| name | workbench-mqtt |
| description | Use this skill whenever tests involve MQTT communication — starting/stopping the mosquitto broker on the workbench Pi, publishing test messages, subscribing to topics, or verifying ESP32 MQTT client behavior. The broker runs on the Pi's WiFi AP network (192.168.4.1:1883) so DUTs can reach it without internet. Use for MQTT integration tests, pub/sub verification, and broker lifecycle management. Triggers on "MQTT", "broker", "mosquitto", "publish", "subscribe", "topic", "MQTT test". |
ESP32 MQTT Broker
Base URL: http://workbench.local:8080
Step 0: Discover Workbench
Before using any workbench API, ensure workbench.local resolves:
curl -s http://workbench.local:8080/api/info
If that fails, run the discovery script from the workbench repo:
sudo python3 .claude/skills/esp-idf-handling/discover-workbench.py --hosts
The workbench can run an MQTT broker (mosquitto) for testing ESP32 devices that use MQTT for communication. The broker is accessible to devices connected to the workbench's WiFi AP.
Endpoints
| Method | Path | Purpose |
|---|
| POST | /api/mqtt/start | Start the MQTT broker |
| POST | /api/mqtt/stop | Stop the MQTT broker |
| GET | /api/mqtt/status | Check broker status |
Examples
curl -X POST http://workbench.local:8080/api/mqtt/start
curl http://workbench.local:8080/api/mqtt/status
curl -X POST http://workbench.local:8080/api/mqtt/stop
MQTT Broker Details
| Property | Value |
|---|
| Broker IP | workbench.local (from LAN) or 192.168.4.1 (from workbench AP) |
| Default port | 1883 |
| Authentication | None (open broker for testing) |
Common Workflows
-
Test ESP32 MQTT client:
- Ensure device is on workbench WiFi (see workbench-wifi)
POST /api/mqtt/start — start broker- Device connects to
192.168.4.1:1883
- Monitor device behavior via serial or UDP logs (see workbench-logging)
POST /api/mqtt/stop — stop broker when done
-
Test MQTT disconnect/reconnect:
- Start broker, let device connect
POST /api/mqtt/stop — device loses MQTT- Monitor device's reconnection behavior
POST /api/mqtt/start — device should reconnect
-
Test MQTT + WiFi together:
- Start AP + broker
POST /api/wifi/ap_stop — device loses both WiFi and MQTTPOST /api/wifi/ap_start + POST /api/mqtt/start — restore both- Verify device recovers
Troubleshooting
| Problem | Fix |
|---|
| Broker won't start | Check if mosquitto is installed on the workbench Pi |
| Device can't connect | Ensure device is on workbench WiFi; use broker IP 192.168.4.1 from AP clients |
| Broker status shows stopped | Start it with POST /api/mqtt/start |
