MQTT integration (optional) — Open-FDD + diy-bacnet-server

Open-FDD does not require MQTT for core FDD, BACnet scraping, or the web UI. MQTT is optional and aimed at future edge/automation patterns and generic brokers (typically Mosquitto), not a specific cloud vendor.

What the stack can do today

  1. Mosquitto (compose profile)
    Run ./scripts/bootstrap.sh --with-mqtt-bridge to start a broker on localhost:1883 (see Getting started and Quick reference).

  2. BACnet2MQTT (diy-bacnet-server)
    When BACNET2MQTT_ENABLED=true and MQTT_BROKER_URL point at that broker, diy-bacnet-server publishes per-point state under MQTT_BASE_TOPIC (default bacnet2mqtt) and can publish Home Assistant discovery under HA_DISCOVERY_TOPIC. This is documented in the diy-bacnet-server repo (README and HOME_ASSISTANT_MQTT_CHEATSHEET.md).

  3. MQTT RPC gateway (experimental, diy-bacnet-server)
    When MQTT_RPC_GATEWAY_ENABLED=true, the same gateway process can subscribe to {MQTT_RPC_TOPIC_PREFIX}/cmd and publish structured acks on .../ack, using the same method names as HTTP JSON-RPC (server_hello, client_whois_range, client_read_property, etc.). Optional telemetry topics advertise supported methods and periodic metadata.
    Configure via stack/.env (variables are passed through stack/docker-compose.yml to the bacnet-server service). See the upstream MQTT RPC gateway section for topic layout and security notes (TLS, ACLs).

Open-FDD product scope

  • Core data path remains HTTP JSON-RPC from the BACnet scraper and API to diy-bacnet-server.
  • MQTT features are additive: monitoring via BACnet2MQTT, command/ack experimentation via the RPC gateway, without replacing the database-backed scraper or auth model (OFDD_BACNET_SERVER_API_KEY → BACNET_RPC_API_KEY on the gateway).