This statement defines the expected capabilities of systems wishing to conform to the ''CRD Client'' role. This role is responsible for initiating CDS Hooks calls and consuming received decision support. It is also responsible for returning data requested by the CRD Server needed to provide that decision support. This capability statement doesn't define the CDS Hooks capabilities as there is no standard way to do that as yet. Instead, it focuses on the 'server' capabilities needed to respond to CRD Server queries. These capabilities are based on US Core.

In addition to the U.S. core expectations, the CRD Client SHALL support all 'SHOULD' 'read' and 'search' capabilities listed below for resources referenced in supported hooks and order types if it does not support returning the associated resources as part of CDS Hooks pre-fetch. The CRD Client SHALL also support 'update' functionality for all resources listed below where the client allows invoking hooks based on the resource.