Block Kit is a UI framework for Slack apps that offers a balance of control and flexibility when building experiences in messages and other surfaces.

Customize the order and appearance of information and guide users through your app's capabilities by composing, updating, sequencing, and stacking blocks — reusable components that work almost everywhere in Slack.

Browse the available blocks, get started with an app template, or dig into the documentation.

Building blocks

Blocks are visual components that can be stacked and arranged to create app layouts.

Read our guide to learn how you can construct stacks of blocks and add them to your app's surfaces.

Block Kit Builder Block Kit Builder
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Interactivity in blocks

Block Kit makes interacting with users intuitive and stylish. Use special components to inject an app with interactivity.

Read our overview to get a quick taster of the interactive components available, and pointers on how to integrate interactivity into your app.

Block Kit Builder

Shuffle and stack blocks to quickly prototype layouts in Slack. When you're ready, we'll provide the payload so all you have to do is copy and paste it into your app's code.

Design layouts with Block Kit Builder. Or save time designing your app by starting with one of our templates.

Block Kit Builder Block Kit Builder