WebSocket identification of each connection, how?

Question

Node.js

How to store connections and send msg to the right client is clear.
But how to understand that this msg came from Vasya and not from Petya?
Sample message { 'msg' : 'Hi!' }

Answer 1

Add the message initiator object to the mailing list (i.e. the user who created this message)
{msg : 'msg', fromUser : ?}