When users interact with Google Chat apps, the app synchronously receives and can respond to an event. Examples of event types include messages, @mentions, card clicks, and getting added to or removed from a space.
Chat apps can respond to these events with either a text message or card message, each of which is represented as a JSON object. This guide explains how to implement interactive features in card messages
Text messages
Text messages are perfect for simple notifications. They support @mentions and basic formatting like bold, italics, and code.
For example, an app might use a text message to notify software developers that code freeze is approaching:
To learn more, see Send a text message.
Card messages
Card messages support a defined layout, interactive UI elements like buttons, and rich media like images. Use card messages to present detailed information, gather information from users, and guide users to take a next step. Card messages can appear in a conversation stream as a message on its own or appended to a text message, or as dialog windows that open over a conversation.
For example, an app might use a card message to run a poll:
To help users complete multi-step processes, like filling in form data, cards can be strung together sequentially in a dialog. Dialogs open in windows that let apps interact with a user directly.
For example, an app might start a dialog to gather contact details:
To learn more, see Send a card message.