A Checkmk extension for monitoring Homematic CCU2, CCU3, and RaspberryMatic systems through a lightweight TCP agent add-on running on the CCU. It monitors CCU information, service messages, low-battery and unreachable devices, radio duty cycle, climate channels, power plugs, and door/window contacts. Configurable thresholds, metrics, graphs, and perfometers support meaningful alerting and operational visibility. The add-on supports Checkmk 2.4 and 2.5 and is installed manually on the Homematic controller, independently of the Checkmk Agent Bakery.