QuickReplies
Quick Reply messages have a title to present to the user along with a selection of quick response Action.ReplyButton. The buttons should also be presented to the user, and if the user taps a button, the associated postback should be sent together with the text of the button as a reply message (on behalf of the user). The action can be invoked only once, and the integrating applications have to prevent multiple uses.
Properties
Attachments provided with the message. This field can be empty. It contains attachments that the user or agent sent alongside with the message.
Author associated with this message.
The direction in which the message is sent.
Optional fallback text which can be used if UI integration doesn't support concrete subtype of Message.
The otherwise uncategorizable properties for this message. It can contain anything from message status to custom properties.