Publish

Publishes an MQTT message.

Requires permission to access the Publish action.

For more information about MQTT messages, see MQTT Protocol in the AWS IoT Developer Guide.

For more information about messaging costs, see AWS IoT Core pricing - Messaging.

Request Syntax


POST /topics/topic?qos=qos&retain=retain HTTP/1.1

payload

The request uses the following URI parameters.

qos

The Quality of Service (QoS) level. The default QoS level is 0.

Valid Range: Minimum value of 0. Maximum value of 1.

A Boolean value that determines whether to set the RETAIN flag when the message is published.

Setting the RETAIN flag causes the message to be retained and sent to new subscribers to the topic.

Valid values: true | false

Default value: false

The name of the MQTT topic.

Required: Yes

The request accepts the following binary data.

The message body. MQTT accepts text, binary, and empty (null) message payloads.

Publishing an empty (null) payload with retain = true deletes the retained message identified by topic from AWS IoT Core.


HTTP/1.1 200

If the action is successful, the service sends back an HTTP 200 response with an empty HTTP body.

InternalFailureException

An unexpected error has occurred.

HTTP Status Code: 500

InvalidRequestException

The request is not valid.

HTTP Status Code: 400

MethodNotAllowedException

The specified combination of HTTP verb and URI is not supported.

HTTP Status Code: 405

UnauthorizedException

You are not authorized to perform this operation.

HTTP Status Code: 401