Jsonnet Block
Availability: Slack integration only
Jsonnet is a JSON to JSON templating language, which means that combining Jsonnet with your user data allows you to build and send dynamic, custom Slack blocks in your notifications.

Use Cases
Send dynamic, custom Slack blocks in your notifications.
To help you build common Block Kit actions with Jsonnet, Courier has several Jsonnet template blocks to choose from such as buttons, drop-downs, images, and more.
You can also build your own Block Kit elements from scratch. The Jsonnet Block expects a single Block Kit element or an array of elements.

Watch: Designing Slack notifications using Block Kit and Jsonnet.
Read more: Courier Live: Designing Slack Notifications using Block Kit and Jsonnet
Read more: setting up Slack notifications with Courier.
Read more about Content Blocks.