I definitely want jsonschema, it's a standard and i can use it for many tools. openapi spec is also a standard and built on top of jsonschema. I can use jsonschema to generate models, types, servers, client sdks, automate forms etc. I think it's better than grpc for some of these things, plus protobufs and grpc have bunch of tooling that i can pretend to understand but in depth i don't really.