When a DCM device starts up, it needs to know which product slots it has, what their properties are, and any device-type-specific configuration values. This information is delivered to the device over MQTT - firmware does not call any HTTP endpoint directly.
The GPM data model is built around a single master item catalogue connected to four supporting concepts — categories and hierarchies, attributes and values, relationships, and actions (CTAs). Understanding how these relate is the key to understanding how Raytio's product catalogue works.
GPM uses an extensible attribute pattern to attach typed metadata to items. This allows each domain, such as insurance, radiology, or beauty, to define its own attribute sets while using the same product catalogue model. These domains and attributes are examples; they can be extended for other product and service catalogues.