MQTT Bridge

The MQTT bridge publishes every entity to a broker as retained topics, subscribes to write topics for writable entities, and reports availability via a Last-Will message. Like every other surface, the topic set is generated from the active inverter’s manifest.

Enabling

Configure MQTT from Settings → MQTT & Home Assistant (recommended), or seed it from environment variables (MQTT_ENABLED, MQTT_BROKER_URL, MQTT_TOPIC_PREFIX, MQTT_USERNAME, MQTT_PASSWORD).

Enabling, disabling, or changing the config takes effect live — the bridge is rebuilt without a restart. The Settings tab has a Test connection button and a live status badge.

Topic layout

All topics are rooted at <prefix>/<inverterId>, where prefix defaults to sunreye and inverterId is the active profile’s id.

Topic	Direction	Retained	Payload
<prefix>/<inverterId>/<topic>	publish (state)	✅	The entity’s value as a string.
<prefix>/<inverterId>/<topic>/set	subscribe (write)	—	A numeric value to write.
<prefix>/<inverterId>/status	publish (availability)	✅	online / offline.

<topic> is each entity’s manifest topic (a /-separated suffix). State is published only while connected — stale samples are not queued.

Writes

Only writable entities get a .../set command topic. When a message arrives:

1. The payload is parsed as a number (NaN is rejected and logged).
2. The value is validated against the entity’s constraint (range or enum) — the same validation used by the REST API and the dashboard.
3. On success the write is pushed to the inverter; invalid writes are dropped with a warning.

Example (publish a new max charge current):

mosquitto_pub -t 'sunreye/deye-sg05lp3/settings/battery/max_charge_current/set' -m '40'

Availability (Last-Will)

• On connect, the bridge publishes online (retained) to <prefix>/<inverterId>/status.
• A broker-registered Last-Will publishes offline (retained) if the connection drops.
• On graceful shutdown it publishes offline before disconnecting.

Home Assistant uses this topic for entity availability.

Home Assistant

When Home Assistant discovery is enabled, the bridge also publishes MQTT Discovery configs so SunReye auto-populates in Home Assistant. See Home Assistant.