KrotoDC - gRPC in Kotlin with Dataclasses https://medium.com/@icycle0409/introducing-krotodc-use-protobuf-and-grpc-with-kotlin-dataclasses-3144d0b20032

- A protoc plugin data class generator that can be used as a substitute for existing Java protobuf classes that need to be constructed by a builder (which isn't very kotlin-ish).
- generates coroutine service base and stubs that use the generated classes as request/response types, allowing you to completely avoid using Java classes.
- Since it also generates converter extension functions between the generated types and Java types, you can still easily use protobuf-specific features such as serialization.
- Additionally provides Kotlin-specific features (optional fields as nullable, oneof fields as sealed classes).