> For the complete documentation index, see [llms.txt](https://docs.caf.io/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.caf.io/caf-api/core-api/available-resources/face-authentication.md).

# Face Authentication

{% hint style="warning" %}
**This API is deprecated.**

The Core API is no longer recommended for new integrations. It will remain functional exclusively for existing clients. Migration to the [Connect API](/caf-api/connect/getting_started.md) is strongly recommended.

For more details, see the [Deprecation Policy](/caf-api/deprecation-policy-for-resources.md).
{% endhint %}

## Face Authentication

Face Authentication is a biometric service that enables face registration and authentication through facial comparison. This resource provides endpoints to register faces for individuals and query facial authentication attempts.

### Face Registration

The registration endpoint allows associating a facial image with a person identifier (`personId`), creating a biometric reference that will be used later for authentication.

{% hint style="info" %}
Faces registered by this endpoint will be used for facial comparison through the CafSdk or [CafFaceLiveness](https://docs.caf.io/caf-sdk/web-javascript/getting-started/face-liveness-and-face-authenticator) SDKs. SDKs documented as deprecated will not necessarily use these facial registrations.
{% endhint %}

{% openapi src="/files/jozcEJrHkbFiuvJKEnR5" path="/faces" method="post" %}
[gtw-register-faces.yaml](https://3218940882-files.gitbook.io/~/files/v0/b/gitbook-x-prod.appspot.com/o/spaces%2FbVxCOSyBojfSIE5fcpfH%2Fuploads%2Fgit-blob-8946119014b641aa3ab7c72f748285028c5d0cb1%2Fgtw-register-faces.yaml?alt=media)
{% endopenapi %}

### Face Authentication Attempt Query

The query endpoint allows retrieving information about a specific facial authentication attempt, including URLs of the images used.

{% openapi src="/files/OVoALMML1aVBHCoNPy4h" path="/faces/attempts/{attemptId}" method="get" %}
[gtw-get-attempt.yaml](https://3218940882-files.gitbook.io/~/files/v0/b/gitbook-x-prod.appspot.com/o/spaces%2FbVxCOSyBojfSIE5fcpfH%2Fuploads%2Fgit-blob-d6851ab0ed44fd1a868008f8436dcc350708d0cd%2Fgtw-get-attempt.yaml?alt=media)
{% endopenapi %}

{% hint style="warning" %}
**Important Notice about Integrations**

To ensure the stability and security of our services, it is mandatory to implement integrations with Caf APIs exclusively via backend/server-side, as frontend calls (via browser or client-side) may be blocked by our systems when multiple IPs or browser user agents are detected. Furthermore, client-side integrations expose authentication keys to the risk of leakage and malicious use, which may lead to unauthorized resource consumption and additional charges. Authentication keys found to be used in incorrect implementations will be immediately deactivated.

We always recommend: (1) implementing on the backend, (2) using proper headers and authentication, and (3) never exposing credentials on the client-side. Please refer to our documentation for details or contact our technical support team.
{% endhint %}


---

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