Zigbee‑on‑Host (ZoH) is an open‑source Zigbee protocol stack that runs on a host computer and talks to a radio co‑processor via the Spinel STREAM_RAW interface (compatible with OpenThread RCP firmware from Silabs, TI, Nordic, etc.). It provides a full‑featured coordinator/Trust‑Center implementation that can be used with Zigbee2MQTT or as a flexible test‑bed for Zigbee development and security research, allowing custom frame crafting and network‑state manipulation.