---
title: Alerts & Notifications
description: Set threshold-based alerts on container metrics and route them to Discord, Slack, or any webhook.
---

Sencho can watch your containers for resource anomalies and notify you when thresholds are breached. Alerts are defined per stack, and notifications are delivered through external agents you configure.

<Frame>
  <img src="/images/alerts-notifications/notifications-settings.png" alt="Notifications & Alerts settings showing Discord, Slack, and Webhook tabs" />
</Frame>

## How alerts work

Sencho's monitoring service samples container metrics every minute and evaluates all defined alert rules. When a rule's condition holds true for the configured duration, a notification is dispatched. A cooldown period prevents the same alert from firing repeatedly.

## Setting up a notification agent

At least one agent must be enabled before alerts can be delivered. Go to **Settings → Notifications**.

### Discord

1. In Discord, go to your server's **Settings → Integrations → Webhooks**
2. Click **New Webhook**, choose a channel, and copy the webhook URL
3. In Sencho, open **Settings → Notifications → Discord**, paste the URL, enable the toggle, and click **Save**
4. Click **Test** to send a test message

### Slack

1. In Slack, go to **api.slack.com/apps**, create an app, and add the **Incoming Webhooks** feature
2. Activate it and copy the generated webhook URL for your chosen channel
3. In Sencho, open **Settings → Notifications → Slack**, paste the URL, enable the toggle, and click **Save**

### Generic Webhook

Any HTTP endpoint that accepts a POST with a JSON body can receive Sencho alerts. Go to **Settings → Notifications → Webhook**, enter the URL, and click **Save**.

The payload format is:
```json
{
  "level": "warning",
  "message": "cpu_percent exceeded 90% for 5 minutes on stack my-app",
  "timestamp": "2026-03-22T10:00:00.000Z"
}
```

## Creating stack alerts

Stack alerts are configured per-stack. Right-click a stack in the sidebar (or click the **⋮** button) and select **Alerts**.

<Frame>
  <img src="/images/stack-management/stack-context-menu.png" alt="Stack context menu showing the Alerts option" />
</Frame>

The alerts sheet shows existing rules for the stack and a form to create new ones.

### Alert fields

| Field | Description |
|-------|-------------|
| **Metric** | The container metric to watch |
| **Operator** | Comparison operator: `>`, `>=`, `<`, `<=`, `==` |
| **Threshold** | The value to compare against |
| **Duration (minutes)** | How long the condition must hold before firing |
| **Cooldown (minutes)** | Minimum time between repeated notifications for this rule |

### Available metrics

| Metric | Unit | Description |
|--------|------|-------------|
| `cpu_percent` | % | CPU usage relative to total host cores |
| `memory_mb` | MB | RSS memory used by the container |
| `memory_percent` | % | Memory used as a fraction of the host total |
| `net_rx` | bytes/s | Inbound network rate |
| `net_tx` | bytes/s | Outbound network rate |
| `restart_count` | count | Number of times the container has restarted |

### Example: alert on high CPU

To alert when any container in a stack uses more than 80% CPU for over 5 consecutive minutes, with a 30-minute cooldown:

| Field | Value |
|-------|-------|
| Metric | `cpu_percent` |
| Operator | `>` |
| Threshold | `80` |
| Duration | `5` |
| Cooldown | `30` |

## Notification history

All dispatched notifications appear in the **notification bell** (top-right of the nav bar). Click it to see recent alerts with their level, message, and timestamp. Mark all as read or clear individual entries from there.

<Note>
  Notifications only reach external agents (Discord, Slack, Webhook) if at least one agent is enabled. Dashboard notifications appear regardless.
</Note>