Slack, Discord & webhook notifications

Send alert notifications to Slack channels, Discord servers, or any HTTP endpoint.

Kener can post alert notifications to Slack, Discord, and arbitrary HTTP endpoints. All three use the same delivery mechanism — an HTTP POST to a URL — but each has its own default payload format.

Slack

Slack setup

Kener posts to Slack using an Incoming Webhook. Each webhook URL is tied to a specific channel.

1. Create a Slack app and enable incoming webhooks

   1. Go to api.slack.com/apps and click Create New App → From scratch.
   2. Name the app (e.g. “Kener Alerts”) and pick a workspace.
   3. In the left sidebar, click Incoming Webhooks and toggle Activate Incoming Webhooks on.
2. Add a webhook to a channel

   Click Add New Webhook to Workspace, pick the channel you want alerts in, and click Allow.

   Copy the webhook URL — it looks like:

   https://hooks.slack.com/services/T00000000/B00000000/XXXXXXXXXXXXXXXXXXXXXXXX
   
3. Create a Slack trigger in Kener

   1. In the Kener admin dashboard, go to Triggers → New Trigger.
   2. Set Trigger Type to slack.
   3. Paste the webhook URL into the URL field.
   4. Give the trigger a Name and click Create Trigger.
4. Test the trigger

   After saving, click Test Trigger. Kener sends a sample TRIGGERED notification to the channel.

Default Slack payload

Kener uses Slack’s Block Kit format by default:

{
  "blocks": [
    {
      "type": "header",
      "text": {
        "type": "plain_text",
        "text": "{{#is_triggered}}🚨 Alert Triggered{{/is_triggered}}{{#is_resolved}}✅ Alert Resolved{{/is_resolved}}",
        "emoji": true
      }
    },
    {
      "type": "section",
      "text": {
        "type": "mrkdwn",
        "text": "*{{alert_name}}*"
      }
    },
    {
      "type": "divider"
    },
    {
      "type": "section",
      "fields": [
        { "type": "mrkdwn", "text": "*Status:*\n{{alert_status}}" },
        { "type": "mrkdwn", "text": "*Severity:*\n{{alert_severity}}" },
        { "type": "mrkdwn", "text": "*Alert Type:*\n{{alert_for}}" },
        { "type": "mrkdwn", "text": "*Alert Value:*\n{{alert_value}}" },
        { "type": "mrkdwn", "text": "*Failure Threshold:*\n{{alert_failure_threshold}}" },
        { "type": "mrkdwn", "text": "*Success Threshold:*\n{{alert_success_threshold}}" }
      ]
    },
    {
      "type": "section",
      "text": {
        "type": "mrkdwn",
        "text": "*Message:*\n{{alert_message}}"
      }
    },
    {
      "type": "context",
      "elements": [
        { "type": "mrkdwn", "text": "🕐 *Time:* {{alert_timestamp}}" },
        { "type": "mrkdwn", "text": "🆔 *Alert ID:* {{alert_id}}" }
      ]
    },
    {
      "type": "divider"
    },
    {
      "type": "actions",
      "elements": [
        {
          "type": "button",
          "text": { "type": "plain_text", "text": "{{alert_cta_text}}", "emoji": true },
          "url": "{{alert_cta_url}}",
          "style": "{{#is_triggered}}danger{{/is_triggered}}{{#is_resolved}}primary{{/is_resolved}}"
        }
      ]
    },
    {
      "type": "context",
      "elements": [
        { "type": "mrkdwn", "text": "Sent from *{{site_name}}* monitoring system" }
      ]
    }
  ]
}

You can replace this with your own Block Kit JSON in the Custom Slack Payload field when editing the trigger.

Discord

Discord setup

Kener posts to Discord using channel webhooks.

1. Create a Discord webhook

   1. Open your Discord server. Right-click the channel you want alerts in and click Edit Channel.
   2. Go to Integrations → Webhooks → New Webhook.
   3. Give it a name (e.g. “Kener”) and click Copy Webhook URL.

   The URL looks like:

   https://discord.com/api/webhooks/1234567890/xxxxxxxxxxxxxxxxxxxxxxxxxxxx
   
2. Create a Discord trigger in Kener

   1. In the Kener admin dashboard, go to Triggers → New Trigger.
   2. Set Trigger Type to discord.
   3. Paste the webhook URL into the URL field.
   4. Give the trigger a Name and click Create Trigger.
3. Test the trigger

   After saving, click Test Trigger to send a sample message to the Discord channel.

Default Discord payload

Kener posts a rich embed message by default:

{
  "username": "{{site_name}}",
  "avatar_url": "{{site_logo_url}}",
  "content": "{{#is_triggered}}🚨 **Alert Triggered**{{/is_triggered}}{{#is_resolved}}✅ **Alert Resolved**{{/is_resolved}}",
  "embeds": [
    {
      "title": "{{alert_name}}",
      "url": "{{alert_cta_url}}",
      "color": "{{#is_triggered}}15158332{{/is_triggered}}{{#is_resolved}}3066993{{/is_resolved}}",
      "fields": [
        { "name": "📊 Status",             "value": "{{alert_status}}",             "inline": true },
        { "name": "⚠️ Severity",           "value": "{{alert_severity}}",           "inline": true },
        { "name": "📋 Alert Type",         "value": "{{alert_for}}",                "inline": true },
        { "name": "📈 Alert Value",        "value": "{{alert_value}}",              "inline": true },
        { "name": "🔻 Failure Threshold",  "value": "{{alert_failure_threshold}}", "inline": true },
        { "name": "🔺 Success Threshold",  "value": "{{alert_success_threshold}}", "inline": true },
        { "name": "📝 Message",            "value": "{{alert_message}}",            "inline": false }
      ],
      "footer": {
        "text": "{{alert_cta_text}} | Alert ID: {{alert_id}} | {{site_name}} Monitoring",
        "icon_url": "{{site_logo_url}}"
      },
      "timestamp": "{{alert_timestamp}}"
    }
  ]
}

The color field uses Discord’s integer color format: 15158332 (red) for TRIGGERED and 3066993 (green) for RESOLVED.

You can replace this with your own JSON in the Custom Discord Payload field.

Webhook

Custom webhook setup

A webhook trigger sends an HTTP POST to any URL with a JSON body. Use this for PagerDuty, Opsgenie, custom scripts, or any service that accepts webhooks.

1. Prepare your endpoint

   Your endpoint must accept HTTP POST requests with Content-Type: application/json. It should return a 2xx status code on success.

2. Create a webhook trigger in Kener

   1. In the admin dashboard, go to Triggers → New Trigger.
   2. Set Trigger Type to webhook.
   3. Enter the destination URL.
   4. Give the trigger a Name and click Create Trigger.
3. Add authentication headers (optional)

   Under Headers, click Add Header for each header your endpoint requires. Common examples:

   Key	Value
   Authorization	Bearer your-token
   X-API-Key	your-api-key
   X-Custom-Header	value

   To keep secrets out of the database, reference environment variables:

   Authorization: Bearer {{ENV_WEBHOOK_TOKEN}}
   

   Kener resolves {{ENV_...}} patterns against process.env at send time.

4. Customise the payload (optional)

   The default JSON payload (see below) covers all alert fields. You can replace it with your own Mustache template in the Custom Webhook Body field.

5. Test the trigger

   After saving, click Test Trigger to POST a sample payload to your endpoint.

Default webhook payload

{
  "alert_id": {{alert_id}},
  "alert_name": "{{alert_name}}",
  "alert_for": "{{alert_for}}",
  "alert_value": "{{alert_value}}",
  "alert_status": "{{alert_status}}",
  "alert_severity": "{{alert_severity}}",
  "alert_message": "{{alert_message}}",
  "alert_source": "{{alert_source}}",
  "alert_timestamp": "{{alert_timestamp}}",
  "alert_cta_url": "{{alert_cta_url}}",
  "alert_cta_text": "{{alert_cta_text}}",
  "alert_incident_id": {{#alert_incident_id}}{{alert_incident_id}}{{/alert_incident_id}}{{^alert_incident_id}}null{{/alert_incident_id}},
  "alert_incident_url": {{#alert_incident_url}}"{{alert_incident_url}}"{{/alert_incident_url}}{{^alert_incident_url}}null{{/alert_incident_url}},
  "alert_failure_threshold": {{alert_failure_threshold}},
  "alert_success_threshold": {{alert_success_threshold}},
  "is_resolved": {{is_resolved}},
  "is_triggered": {{is_triggered}},
  "site_url": "{{site_url}}",
  "site_name": "{{site_name}}",
  "site_logo_url": "{{site_logo_url}}",
  "colors_up": "{{colors_up}}",
  "colors_down": "{{colors_down}}",
  "colors_degraded": "{{colors_degraded}}",
  "colors_maintenance": "{{colors_maintenance}}"
}

alert_incident_id and alert_incident_url are null when no incident was created for the alert.

Headers sent by Kener

Kener always includes these default headers. Custom headers you add override them if the key matches:

Header	Value
user-agent	Kener/<version>
accept	application/json
content-type	application/json

Attach a trigger to an alert config

All three channel types attach to alert configs the same way:

1. Go to Alerts → Create Alert (or edit an existing one).
2. Configure the monitor, condition, and thresholds.
3. Under Notification Triggers, check the trigger(s) you want to notify.
4. Click Create Alert.

See alert triggers for the full steps and field reference.

Troubleshooting

Test trigger succeeds but alerts never fire

Check that the alert config is Active (the toggle on the alerts list). Also confirm that the monitor has reached the failure_threshold number of consecutive failures — Kener does not send a notification on the first failure if the threshold is greater than 1.

Slack returns 400 or 'invalid_payload'

The payload is not valid Block Kit JSON. Check that your custom template is valid JSON and that Mustache conditionals don’t break the structure. Test with the default template first to confirm the webhook URL is correct.

Discord returns 401 Unauthorized

The webhook URL is invalid or has been deleted. Go back to Discord server settings, regenerate the webhook, and update the trigger URL.

Webhook endpoint returns non-2xx

Kener logs the response status and body to the console when delivery fails. Check your server logs. Common causes: missing authentication header, wrong content type expected by the endpoint, or payload schema mismatch.