> ## Documentation Index
> Fetch the complete documentation index at: https://docs.coreflux.org/llms.txt
> Use this file to discover all available pages before exploring further.

# MQTT Overview

> Browse topics, publish messages, and see who's connected — all from your Coreflux HUB

<Frame caption="Data Viewer in Coreflux HUB — topic tree with publish controls">
  <img src="https://mintcdn.com/coreflux/W9CJ-kgVY3a3sCeL/images/hub-mqtt-overview.png?fit=max&auto=format&n=W9CJ-kgVY3a3sCeL&q=85&s=ffad2c5474710576abfd996921cd1f80" alt="Coreflux HUB Data Viewer showing the publish panel on the left, the topic tree expanded to $SYS/Coreflux/Resources, and the Resources/MemoryInfoTotal topic plotted live on the right" width="1024" height="639" data-path="images/hub-mqtt-overview.png" />
</Frame>

## Your MQTT Dashboard

Welcome to your built-in MQTT toolbox. From here you can browse every topic on your broker, publish test messages, and check which clients are online — all without leaving the Coreflux HUB. Two widgets are ready for you: **Data Viewer** for topics and messages, and **Connected Clients** for monitoring connections.

<Tip>
  **No need to install external tools** — the Data Viewer is built right into the Coreflux HUB.
</Tip>

## Pick the Right Widget

| Widget                | You want to...                                            |
| --------------------- | --------------------------------------------------------- |
| **Data Viewer**       | Browse topics, inspect payloads, or publish test messages |
| **Connected Clients** | See who's connected and check connection health           |

***

## Next Steps

<CardGroup cols={2}>
  <Card title="Data Viewer" icon="search" href="/coreflux-hub/mqtt/data-viewer">
    Subscribe to topics, browse the topic tree, and publish messages.
  </Card>

  <Card title="Connected Clients" icon="users" href="/coreflux-hub/mqtt/connected-clients">
    View active MQTT client connections and their status.
  </Card>
</CardGroup>