I don't seem to have sufficient privileges in other forums where I could have made this query but I am a user of AddonChat. There is a parameter where variables can be placed to recognize the identification of users that will login them into the chat automatically.
Right now I'm using the demo forum. I'm also a support tech for AddonChat and we have a number of users who want an integration script where our chat software can be integrated with their XenForo forums. This will help me to kick start the project and at least give them a small alternative till our developers can write an authentication script.