Especially for generating large numbers of groups and repositories from the API, it would be super helpful to have a policy.create API function. In our scenario, we want to create custom policies to restrict the visibility of student repositories.
As far as I can see, creating custom policies from the API cannot be achieved at the moment. Wikimedia has already an extension to achieve this goal.
Root Problem: I run a class of 50 students every semester. We want to use Phabricator to learn concepts of operating system constructions and the students get graded on the code they commit into Phabricator. We don't want students seeing each others work, so we want to pre-fill repositories with policies that enforce this visibility so no cheating occurs. Furthermore, a tutor group should also have the possibility to view the repository. Because of the large number of repositories and groups, we have to ease production as much as possible with Conduit.