Slack Gateway

BMO can expose a Slack Socket Mode gateway for direct messages via:

bmo gateway --config gateway.yaml

Supported scope

• Slack is the only built-in gateway adapter in this repo.
• Direct messages are the only supported interaction mode.
• Group channels, thread routing, and mention-based activation are not supported by this gateway.

Health model

If you start the gateway with --addr, BMO exposes:

• GET /health for liveness only

/health does not validate Slack credentials or adapter connectivity. Treat a healthy response as process liveness only.

For local readiness without contacting Slack, run:

bmo gateway check --config gateway.yaml
bmo gateway check --config gateway.yaml --json

The check validates the YAML config, supported Slack channel shape, direct-message routing scope, local gateway session store, worker capacity, and liveness binding. Output is token-redacted. Add --live-slack only when you intentionally want BMO to call Slack Web API methods with the configured credentials.

Configuration

Use a YAML config file:

approval_mode: 0 # auto approval
channels:
  - type: slack
    slack:
      app_token: xapp-...
      bot_token: xoxb-...
router:
  dm_scope: 2 # per channel+peer direct-message sessions

Gateway approval mode supports auto approval. Use a DM routing scope that matches how you want direct messages mapped into BMO sessions.

Slack app setup

Configure the Slack app around the BMO gateway contract: Slack-only, DM-first, Socket Mode.

1. Create the Slack app

• Create a new internal Slack app for the target workspace.
• Add a bot user to the app.

2. Enable Socket Mode

• Turn on Socket Mode for the app.
• Create an app-level token (xapp-...).
• Grant the app-level token the connections:write scope.

BMO uses the app token to open the Socket Mode connection.

3. Configure bot scopes

Add these bot token scopes:

• chat:write
• im:history

BMO uses the bot token for auth.test, DM event handling, and message replies.

4. Subscribe to the DM event

Under Event Subscriptions, enable events and add:

• message.im

The gateway listens for Slack direct-message events.

5. Install the app to the workspace

• Install or reinstall the app after scopes and events are configured.
• Copy the bot token (xoxb-...) after installation.

6. Provide both tokens to BMO

You need both:

• app_token: xapp-...
• bot_token: xoxb-...

7. Start the gateway

Check local posture first:

bmo gateway check --config gateway.yaml

This command does not send a Slack DM and does not contact Slack unless you add --live-slack.

bmo gateway --config gateway.yaml

Optional liveness endpoint:

bmo gateway --config gateway.yaml --addr :8081

8. Verify behavior

• Send the bot a direct message in Slack.
• Confirm BMO receives it and replies.
• Confirm Slack channels remain ignored.

Limits

• The /health endpoint exposes liveness, not readiness; use bmo gateway check for local readiness posture.
• No support for Slack channels or mention-triggered activation.
• Slack MCP tools are configured separately and are not this inbound gateway.
• Teams, Mattermost, Telegram, Discord, and Google Chat adapters are not implemented.