API for Object Mapping in PHP

We have so many ORM (Object Relational Mapping) software: http://en.wikipedia.org/wiki/List_of_object-relational_mapping_software#PHP

How about mapping API objects?

We are not using a database, but an API. So all data comes from the REST API.

Classic ORMs don't seem to handle this. Looks like I have to make my own using Zend Code Generator: http://framework.zend.com/manual/en/zend.codegenerator.html