I am converting my proto to typescript with https://github.com/improbable-eng/grpc-web and until recently also used their go server library. That meant my grpc servers were listening on 2 ports, gRPC and gRPC-web. I since replaced the gRPC-web part with envoy. Works fine together with the gRPC-web typescript.
The gist should give you an idea how to set up a small example.
https://gist.github.com/codesuki/f0514368a30b483058007f5fe38...