# Admissionregistration

LLMS index: [llms.txt](/llms.txt)

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Section pages:

- [MutatingAdmissionPolicy](/docs/reference/kubernetes-api/admissionregistration/mutating-admission-policy-v1/): MutatingAdmissionPolicy describes the definition of an admission mutation policy that mutates the object coming into admission chain.
- [MutatingAdmissionPolicyBinding](/docs/reference/kubernetes-api/admissionregistration/mutating-admission-policy-binding-v1/): MutatingAdmissionPolicyBinding binds the MutatingAdmissionPolicy with parametrized resources. MutatingAdmissionPolicyBinding and the optional parameter resource together define how cluster administrators configure policies for clusters.

For a given admission request, each binding will cause its policy to be evaluated N times, where N is 1 for policies/bindings that don't use params, otherwise N is the number of parameters selected by the binding. Each evaluation is constrained by a [runtime cost budget](https://kubernetes.io/docs/reference/using-api/cel/#runtime-cost-budget).

Adding/removing policies, bindings, or params can not affect whether a given (policy, binding, param) combination is within its own CEL budget.
- [MutatingWebhookConfiguration](/docs/reference/kubernetes-api/admissionregistration/mutating-webhook-configuration-v1/): MutatingWebhookConfiguration describes the configuration of and admission webhook that accept or reject and may change the object.
- [ValidatingAdmissionPolicy](/docs/reference/kubernetes-api/admissionregistration/validating-admission-policy-v1/): ValidatingAdmissionPolicy describes the definition of an admission validation policy that accepts or rejects an object without changing it.
- [ValidatingAdmissionPolicyBinding](/docs/reference/kubernetes-api/admissionregistration/validating-admission-policy-binding-v1/): ValidatingAdmissionPolicyBinding binds the ValidatingAdmissionPolicy with paramerized resources. ValidatingAdmissionPolicyBinding and parameter CRDs together define how cluster administrators configure policies for clusters.

For a given admission request, each binding will cause its policy to be evaluated N times, where N is 1 for policies/bindings that don't use params, otherwise N is the number of parameters selected by the binding.

The CEL expressions of a policy must have a computed CEL cost below the maximum CEL budget. Each evaluation of the policy is given an independent CEL cost budget. Adding/removing policies, bindings, or params can not affect whether a given (policy, binding, param) combination is within its own CEL budget.
- [ValidatingWebhookConfiguration](/docs/reference/kubernetes-api/admissionregistration/validating-webhook-configuration-v1/): ValidatingWebhookConfiguration describes the configuration of and admission webhook that accept or reject and object without changing it.