steamdeck2mqtt

A battery-efficient, event-driven bridge that pushes live Steam Deck status to Home Assistant over MQTT.

• Survives SteamOS updates. It lives under $HOME and never touches the read-only rootfs, so there's no steamos-readonly disable to redo after each update (the thing that breaks go-hass-agent).
• Easy on the battery. One mostly-idle main loop, driven by D-Bus and udev events instead of polling, so changes reach HA in about a second.
• Knows what you're playing, everywhere. Detects the running game in Gaming and Desktop Mode, reports Steam Remote Play and Moonlight streams, and tells native from Proton. It also makes a best-effort attempt to pull the console and ROM out of emulator front-ends.

Documentation

Everything appears as one Home Assistant device, Steam Deck. The ID column is the MQTT object id; HA exposes it as e.g. sensor.steam_deck_battery. Whole groups can be toggled off in config.toml under [entities].

Battery & power

Live on change; power, temperatures, time remaining and the charge limit refresh every ~90 s.

Entity	ID	Type	Notes
Battery	battery	sensor %
Battery charging	battery_charging	binary
AC power	ac_power	binary	charger connected
Battery power	battery_power	sensor W	charge/discharge magnitude
Battery state	battery_state	sensor	charging, discharging, full, pending_charge, etc.
Battery temperature	battery_temperature	sensor °C
Battery charge limit	battery_charge_limit	sensor %	100 = no limit
Battery time to full	battery_time_to_full	sensor min	while charging
Battery time to empty	battery_time_to_empty	sensor min	while discharging

Dock & display

Live on change.

Entity	ID	Type	Notes
External display	external_display	binary	DP/HDMI connected
USB host	usb_host	binary	dock or hub attached
Docked	docked	binary	external display or USB host

There's no real "docked" bit on SteamOS, and a wall charger gives neither a display nor a USB host, so the raw signals are exposed separately. Build your own meaning in HA if you like.

Session

Suspended is instant; Wi-Fi values refresh every ~90 s.

Entity	ID	Type	Notes
Suspended	suspended	binary
Wi-Fi SSID	wifi_ssid	sensor	empty when not connected
Wi-Fi signal	wifi_signal	sensor dBm

Game

Instant in Gaming Mode; otherwise polled every 5 s on AC, 15 s on battery.

Entity	ID	Type	Notes
Game	game	sensor	running title, or emulated ROM; empty when no game
Game state	game_state	sensor (enum)	in-game / steam-ui / none / desktop-mode
Gaming mode	gaming_mode	binary	on in Gaming Mode, off in Desktop Mode
Game platform	game_platform	sensor	Native / Proton / emulated (e.g. SNES) / Remote Play / Moonlight
Game App ID	game_app_id	sensor	Steam AppID

The neat part is how far detection reaches. Anything launched through Steam shows up in both Gaming Mode and Desktop Mode, with the right Game platform attached: Native, Proton, the emulated console behind a front-end (like ES-DE or RetroArch) with Game showing the inner ROM, or Remote Play / Moonlight when you're streaming the Deck from another machine. Apps started outside Steam aren't tracked.

Library & downloads

Updates live during a download (installed games only).

Entity	ID	Type	Notes
Games installed	games_installed	sensor	across internal + SD
Updates queued	updates_queued	sensor
Downloading	downloading	binary
Downloading game	downloading_game	sensor
Download progress	download_progress	sensor %
Download paused	download_paused	binary

System

Re-checked every 5 s on AC, 15 s on battery, but only published when a value changes (mostly static, so usually nothing is sent).

Entity	ID	Type	Notes
SteamOS version	steamos_version	sensor
Kernel version	kernel_version	sensor
Steam version	steam_version	sensor
BIOS version	bios_version	sensor
Model	model	sensor	OLED or LCD
Uptime	uptime	sensor (timestamp)	shown as relative in HA
Storage free / total / used	storage_free / storage_total / storage_used	sensor GB	internal /home
SD Card	sd_card	binary	card inserted
SD Card free / total / used	sd_card_free / sd_card_total / sd_card_used	sensor GB	unknown when no card

Controls

Read-only; refreshed every 5 s on AC, 15 s on battery.

Entity	ID	Type	Notes
Brightness	brightness	sensor %
Volume	volume	sensor %
Volume muted	volume_muted	binary
Microphone	microphone	sensor %	level
Wi-Fi	wifi	binary	radio on/off
Bluetooth	bluetooth	binary	radio on/off
Airplane mode	airplane_mode	binary
Bluetooth devices	bluetooth_devices	sensor	connected count
Bluetooth device names	bluetooth_device_names	sensor	connected names

Performance

Refreshed every 5 s on AC, 15 s on battery.

Entity	ID	Type	Notes
FPS	fps	sensor fps	Gaming Mode only
GPU usage	gpu_usage	sensor %
GPU temperature	gpu_temperature	sensor °C
GPU power	gpu_power	sensor W
CPU usage	cpu_usage	sensor %
CPU temperature	cpu_temperature	sensor °C
RAM used	ram_used	sensor %
Fan speed	fan_speed	sensor rpm

Use cases

A few automations these entities make easy:

• Cinema mode for the couch. When Game becomes non-empty while Docked is on, dim the room lights and flip the TV to the Deck's input, then bring them back when the game closes.
• Battery care. Cut a charging smart plug when Battery reaches your Battery charge limit, or ping your phone when Battery runs low while AC power is off.
• Download babysitting. Get a notification (or turn on a lamp) the moment Downloading flips off, so you know a big install finished without watching Download progress.
• Now-playing presence. Set a desk lamp colour or a do-not-disturb flag while Game state is in-game, and clear it in the Steam UI or Desktop Mode.
• Heat watch. If CPU temperature, GPU temperature or Fan speed climbs during a session, switch on a desk fan via a smart plug and nudge you.
• Wake the host. When Game platform reads Moonlight or Remote Play you're streaming from another machine, so power on that gaming PC or set its scene.
• Update nudge. When Updates queued goes above zero, remind yourself to dock and update overnight.

How it works

Battery and power come from UPower, suspend from logind, dock and display hotplug from udev, and the running game from gamescope. These all arrive as events, so there's nothing to poll. The only timers are a ~90 s heartbeat (keepalive plus a refresh of slow-moving values) and a game poll every 5 s on AC, 15 s on battery, for the few things Steam doesn't signal.

It publishes a final snapshot before the Deck suspends and refreshes on resume, without blocking sleep. A Last-Will marks the device offline if the Deck drops; it re-announces itself and re-publishes everything when it or Home Assistant reconnects. Idle cost is roughly one or two CPU wakeups per minute.

Install

cd ~/dev/steamdeck2mqtt
./install.sh                       # vendors paho, writes config, installs+enables the user service
$EDITOR ~/.config/steamdeck2mqtt/config.toml   # set broker host / username / password
python3 steamdeck2mqtt.py --dump     # sanity-check: prints every signal it can read, no MQTT
systemctl --user start steamdeck2mqtt
journalctl --user -u steamdeck2mqtt -f

A Steam Deck device appears under Settings > Devices & Services > Devices.

Uninstall

./install.sh uninstall     # stops the service AND removes the retained device from HA