Mockleus is a stateless service mimicking a read only interface for the Nucleus identity 1.0 API. This is not a replacement for Nucleus and it does not aim to be, instead it's aim is to ease load testing removing the dependancy on the LT environment. It currently supports users, personas, entitlements, authtokens and encrypted tokens.
Get a overview of the current work load on Mockleus. In the metrics section you will get a real-time break down on every requester and the amount of calls they are currently doing.
Over here you can play around with a web based REST client and try out some calls against Mockleus and see the responses you get in return.
Have a look at the running config and what personas/entitlements Mockleus will handle.