Gnostic
A compiler for APIs described by the OpenAPI Specification with plugin
...Using these protobuf models, developers can safely parse, validate, and manipulate OpenAPI specifications, resolve dependencies, and export results as JSON, YAML, or binary files. Gnostic also provides a plugin interface similar to protoc, enabling integration with external API tooling and the generation of additional artifacts, such as annotated protobuf APIs, Go clients, and vocabulary summaries. It supports multiple OpenAPI versions (v2, v3) and Google Discovery Documents.