syntax = "proto3"; package geco.echo.v1; option go_package = "github.com/user/pkg;pkg"; import "google/protobuf/timestamp.proto"; import "google/api/annotations.proto"; message StringMessage { string value = 1; google.protobuf.Timestamp timestamp = 2; } service EchoService { rpc Echo(StringMessage) returns (StringMessage) { option(google.api.http) = { post: "/v1/echo/message" body: "*" }; } }