Slack Troubleshooting

How Dust's Slack Integration Works

Dust's Slack integration has two layers: Slack Apps and Features.

Understanding Slack Apps

A Slack app is the foundation. When you install a Slack app, it creates a bot user in your workspace. Without the app installed, there's no bot to invite. Without the bot invited, there's no feature to use.

Slack App	What It Creates	What It Enables
Dust Data Sync	`@Dust Data Sync` bot	Message syncing to Dust (your channels become searchable by agents) with Dust Slack Connection
Dust	`@Dust` bot	Interactive chat with agents directly in Slack
Dust Slack Tools	-	Slack Tool or Slack Bot Tool capability in Dust

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Why three Slack Apps?
Each app has a distinct job. Dust Data Sync reads and indexes your messages so agents can search them later (see Slack Connection). Dust is the interactive bot that responds when you mention it (see Dust in Slack). Separating these keeps permissions clear and lets you control each independently.

Understanding the Features

Feature	Slack App Required	Additional Step	What Happens
Message sync	Dust Data Sync	Select channel in Dust connection manager	Messages flow into your Dust data sources
Semantic search	Dust Data Sync	None (automatic once synced)	Agents search your Slack history intelligently
@Dust chat	Dust	Invite `@Dust` to the channel	Chat with agents directly in Slack
Slack tools	Dust Slack Tools	Personal OAuth flow in Dust	Agents search/post Slack on your behalf

Now that the basics are clear, let's dive into the troubleshooting usual suspects!

Slack Connection Issues

Private channel not appearing

Why this happens: Slack apps cannot see private channels until explicitly invited. This is a Slack security feature—private means private until you grant access.

How to fix it:

Open the private channel in Slack
Type /invite @Dust Data Sync and press Enter
Wait 2–5 minutes for Slack to propagate the change
Refresh the connection manager in Dust

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Inviting is not the same as syncing
Inviting the bot makes the channel visible in Dust's connection manager. But messages only sync after you explicitly select that channel in Spaces → Connections → Slack → Add / Remove data (:doc:/slack-connection). This gives you control over exactly what data enters Dust.

Channel not syncing

Why this happens: Either the bot isn't in the channel, or the channel isn't selected in Dust's connection manager.

How to fix it:

In Slack, type /invite @Dust Data Sync and press Enter
In Dust, go to Spaces → Connections → Slack → Add / Remove data (see Slack Connection)
Verify the channel appears and is selected
If already selected but not syncing, unselect it, save, then re‑select it

To check if the bot is in a channel: Click the channel name in Slack, go to Integrations, and look for Dust Data Sync in the list.

Historical messages missing

Why this happens: Slack's API only provides messages from after the bot joined the channel. This is a Slack platform limitation, not a Dust limitation. Slack doesn't expose historical messages to newly‑invited bots.

"Failed to retrieve permissions" error

Why this happens: When you first load the connection manager on a large workspace (1000+ channels), Dust needs to cache the full channel list. This takes time, and the error appears while that cache is building.

How to fix it: Wait 5 minutes, then refresh the page. The cache should be populated.

Can't see Slack integration toggle

Why this happens: Either you don't have admin permissions in Dust, or your Slack connection predates December 2024 and needs migration.

How to fix it:

Verify you're a Dust workspace admin
If your connection was set up before December 2024, follow the Slack Connection setup guide to create your own Slack App.
To enable the interactive bot, go to Workspace Management → Workspace Settings → Integrations and toggle Slack on (:doc:/slack).

@Dust Bot Issues

@Dust not responding

Why this happens: The bot isn't in the channel, the Slack integration is disabled in Dust, or you're trying to use it in a DM.

How to fix it:

In Dust, go to Workspace Management → Workspace Settings → Integrations and verify Slack is toggled on (:doc:/slack).
In the Slack channel, type /invite @Dust and press Enter
Mention the bot: @Dust your question here

To remove the bot from a channel: Type /remove @Dust and press Enter.

🗯️
DMs are not supported
@Dust works in public and private channels only. It does not respond in direct messages (:doc:/slack). This is by design—channels provide shared context that makes agent responses more useful to everyone.

Bot doesn't see full conversation

Why this happens: When you mention @Dust, it only receives the thread it's mentioned in—not the entire channel history. This keeps responses fast and focused.

What you can do:

Include relevant context directly in your message
Use Slack threads: mention @Dust within a thread so it sees all the thread's messages
Reference specific details: "Based on the pricing we discussed above, what's our discount policy?"

Calling a specific agent

How to do it: Use + or ~ before the agent name:

@Dust +sales-helper What's our discount policy?
@Dust ~hr-helper What's the PTO policy?

For public channels: You can set a default agent in the agent's settings (the agent must be published). When anyone mentions @Dust in that channel, your chosen agent responds automatically (:doc:/slack).

⚠️
Private channel limitation
You cannot set a default agent for private channels. In private channels, always use the +agent-name or ~agent-name syntax to call specific agents.

Auto‑reply without @mention

Why this might not work: Auto‑reply requires configuration and may have availability restrictions depending on your plan.

Options:

Agent settings: Configure a default agent for specific public channels in the agent's settings page (:doc:/slack).
Slack Workflows: Use Slack Workflows to trigger agents based on events like emoji reactions or schedules.

⚠️
Workflows require whitelisting
Slack workflows must be enabled for your workspace by Dust. Contact [email protected] with your workspace URL and workflow name to request access (see Slack Workflows).

Slack Tools Issues

Poor search results

Why this happens: Search quality depends on which search method is available in your Slack workspace.

Tool	What It Requires	How It Works
Semantic Search Messages	Slack AI add‑on enabled	Uses natural language understanding—better results
Search Messages	Nothing	Keyword matching only, less accurate

What you can do:

Check if your Slack workspace has the AI add‑on enabled
When using keyword search, be specific and exact
Try multiple searches with different keyword combinations

Actions appear from my name

Why this happens: Slack tools use your personal OAuth credentials. When an agent posts a message or performs an action, Slack sees it as coming from you. This is intentional—it means agents can only do what you're allowed to do (:doc:/slack-mcp).

If you need bot identity: Contact [email protected] to request access to the Slack Bot tool, which posts as a bot instead of you. Note: the bot version only works in public channels where the bot has been invited (:doc:/beta-slack-tool-using-bot-credentials).

Tool not appearing in agent builder

Why this happens: You haven't connected your personal Slack credentials to Dust's tools yet.

How to fix it:

Go to Spaces → Tools → Add Tools
Select Slack from the list
Complete the OAuth flow with your Slack account
The Slack tools now appear when building agents (:doc:/slack-mcp).

Setup and Migration Issues

Can't create Slack app

Why this happens: You don't have the required Slack permissions, the manifest was modified, or you selected the wrong workspace.

How to fix it:

Verify you're a Slack Owner or Admin (not just a member)
Copy the manifest exactly as provided in the Dust docs—do not edit it (:doc:/slack-connection)
When Slack prompts you to select a workspace, choose the correct one

How to check your Slack role:

Click your workspace name in Slack (top‑left corner)
Go to Settings & administration → Manage members
Search for your name—your role appears next to it

Connection broke after editing app

Why this happens: Certain Slack app settings are critical to the Dust connection. Changing them breaks the authentication flow.

Settings you must not change:

OAuth scopes or permissions
Redirect URLs
Credentials (Client ID, Client Secret, Signing Secret)

If you rotated credentials for security reasons: Update them immediately in Spaces → Connections → Slack → Manage → Edit (:doc:/slack-connection#managing-permissions). Enter the new credentials from your Slack app's Basic Information page. The connection should resume automatically.

Legacy connection migration

Why this matters: Slack connections created before December 2024 use a shared Dust app. These connections work until March 3, 2026, but must be migrated to your own Slack app before that deadline (:doc:/slack-connection).

How to fix it: Follow the Slack Connection setup guide. The process takes about 2 minutes and involves creating your own Slack app from a manifest.

Permission Issues

App pending approval

Why this happens: Your Slack workspace has an app approval workflow enabled. New apps require admin approval before they can be used.

How to fix it: Ask your Slack admin to approve the app in Slack Admin → Manage Apps → App Requests.

Can't see all channels

Why this happens: Dust has its own permission layer that controls who can select which channels for syncing.

How to fix it: Check Spaces → Connections → Slack to see access restrictions and which spaces receive which data (:doc:/slack-connection#managing-permissions).

"You don't have permission" error

Why this happens: The action requires a Slack role you don't have.

Action	Required Slack Role
Install apps	Owner or Admin
Manage existing apps	Owner, Admin, or App Manager
Invite bots to channels	Any member of that channel

Known Limitations

Limitation	Why It Exists
One interactive bot per Dust workspace	You can sync multiple Slack workspaces as data sources, but only one can have the `@Dust` bot active. This prevents confusion about which bot responds.
Bot messages not synced	Messages from `@Dust` and other bots are intentionally excluded from sync. This prevents AI‑generated content from being treated as source material, which could propagate mistakes. (:doc:`/slack-connection#data-synchronization`)
No default agent in private channels	Slack's Terms of Service restrict certain bot behaviors in private channels. Use `@Dust +agent-name` syntax instead.
Thread links sometimes approximate	When messages aren't threaded, Dust links to the approximate location in the channel rather than the exact message. Use threads for precise linking. (:doc:`/slack-connection#slack-connection-specificities`)

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Best practice: Use threads
Post your topic as the first message, then continue the conversation in a thread. This improves Dust's ability to retrieve relevant context and provides accurate message links (:doc:/slack-connection#slack-connection-specificities).

Still Stuck?

Email [email protected] with:

What you did, what you expected, what happened instead
Dust URL where you see the issue
Slack message, thread, or channel URL
Any error message