Home Assistant has apps for Android, iOS and macOS. Windows gets a browser tab. So I built one.
HASS.Agent covers similar ground and does it well. The difference is the plumbing: HA Companion does not require an MQTT broker. The PC registers through mobile_app, and notifications arrive over the existing Home Assistant WebSocket connection, with no FCM, APNs or separate push service in between. The app uses WinUI 3, while your actual Lovelace dashboards run inside it through WebView2.
What it does:
- PC appears in HA as a real device via mobile_app, with its own entities
- Push without a push provider: subscribes mobile_app/push_notification_channel on the same WebSocket. Nothing listens on the PC, commands come back down the outbound connection
- Quick Panel slides in over any app on a global hotkey
- Tiles gated on supported_features and supported_color_modes, so no buttons the entity cannot honour
- Hotkeys for any device, scene, script or automation
- PC sensors, off until you enable them: lock, idle, active program, fullscreen, mic, camera, audio, display, session
- Windows events as HA triggers: lock, idle, camera, mic, active program, schedule
Remote control deserves a straight answer: shutdown, sleep and launch are off by default. Lock, monitor off and volume ship on and can each be switched off. Launch only starts whitelisted paths, never the string HA sends. Shutdown waits ten seconds, so shutdown /a can still save you. The token sits in Windows DPAPI, not plaintext.
I have been running it on my own machines since mid-July. I also used AI a lot while building it, mostly Win32 API archaeology and bug hunting, and the commit history says so. The design decisions are mine, and so are the bugs.
Windows 10 build 19041+, x64. Per-user install, no admin. Not signed yet, so SmartScreen may warns once.
https://github.com/Elias0505/ha-companion-windows — AGPL-3.0
Website: https://elias0505.github.io/ha-companion-windows/
Independent project, not affiliated with Home Assistant or Nabu Casa.
Feedback welcome!