Both. And if your external clients rather consume a JSON/REST API, it's easy to derive that from a gRPC API. You can do it right there in your protobuf definiti

Both. And if your external clients rather consume a JSON/REST API, it's easy to derive that from a gRPC API. You can do it right there in your protobuf definition. It's actually easier to do it that way than to deal with OpenAPI's wall of yaml.