gRPC with proto3 / how to make intermediate service proto file definition independent

[visha...@gmail.com]

Intermediate service receives a json request and then it distributes among worker services. 

It then accumulates results and responds pack as json. 

Problem is intermediate service has to know proto definition to decide which service to send request  . 

This couple intermediate service and worker with shared proto definition . 

Is there any way to make no change in intermediate service and get new fields in worker service.