| Name | Type | Description | Notes |
|---|---|---|---|
| type | String | The type of system activity that generated the message. The value of this field determines the dynamic content that is rendered to the end-user / agent when viewing this message. Each `type` value will have a set of pre-defined, localized strings that describe the activity. | [default to 'ticket:closed'] |
| data | {String: Object} | No additional data is supplied with the "ticket:closed" activity type at this time. | [optional] |