Programming

Honestly not sure about Swagger, I've only ever used swagger-ui to show the API docs on a webpage. OpenAPI as a standard and openapi-generator are not abandoned and quite active. I'll give you an example of how I use it.

I have a FastAPI server in python that defines some endpoints and data models that it can work with, it exports an openapi.json definition. I also have a common schemas library defined with pydantic that also exports an openapi.json (python was chosen to make it easier for other team members to make quick changes). This schemas library is also imported in the FastAPI app, basically only the data models are shared.

I use the FastAPI/openapi.json to generate C++ code in one application (the end user app) using the openapi-generator-cli, serialize/deserialize is handled by the generated code, since the pydantic schema is a dependency of the FastAPI server, both the endpoints and data models get generated. The pydantic/openapi.json is also used by our frontend written in typescript to generate data models only since the frontend doesn't need to call FastAPI directly but it has an option to in the future by generating from FastAPI/openapi.json instead.

This ensures that we're using the same schema across all codebases. When I make changes to the schema, the code gets re-generated and included in the new c++/web app builds. There's multiple ways to go about versioning, but for data only schema I'd just keep it backwards compatible forever (by adding new props as optional field rather than required and slowly deprecating/removing props that are no longer used).

I found this to be more convoluted than just using something like gRPC/Protobuf (which can also be serialized from JSON), I've used it before and it was great. But for other devs that need to change a few lines of python and not having to deal with protobuf compiler, it's a more frictionless solution at the cost of more moving parts and some CICD setup on my side.

Obligatory "JSON APIs are not REST because JSON is not hypermedia".

GraphQL is a mess too as you throw out any ability to reason about query performance and it still requires thick clients with complicated/duplicated business logic.

If you're doing RoR anyway, then go for https://htmx.org/. It's much, much simpler and closer to how the web was originally designed. Highly recommend this book the author wrote on the subject (also provides tutorials walking through building an app): https://hypermedia.systems/book/contents/.