Kradle ExternalWriteIntent overview

ExternalWriteIntent records an intended write to an external provider so policy, rate limits, and conflict checks can gate mutation. It is owned by the external-backends service and participates in provider synchronization. Atlas models it as a external-backend CRD with Namespaced scope, v1alpha1 storage version, and source-backed Kubernetes API metadata so controller, policy, UI/API, and provider edges can target the exact resource kind.