I think you are talking about Cluster Management API for Dynatrace Managed. If you will go to Cluster Management API page from your account menu, you will see all available endpoints. It's not present in SaaS installation. Actually I don't see there any option to check license through the API.
We figured out that the /entity/infrastructure/hosts endpoint, has JSON conatining host info as consumedHostUnits":"
which did give us information about total license used.
Hi guys, we have the same "problem" now, we need to grep licence information from Dyntrace for our service reporting automatically out of the system. Does anyone know if there is a way today on the actual version ?