---
title: MQTT Client
slug: uns/mqtt-client
docTags: 
createdAt: 2025-01-24T19:35:17.943Z
---

# Overview

The **MQTT Client** tool allows users to publish messages, access subscriptions, and perform quick troubleshooting.

On the *MQTT Client* page, you can:

- View messages as they are published to the broker in real-time. 
- Add subscriptions to specific topics, with support for wildcard characters for broader topic coverage.
- Send messages to the broker with custom topics, retain properties, and QoS settings. 

# Access MQTT Client UI

**To access the MQTT Client pane: **

1. Log in to **Litmus UNS**.
2. From the Navigation panel, select **Tools**.
   The *MQTT Client *pane appears.

![](https://api.archbee.com/api/optimize/SSUUxKZUk9bFTEPNn_6Zo/yBwxQT0WrMMwdSVKcKGRA_image.png)

Refer to the following actions you can take from the MQTT Client's web UI:

| **Action**                       | **Details**                                                                                                                                                                                                                                                                                                                                                                                   |
| -------------------------------- | --------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |
| \[1] **Connection Status ** | Displays the current status of the connection to the MQTT broker ( "Connected", "Disconnected").                                                                                                                                                                                                                                                                                              |
| \[2] **Add Subscription**        | Add a new topic subscription. Supports wildcard characters for flexible topic matching.                                                                                                                                                                                                                                                                                                       |
| \[3] **Filter**                  | Allows users to filter messages based on criteria such as topic or content.                                                                                                                                                                                                                                                                                                                   |
| \[4]** Auto-scroll**        | Enable or disable automatic scrolling for the message feed.                                                                                                                                                                                                                                                                                                                                   |
| \[5] **Message Feed**            | Displays all received messages for subscribed topics in real-time.                                                                                                                                                                                                                                                                                                                            |
| \[6] **Publish Message Panel**   | - **Topic**: Input the topic to which the message should be published.<br />- **Message**: Enter the payload to be sent.<br />- **Retain**: A toggle to determine whether the message is retained by the broker.<br />- **QoS Selection**: Choose the Quality of Service level for message delivery (0, 1, or 2).<br />- **Send Button**: Publish the entered message to the specified topic. |

# Troubleshooting

- What should I do if I am experiencing connection issues?
  - Verify the broker URL and port, and ensure proper Web Socket configuration (e.g., using `wss://`). &#x20;
- What if I cannot receive any messages?
  - Confirm that the subscription topic path matches the publisher's topic and check if wildcard usage is appropriate. &#x20;
- What can I do if I'm unable to publish messages?
  - Validate that the topic and message payload format are correct, and ensure that the broker is online and accepting connections. &#x20;