Hi guys,
I wrote an addon for decoding protobuf, looks like:

To use it:

• Make sure you are not using the downloaded mitmproxy binary, they don't work with additional python scripts, as described here, use pip install mitmproxy instead.
• pip install protod
• Download this addon file: https://github.com/aj3423/protod/blob/master/example/mitmproxy_proto_view.py
• mitmproxy -s mitmproxy_proto_view.py -r my_saved.dump
• It's applied to the req/resp if itscontent_type contains string proto

Maybe with some modification, it can also be applied to Grpc requests, or a new Renderer for mitmweb.