Introducing the Slack app toolkit

The happy path for building engaging Slack apps

Ellie Powers
Oct 22 · 6 min read
Illustration and design by Casey Labatt Simon.

Since launching five years ago, the Slack Platform has evolved — as has our customer base. We’ve grown to 12 million Daily Active Users with half of those users based outside the U.S. and working in non-technical roles. As Slack users become more diverse and global, our priority is to give you the tools to build for them.

Today at Spec, our developer conference, we announced the Slack app toolkit — the happy path for building engaging apps on Slack. Over time, we expect that all Slack apps will be built with these components.

The Slack app toolkit provides the fundamentals for building apps that are easy for any type of customer to discover, understand, and use — so you can drive deeper adoption of what you create.

The toolkit has four components, and we’re making enhancements to each:

  • Permissions, the way your app requests access to data on a workspace
  • Block Kit, the UI framework for Slack apps
  • Surfaces, the places where people interact with Block Kit in Slack
  • Actions, simple shortcuts users can perform with your app — like create a task or file a ticket.

Let’s dive in and explore what’s new.

Permissions: Building enterprise-ready apps

To gain adoption in the enterprise, apps must first be approved by security-conscious admins. Previously, the bot token issued you a broad set of scopes, without the option to specify exactly what you needed.

Granular permissions are now available for the bot token, enabling you to request only the information your app needs to function, and nothing more. Access less information, and make it simpler for admins to understand what your app can see and do in a workspace.

Granular permissions also offer a more reliable experience for you and your users. The updated bot token wraps in app functionality that was previously dispersed across both bot and user tokens. Apps using granular permissions will continue to work even when the original user who installed it leaves a workspace.

You can access granular permissions in open beta today, and by doing so, unlock access to forward-looking platform features.

Block Kit: Slack’s app UI framework

Earlier this year, we released Block Kit, the UI framework for Slack apps made up of stackable “blocks,” or bits of app UI. With Block Kit, you can build richer, more actionable experiences for your app users.

Thanks to your feedback, we continue to enhance Block Kit and the Builder. New blocks, like input, multi-line input, multi-selects and radio buttons are available today; checkboxes are coming soon.

Surfaces: Your app in more places

Let’s talk about where you can build with Block Kit in Slack. You can already construct app messages with Block Kit, but we want to enable you to create more engaging, persistent experiences — to make apps simpler to discover, understand, and use.

Today we announced that Block Kit is now available in two new surfaces, giving your app more real estate within Slack.

App home

Now you can go beyond conversation-based interactions with the home tab — a fully customizable, interactive surface to showcase what your app can do.

People who click on your app in the sidebar will automatically land in this new space. They won’t need to remember slash commands or how to interact with a conversational bot — though power users can still do that, if they’d like.

Let’s say you want your app to welcome a new user and explain what your app does. You can use the home tab for quick, contextual onboarding. Or you might dynamically display information about someone’s specific work with your app — like upcoming tasks, pending expenses, or recent survey results.

For example, Google Calendar’s home tab displays your meetings and events for the day — including actions to Join Zoom meeting, View details, Change response, or Delete event.

Google Calendar in the home tab uses Block Kit buttons, overflow menus, datepicker, dividers, and section blocks to display user-specific daily meetings and events.

The home tab open beta begins rolling out today, continuing over the next week.


Let’s say you want to collect a series of inputs from someone in Slack — like submitting expenses or reporting a bug. Modals are a new Block-Kit-enabled interactive surface that enable more advanced workflows for apps in Slack.

If you’re familiar with dialogs, modals replace this functionality — and add so much more. You can configure up to 100 blocks in a modal for a more actionable, personalized experience. Aside from collecting structured user input, you can also use a modal to display information; for example, you can use modals to report on metrics, track project status, or display a robust FAQ.

For instance, Streak, a CRM for Gmail, uses informational modals to allow people to dynamically search, view, edit and share details about current sales deals.

Streak leverages Block Kit in modals for a robust, informative, and action-oriented app experience.

You can also string modals together in a multi-step workflow that enables booking flows — like booking travel, ordering food, or registering for courses — with less context switching.

Bridge, a learning and development platform, offers an enrollment flow that enables people in Slack to search, browse, and enroll in their company’s course offerings.

The Bridge app, now available in the Slack App Directory, uses multi-step and dynamic modals.

Modals give you a focused space for clear, proactive communication so your users know exactly what your app is doing. For instance, will they lose their work? Will their submission post to a public channel? Did they successfully complete the workflow? A speed bump or confirmation modal is perfect for this.

Qualtrics, an experience management platform, applied this best practice to their Slack app. After sending a questionnaire through the Qualtrics app, users will see a handy confirmation that it was sent. This modal includes dynamic details based on user input — like the people or channels the study was sent to.

The Qualtrics app displays a dynamic confirmation modal as the final step in their Slack workflow.

Modals are available to all developers and customers today.

Actions: Apps in context

Actions are simple shortcuts that people can use to quickly complete a task with your app — like reporting a bug, requesting time off, or starting a meeting.

Last year, we launched the first kind of app action: the ability to turn a Slack message into a task, ticket, sales lead, and more. Now we’re extending actions to more places beyond messages — enabling users to take quick action in the context of their work from anywhere in Slack.

Soon you’ll be able to access actions across a collection of intuitive places in Slack — like pinned to a channel, searchable in the quick switcher, and accessible from a universal actions menu.Through these touchpoints, your app will be more accessible to users, precisely where and when they need it.

Stay tuned for updates on actions in more places next year.

But wait, there’s more!

In addition to the Slack app toolkit, you’ll soon benefit from more app visibility in Slack. One of these improvements is a redesigned app launcher — a prominent place to browse installed and recommended apps for your team.

The redesigned app launcher will be easy to find in Slack. Click to view apps installed in your workspace, and scroll for a list of recommended apps.

Getting started

Start building with the Slack app toolkit by visiting the Slack API documentation. Want to go deeper with our product and engineering teams? Register for our upcoming webinars to get your hands on the keyboard with these new features and your questions answered live.

Questions? Email us at or send a tweet to @SlackAPI.

Slack Platform Blog

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Ellie Powers

Written by

Director of Product at Slack

Slack Platform Blog

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