Gradual rollouts

Widen a flag a few percent at a time, by hand or on a schedule with guardrails.

By hand

Set a percentage in the dashboard. Users are assigned by a hash of their key, so the same person keeps the same answer as the percentage grows.

On a schedule

await plinth.rollout('checkout-v2', {
  steps: [1, 5, 25, 50, 100],
  every: '1d',
  pauseIf: { errorRate: '> 1%' },
});

Guardrails

A guardrail is a metric with a limit. When it is crossed, the rollout holds at its current step and the flag’s owner is notified. Connect Datadog or Sentry to use their monitors, or use your own events.

Business hours

Add hours: 'business' and steps only happen on working days, between 09:00 and 17:00 in the project’s time zone.