Displays a card to the user using either a smaller thumbnail layout or larger hero layout (the attachments contentType determines which). All of the cards fields are optional so this card can be used to specify things like a keyboard on certain channels. Some channels may choose to render a lower fidelity version of the card or use an alternate representation.
Set of actions applicable to the current card. Not all channels support buttons or cards with buttons. Some channels may choose to render the buttons using a custom keyboard.
Messaging supports all media formats: audio, video, images and thumbnails as well to optimize content download.
Subtitle appears just below Title field, differs from Title in font styling only.
This action will be activated when user taps on the card. Not all channels support tap actions and some channels may choose to render the tap action as the titles link.
Text field appears just below subtitle, differs from Subtitle in font styling only.
Title of the Card.