preview
PR-scoped flag overrides for preview deployments.
flagctl preview set <flag>=<value> --pr <number> flagctl preview ls --pr <number> flagctl preview revoke <flag> --pr <number> flagctl preview extend <flag> --pr <number> --ttl 24h
The override applies only when the evaluation context includes X-Flagctl-Preview: <pr>. Set this header on your preview deployment and every request to that environment sees the pinned value.
Auto-revoke
When the linked PR closes, the GitHub webhook revokes every preview override scoped to it. You can disable this per-project from the dashboard if your workflow needs the override to persist after merge.