[Noob Alert] Doing User Management and Leaderboards with Storyline

What is the best way to incorporate user management and gamification elements with Storyline content?

We plan to build HTML5 login and gamification and then incorporate Storyline content here but that would require Storyline to communicate the user id and other data back and forth with the PHP application. Is this possible using Storyline 2? I heard about Storyline Online API but that's limited only for Online users I believe. 

Thanks for any help with this!

Mahesh