Home Assistant adds alarm and maintenance event entities for UniFi Protect sensors that report smoke-detector support. Smoke and carbon-monoxide alarm events sit alongside self-tests, low battery, cleaning requests, faults and end-of-life notices.
These are events, rather than a continuously active smoke or carbon-monoxide state: the public interface does not supply that state. The change uses the detector’s advertised capabilities, including USL Smoke and UP Sense devices that expose the smoke flag.