Slack

Slack is a team communication tool that allows you to chat, share files, and collaborate with your team.

Authentication Types

Slack supports 3 authentication methods:

• OAuth - Create your own Slack app with custom scopes. Every user connects with their Slack account.

  • Pros: Full control, per-user tracking, production-ready
  • Cons: ~2 min setup

• Instant OAuth - Use Willow's pre-configured Slack app for the fastest setup.

  • Pros: Fastest setup, no configuration needed
  • Cons: Limited scopes, not recommended for production

• API Key - Use a bot token or user token for all users.

  • Pros: Easy setup
  • Cons: Less secure, no per-user tracking

Setting up OAuth

1. Go to https://api.slack.com/apps

2. Click Create New App

3. Choose From scratch

4. Enter an App Name and select the Workspace to develop in

5. Click Create App

6. In the left sidebar, go to OAuth & Permissions

7. Scroll down to Scopes and add the User Token Scopes you need

8. Scroll up and click Install to Workspace

9. Review the permissions and click Allow

10. In the left sidebar, go to Basic Information

11. Under App Credentials, copy the Client ID and Client Secret

12. In Willow, paste the Client ID and Client Secret

13. Note the Redirect URL for your deployment:

    • For SaaS deployments: https://{org}.mcp-s.com/{org}/api/auth/callback
    • For On-Premise deployments: {connectUrl}/{org}/api/auth/callback

14. In Slack, go to OAuth & Permissions and add the Redirect URL under Redirect URLs

15. In Willow, select the same scopes you configured in Slack

16. Click Save Changes

OAuth Scopes

The following scopes are available for Slack OAuth:

Category	Scope	Access
Channels & Conversations	channels:history	Read
	channels:read	Read
	channels:write	Write
	groups:history	Read
	groups:read	Read
	groups:write	Write
	im:history	Read
	im:read	Read
	im:write	Write
	mpim:history	Read
	mpim:read	Read
	mpim:write	Write
	chat:write	Write
Reactions & Pins	reactions:read	Read
	reactions:write	Write
	pins:read	Read
	pins:write	Write
Bookmarks	bookmarks:read	Read
	bookmarks:write	Write
Reminders	reminders:read	Read
	reminders:write	Write
Canvases & Lists	canvases:read	Read
	canvases:write	Write
	lists:read	Read
	lists:write	Write
Files	files:read	Read
	files:write	Write
Users & Workspace	team:read	Read
	usergroups:read	Read
	usergroups:write	Write
	users:read	Read
	users:read.email	Read
	users:write	Write
	users.profile:read	Read
	users.profile:write	Write
Search	search:read	Read

Generating an API Key (Bot Token)

1. Go to https://api.slack.com/apps

2. Select your app or create a new one

3. Go to OAuth & Permissions

4. Under Bot Token Scopes, add the scopes you need

5. Install the app to your workspace

6. Copy the Bot User OAuth Token (starts with xoxb-)

7. Paste the token into Willow

Restricting which channels tools can read

Slack ships predefined conditions that keep sensitive channels out of reach of the model, without disabling the read tools entirely. Attach them to get_channel_history and get_thread_replies from the Tools tab:

Condition	Effect
Block specific channels	Blocks reads from the channels you select.
Block channels by name	Blocks reads from channels whose name matches a glob pattern, for example *sensitive* or exec-*. Applies to channels created later.
Only allow channels by name	Blocks every channel whose name matches none of your allowed patterns.

Slack also ships webhook conditions that filter workflow events by channel or user. See Conditions.