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MQTT Topics Documentation

Introduction

This document describes the MQTT topics published by the Genius Gateway. The gateway supports both Home Assistant auto-discovery and custom MQTT topics for integration with other home automation systems connecting to a MQTT broker.

MQTT Configuration

MQTT functionality is mainly configured via web frontend or HTTP API endpoints:

  • Framework MQTT Settings: /rest/mqttSettings - Basic MQTT connection settings
  • Simple Alarm Publishing: /rest/alarm-publishing - Genius Gateway specific publishing options

Framework MQTT Topics (ESP32 SvelteKit)

Device Status Topic (LWT)

Topic 

genius-gateway/{device-mac}/status

device-mac format

device-mac is the device's MAC address with lowercase hex digits and without any delimiters.
E.g.: 1A:2B:3C:4D:5E:6F 1a2b3c4d5e6f

Description: Framework device online/offline status using MQTT Last Will and Testament (LWT)

QoS: 1

Retain: true

Payloads

Published when device connects to MQTT broker: 

"online"

Published automatically by broker when device disconnects (LWT message): 

"offline"

Home Assistant Auto-Discovery

The gateway supports Home Assistant's MQTT Discovery protocol for automatic device integration.

Gateway Device

The Genius Gateway itself is published as a Home Assistant device with diagnostic sensors, remote control buttons, and configuration switches.

Requirements:

Overview

The gateway device publishes:

  • 1 Status Sensor - Registers the gateway device in Home Assistant
  • 2 Diagnostic Sensors - Free heap memory (%) and core temperature (°C)
  • 1 Restart Button - Remote gateway restart capability
  • 4 Configuration Switches - Remote control of gateway settings

Topic Structure: 

{discovery_prefix}genius-gateway/{gateway_device_id}

Gateway Device ID Format

The gateway_device_id follows the format genius-gateway-{device-mac}, where device-mac is the device's MAC address with lowercase hex digits and without any delimiters.
E.g.: 1A:2B:3C:4D:5E:6F genius-gateway-1a2b3c4d5e6f

Device Status Sensor

Topic 

{discovery_prefix}sensor/{gateway_device_id}/status/config

Example: homeassistant/sensor/genius-gateway-1a2b3c4d5e6f/status/config

Description: Device registration sensor that makes the gateway visible in Home Assistant

QoS: 0

Retain: true

Payload 

{
  "~": "homeassistant/genius-gateway/genius-gateway-1a2b3c4d5e6f",
  "name": "Status",
  "unique_id": "genius-gateway-1a2b3c4d5e6f_status",
  "state_topic": "~/status/state",
  "value_template": "{{value_json.state}}",
  "icon": "mdi:heart-pulse",
  "entity_category": "diagnostic",
  "device": {
    "identifiers": ["genius-gateway-1a2b3c4d5e6f"],
    "name": "Genius Gateway",
    "manufacturer": "Genius Gateway Project",
    "model": "Genius Gateway",
    "sw_version": "1.1.0",
    "configuration_url": "http://192.168.1.100"
  }
}

Payload Fields

  • ~ - Topic prefix (base path for relative references)
  • name - Entity name shown in Home Assistant
  • unique_id - Unique identifier for this sensor
  • state_topic - Relative path to state topic
  • value_template - Jinja2 template to extract state from JSON
  • icon - Material Design icon identifier
  • entity_category - Category (diagnostic for system status)
  • device - Device information object
  • identifiers - Device identifier (array with gateway device ID)
  • name - Device name shown in Home Assistant
  • manufacturer - Project name
  • model - Device model
  • sw_version - Current firmware version
  • configuration_url - Web interface URL (only included if gateway has valid IP)

State Topic: {discovery_prefix}genius-gateway/{gateway_device_id}/status/state

State Payload 

{
  "state": "online"
}

Publishing Behavior

Home Assistant Integration

  • Automatically creates gateway device with all associated entities
  • Provides device information panel with manufacturer, model, and firmware version
  • Links to gateway web interface via configuration URL

Diagnostic Sensors

The gateway publishes two diagnostic sensors that share a common state topic for efficient updates.

Free Heap Sensor

Config Topic 

{discovery_prefix}sensor/{gateway_device_id}/free_heap/config

Example: homeassistant/sensor/genius-gateway-1a2b3c4d5e6f/free_heap/config

Description: Monitors available heap memory as percentage of total heap

QoS: 0

Retain: true

Config Payload 

{
  "~": "homeassistant/genius-gateway/genius-gateway-1a2b3c4d5e6f",
  "name": "Free Heap",
  "unique_id": "genius-gateway-1a2b3c4d5e6f_free_heap",
  "state_topic": "~/diagnostics/state",
  "value_template": "{{value_json.free_heap_percent|round(1)}}",
  "unit_of_measurement": "%",
  "state_class": "measurement",
  "icon": "mdi:memory",
  "entity_category": "diagnostic",
  "device": {
    "identifiers": ["genius-gateway-1a2b3c4d5e6f"]
  }
}

Core Temperature Sensor

Config Topic 

{discovery_prefix}sensor/{gateway_device_id}/core_temp/config

Example: homeassistant/sensor/genius-gateway-1a2b3c4d5e6f/core_temp/config

Description: Monitors ESP32 internal core temperature

QoS: 0

Retain: true

Config Payload 

{
  "~": "homeassistant/genius-gateway/genius-gateway-1a2b3c4d5e6f",
  "name": "Core Temperature",
  "unique_id": "genius-gateway-1a2b3c4d5e6f_core_temp",
  "state_topic": "~/diagnostics/state",
  "value_template": "{{value_json.core_temp|round(1)}}",
  "unit_of_measurement": "°C",
  "device_class": "temperature",
  "state_class": "measurement",
  "icon": "mdi:thermometer",
  "entity_category": "diagnostic",
  "device": {
    "identifiers": ["genius-gateway-1a2b3c4d5e6f"]
  }
}

Diagnostic State Topic

Topic 

{discovery_prefix}genius-gateway/{gateway_device_id}/diagnostics/state

Example: homeassistant/genius-gateway/genius-gateway-1a2b3c4d5e6f/diagnostics/state

Description: Combined state topic for both diagnostic sensors

QoS: 0

Retain: false

Payload 

{
  "free_heap_percent": 73.5,
  "core_temp": 42.3
}

Payload Fields

  • free_heap_percent - Available heap memory as percentage of total heap (float, 0-100)
  • core_temp - ESP32 internal core temperature in degrees Celsius (float)

Publishing Behavior

  • Published immediately after config messages (initial state)
  • Published every 60 seconds via timer
  • Re-published when MQTT connection is established
  • Published only if Home Assistant Integration is enabled

Home Assistant Integration

  • Automatically creates sensor entities with proper units and device classes
  • Enables historical data tracking and graphing
  • Can trigger automations based on memory or temperature thresholds
  • Useful for monitoring gateway health and detecting potential issues

Restart Button

Config Topic 

{discovery_prefix}button/{topicNamespace}/{gateway_device_id}/restart/config

Example: homeassistant/button/genius-gateway/genius-gateway-1a2b3c4d5e6f/restart/config

topicNamespace format

topicNamespace is the slugified device name, e.g. genius-gateway. Together with the device ID, the config topic node becomes genius-gateway/genius-gateway-1a2b3c4d5e6f. This scoping ensures entities from different gateway instances never collide on a shared MQTT broker.

Description: Button entity for remotely restarting the gateway

QoS: 0

Retain: true

Config Payload 

{
  "~": "homeassistant/genius-gateway/genius-gateway-1a2b3c4d5e6f",
  "name": "Restart",
  "unique_id": "genius-gateway-1a2b3c4d5e6f_restart",
  "command_topic": "~/restart/command",
  "payload_press": "PRESS",
  "icon": "mdi:restart",
  "device": {
    "identifiers": ["genius-gateway-1a2b3c4d5e6f"]
  }
}

Key Fields

  • command_topic - Topic where button press commands are published
  • payload_press - Payload sent when button is pressed ("PRESS")
  • icon - Restart icon for visual identification
  • No entity_category — Restart appears under Controls on the HA device page

Command Topic: {discovery_prefix}genius-gateway/{gateway_device_id}/restart/command

Command Payload 

"PRESS"

Publishing Behavior

  • Config published when MQTT connection is established
  • Config re-published when MQTT settings change
  • Gateway subscribes to command topic automatically
  • Trigger immediate gateway restart on command reception

Home Assistant Integration

  • Automatically creates button entity
  • Press button to restart gateway remotely
  • Useful for maintenance and troubleshooting without physical access
  • Can be used in automations (e.g., scheduled restarts)

Configuration Switches

Four switches provide remote control of gateway configuration settings that affect device discovery and alert processing.

Config Topic Pattern 

{discovery_prefix}switch/{gateway_device_id}/{switch_suffix}/config

Switch Types:

Suffix Display Name Setting Controlled
alert_unknown Alert on Unknown Detectors Process alerts from unregistered smoke detectors
line_commissioning Add Line from Commissioning Auto-add alarm lines from commissioning packets
line_alarm Add Line from Alarm Auto-add alarm lines from alarm packets
line_test Add Line from Line Test Auto-add alarm lines from line test packets

Config Payload Example (Alert on Unknown Detectors) 

{
  "~": "homeassistant/genius-gateway/genius-gateway-1a2b3c4d5e6f",
  "name": "Alert on Unknown Detectors",
  "unique_id": "genius-gateway-1a2b3c4d5e6f_alert_unknown",
  "state_topic": "~/gateway/state",
  "value_template": "{{ value_json.alert_unknown }}",
  "command_topic": "~/gateway/alert_unknown/set",
  "icon": "mdi:toggle-switch-off-outline",
  "entity_category": "config",
  "device": {
    "identifiers": ["genius-gateway-1a2b3c4d5e6f"]
  }
}

Key Fields

  • state_topic - Shared JSON topic publishing all switch states
  • value_template - Template to extract specific switch state from JSON
  • command_topic - Individual topic accepting ON / OFF commands
  • entity_category - config for configuration entities

Central State Topic: 

{discovery_prefix}genius-gateway/{gateway_device_id}/gateway/state

State Payload (JSON with all switches) 

{
  "alert_unknown": "ON",
  "line_commissioning": "OFF",
  "line_alarm": "OFF",
  "line_test": "ON"
}

Individual Command Topics: 

{discovery_prefix}genius-gateway/{gateway_device_id}/gateway/{objectId}/set

Examples: - homeassistant/genius-gateway/genius-gateway-1a2b3c4d5e6f/gateway/alert_unknown/set - homeassistant/genius-gateway/genius-gateway-1a2b3c4d5e6f/gateway/line_commissioning/set - homeassistant/genius-gateway/genius-gateway-1a2b3c4d5e6f/gateway/line_alarm/set - homeassistant/genius-gateway/genius-gateway-1a2b3c4d5e6f/gateway/line_test/set

Command Payloads

Turn setting ON: 

"ON"

Turn setting OFF: 

"OFF"

Publishing Behavior

  • Config published when MQTT connection is established
  • Config re-published when MQTT settings change
  • Combined JSON state published immediately after configs (initial state)
  • Single JSON state published when any setting changes (via web interface or MQTT)
  • Gateway subscribes to all individual command topics automatically

Home Assistant Integration

  • Automatically creates switch entities grouped under gateway device
  • Toggle switches to modify gateway settings remotely
  • State synchronization between Home Assistant and gateway web interface
  • Can be used in automations for dynamic behavior control
  • Useful for temporarily enabling/disabling features without accessing web UI
  • Efficient state updates - All switches updated with a single MQTT message

Setting Synchronization

Changes made via Home Assistant switches are immediately reflected in the gateway web interface and vice versa. All settings are synchronized bidirectionally.

Efficient State Updates

All four configuration switches share a single JSON state topic. When any setting changes (even just one), all states are published in a single MQTT message, reducing network traffic and ensuring atomic updates.

Firmware Update Entity

The gateway publishes an update entity that integrates with Home Assistant's update functionality to manage firmware updates.

Config Topic 

{discovery_prefix}update/{gateway_device_id}/firmware/config

Example: homeassistant/update/genius-gateway-1a2b3c4d5e6f/firmware/config

Description: Update entity for firmware management with automatic version checking

QoS: 0

Retain: true

Config Payload 

{
  "~": "homeassistant/genius-gateway/genius-gateway-1a2b3c4d5e6f",
  "name": "Firmware Update",
  "unique_id": "genius-gateway-1a2b3c4d5e6f_firmware_update",
  "state_topic": "~/update/state",
  "command_topic": "~/update/install",
  "payload_install": "INSTALL",
  "title": "Genius Gateway Firmware",
  "device_class": "firmware",
  "entity_category": "config",
  "icon": "mdi:cloud-download",
  "device": {
    "identifiers": ["genius-gateway-1a2b3c4d5e6f"]
  }
}

Key Fields

  • state_topic - Topic publishing firmware version information
  • command_topic - Topic accepting update installation commands
  • payload_install - Payload to trigger update installation ("INSTALL")
  • device_class - Device class (firmware for firmware updates)
  • title - Update entity title
  • entity_category - Category (config for configuration entities)

State Topic: {discovery_prefix}genius-gateway/{gateway_device_id}/update/state

State Payload

When no update is available: 

{
  "installed_version": "1.1.0",
  "latest_version": "1.1.0",
  "title": "Genius Gateway Firmware 1.1.0",
  "release_url": "https://github.com/hmbacher/genius-gateway/releases/latest"
}

When update is available: 

{
  "installed_version": "1.1.0",
  "latest_version": "1.2.0",
  "title": "Genius Gateway Firmware 1.2.0",
  "release_url": "https://github.com/hmbacher/genius-gateway/releases/latest"
}

State Fields

  • installed_version - Currently installed firmware version
  • latest_version - Latest available firmware version from GitHub releases
  • title - Human-readable update title
  • release_url - URL to GitHub releases page

Command Topic: {discovery_prefix}genius-gateway/{gateway_device_id}/update/install

Command Payload 

"INSTALL"

Publishing Behavior

  • Config published when MQTT connection is established
  • Config re-published when MQTT settings change
  • State published after GitHub version check (periodic and on-demand)
  • State updated when new firmware version is detected
  • Gateway subscribes to command topic automatically

Update Process

  1. Gateway periodically checks GitHub for new releases
  2. When update is available, state reflects new version
  3. User can trigger installation via Home Assistant or web interface
  4. Gateway downloads firmware from GitHub releases
  5. Firmware is validated and installed
  6. Gateway automatically restarts with new version

Home Assistant Integration

  • Automatically creates update entity with current and available versions
  • Shows "Update Available" badge when new firmware is released
  • Links to GitHub releases page for release notes
  • Click "Install" in Home Assistant to trigger OTA update
  • Progress tracking via web interface and event notifications

Internet Connection Required

Firmware updates require an active internet connection to download from GitHub. The gateway must be able to reach github.com and objects.githubusercontent.com.

Smoke Detectors

Each configured smoke detector is published as an HA sub-device nested under the main Genius Gateway device.

Requirements:

Overview

Each smoke detector sub-device publishes:

  • 1 binary_sensor (Control) — smoke device class, alarm state ON/OFF
  • 3 binary_sensor (Diagnostic) — battery low, smoke detector fault, radio module fault; available after acoustic readout
  • 11 sensor (Diagnostic) — deinstallation count, last service timestamp, radio module model, alarm line ID, alarm line, production date, radio module serial, total alarm count, 3-month alarm count, radio interference; available after acoustic readout

Readout-derived entities (all except the main smoke sensor) report as unavailable until the first acoustic readout is performed via the gateway's SmartSonic interface.

Topic Structure:

All smoke detector topics are nested under the main gateway base topic. The sub-device identifier is based on the stable internal device ID (not the serial number), so topics remain stable across serial-number corrections: 

{discovery_prefix}{main_namespace}/{main_device_id}/genius-{device_id}/...

For example, with the default prefix and gateway device ID genius-gateway-aabbcc: 

homeassistant/genius-gateway/genius-gateway-aabbcc/genius-1746234159/...

Device ID vs Serial Number

device_id is a stable internal identifier assigned when the detector is first registered. It is independent of the smoke detector serial number and does not change if the serial number is corrected later.

Smoke Alarm Binary Sensor

Config Topic Pattern 

{discovery_prefix}binary_sensor/{device_id}/smoke/config

Example: homeassistant/binary_sensor/genius-1746234159/smoke/config

Description: Main alarm state sensor for the smoke detector

QoS: 0

Retain: true

Config Payload 

{
  "~": "homeassistant/genius-gateway/genius-gateway-aabbcc/genius-1746234159",
  "name": "Smoke Detector",
  "unique_id": "genius-1746234159_smoke",
  "device_class": "smoke",
  "state_topic": "~/smoke/state",
  "entity_picture": "http://192.168.1.100/hekatron-genius-plus-x.png",
  "device": {
    "identifiers": ["genius-1746234159"],
    "name": "Genius Plus X",
    "manufacturer": "Hekatron Vertriebs GmbH",
    "model": "Genius Plus X",
    "serial_number": "12345678",
    "suggested_area": "Living Room",
    "configuration_url": "http://192.168.1.100/gateway/smoke-detectors",
    "via_device": "genius-gateway-aabbcc"
  }
}

Key Fields

  • ~ - Base topic (sub-device path nested under main gateway device)
  • device_class - smoke
  • state_topic - Plain string ON / OFF
  • entity_picture - Detector icon URL (omitted if no valid IP)
  • device.identifiers - Stable device ID (genius-{device_id})
  • device.name / device.model - Smoke detector model name (e.g. "Genius Plus X")
  • device.suggested_area - Populated from the detector's configured location
  • device.via_device - Links this sub-device to the main gateway device

State Topic: {base_topic}/genius-{device_id}/smoke/state

State Values

  • OFF — Not alarming
  • ON — Actively alarming

Publishing Behavior

  • Config published when detector is first registered or on MQTT (re)connect
  • State published when alarm state changes and on MQTT (re)connect

Readout-Derived Diagnostic Entities

All 13 readout-derived diagnostic entities share a single state topic that carries a JSON object with all values. Availability is folded into the same JSON payload — no separate availability topic is needed.

Shared State Topic 

{base_topic}/genius-{device_id}/diagnostics/state

QoS: 0    Retain: true

JSON Payload Example: 

{
  "available": true,
  "battery_low": false,
  "device_fault": false,
  "radio_fault": false,
  "deinstall_count": 2,
  "last_readout": "2026-04-30T14:22:00",
  "radio_module_model": "FM Basis X",
  "alarm_line_id": 123456789,
  "alarm_line": "A.0",
  "production_date": "01.03.22",
  "radio_module_serial": 987654321,
  "alarm_count_total": 5,
  "alarm_count_3m": 1,
  "radio_interference": 12.5
}

available is false (and all other fields absent or stale) until the first successful acoustic readout. Each entity's discovery config uses availability_template on this same topic:

availability_topic: "{base_topic}/genius-{device_id}/diagnostics/state"
availability_template: "{{ 'online' if value_json.available else 'offline' }}"

Discovery Config Topic Pattern: 

{discovery_prefix}{component}/{topicNamespace}/{gateway_device_id}/genius-{device_id}/{object_id}/config

Diagnostic binary_sensor entities (value_template extracts a boolean as ON/OFF):

Object ID Name Device Class value_template
battery_low Battery battery {{ 'ON' if value_json.battery_low else 'OFF' }}
device_fault Smoke Detector State problem {{ 'ON' if value_json.device_fault else 'OFF' }}
radio_fault Radio Module State problem {{ 'ON' if value_json.radio_fault else 'OFF' }}

Diagnostic sensor entities (value_template extracts the relevant field):

Object ID Name Unit / Class JSON field
deinstallation_count Deinstallation Count total_increasing deinstall_count
last_readout Last Service timestamp last_readout
radio_module_model Radio Module Model — radio_module_model
alarm_line_id Alarm Line ID — alarm_line_id
alarm_line Alarm Line — alarm_line
production_date Production Date — production_date
radio_module_serial Radio Module Serial — radio_module_serial
alarm_count_total Alarms (Total) total_increasing alarm_count_total
alarm_count_3m Alarms (3 Months) measurement alarm_count_3m
radio_interference Radio Interference % / measurement radio_interference

Publishing Behavior

  • Configs published on MQTT (re)connect alongside the main smoke sensor config
  • State published immediately after a successful acoustic readout
  • State re-published on MQTT (re)connect; available: false until first readout

Migration from pre-1.x firmware

Firmware upgrading from a version that used per-entity state topics will automatically clear the 13 stale retained state topics and the old readout/avail topic on the first MQTT connect after upgrade. Entity history and customizations in Home Assistant are preserved because all object IDs remain unchanged.

Alarm Lines

The following topics enable remote control of alarm line actions (line tests and fire alarm tests) via MQTT.

Requirements:

Overview

Each configured alarm line is published as an HA sub-device nested under the main Genius Gateway device. Each sub-device contains:

  • 4 Button entities for triggering actions (line test start/stop, fire alarm start/stop)
  • 1 Sensor entity for transmission state monitoring

Topic Structure:

All alarm line topics are nested under the main gateway base topic: 

{discovery_prefix}{main_namespace}/{main_device_id}/genius-alarmline-{line_id}/...

For example, with the default prefix and a gateway device ID genius-gateway-aabbcc: 

homeassistant/genius-gateway/genius-gateway-aabbcc/genius-alarmline-123456789/...

Button Entities Configuration

Topic Pattern 

{discovery_prefix}button/{topicNamespace}/{gateway_device_id}/genius-alarmline-{line_id}/{object_id}/config

Description: Configuration messages for Home Assistant button discovery

QoS: 0

Retain: true

Button Object IDs:

  • linetest-start - Start Line Test
  • linetest-stop - Stop Line Test
  • firealarm-start - Start Fire Alarm
  • firealarm-stop - Stop Fire Alarm

Example Payload (Start Line Test) 

{
  "~": "homeassistant/genius-gateway/genius-gateway-aabbcc/genius-alarmline-123456789",
  "name": "Start Line Test",
  "unique_id": "genius-alarmline-123456789_linetest-start",
  "command_topic": "~/linetest-start/set",
  "icon": "mdi:map-marker",
  "availability": [{
    "topic": "homeassistant/genius-gateway/genius-gateway-aabbcc/genius-alarmline-123456789/transmission/state",
    "value_template": "{% if value == 'Nothing' %}online{% else %}offline{% endif %}"
  }],
  "availability_mode": "all",
  "device": {
    "identifiers": ["genius-alarmline-123456789"],
    "name": "Alarm Line 'First Floor'",
    "manufacturer": "Genius Gateway Project",
    "model": "Genius Plus X Alarm Line",
    "via_device": "genius-gateway-aabbcc"
  }
}

Key Fields

  • ~ - Base topic (sub-device path nested under main gateway device)
  • name - Button name displayed in Home Assistant
  • unique_id - Unique identifier for this button
  • command_topic - Topic where HA sends button press commands
  • icon - Material Design icon identifier
  • availability - Button unavailable while a transmission is active
  • device.via_device - Links this sub-device to the main gateway device in HA

Publishing Behavior

Home Assistant Integration

  • Each alarm line appears as a separate HA sub-device under the gateway
  • All 4 buttons and the sensor are grouped on that device's page
  • Buttons become unavailable during active transmissions

Command Topics

Topic Pattern 

{main_base_topic}/genius-alarmline-{line_id}/{button_object_id}/set

Description: HA sends to these topics when a button is pressed in the UI or via automation

QoS: 0

Retain: false

Button Object IDs → Actions:

  • linetest-start/set → Start Line Test RF transmission
  • linetest-stop/set → Stop Line Test RF transmission
  • firealarm-start/set → Start Fire Alarm RF transmission
  • firealarm-stop/set → Stop Fire Alarm RF transmission

Command Behavior

  • Each button has its own dedicated command topic (no wildcard, no JSON payload parsing)
  • Triggers RF transmission immediately if no other transmission is active
  • Ignored if a transmission is currently in progress (buttons shown as unavailable via availability topic)
  • Updates transmission state sensor on start; resets to "Nothing" on completion

Transmission Blocking

Only one transmission can be active at a time. Buttons are automatically shown as unavailable in HA while a transmission is in progress.

Transmission State Sensor

Config Topic 

{discovery_prefix}sensor/{topicNamespace}/{gateway_device_id}/genius-alarmline-{line_id}/transmission/config

Example: homeassistant/sensor/genius-gateway/genius-gateway-aabbcc/genius-alarmline-123456789/transmission/config

State Topic 

{main_base_topic}/genius-alarmline-{line_id}/transmission/state

Example: homeassistant/genius-gateway/genius-gateway-aabbcc/genius-alarmline-123456789/transmission/state

Description: Current transmission status of the alarm line (plain string, not JSON)

QoS: 0

Retain: true

State Values

  • Nothing — No active transmission, all buttons available
  • Line Test Start — Line test start transmission in progress
  • Line Test Stop — Line test stop transmission in progress
  • Fire Alarm Start — Fire alarm start transmission in progress
  • Fire Alarm Stop — Fire alarm stop transmission in progress

Publishing Behavior

  • Published when transmission starts (state shows action type)
  • Published when transmission completes (state resets to Nothing)
  • Published when transmission times out (state resets to Nothing)
  • Re-published on MQTT (re)connect via HA sub-device mechanism
  • Controls button availability (buttons shown as unavailable when state ≠ Nothing)

Home Assistant Integration

  • Appears under the alarm line sub-device as a Diagnostic sensor
  • Used by button availability templates
  • Can trigger automations based on transmission state changes

Global Alarm State Topic

Topic (Default) 

smarthome/genius-gateway/alarm

Description: Global alarm state aggregated from all smoke detectors

QoS: 0

Retain: true

Payload:

Published if all devices are in standby: 

{
  "isAlarming": false,
  "numAlarmingDevices": 0
}

Published when two smoke detectors are alarming (example): 

{
  "isAlarming": true,
  "numAlarmingDevices": 2
}

Payload Fields

  • isAlarming - Global alarm state (boolean)
    • true - At least one smoke detector is alarming
    • false - No smoke detectors alarming
  • numAlarmingDevices - Number of smoke detectors currently in alarm state (integer)

Publishing Behavior

  • Published when an alarm starts on any smoke detector
  • Published when an alarm ends on any smoke detector (silenced by detector or manually via the API)
  • Published when all alarms are reset at once (via the end alarms API)
  • Published when MQTT connection is established or re-established — overwrites any stale retained message left from before a restart

Alarm state after restart

Genius Gateway does not persist the active alarm state across restarts. After a restart, isAlarming is always false and numAlarmingDevices is always 0, regardless of the state before the restart. The retained message on the broker is updated immediately on MQTT connect.

Independent of Home Assistant integration

Simple alarm publishing works independently of the Home Assistant integration. It is controlled solely by the Enable simple alarm publishing toggle and does not require HAIntegrationEnabled.

Integration

This topic enables integration with all smart home systems that support MQTT.