The "data" property contains a response message. Its contents are defined by the action. It is an empty array when no results are available. The following is an example of the data property from a code package action.

  "result": {
    "data": [
      {
        "codeId": 6,
        "databaseName": "faircom",
        "ownerName": "admin",
        "codeName": "convertAndCategorizeTemperature",
        "codeVersion": 1,
        "clonedCodeId": 1,
        "codeStatus": "active",
        "codeLanguage": "javascript",
        "serviceName": "javascript",
        "codeType": "module",
        "description": "optional new description",
        "metadata": {},
        "createdBy": "ADMIN",
        "createdOn": "2025-08-25T21:48:38.109",
        "updatedBy": "ADMIN",
        "updatedOn": "2025-08-25T21:48:38.109",
        "comment": "Cloned from convertTemperature",
        "codeFormat": "utf8"
      },
    ]

The "cleanSession" property is a synonym for "temporarySession" (see "temporarySession"). It exists for name compatibility with MQTT. Use "temporarysession" because its name is more intuitive.

The "cleanSession" property specifies whether or not to clean the session after the client disconnects. When true, the MQ engine resets the current session, and when the client disconnects, the engine removes the session's settings, subscriptions, and message position. Because you normally want the engine to remember your message position between sessions, you rarely set "cleanSession" to true.

The "connectionStatus" property is returned by the "describeMqSessions" action to indicate if and how a client is connected to an MQ session. It has the following values:

Example

 "defaultResponseOptions": {
      "binaryFormat": "hex",
      "dataFormat": "objects",
      "numberFormat": "number",
      "variantFormat": "json"
    }

The "numberFormat" property defines the format of JSON numbers. For more details, see "numberFormat". 

The "defaultVariantFormat" property sets the default value of the "variantFormat" property when a JSON Action request does not include it.

The "keepAliveSeconds" property specifies how often (in seconds) the broker expects a message to be sent. The server will retain a temporary session as long as the client performs an MQ Message action within the keep alive timeout period, which is "keepAliveSeconds" x 1.5. Once there is no activity, the server starts the session expiry timer to remove the temporary session. If there is no session activity within the number of seconds specified in the "sessionExpiryInternal" property, the server removes the session.

The "port" property is an integer that specifies the port number.

The "publishedTopics" property returns a list of the topics the client has published since the session was first created.

The "sessionStatus" property specifies the status of an MQTT or MQ API session as "normal", "hidden", "banned", or "inactive" to hide its visibility in API results and the dashboard views, ban a client from connecting, or mark a client as inactive. A banned session prevents clients from using the session to publish and subscribe to messages. When "sessionStatus" is omitted, it defaults to "normal".

The "maxHealthyBacklogRatePerMinute" property sets the maximum number of backlog messages per minute for a healthy session. A backlog message is one the server has not yet published to subscribers. The backlog of a topic grows when the incoming message rate exceeds the outgoing. You can set it to any positive integer or whole number, such as 10 or 0.1. The default value is 0, which sets no upper bound.

A connected session is healthy when its message backlog rate does not exceed the maximum. The "describeMqSessions" action returns the "maxHealthyBacklogRatePerMinute" property and the "sessionHealth" property to report the health of a session.

The "maxHealthySendRatePerMinute" property sets the maximum number of messages per minute for a healthy session. You can set it to any positive integer or whole number, such as 10 or 0.1. The default value is 0, which sets no upper bound.

A connected session is healthy when its message send rate does not exceed the maximum. The "describeMqSessions" action returns the "maxHealthySendRatePerMinute" property and the "sessionHealth" property to report the health of a session.

The "maxHealthySubscribedTopicFiltersCount" property sets the maximum number of topic filters for a healthy session. You can set it to any positive integer, such as 10. The default value is 0, which sets no upper bound.

A connected session is healthy when it has subscribed to at most the maximum number of topic filters. The "describeMqSessions" action returns the "maxHealthySubscribedTopicFiltersCount" property and the "sessionHealth" property to report the health of a session.

A topic filter may include MQTT wildcard characters, which allows one topic filter to subscribe to many topics. The "maxHealthySubscribedTopicFiltersCount" property does not limit the number of topics.

The "minHealthySubscribedTopicFiltersCount" property sets the minimum number of topic filters for a healthy session. You can set it to any positive integer, such as 10. The default value is 0, which sets no lower bound.

A connected session is healthy when it has subscribed to at least the minimum number of topic filters. The "describeMqSessions" action returns the "minHealthySubscribedTopicFiltersCount" property and the "sessionHealth" property to report the health of a session.

A topic filter may include MQTT wildcard characters, which allows one topic filter to subscribe to many topics. The "minHealthySubscribedTopicFiltersCount" property does not limit the number of topics the wildcards match - rather, it establishes a lower bound on the number of subscribed topic filters an MQ Session is allowed to have.

The "sessionHealth" property describes the session health. For more details, see "sessionHealth". 

The "temporarySession" property makes a session temporary or permanent. When set to true, the session is temporary; otherwise, it is permanent.

When true, the MQ engine resets the current session, and when the client disconnects, the engine removes the session's settings, subscriptions, and message position. Because you normally want the engine to remember your message position between sessions, you rarely set "temporarySession" to true.

Use the "temporarySession" property to control session permanency rather than the "cleanSession" property because its name is more intuitive. The server returns an error if you include both and set them to opposite values.

The "willPayload" property is required when a will message is present. It contains the payload of the last will message. You can set it to any JSON value, including binary values embedded in a JSON string or array.

The property "willQoS" is reserved. The server sets it to 2.

When true, “willRetain” tells the FairCom server to send the will message to new subscribers as the first message they receive when subscribing to a topic.