Session Meta API provides all session attributes

The wamp.session.on_join meta event message and the response to a wamp.session.get meta procedure includes the attributes specified by the WAMP specification (session, authid, authrole, authmethod, authprovider, transport), and includes all attributes from the session HELLO message. This allows clients to provide more information about themselves, via HELLO, that may then be used by other sessions to make decisions about who to send messages to.