> For the complete documentation index, see [llms.txt](https://docs.incari.com/incari-studio/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.incari.com/incari-studio/2021.1/toolbox/communication/mqtt/events/onmqtttopic.md).

# On MQTT Topic

## Overview

![The On MQTT Topic Node.](/files/-MhIwQrvlTHFt7jVyTJC)

**On MQTT Topic** is an **Event Listener Node** that executes when it receives a `Topic`.

## Attributes

| Attribute       | Type           | Description                                        |
| --------------- | -------------- | -------------------------------------------------- |
| `Configuration` | **Drop-down**  | The connection, or signal name, that will be used. |
| `Topic`         | **User Input** | The key in the **MQTT** key/value pair.            |

## See Also

* [**On MQTT Start**](/incari-studio/2021.1/toolbox/communication/mqtt/events/onmqttstart.md)
* [**On MQTT Stop**](/incari-studio/2021.1/toolbox/communication/mqtt/events/onmqttstop.md)

## External Links

* [*An in-depth explanation of Topics*](http://www.steves-internet-guide.com/understanding-mqtt-topics/#:~:text=%20Understanding%20MQTT%20Topics%20%201%20The%20%24SYS,publish%20to%20an%20individual%20topic.%20That...%20More%20)


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