Feature flags

Simple terms

Feature flags are controlled switches or payloads for engineering rollouts, not visual A/B test DOM changes.

Runtime toggles for off/on variants, typed payloads, rollout percentages, targeting, and source-experiment promotion.

Routes

• /flags

Implementation behavior

• Flags use the same targeting and rollout concepts as experiments but return a decision payload instead of DOM mutation behavior.
• A flag has status, key, rollout, targeting, variants, default/off value, and optional source experiment.
• Decision debugger explains why a visitor would receive a variant.
• Flags can be activated, paused, archived, or created from successful experiments.

How to use it

• Use flags when engineering needs a controlled rollout or remote configuration.
• Keep payloads typed and stable so application code can consume them safely.
• Test decisions with the debugger before activating.
• Archive flags that are permanently shipped in application code.

When not to use it

• Do not use a flag when you need experiment analytics and variant conversion tracking.
• Do not put secret or unsafe values in flag payloads consumed by the browser.
• Do not keep temporary rollout flags alive after the feature is permanently shipped.

Implementation source

• Pages live under src/app/(dashboard)/flags.
• Handlers live under /api/flags plus activate, pause, and archive routes.
• Flags share targeting and rollout ideas with experiments but return typed decision payloads instead of DOM mutations.

Data and API

• Flag and flag variant models plus targeting JSON.
• APIs under /api/flags, /api/flags/[id], /api/flags/[id]/activate, /api/flags/[id]/pause, /api/flags/[id]/archive, and experiment-to-flag creation.
• Runtime decisions are delivered through configuration and flag evaluation endpoints.

Failure modes

• Application sees default value: flag paused, key mismatch, targeting miss, or rollout percentage excludes visitor.
• Bad payload breaks consuming app code: validate schema and defaults before activation.
• Old flags create confusion: archive retired rollouts.