flag-prune

Feature flag provider cleanup guides

Use flag-prune to remove stale Unleash, LaunchDarkly, PostHog, Statsig, and OpenFeature feature flags from JavaScript, TypeScript, React, and Node.js code.

Choose your provider:

Provider Common primitive APIs
Unleash useFlag("key"), unleash.isEnabled("key")
LaunchDarkly useBoolVariation("key", false), client.variation("key", ...)
PostHog posthog.isFeatureEnabled("key"), useFeatureFlagVariantKey("key")
Statsig client.checkGate("key")
OpenFeature client.getBooleanValue("key", false), useBooleanFlagValue("key", false)

Safe workflow

  1. Confirm the final value in your feature flag provider.
  2. Run flag-prune without --write.
  3. Review the dry-run diff.
  4. Run the same command with --write.
  5. Run your project’s typecheck, lint, and tests.
npx flag-prune --set 'client.isEnabled("old-feature")=true' src
npx flag-prune --set 'client.isEnabled("old-feature")=true' --write src

Supported values

flag-prune replaces primitive results: booleans, strings, numbers, or null. The configured call prefix must be static and exact. Later arguments may vary, so a rule containing only the flag key can match calls that also receive context or fallback values.

Do not replace a whole call that returns an object, such as a detailed evaluation or variant result. Use a primitive-returning API, or refactor the result to a primitive before pruning it.

Read Flag rules for complete matching details and Getting started for the general CLI workflow.

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