syntax = "proto3"; package echo; service Echo { rpc DoEcho (EchoRequest) returns (EchoRequest) {} } message EchoRequest { string message = 1; } message AddRequest { fixed32 addX = 1; fixed32 addY = 2; } message AddResponse { fixed32 answer = 1; } service Add { rpc DoAdd (AddRequest) returns (AddResponse) {} }