New Block Kit Components

Slack has introduced three new components to help developers showcase app and agent workflows:

• task_card block: Displays individual tasks with clear visual hierarchy
• url_source element: Embeds clickable URL references directly within task cards
• plan block: Aggregates multiple task cards into a unified, comprehensive view

Streaming API Enhancements

The text-streaming API methods now support two powerful new parameters:

• task_display_mode: Controls whether tasks are presented individually or as part of a complete plan view
• chunks: Allows you to update task cards and plans dynamically, with support for both structured task updates and plain markdown content

Getting Started

Developers can begin implementing these features using the existing text-streaming methods:

• chat.startStream
• chat.appendStream
• chat.stopStream

The Slack documentation includes a dedicated guide on developing AI apps with working examples and best practices for leveraging these new components.