8.3k stars · MIT core + commercial enterprise directories · v5.0.1 (2026-08-19) · Track this in Scout
Self-hosted feature flags and A/B tests — flags are worth it today, experiments only once traffic exists.
▶Repo detailsthe review · specs · pros & cons
What it is
A self-hosted platform for feature flags and A/B experiments, with a statistics engine that reads results directly from your own data warehouse. It has SDKs for React and Python among two dozen others.
What it is good for. Worth being straight about this one, because it is the entry most likely to waste time if taken at face value. The experimentation half is not yet useful on a small site: reaching statistical significance on a landing-page test needs thousands of visitors, and running underpowered tests is worse than running none because you will act on noise. The flag half, though, is worth it today — shipping a half-finished feature behind a flag that only the team can see means you stop maintaining long-lived branches, and turning a broken feature off becomes a toggle rather than a redeploy at midnight. Install it for the flags, get the habit, and let the experiments become useful later.
- Flags alone justify it — safer releases, no long-lived branches, instant rollback
- Reads from your own Postgres, so the numbers stay where your data already is
- First-class React and Python SDKs, among the two dozen it ships
- Heaviest install here: it wants MongoDB alongside Postgres
- The experiment engine is useless below a few thousand visitors — do not let it flatter you
- Open core: some directories carry an enterprise licence, so check before relying on a feature
