syntax = "proto3"; package my_application; option go_package = "my_applicationpb"; option java_multiple_files = true; option java_outer_classname = "ServiceProto"; option java_package = "com.my_application"; import "uuid.proto"; message MyMessage { uuid.Uuid message_id = 1; string some_payload = 2; } service MyService { rpc GetUuid(MyMessage) returns (uuid.Uuid){ } rpc GetMyMessage(uuid.Uuid) returns (MyMessage){ } }