publish-mqtt-messagelisted

# publish-mqtt-message Publish a payload to an exact MQTT topic through a TopicGate broker. This is a **control-mode** operation that sends data to external consumers and may operate physical devices. ## MCP server not available If the `topicgate` MCP server is not connected or `publish` cannot be found, stop and tell the user: > The TopicGate MCP server is not active or is running in read-only mode. > Publishing requires control mode (`--mode control`). > Install TopicGate, configure the server with `"args": ["--mode", "control"]`, > and restart your MCP harness. Do not attempt to call any other tool as a substitute. ## Tool Call `publish`: | Parameter | Required | Description | |---|---|---| | `broker_id` | yes | Broker UUID or unique case-insensitive profile name | | `topic` | yes | Exact MQTT topic (not a wildcard filter) | | `payload` | yes | The message content | | `payload_encoding` | yes | Must be `utf-8` or `base64` — always set explicitly | ## Safety — ALWAYS follow these steps 1. **Confirm the broker** — verify the correct broker is active and connected. 2. **Confirm the topic** — the topic must be an exact publish topic, never a wildcard. 3. **Confirm the payload** — verify encoding, content, and intent with the user. 4. **Require explicit user intent** — never publish speculatively or as part of a broader automation unless the user has explicitly approved the broker, topic, encoding, and payload. MQTT publishing may operate physical devices, trig