---
title: Alerts
summary: null
url: https://www.fastly.com/documentation/reference/api/observability/alerts
---

Alerts send notifications to custom integrations (e.g., Slack channels, PagerDuty, Microsoft teams and New Relic) when an observed metric either exceeds or falls below a threshold.

- [Definitions](https://www.fastly.com/documentation/reference/api/observability/alerts/definition/) - Definitions are used to configure alerts on how to observe a metric.
- [History](https://www.fastly.com/documentation/reference/api/observability/alerts/history/) - Alerts history presents the past event notifications sent when observed metrics thresholds were triggered.