Well, I always try to keep in mind the distinction between protobuf the structured encoding and protobuf the code generator. You can use the former without the latter. Considering that the project doesn't even ship a codegen for Rust, you're already doing that. So if there's some more convenient API you'd like, you can just have it. You can also do this with protoc plugins and the official codegen, or you can hand-roll your own protocol parsers which isn't that crazy with such a simple format.