# Alertmanager

> Apache-2.0 Prometheus alert routing and silencing

**Category:** Observability  
**Pricing:** open-source  
**URL:** https://prometheus.io/docs/alerting/latest/alertmanager/  
**GitHub:** https://github.com/prometheus/alertmanager  
**Added:** 2026-10-18

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## The Hook

Alertmanager takes alerts from Prometheus and other clients, deduplicates and groups them, and routes them to email, PagerDuty, Opsgenie, Slack or any webhook, with silences and inhibition rules.

## What's Good

Apache-2.0 (prometheus/alertmanager), release v0.34.1 (2026-09-17), part of the Prometheus project. Routing trees decide who gets what. Grouping turns alert storms into single notifications. It can run clustered for high availability. Precompiled binaries and Docker images. ★~8.7k.

## The Catch

All configuration is YAML, and routing trees get hard to reason about at scale. There is no on-call scheduling or escalation; pair it with an incident tool for that. The UI is basic.

## Verdict

The standard alert router for any Prometheus setup.