I'm on the forum today to learn how to do just this. :-)
Extensive searching has found this "article":
https://www.vbulletin.com/forum/cont...ess-Mobile-API
Well, it says it's an "article", but really all is says is to use the "login_login method". I need to find how to begin using the methods, or see some code just to figure how to start. Hope that links helps and we find where we are going from here. Looks like we're on our own!