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 item attributes are powered by the generic Foundation Extensible Fields (FND EFF) system using entitytype = 'GPMITEM'. This lets any domain — insurance, radiology, beauty — define typed attribute sets on items without schema changes, while sharing a single consistent model across the platform.