protobuf/header.proto

// required fields will be filled in for you by ApplicationBase
// if you choose not to do so yourself
message Header
{
  //
  // time
  //

  // seconds since 01/01/1970 00:00:00 UTC
  required double unix_time = 1; 
  // boost::posix_time::to_iso_string(boost::posix_time::ptime)
  required string iso_time = 2;

  //
  // source
  //
  required string source_app = 3;
  required string source_platform = 4;
  optional string source_additional = 5;

  //
  // destination
  //
  enum PublishDestination { self = 1; other = 2; all = 3; }
  optional PublishDestination dest_type = 6 [default = self];
  optional string dest_platform = 7; // required if dest_type == other  
}