What is GO Feature Flag used for?

GO Feature Flag is a lightweight, self-hosted feature flag solution built on OpenFeature, with a relay proxy, file-based flag configuration, and rollout strategies. It is a good fit for progressive delivery of new features and running experiments with flag variations.

Is GO Feature Flag open source?

Yes. GO Feature Flag is open source under the MIT licence. Its source code is on GitHub at thomaspoignant/go-feature-flag and is written mainly in Go.

Is GO Feature Flag free?

Yes. GO Feature Flag is open source, so the software itself is free to use.

Can I self-host GO Feature Flag?

Yes. GO Feature Flag can be self-hosted on your own server or infrastructure; there is no official hosted version.

What is GO Feature Flag an alternative to?

GO Feature Flag is an open-source alternative to ConfigCat, DevCycle, Split and LaunchDarkly. Other open-source alternatives to ConfigCat include FeatureProbe, Unleash and Flagsmith.

Is GO Feature Flag actively maintained?

Yes. The most recent commit to GO Feature Flag was on 2 October 2026, and the latest release is v1.56.0, published on 2 October 2026. The project has 2.1k stars on GitHub.

GO Feature Flag: open-source alternative to ConfigCat

About GO Feature Flag

GO Feature Flag is a simple, complete, and lightweight feature flag solution that you host yourself. It is written in Go, 100% open source under the MIT license, and part of the OpenFeature ecosystem, which means it can be used from many languages through OpenFeature SDKs and a relay proxy.

You write flag configuration in files that can live in a storage location of your choice, then evaluate flags in your code with an evaluation context. The documentation covers flag file format, rule format, targeting, custom bucketing, variations, gradual and complex rollout strategies, notifiers for flag changes, data export, and a command-line tool. Topics also reference experimentation and continuous delivery.

The project asks adopters to add themselves to a public list and accepts sponsorship. It suits engineering teams that want to ship code safely behind flags and run progressive rollouts or experiments without paying for a commercial feature management service.

Key features

Flags defined in configuration files
Relay proxy for any language
OpenFeature SDK compatibility
Rules, variations, and custom bucketing
Progressive and complex rollouts
Notifiers and data export
Command-line tool

Good fit for

→Progressive delivery of new features
→Running experiments with flag variations

Built with: Go
Tags: feature-flags; openfeature; go; experimentation; continuous-delivery; self-hosted; rollout; toggles

GO Feature Flag: questions and answers

What is GO Feature Flag used for?: GO Feature Flag is a lightweight, self-hosted feature flag solution built on OpenFeature, with a relay proxy, file-based flag configuration, and rollout strategies. It is a good fit for progressive delivery of new features and running experiments with flag variations.
Is GO Feature Flag open source?: Yes. GO Feature Flag is open source under the MIT licence. Its source code is on GitHub at thomaspoignant/go-feature-flag and is written mainly in Go.
Is GO Feature Flag free?: Yes. GO Feature Flag is open source, so the software itself is free to use.
Can I self-host GO Feature Flag?: Yes. GO Feature Flag can be self-hosted on your own server or infrastructure; there is no official hosted version.
What is GO Feature Flag an alternative to?: GO Feature Flag is an open-source alternative to ConfigCat, DevCycle, Split and LaunchDarkly. Other open-source alternatives to ConfigCat include FeatureProbe, Unleash and Flagsmith.
Is GO Feature Flag actively maintained?: Yes. The most recent commit to GO Feature Flag was on 2 October 2026, and the latest release is v1.56.0, published on 2 October 2026. The project has 2.1k stars on GitHub.