A CPG Client provides the patient context and data a CPG Service needs, presents the resulting guidance to users at the appropriate point in the workflow, and records the decisions and activities that follow from it (for example, accepting or rejecting a proposal, or recording the event that fulfills it).

A CPG Client always works with a CPG Service. A system that imports and executes guideline content natively, such as an EHR that implements the logic of a computable guideline directly, acts as both a CPG Client and a CPG Service. The specific interactions depend on the level of enablement, as described on the Actors page.