# apiextensions-apiserver
Implements: https://github.com/kubernetes/design-proposals-archive/blob/main/api-machinery/thirdpartyresources.md
It provides an API for registering `CustomResourceDefinitions`.
## Purpose
This API server provides the implementation for `CustomResourceDefinitions` which is included as
delegate server inside of `kube-apiserver`.
## Compatibility
HEAD of this repo will match HEAD of k8s.io/apiserver, k8s.io/apimachinery, and k8s.io/client-go.
## Where does it come from?
`apiextensions-apiserver` is synced from https://github.com/kubernetes/kubernetes/blob/master/staging/src/k8s.io/apiextensions-apiserver.
Code changes are made in that location, merged into `k8s.io/kubernetes` and later synced here.