What is Sloth used for?

Sloth generates Prometheus SLO recording rules and multi-window multi-burn-rate alerts from a simple spec, as a CLI or a Kubernetes controller. It is a good fit for standardizing SLOs across many services and generating burn-rate alerts without handwritten PromQL.

Is Sloth open source?

Yes. Sloth is open source under the Apache-2.0 licence. Its source code is on GitHub at slok/sloth and is written mainly in Go.

Yes. Sloth is open source, so the software itself is free to use.

What are some alternatives to Sloth?

Similar open-source tools in the Monitoring & Observability category include Prometheus, Robusta and Karma. SaaS products in the same category include Chronosphere, Groundcover and Honeycomb.

Is Sloth actively maintained?

Yes. The most recent commit to Sloth was on 4 September 2026, and the latest release is v0.16.0, published on 4 April 2026. The project has 2.6k stars on GitHub.

Sloth: open-source monitoring & observability

About Sloth

Sloth is a tool that generates service level objectives for Prometheus. You write a simple, readable SLO spec, and Sloth produces the recording rules and alerts needed to measure it, using multi-window, multi-burn-rate alerting. The aim is understandable, uniform, and reliable SLOs for any kind of service. It is written in Go and released under the Apache-2.0 license.

It follows the Google SRE approach to SLOs, supports custom SLI plugins, and also has an OpenSLO topic. A Kubernetes controller mode integrates with the Prometheus Operator so that SLO definitions can be managed as resources in a cluster. The maintainers say it is actively developed, with upcoming work on making SLO generation more flexible.

Documentation and examples are available at sloth.dev. Sloth suits SRE and platform teams that want a consistent way to define reliability targets and alerting across many services without hand-writing complicated PromQL for each one.

Key features

Simple SLO specification format
Generated Prometheus recording rules
Multi-window multi-burn-rate alerts
Custom SLI plugins
Kubernetes controller for Prometheus Operator
OpenSLO compatibility

Good fit for

→Standardizing SLOs across many services
→Generating burn-rate alerts without handwritten PromQL

Built with: Go; Kubernetes
Tags: slo; prometheus; sre; alerting; kubernetes; observability; monitoring; go

Sloth: questions and answers

What is Sloth used for?: Sloth generates Prometheus SLO recording rules and multi-window multi-burn-rate alerts from a simple spec, as a CLI or a Kubernetes controller. It is a good fit for standardizing SLOs across many services and generating burn-rate alerts without handwritten PromQL.
Is Sloth open source?: Yes. Sloth is open source under the Apache-2.0 licence. Its source code is on GitHub at slok/sloth and is written mainly in Go.
Is Sloth free?: Yes. Sloth is open source, so the software itself is free to use.
What are some alternatives to Sloth?: Similar open-source tools in the Monitoring & Observability category include Prometheus, Robusta and Karma. SaaS products in the same category include Chronosphere, Groundcover and Honeycomb.
Is Sloth actively maintained?: Yes. The most recent commit to Sloth was on 4 September 2026, and the latest release is v0.16.0, published on 4 April 2026. The project has 2.6k stars on GitHub.