chat_user* add_local_user(  
    PCWSTR xboxUserId  
)  

chat_user* newLocalChatUser = chat_manager::singleton_instance().add_local_user(<local_user_xuid>);

size_t chatUserCount; 
chat_user_array chatUsers; 
chat_manager::singleton_instance().get_remote_chat_users(&chatUserCount, &chatUsers); 
for (uint32_t chatUserIndex = 0; chatUserIndex < chatUsercount; ++chatUserIndex) 
{ 
    chat_user* chatUser = chatUsers[chatUserIndex]; 
    game_chat_communication_relationship_flags relationship = game_chat_communication_relationship_flags::none; 
    if (chatUser can send and receive to/from newLocalChatUser) 
    { 
        relationship = c_communicationRelationshipSendAndReceiveAll; 
    } 
    else if (chatUser can send to newLocalChatUser) 
    { 
        relationship = c_communicationRelationshipSendAll; 
    } 
    else if (chatUser can receive from newLocalChatUser) 
    { 
        relationship = c_communicationRelationshipReceiveAll; 
    } 

    newLocalChatUser->set_communication_relationship(chatUser, relationship); 
}