Feature Flags

Demo

Click to play with sound.

---
name: Feature Flags
description: Implement safe, controllable feature flags.
---

# Feature Flags

Decouple deploy from release; ship code dark and turn it on safely.

## Flag types

- Release flags: gate unfinished features. Short-lived; remove after rollout.
- Ops flags / kill switches: disable a feature or dependency in an incident.
- Experiment flags: A/B tests with metrics.
- Permission flags: gate features by plan or entitlement.

Don't mix purposes in one flag — lifecycle and ownership differ.

## Evaluation

```ts
const ctx = { userId, plan, country };
if (flags.isEnabled('new-checkout', ctx)) {
  renderNewCheckout();
} else {… install to load the full skill