Filtering Rules

Filtering rules let you control which notifications reach which channels. Instead of sending everything everywhere, route messages based on priority, tags, or payload content.

How Filtering Works

Each channel can have filtering rules attached. When a notification arrives, Alphorn evaluates the rules for each channel:

• Match — The notification is delivered to that channel
• No match — The notification is skipped for that channel
• No rules — All notifications are delivered (default behavior)

Filter Types

Priority

Route based on notification priority (1–5):

• priority >= 4 — Only critical and urgent notifications
• priority == 1 — Only low-priority notifications
• priority >= 2 AND priority <= 4 — Medium to high priority

Tags

Route based on notification tags:

• tags CONTAINS "deploy" — Any notification tagged with "deploy"
• tags CONTAINS "production" AND tags CONTAINS "error" — Must have both tags

Title & Message

Match against notification content:

• title CONTAINS "deploy" — Title includes "deploy"
• message CONTAINS "error" — Message includes "error"

JSON Payload Paths

For structured payloads, match against specific JSON paths:

• payload.environment == "production" — Match a specific field
• payload.metrics.cpu > 90 — Numeric comparison

Combining Conditions

Combine multiple conditions with AND/OR logic:

priority >= 4 AND tags CONTAINS "production"

tags CONTAINS "deploy" OR tags CONTAINS "release"

Example Setup

Scenario: Critical notifications (priority 4+) go to Email and Telegram so you never miss them. Everything goes to Slack for team visibility.

A notification with priority: 2 goes to Slack only. A notification with priority: 5 goes to Slack, Email, and Telegram.