is an open-source, MIT licensed, monitoring and alerting system by Stack Exchange. It has an expressive domain specific language for evaluating alerts and creating detailed notifications. It also lets you test your alerts against history for a faster development experience.

Project Status (2019-11)

Skyscanner is delighted to announce that as of 18th November 2019, we'll be officially taking over Bosun's ownership and maintainership from Stack Exchange (home of

We would like to thank StackExchange for their time, ensuring a smooth transition process, and for everyone’s hard work and input towards making this project a success. A special thanks to Kyle Brandt for initiating the Bosun project and leading it for many years.

We will continue to welcome the open-source community code contributions on this project. Look out for updates on our plans and next steps in the near future.

Try It

Want to jump right in? Follow our quick start tutorial to get Bosun, OpenTSDB, and scollector up quickly using our published docker images.

Download It

Download the prebuilt binaries for Bosun and our optional but valuable monitoring agent (Currently works only with OpenTSDB) scollector for Windows, Linux, and Mac.

Get Help

Join us in our Slack room. Get an invite. You can open issues on GitHub to report bugs or discuss new features.


Use Bosun's flexible expression language to evaluate time series in an exacting way

Create notifications using Bosun's template language: include graphs, tables, and contextual information

Save time by testing alerting against historical data and reduce alert noise before an alert goes into production

Supports querying OpenTSDB, Graphite, and Logstash-Elasticsearch

Runs on Linux, Windows, Mac, or any operating system supported by Go

Use our agent scollector to get monitoring of Windows, Linux, and many common applications

Supports arbitrary dimensions (not just host based), aggregations, and automatically incorporating new tags (hosts, services, ..) as they appear

Scollector auto detects new services and starts sending metrics immediately; properly designed alerts will apply to these new services which reduces maintenance