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Slack Message Event Handler

Mango allows you to handle any event by sending a Slack message to a channel in your workspace. When an event is triggered (such as an alarm condition, a data source error, or a system event), the Slack message event handler sends a notification to the configured Slack channel using a bot user. This provides real-time visibility into your SCADA system directly within your team's communication platform.

Prerequisites​

Before configuring the Slack event handler in Mango, you need a Slack workspace and a configured Slack application with a bot user. If you do not have a workspace, create one at https://slack.com/create.

Step 1: Create a Slack App​

  1. Log into your Slack account in a browser.
  2. Navigate to https://api.slack.com/apps.
  3. Click Create New App.
  4. Give your app a descriptive name (e.g., "Mango SCADA Alerts").
  5. Select the workspace where you want the app to operate.
  6. Click Create App.

Step 2: Create a Bot User​

  1. In your app's settings, navigate to the Bot Users tab (under Features).
  2. Click Add a Bot User.
  3. Give the bot an appropriate display name (e.g., "Mango Bot").
  4. Set the default username.
  5. Click Add Bot User.

Step 3: Install the App to Your Workspace​

  1. Navigate to the Install App tab in your app's settings.
  2. Click Install App to Workspace.
  3. Authorize the bot user by clicking Allow.
  4. A notification will be posted to the workspace confirming the installation.
  5. After installation, you will see a Bot User OAuth Token starting with xoxb-. Copy this token -- you will need it for the Mango configuration.

Step 4: Invite the Bot to Channels​

The bot can only send messages to channels it has been invited to:

  1. Open the Slack channel where you want to receive Mango notifications.
  2. Click on the channel name to open channel settings.
  3. Click Add more people (or Integrations > Apps).
  4. Search for your bot name and add it to the channel.

Repeat this for each channel you want to receive notifications in. The bot must be invited to a channel before it can post messages there.

Note: The channel must be a public channel. The bot cannot post to private channels unless explicitly invited.

Step 5: Configure the Slack Event Handler in Mango​

  1. Navigate to the Event Handlers page in Mango.
  2. Create a new event handler and select Slack Message as the type.
  3. Give the event handler a descriptive name (e.g., "Critical Alarms to #ops-alerts").

Slack Message Settings​

Switch to the Slack Message tab and configure:

SettingDescription
Slack bot tokenThe Bot User OAuth Token from your Slack app (starts with xoxb-).
ChannelThe Slack channel name where messages will be posted. Enter the name without the # prefix (e.g., ops-alerts not #ops-alerts).

Slack Message event handler configuration showing bot token and channel fields

Switch to the Event Types tab and select the events you want to trigger Slack notifications:

  • Data point event detectors (high limit, low limit, state changes)
  • Data source events (connection errors, poll failures)
  • System events (startup, shutdown, user login)
  • Publisher events (queue warnings)
  • Scheduled events from the Advanced Scheduler

Event type selection for the Slack message handler

You can create multiple Slack event handlers with different configurations to route different event types or severity levels to different Slack channels. For example:

  • Critical and Life Safety alarms to #ops-critical
  • Warning and Urgent alarms to #ops-alerts
  • Information-level events to #ops-info

Message Format​

When an event triggers the Slack handler, the message posted to the channel includes:

  • The event's alarm level (e.g., Warning, Critical)
  • The event message describing what triggered the alarm
  • The timestamp of when the event occurred
  • The event ID for reference

Troubleshooting​

  • Messages not appearing: Verify that the bot token is correct and has not been regenerated since configuration. Check that the bot has been invited to the target channel.
  • Invalid token errors: Regenerate the Bot User OAuth Token from the Slack app settings and update it in Mango.
  • Channel not found: Ensure the channel name is entered without the # prefix. Verify the channel exists and is public.
  • Rate limiting: Slack imposes rate limits on bot messages. If Mango generates many events rapidly, some messages may be delayed. Consider raising the alarm level threshold for Slack notifications to reduce volume.
  • Bot permissions: Ensure the bot has the chat:write scope. This is typically configured in the OAuth & Permissions section of your Slack app settings.

Best Practices​

  • Use separate channels for severity levels: Route critical alarms to a high-priority channel with aggressive notification settings, and informational events to a lower-priority channel.
  • Configure alarm levels carefully: Sending every Information-level event to Slack can create notification fatigue. Focus on Warning and above for Slack notifications.
  • Name handlers descriptively: Use names like "Critical Alarms -> #ops-critical" so the purpose is clear when reviewing event handler configurations.
  • Test with low-severity events first: Create a test event detector at the Information level to verify the Slack integration works before relying on it for critical alarms.
  • Rotate bot tokens periodically: For security, regenerate the bot token periodically and update the configuration in Mango.