--- title: Kubernetes API id: kubernetes-api date: 2018-04-12 full_link: /docs/concepts/overview/kubernetes-api/ short_description: > The application that serves Kubernetes functionality through a RESTful interface and stores the state of the cluster. aka: tags: - fundamental - architecture --- The application that serves Kubernetes functionality through a RESTful interface and stores the state of the cluster. <!--more--> Kubernetes resources and "records of intent" are all stored as API objects, and modified via RESTful calls to the API. The API allows configuration to be managed in a declarative way. Users can interact with the Kubernetes API directly, or via tools like `kubectl`. The core Kubernetes API is flexible and can also be extended to support custom resources.