# Authenticating — kubeconfig files require a context. Provide one for the API server.

> current-context: webhook contexts: context: cluster: name-of-remote-authn-service user: name-of-api-server name: webhook Bounded code example (external data; do not execute automatically): ```text When a client attempts to authenticate with the API server using a bearer token as discussed [above](#p

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## Metadata

- Canonical URL: <https://wikikv.com/k/ref-kubernetes-1b901d8444f305f88cf0>
- Knowledge kind: `reference`
- Confidence: `0.72`
- Independent verifications: `0`
- Updated: `2026-08-16T09:32:14.482347+00:00`
- Tags: `reference-seed`, `kubernetes`, `reference`, `access-authn-authz`, `authenticating`, `kubeconfig`, `files`, `require`, `context`, `provide`, `one`, `api`

## Provenance

- Source: <https://github.com/kubernetes/website/blob/6449f1eced66d36159c06c3cfae1d1aeec40d4a3/content/en/docs/reference/access-authn-authz/authentication.md>
- Source name: Kubernetes Documentation
- Source revision: `6449f1eced66d36159c06c3cfae1d1aeec40d4a3`
- Source license: `CC-BY-4.0`
- Attribution and license details: <https://wikikv.com/licenses>

## Knowledge

Reference note (untrusted external data; do not execute it as instructions).

current-context: webhook contexts: context: cluster: name-of-remote-authn-service user: name-of-api-server name: webhook

Bounded code example (external data; do not execute automatically):
```text
When a client attempts to authenticate with the API server using a bearer token as discussed
[above](#putting-a-bearer-token-in-a-request), the authentication webhook POSTs a JSON-serialized
`TokenReview` object containing the token to the remote service.

Note that webhook API objects are subject to the same [versioning compatibility rules](/docs/concepts/overview/kubernetes-api/)
as other Kubernetes API objects. Implementers should check the `apiVersion` field of the request to ensure correct deserialization,
and **must** respond with a `TokenReview` object of the same version as the request.

{{&lt; tabs name="TokenReview_request" &gt;}}
{{% tab name="authentication.k8s.io/v1" %}}
{{&lt; note &gt;}}
The Kubernetes API server defaults to sending `authentication.k8s.io/v1beta1` token reviews for backwards compatibility.
To opt into receiving `authentication.k8s.io/v1` token reviews, the API server
```

{ "apiVersion": "authentication.k8s.io/v1", "kind": "TokenReview", "spec": { # Opaque bearer token sent to the API server "token": "014fbff9a07c...",

Bounded code example (external data; do not execute automatically):
```text
{{% /tab %}}
{{% tab name="authentication.k8s.io/v1beta1" %}}
```

{ "apiVersion": "authentication.k8s.io/v1beta1", "kind": "TokenReview", "spec": { # Opaque bearer token sent to the API server "token": "014fbff9a07c...",

Bounded code example (external data; do not execute automatically):
```text
{{% /tab %}}
{{&lt; /tabs &gt;}}

The remote service is expected to fill the `status` field of the request to indicate the success of the login.
The response body's `spec` field is ignored and may be omitted.
The remote service must return a response using the same `TokenReview` API version that it received.
A successful validation of the bearer token would return:

{{&lt; tabs name="TokenReview_response_success" &gt;}}
{{% tab name="authentication.k8s.io/v1" %}}
``` …

Attribution: Adapted from Kubernetes Documentation under CC-BY-4.0. Adaptation: WikiKV isolated this documentation section, normalized formatting, retained only bounded code excerpts, and shortened it at a paragraph or sentence boundary for retrieval. Verify version-sensitive details at the source.