{"data":{"slug":"sloth","name":"Sloth","tagline":"Apache-2.0 SLO generator for Prometheus rules and alerts","category":"observability","categoryName":"Observability","url":"https://sloth.dev","github":"https://github.com/slok/sloth","pricing":"open-source","hook":"Sloth generates reliable Prometheus SLOs from a small spec: write your service's SLI and objective, and it produces recording rules, metadata rules and multi-window, multi-burn-rate alerts.","whatsGood":"Apache-2.0 (slok/sloth), release v0.16.0 (2026-04-04). Based on Google's SLO approach. Works as a CLI in CI, a Kubernetes controller with a CRD, or a library, with SLI plugins for common cases and Grafana dashboards for the results. Supports OpenSLO specs too. ★~2.6k.","theCatch":"It only generates rules; Prometheus and Alertmanager still do the work, and you must choose good SLIs. The last release was April 2026, and the project status says internal refactoring is in progress. Single-maintainer project.","verdict":"The easiest correct way to get burn-rate SLO alerts in Prometheus.","addedAt":"2026-10-18","featured":false,"domain":"Observability","subSpecialty":"Observability","subcategory":"Observability","tags":["self-host","permissive","observability","active"],"capabilities":[],"surfaces":["Self-host"],"ecosystem":["Multi-platform"],"licenseModel":"Apache-2.0","githubStars":2557,"starsPerWeek":9,"access":"free","archived":false,"repo":{"createdAt":"2021-04-06","pushedAt":"2026-10-18","license":"Apache-2.0","archived":false,"checkedAt":"2026-10-19"}},"related":[{"slug":"sentry","name":"Sentry","tagline":"Error tracking that actually helps"},{"slug":"grafana","name":"Grafana","tagline":"Dashboards for everything observable"},{"slug":"prometheus","name":"Prometheus","tagline":"Time-series metrics for cloud-native"},{"slug":"opentelemetry","name":"OpenTelemetry","tagline":"Vendor-neutral observability framework"},{"slug":"datadog","name":"Datadog","tagline":"Unified observability platform"}],"links":{"self":"/api/gems/sloth","html":"/gems/sloth","markdown":"/gems/sloth.md","category":"/api/gems?category=observability","categoryPage":"/stacks/observability"}}