code generation goes both ways. You can generate the schema from a service in FastAPI o

Don't see much of a reason to use it, its also important to mention that code generation goes both ways. You can generate the schema from a service in FastAPI or Spring and generate the client code from that schema. There are already existing code and schema generators for almost every strongly typed language and web framework, including Go, Scala, Typescript, Java and Rust. You never have to actually write any OpenAPI schema yourself nowadays. This also doesn't seem to address the one problem I always had with OpenAPI: Polymorphic types. Mapping an OpenAPI schema between strongly typed languages like Scala or TypeScript. OpenAPI 3 supports this now with discriminators but most code or schema generators aren't supporting this very well or at all yet. https://swagger.io/docs/specification/data-models/inheritance-and-polymorphism/ https://swagger.io/docs/specification/data-models/inheritanc...