Simply Explained (for Golang) — How to start .proto file? syntax = "proto3"; Without the line above, the complier for protocol buffer will assume the syntax is based on proto2. Specify Field Types All fields are scalar type: string, float, int32, int64, uint32, uint64, sint32, sint64, fixed32 (always 4 bytes), fixed64 , bool, string, bytes etc. message Foo { //this is a message…