MqttHeaders - Amazon IoT
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MqttHeaders

Specifies MQTT Version 5.0 headers information. For more information, see MQTT from Amazon IoT Core Developer Guide.

Contents

contentType

A UTF-8 encoded string that describes the content of the publishing message.

For more information, see Content Type from the MQTT Version 5.0 specification.

Supports substitution templates.

Type: String

Length Constraints: Minimum length of 0. Maximum length of 1024.

Required: No

correlationData

The base64-encoded binary data used by the sender of the request message to identify which request the response message is for when it's received.

For more information, see Correlation Data from the MQTT Version 5.0 specification.

Note

This binary data must be based64-encoded.

Supports substitution templates.

Type: String

Length Constraints: Minimum length of 0. Maximum length of 1024.

Required: No

messageExpiry

A user-defined integer value that will persist a message at the message broker for a specified amount of time to ensure that the message will expire if it's no longer relevant to the subscriber. The value of messageExpiry represents the number of seconds before it expires. For more information about the limits of messageExpiry, see Amazon IoT Core message broker and protocol limits and quotas from the Amazon Reference Guide.

Supports substitution templates.

Type: String

Length Constraints: Minimum length of 0. Maximum length of 1024.

Required: No

payloadFormatIndicator

An Enum string value that indicates whether the payload is formatted as UTF-8.

Valid values are UNSPECIFIED_BYTES and UTF8_DATA.

For more information, see Payload Format Indicator from the MQTT Version 5.0 specification.

Supports substitution templates.

Type: String

Length Constraints: Minimum length of 0. Maximum length of 1024.

Required: No

responseTopic

A UTF-8 encoded string that's used as the topic name for a response message. The response topic is used to describe the topic which the receiver should publish to as part of the request-response flow. The topic must not contain wildcard characters.

For more information, see Response Topic from the MQTT Version 5.0 specification.

Supports substitution templates.

Type: String

Length Constraints: Minimum length of 0. Maximum length of 1024.

Required: No

userProperties

An array of key-value pairs that you define in the MQTT5 header.

Type: Array of UserProperty objects

Array Members: Minimum number of 1 item. Maximum number of 100 items.

Required: No

See Also

For more information about using this API in one of the language-specific Amazon SDKs, see the following: