Developer Guide

View Device MQTT Messages with the AWS IoT MQTT Client

You can use the AWS IoT MQTT client to better understand the MQTT messages sent by a device.

Devices publish MQTT messages on topics. You can use the AWS IoT MQTT client to subscribe to these topics to see these messages.

To view MQTT messages:

  1. In the AWS IoT console, in the left navigation pane, choose Test.

  2. Subscribe to the topic on which your thing publishes. In the case of the AWS IoT button, you can subscribe to iotbutton/+ (note that + is the wildcard character). In Subscribe to a topic, in the Subscription topic field, type iotbutton/+, and then choose Subscribe to topic.

    Choosing Subscribe to topic above, results in the topic iotbutton/+ appearing in the Subscriptions column.

  3. Press your AWS IoT button, and then view the resulting message in the AWS IoT MQTT client. If you do not have a button, you will simulate a button press in the next step.


    The AWS IoT Button FAQs contains useful button LED color pattern information.

  4. To use the AWS IoT console to publish a message:

    On the MQTT client page, in the Publish section, in the Specify a topic and a message to publish… field, type iotbutton/ABCDEFG12345. In the message payload section, type the following JSON:

    { "serialNumber": "ABCDEFG12345", "clickType": "SINGLE", "batteryVoltage": "2000 mV" }

    Choose Publish to topic. You should see the message in the AWS IoT MQTT client (choose iotbutton/+ in the Subscription column to see the message).