Every time you call an api, you will also receive a reponse for it. And other players will get a notification about it.
Suppose there are 4 players in a room and you sent 1 chat message. You yourself will get onSendChatDone method and every one will get onChatReceived listener. So total no. of messages will be 6. 1 for calling api, 1 for response and 4 notifications.