mysticlight

Per-zone Home Assistant control for MSI Mystic Light motherboard RGB — via OpenRGB and MQTT discovery.

Home Assistant's built-in OpenRGB integration exposes each RGB device as a single light. This bridge gives you one HA light per motherboard zone (onboard LEDs, JRAINBOW/JRGB headers), the hardware effect list, and a bonus: a system-pressure health mode that turns your onboard LEDs into a glanceable machine-health indicator.

your PC                                         Home Assistant
┌─────────────────────────────────────┐
│ MSI Mystic Light USB (1462:b926)    │
│   ↑ hidraw                          │
│ openrgb --server (127.0.0.1:6742)   │        ┌──────────────────┐
│   ↑ OpenRGB SDK                     │  MQTT  │ MQTT broker      │
│ mysticlightd ───────────────────────┼───────→│  ↓ discovery     │
│   • per-zone lights + effect select │        │ lights, sensor,  │
│   • health sampler → LED painter    │        │ switch, select   │
└─────────────────────────────────────┘        └──────────────────┘

Entities created (MQTT discovery — zero HA-side config)

Entity	What it does
light.mystic_light_<host>_<zone> (one per zone)	RGB color, on/off, brightness (emulated by RGB scaling)
select.mystic_light_<host>_effect	Hardware effects (Breathing, Rainbow, Meteor, …) — device-wide by hardware design; Direct enables per-zone colors
sensor.mystic_light_<host>_system_pressure	0–100 worst-of composite over CPU load, CPU temp, RAM, disk, network, GPU (per-metric attributes included)
switch.mystic_light_<host>_health_mode	ON: the onboard-LED zone becomes a green→red pressure gauge with a breathing pulse when critical; OFF: your manual color returns

Availability is handled via MQTT LWT — kill the daemon and the entities go unavailable instead of lying.

Requirements

• Linux host with an MSI motherboard whose Mystic Light controller OpenRGB supports (USB 1462:b926 etc. — check openrgb --list-devices)
• OpenRGB ≥ 0.9 (SDK server)
• An MQTT broker your Home Assistant uses (with MQTT discovery enabled)
• Python 3.11+; nvidia-smi optional (GPU metric skips gracefully without it)

Install

git clone https://github.com/jphein/mysticlight && cd mysticlight
python3 -m venv venv && venv/bin/pip install -r requirements.txt

cat > .env <<EOF
MQTT_HOST=<your broker>
MQTT_PORT=1883
MQTT_USER=<user>
MQTT_PASSWORD=<password>
NET_IFACE=<your NIC, e.g. enp5s0>
EOF

# adjust paths/User in deploy/*.service, then:
sudo cp deploy/*.service /etc/systemd/system/
sudo systemctl daemon-reload
sudo systemctl enable --now openrgb-sdk mysticlightd

Entities appear in HA automatically under one device named Mystic Light — <hostname>.

Configuration (env vars, all optional beyond MQTT_*)

Var	Default
OPENRGB_HOST / OPENRGB_PORT	127.0.0.1 / 6742	OpenRGB SDK server
VERSION_PORT	7716	/api/version HTTP endpoint
POLL_SECONDS	30	reconcile external color changes into HA
HEALTH_SAMPLE_SECONDS	10	health sampling cadence
NET_IFACE / NET_MBPS	eth0 / 1000	network-saturation metric
HEALTH_ZONE	Onboard LEDs	zone the health painter owns
DEVICE_SLUG / DEVICE_NAME	from hostname	HA device identity

Health thresholds (warn → critical per metric) live in mysticlight/health.py:THRESHOLDS.

Notes & quirks

• Keep the OpenRGB SDK server on localhost — its protocol has no auth.
• Hardware effects are device-wide (MSI firmware limitation); per-zone colors only apply in Direct mode. The health pulse is software-animated for the same reason.
• Zone lists vary by board and are discovered at runtime (e.g. the Z390I Gaming Edge AC reports JRAINBOW1 + Onboard LEDs only).
• The daemon reads system metrics locally, so the health LED keeps working even when Home Assistant is down.

Development

venv/bin/pytest tests/ -q

All translation/health logic is pure and unit-tested (bridge.py, health.py); daemon.py is thin wiring.

License

GPL-3.0-or-later