Hotspot + Usermanager

I’m developing a hotspot system for a client, and part of their requirements is to have a login w/ rate limiting, to record the MAC address assigned to an IP at any given time.

So basically, I’d like to use the user manager to handle all that, allowing a web based signup from the hotspot login page.

Is this possible? Is there already software to do it, or an API available that would allow this to be done?

I thought I should clarify… the problem I’m trying to solve isn’t making the hotspot use the usermanager (That’s easy: RADIUS), the problem I’m trying to solve is how to let users sign themselves up.

User Sign-up is implemented since 2.9.31 version, we are updating documentation about this feature,
http://wiki.mikrotik.com/wiki/User_Manager/User_sign_up