Slack messaging channel

Use this guide to deploy an agent to Slack.

Before you start

Make sure you have:

A Slack workspace where you can create apps
A live agent with an AI model connected
Access to Agents -> your agent -> Deployment

Configure Slack in Budibase

Open your agent in Agents
Go to Deployment
In Messaging channels, click Manage for Slack
Enter:
- Bot token
- Signing secret
- Idle timeout (minutes) (optional)
Click Save channel
Copy the generated Messaging endpoint URL
(Optional) Toggle File attachments to Enabled. This requires a GEMINI_API_KEY to be set in your Budibase server environment.

Configure your Slack app

1. Create or update app

Create a Slack app for your workspace, or use an existing one.

2. Add bot scopes

In OAuth & Permissions, add:

chat:write
app_mentions:read
im:history
channels:history
groups:history
mpim:history
users:read
files:read

3. Configure event subscriptions

Open Event Subscriptions
Enable events
Set Request URL to the Budibase Messaging endpoint URL
Subscribe to bot events:
- app_mention
- message.im
- message.channels
- message.groups
- message.mpim

4. Reinstall app

Reinstall the app to your workspace after changing scopes or events.

5. Invite bot

Invite the bot to channels you want it to serve, for example:

/invite @your-bot

Enable and verify

In Budibase Deployment, toggle Slack to Enabled
In Slack, mention the bot in a channel or send a DM
Run /link and complete the Budibase account linking flow
Run /unlink to disconnect your Budibase account
Send a message and confirm the agent responds

Slack threads are used as conversation boundaries. In a channel thread, you must mention the agent in each message you want it to process. In direct messages (DMs), the agent will respond to every message automatically.

If you send a message before linking, Budibase prompts you privately to complete account linking first.

Slash commands

/ask <message>: Continue the current conversation.
/new <message>: Start a new conversation, clearing the message and file history for the current thread.
/link: Link your Slack user to your Budibase account.
/unlink: Unlink your accounts.

Working with documents (RAG)

When your agent uses documents to answer questions (Retrieval-Augmented Generation), Budibase can provide direct download links to those sources within Slack.

Source citations

In personal conversations (DMs), your agent will automatically append a list of the specific document sources it used to generate its reply. Each source includes a direct, authenticated link to download the file.

To ensure privacy and security, source download links are not provided when the agent is chatting in a channel or group conversation.

Conversation attachments

If File attachments is enabled in the agent deployment settings, users can upload files directly in Slack conversations. The agent will process these files and use their content to answer subsequent questions in that thread.

Supported formats: PDF, CSV, TXT, Markdown, JSON, YAML, and XML.
Limits: Up to 3 files per conversation, maximum 20MB per file.
Clearing files: Use the /new command to clear attached files and start a fresh conversation.

Troubleshooting

Not configured in Budibase: confirm both Bot token and Signing secret are saved.
Slack events not reaching Budibase: re-check Request URL and reinstall the app after scope/event changes.
Bot does not respond in channels: confirm the bot was invited to that channel.
Bot prompts to link before answering: run /link in Slack and complete the link handoff.
Webhook route errors: use the exact Budibase-generated endpoint URL from Deployment.
File processing fails: ensure GEMINI_API_KEY is correctly configured and the Slack app has the files:read scope.