I put a bit of work into documenting how the current writers setup could be reworked into something that’s more compatible with logging levels and slightly more structured output types so that 1) in the future getting JSON or binary output is not a nightmare; and 2) we do less grep-ing for strings at the interface level. It’s writer-callbacks all the way down, but with a little more structure and log levels.
If you have comments on this let’s discuss here and I’ll make changes, or just clone it and edit. If we find some agreement on this I’ll flesh out the binary format (Protobuf/capnproto/whatever) section.