Mattermost Webhook Trigger

Use this guide to send Kener alerts to Mattermost via Incoming Webhooks using the Webhook trigger type.

Mattermost supports Slack-compatible webhook payloads, so you can reuse the same JSON body patterns with minor adjustments.

Quick setup

1. In Mattermost, create an Incoming Webhook and copy the webhook URL.
2. In Kener, go to Manage → Alerting → Triggers.
3. Create a new trigger with:
   • Type: webhook
   • URL: $MATTERMOST_WEBHOOK_URL
   • Headers: [{"key":"Content-Type","value":"application/json"}]
4. Set the webhook body from the example below.
5. Save and run a trigger test.

Example webhook body

{
    "text": "{{#is_triggered}}:rotating_light: Alert Triggered{{/is_triggered}}{{#is_resolved}}:white_check_mark: Alert Resolved{{/is_resolved}}\n\n**{{alert_name}}**\nStatus: {{alert_status}}\nSeverity: {{alert_severity}}\nType: {{alert_for}}\nValue: {{alert_value}}\n\n{{alert_message}}\n\n[{{alert_cta_text}}]({{alert_cta_url}})"
}

Required variables

Verification

After saving the trigger:

1. Use the trigger test button in Kener.
2. Confirm a message appears in the target Mattermost channel.
3. Verify both trigger and resolve flows render as expected.

Troubleshooting

• HTTP 400/403 from Mattermost: Re-check webhook URL and channel permissions.
• No message in channel: Confirm the webhook is active and mapped to the expected channel/team.
• Variables not rendering: Ensure you used Mustache variables like {{alert_name}} and not escaped placeholders.
• Secrets exposed in UI: Use $MATTERMOST_WEBHOOK_URL in URL/body/headers and define it in environment variables.

Related docs

• Alert Triggers
• Alerting Trigger Examples
• Templates