> ## Documentation Index
> Fetch the complete documentation index at: https://docs.blocklight.co/llms.txt
> Use this file to discover all available pages before exploring further.

# Multi-Channel Alerts

> Send alerts to multiple channels: Slack, Discord, Email, Telegram, Webhooks, or custom scripts

Send alerts to multiple channels simultaneously. Each channel can be configured with custom templates and severity filters.

## Supported Channels

* **Log** - Console output (JSON format)
* **File** - Write to file (JSONL format)
* **Webhook** - POST JSON to any HTTP endpoint
* **Slack** - Slack webhook with Block Kit formatting
* **Discord** - Discord webhook with rich embeds
* **Email** - SMTP email notifications
* **Telegram** - Telegram Bot API with MarkdownV2
* **Script** - Execute custom scripts (Python/JavaScript/Bash)

## Configuration

Configure alert channels in `config.yaml`:

```yaml theme={null}
alerting:
  enabled: true
  
  channels:
    - type: "log"
      enabled: true
      min_severity: "WARNING"
    
    - type: "file"
      enabled: true
      path: "output/detections.jsonl"
      min_severity: "NOTICE"
    
    - type: "slack"
      enabled: true
      url: "${SLACK_WEBHOOK_URL}"
      min_severity: "WARNING"
      icon_emoji: ":warning:"
    
    - type: "webhook"
      enabled: true
      url: "https://api.example.com/alerts"
      min_severity: "CRITICAL"
```

## Template Variables

Use Go template syntax in notification messages:

```yaml theme={null}
template: |
  🚨 **{{.RuleName}}** detected
  
  **Severity:** {{.Severity}}
  **Transaction:** {{.TxHash}}
  **Block:** {{.BlockNumber}}
  **Network:** {{.Chain}}
  
  From: {{.Transaction.From}}
  To: {{.Transaction.To}}
  Value: {{.Transaction.Value}} wei
```

### Available Variables

* `{{.RuleName}}` - Rule name
* `{{.Severity}}` - Priority level (NOTICE, WARNING, CRITICAL)
* `{{.TxHash}}` - Transaction hash
* `{{.BlockNumber}}` - Block number
* `{{.Chain}}` - Blockchain name
* `{{.Transaction.*}}` - Full transaction data
* `{{.Description}}` - Rule description
* `{{.Output}}` - Alert output message

## Severity Filtering

Each channel can filter by minimum severity:

* **NOTICE** - All alerts (lowest threshold)
* **WARNING** - Warnings and critical alerts
* **CRITICAL** - Only critical alerts (highest threshold)

## Channel-Specific Features

### Slack

* Block Kit formatting (automatic)
* Custom templates supported
* Icon emoji configuration
* Username customization

### Discord

* Rich embed formatting (automatic)
* Custom templates supported
* Avatar URL configuration
* Username customization

### Email

* HTML formatting
* SMTP configuration
* Multiple recipients
* Subject line customization

### Telegram

* MarkdownV2 formatting
* Bot API integration
* Chat ID configuration

### Script

* Execute custom scripts with finding data as JSON
* Support for Python, JavaScript, Bash, etc.
* Environment variables available

See [Alert Configuration](/deployment/configuration#alert-configuration) for complete setup examples.