Slack

Overview

The Slack provider integrates your digital worker with Slack workspaces. It supports:

• Direct messages (DMs)
• Channel messages
• App mentions
• Interactive components (buttons, menus)
• Block Kit rich messaging
• Slash commands
• Thread replies

Prerequisites

• A Slack workspace
• Admin access to create a Slack app

Setup

1. Create a Slack App

   Go to api.slack.com/apps and click “Create New App”:

   • Choose “From scratch”
   • Enter an app name (e.g., “My Support Bot”)
   • Select your workspace

2. Configure Bot Token Scopes

   Go to OAuth & Permissions → Scopes → Bot Token Scopes:

   Required scopes:

   • chat:write - Send messages
   • im:history - Read DM history
   • im:write - Open DMs
   • users:read - Read user info

   Optional scopes:

   • channels:history - Read channel messages
   • channels:read - List channels
   • files:read - Read files
   • files:write - Upload files

3. Enable Event Subscriptions

   Go to Event Subscriptions:

   • Enable Events
   • Set Request URL: https://your-domain.com/webhook/slack/{tenant}/{team}

   Subscribe to bot events:

   • message.im - DM messages
   • message.channels - Channel messages
   • app_mention - @mentions

4. Enable Interactivity

   Go to Interactivity & Shortcuts:

   • Enable Interactivity
   • Set Request URL: https://your-domain.com/webhook/slack/{tenant}/{team}/interactive

5. Install App to Workspace

   Go to Install App → Install to Workspace

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

6. Get App Credentials

   From Basic Information:

   • App ID
   • Configuration Token (for manifest updates)

7. Configure Provider

   answers.json

   {
     "messaging-slack": {
       "enabled": true,
       "public_base_url": "https://your-domain.ngrok-free.app",
       "api_base_url": "https://slack.com/api",
       "bot_token": "xoxb-xxx-xxx-xxx",
       "slack_app_id": "A07XXXXXX",
       "slack_configuration_token": "xoxe.xoxp-xxx"
     }
   }

8. Run Setup

   gtc setup --answers answers.json ./my-bundle

Configuration Options

Option	Required	Description
enabled	Yes	Enable/disable the provider
public_base_url	Yes	Public URL for webhooks
bot_token	Yes	Bot User OAuth Token (xoxb-...)
slack_app_id	Yes	App ID from Basic Information
slack_configuration_token	No	For automatic manifest updates
api_base_url	No	Slack API URL (default: https://slack.com/api)

Features

Text Messages

- id: reply
  type: reply
  config:
    message: "Hello! How can I help you?"

Markdown Formatting

Slack uses mrkdwn format:

- id: formatted
  type: reply
  config:
    message: |
      *Bold* _Italic_ `code`
      >Blockquote
      • Bullet point

Block Kit Messages

Use Slack’s Block Kit for rich layouts:

- id: rich_message
  type: reply
  config:
    blocks:
      - type: section
        text:
          type: mrkdwn
          text: "*Welcome!*\nHow can I assist you today?"
      - type: divider
      - type: actions
        elements:
          - type: button
            text:
              type: plain_text
              text: "Get Help"
            action_id: "help_clicked"
            value: "help"
          - type: button
            text:
              type: plain_text
              text: "View Status"
            action_id: "status_clicked"
            value: "status"

Interactive Buttons

- id: ask_action
  type: reply
  config:
    message: "What would you like to do?"
    blocks:
      - type: actions
        elements:
          - type: button
            text:
              type: plain_text
              text: "Create Ticket"
            style: primary
            action_id: "create_ticket"
          - type: button
            text:
              type: plain_text
              text: "Cancel"
            style: danger
            action_id: "cancel"

Select Menus

- id: select_option
  type: reply
  config:
    blocks:
      - type: section
        text:
          type: mrkdwn
          text: "Select a category:"
        accessory:
          type: static_select
          action_id: "category_select"
          options:
            - text:
                type: plain_text
                text: "Technical Support"
              value: "technical"
            - text:
                type: plain_text
                text: "Billing"
              value: "billing"
            - text:
                type: plain_text
                text: "General"
              value: "general"

Thread Replies

Reply in a thread:

- id: thread_reply
  type: reply
  config:
    message: "This replies in the thread"
    thread_ts: "{{original_message.thread_ts}}"

File Uploads

- id: upload_file
  type: reply
  config:
    files:
      - url: "https://example.com/report.pdf"
        filename: "report.pdf"
        title: "Monthly Report"

Ephemeral Messages

Messages only visible to one user:

- id: ephemeral
  type: reply
  config:
    message: "Only you can see this"
    ephemeral: true
    user: "{{user_id}}"

Handling Interactions

Button Clicks

flows/on_interaction.ygtc

name: handle_interaction
version: "1.0"

nodes:
  - id: route_action
    type: branch
    config:
      conditions:
        - expression: "action_id == 'help_clicked'"
          next: show_help
        - expression: "action_id == 'create_ticket'"
          next: create_ticket
      default: unknown_action

  - id: show_help
    type: reply
    config:
      message: "Here's how I can help..."

triggers:
  - type: block_action
    target: route_action

Select Menu Changes

- id: handle_select
  type: branch
  config:
    conditions:
      - expression: "selected_value == 'technical'"
        next: technical_flow
      - expression: "selected_value == 'billing'"
        next: billing_flow

Slash Commands

Note

Slash commands require additional app configuration in Slack.

1. Go to Slash Commands in your app settings
2. Create a command (e.g., /support)
3. Set Request URL to your webhook

Handle in your flow:

flows/slash_command.ygtc

name: slash_command
version: "1.0"

nodes:
  - id: handle_command
    type: reply
    config:
      message: "Support bot at your service!"
      response_type: in_channel  # or "ephemeral"

triggers:
  - type: slash_command
    command: "/support"
    target: handle_command

Channel Configuration

Single Channel

greentic.demo.yaml

tenants:
  demo:
    teams:
      support:
        channels:
          slack:
            provider: messaging-slack
            config:
              channel_id: "C1234567890"

Multiple Channels

tenants:
  demo:
    teams:
      support:
        channels:
          slack-general:
            provider: messaging-slack
            config:
              channel_id: "C1234567890"
          slack-vip:
            provider: messaging-slack
            config:
              channel_id: "C0987654321"

Troubleshooting

App Not Receiving Messages

1. Verify Event Subscriptions:

   • Check Request URL is correct
   • Ensure events are enabled
   • Verify bot is subscribed to correct events

2. Check Bot Permissions:

   • Reinstall app after adding scopes
   • Verify bot is in the channel

3. Test Webhook:

   curl https://your-domain.com/webhook/slack/demo/default

“not_authed” Error

Your bot token is invalid or expired. Get a fresh token from OAuth & Permissions.

”channel_not_found” Error

• Verify channel ID is correct
• Ensure bot is added to the channel
• Check channel is not archived

Rate Limiting

Slack rate limits vary by method. Handle gracefully:

- id: reply
  type: reply
  config:
    message: "Response"
    retry_on_rate_limit: true
    max_retries: 3

Security

Caution

Verify Slack request signatures to prevent unauthorized requests.

Greentic automatically validates:

• Request timestamp
• Signature using signing secret
• Token verification

Next Steps

• Block Kit Builder - Design rich messages
• Teams Provider - Add Teams integration
• Flows Guide - Build complex workflows