The Contacts & Organizations, or Rolodex, app provides the Customer Relationship Management (CRM) capabilities of the Rhythm platform. Common integrations with the Rolodex API include finding or updating contact information, demographics, or communication preferences for a Contact or Organization.

Like most of the other Rhythm apps, the Rolodex API includes endpoints for Query Definitions. These endpoints are commonly used to retrieve saved queries, which can then be executed using the Query endpoints of the System API.