Comment 1 for bug 1599632

That's a good idea, at first cloudkitty has been engineered around keystone v2. But most of the deployments now use keystone v3. We plan on moving to a new rating engine, which will enable many more features. Such as by domain/project/user rules, validity period and so on.
I would love that you participate in the design of the new rating engine. We can put it on the agenda for next week's meeting and discuss this.
We'll implement rating engine as a driver so old behavior will be kept but a new driver will be developed to implement new set of features.