Slack Platform

The Slack adapter connects your Ethos agent to a Slack workspace using the Bolt SDK. It handles app mentions, DMs, slash commands, and message shortcuts with per-channel session isolation.

Installation

The Slack adapter ships with the Ethos CLI. If you've already installed @ethosagent/cli, you don't need to install anything else — just enable it in your config.

Setup

1. Create a Slack app

1. Go to api.slack.com/apps → Create New App → From scratch
2. Under OAuth & Permissions, add these Bot Token Scopes:
   • app_mentions:read
   • channels:history
   • chat:write
   • im:history
   • im:read
   • im:write
3. Under Event Subscriptions, enable and add:
   • app_mention
   • message.im
4. Install the app to your workspace and copy the Bot User OAuth Token
5. Copy the Signing Secret from Basic Information

2. Configure

adapters:
  - slack

slack:
  token: "xoxb-YOUR-BOT-TOKEN"
  signingSecret: "YOUR_SIGNING_SECRET"
  appToken: "xapp-YOUR-APP-TOKEN"    # required for Socket Mode
  socketMode: true                    # recommended: no public URL needed

Socket Mode (recommended) — uses a WebSocket connection, so no public URL or TLS is required. Get an app-level token under Basic Information → App-Level Tokens with connections:write scope.

HTTP mode — requires a public URL for the event subscription endpoint:

slack:
  token: "xoxb-..."
  signingSecret: "..."
  port: 3000
  path: "/slack/events"

Triggering the bot

The bot responds to:

1. @mentions in any channel it's in: @YourBot explain this error
2. Direct messages: message the bot directly
3. Slash commands (optional, register in Slack app settings):
   • /ask <message>
   • /new — fresh session
   • /personality <id>

Access control

slack:
  token: "..."
  signingSecret: "..."
  allowedUserIds:
    - "U1234567890"    # Slack user ID
  allowedChannelIds:
    - "C1234567890"    # channel ID

Threads

By default, the bot replies in-thread when the incoming message is already in a thread, and starts a new thread otherwise. Control this:

slack:
  token: "..."
  signingSecret: "..."
  alwaysThread: true    # always reply in thread
  alwaysThread: false   # always reply in channel

Block Kit responses

For structured output, the adapter can format responses using Slack Block Kit. This is off by default:

slack:
  token: "..."
  signingSecret: "..."
  useBlocks: true

When enabled, Markdown headings become Block Kit section dividers, and code blocks become monospace sections.

Sessions

Context	Session key
Channel	slack:<channel-id>
Thread	slack:<thread-ts>
DM	slack:<user-id>

Workflow integration

The Slack adapter exposes a webhook endpoint for Slack Workflow Builder:

POST /slack/workflow
{"text": "...", "userId": "...", "channelId": "..."}

This lets you trigger the agent from automated Slack workflows without a bot mention.

Deployment

See the Deploy a Telegram Agent guide for the PM2 deployment pattern — it applies to Slack too. In Socket Mode, no reverse proxy or domain is required.