...
An Adaptive Card is a JSON-serialized card object model. Developers can edit the JSON for the adaptive card with the template editor. The template editor uses AvalonEdit Textbox to format the template string into JSON format.
...
Data Editor
Data is a JSON-serialized card object model that can be bound to Template JSON.
...
Designer
The result of template JSON can be visualized using the Designer section. This window lets you visualize the card you edit in real-time inside the editor itself.
...