A non-transitory computer-readable medium having program instructions for a method implemented in a content management system (CMS), for providing integration between APPS configured for use with an editor application of the CMS, the method including the following operations: installing a first APP and a second APP in a content project of the CMS, wherein installing the first and second APPs enables functionalities of the first and second APPs to be accessed for the content project through the editor application, wherein the editor application provides an interface for editing the content project; receiving from the first APP a request to invoke an action by the second APP; responsive to receiving the request, then validating contents of the request; responsive to successful validation of the request, then sending an acknowledgement to the first APP, and generating a call to the second APP to invoke the action by the second APP.