Choose Slack (managed) for Slack's official MCP server with an authorized app. Choose Slack (stealth) for browser-session access without an app; see the stealth setup guide. The plugins have separate accounts. The instructions below apply to Slack (managed).
Before you start
- Your server needs an HTTPS address, because Slack returns you to it after you sign in. See Tailscale HTTPS or public HTTPS.
- You need permission to create and install apps in your Slack workspace. An administrator may need to approve the app.
1. Create a Slack app
- In OpenTeam, choose Add on Slack (managed) in Marketplace, and copy the Authorized redirect URI from the plugin's page.
- Open Slack's app dashboard, choose Create New App → From a manifest, and pick your workspace.
- Paste OpenTeam's Slack app manifest. Replace its example redirect URL with the URI you copied from OpenTeam.
- Review the permissions and create the app.
- In the app's Agents settings, turn on Enable Slack MCP Server. Sign-in will seem to work without this, but no tools will load.
- From Basic Information, copy the Client ID and Client Secret into OpenTeam. Use the client secret, not the signing secret.
Keep the app internal to your workspace. Slack doesn't allow unlisted public apps to use its MCP server.
2. Connect and test
- In OpenTeam, choose Save credentials and continue, pick your workspace, and approve access.
- To check the connection, open Manage → Accounts and settings, choose the Slack account, and run a small read under Test a tool. Installed plugins and their connected accounts are available to all bots.
Start with a read-only request:
Find recent decisions about the website launch and summarize them with links. Don't post anything to Slack.
To limit what bots can do in Slack, turn tools off or set them to Deny under Manage → Accounts and settings.
Connect another workspace
Choose Add Another Account on the plugin's page, give the account a name, and sign in to the other workspace. Slack apps belong to one workspace, so a different workspace usually needs its own app. The new account starts with your first app's credentials. To use a second app, open Manage → Accounts and settings, select the new account, enter the app's client ID, set the client secret to Replace and paste the new secret, then choose Save and authorize.
Fix common problems
| Problem | What to do |
|---|---|
| App isn't enabled for Slack MCP Server | Turn on Enable Slack MCP Server under Agents, then choose Restart / refresh tools |
| Redirect mismatch | Check that the app's redirect URL exactly matches the Authorized redirect URI in OpenTeam |
| A channel is missing or a tool is denied | Check your own access to the channel, the app's scopes, and the bot's access |
| Administrator approval required | Finish your workspace's app approval process, then try again |
Keep all the scopes from the manifest in your Slack app. OpenTeam requests all of them when you sign in, so removing one can make sign-in fail.