The term "SMART app" wasn't what was really intended by the submitter. The key is that there might be multiple systems involved. We will add a paragraph to the specification that indicates the following: "The CRD client may actually involve multiple systems. For example, the systems that handle order entry may be different from what is used for appointment booking and different again from the system that exposes information over the FHIR interface. It is possible that a provider environment might use an intermediary to coordinate CRD client calls from multiple systems. Such an architecture is sufficient provided that: Calls are triggered from within the system the user is interacting with at the time the 'hook event' (entering an order, booking an appointment, etc.) occurs. Cards returned are displayed to the user, or in the event of system actions, user-notifications associated with the system actions occur in the application the user was interacting with. The 'access token' and FHIR endpoint exposed to the CRD service has access to all relevant data, independent of which physical data store it resides in. The intermediary could take on the responsibility for the FHIR interface, determining appropriate payer to route calls to, etc." Also, have agreed elsewhere that we'll be updating the graphic to highlight the possibility of intermediaries