Bridge Mode

The bridge mode forwards MQTT beacon and gateway data to Zabbix for monitoring. It is implemented in server/src/bridge.ts.

Overview

The bridge acts as a translator between the MQTT beacon/gateway protocol and Zabbix's monitoring system. It can run standalone (bridge-only) or alongside the full SafeCall server.

How It Works

1. Cache: Periodically fetches the list of known beacons and gateways from the SafeCall REST API
2. Filter: Only processes MQTT messages for devices that exist in the cache
3. Throttle: Applies configurable delays between updates to avoid flooding Zabbix
4. Send: Forwards device metrics to Zabbix via ZabbixSender

Data Forwarded

Beacon Data (from adv1/adv4/adv8)

• Battery level
• Temperature
• Humidity
• SOS/panic button state
• Signal strength

Gateway Data (from alive messages)

• IP address
• Uptime
• Firmware version
• Last seen timestamp

Configuration

Key	Description
bridge_mqtt_url	MQTT broker URL
bridge_mqtt_user	MQTT username
bridge_mqtt_pass	MQTT password
bridge_server_url	SafeCall server URL (for REST cache)
bridge_zabbix_host	Zabbix server hostname
bridge_zabbix_port	Zabbix server port
bridge_endpoint_beacon	REST endpoint for beacon list
bridge_endpoint_gateway	REST endpoint for gateway list
bridge_delay_beacon	Minimum seconds between beacon updates
bridge_delay_gateway	Minimum seconds between gateway updates
bridge_cache_update_interval	Seconds between cache refreshes

LLD Integration

The bridge also supports Zabbix Low-Level Discovery (LLD). The server exposes LLD endpoints:

• GET /lld/beacons — Returns beacon discovery data in LLD format
• GET /lld/gateways — Returns gateway discovery data in LLD format

These are consumed by Zabbix to automatically create monitoring items for new devices.

Standalone Mode

When server_features contains only "bridge", the server starts in standalone bridge mode. This only requires MQTT and Zabbix configuration — no database, HTTP server, or JWT setup is needed.