what options are there to license my rails application to endusers, like concurrent users or counted users. How can we manage that with rails, or so I need to write something from scratch

SO I have created an rails application, that I want to distribute for a fee.

It will be hosted on AWS elastic servers with autoscale.

I need to somehow have the ability to generate liceses for my enduser customers for my application. I was thinking on something like number of concurrent users per customer, or named users per customer. The named users thing is fairly easy to do, but I feel the concurrent user model is more interesting and does better reflect the actual use of the product.

Are there any good out of the box Rails methods to handle this?