I am trying to programmatically create tasks / errors in Maniphest: https://www.phacility.com/phabricator/maniphest/
but I cannot find a RESTful API that can do this.
Am I completely missing something? or not currently one
Conduit ( https://secure.phabricator.com/book/phabricator/article/conduit/ ) should work for you. There is a method called createtask (looks like https://secure.phabricator.com/conduit/method/maniphest.createtask/ ), which is exactly what you are looking for.