> For the complete documentation index, see [llms.txt](https://docs.facephi.com/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.facephi.com/docs.facephi-en/rest-api/identity-api/identity-api-reference/users/users-blacklists/enroll-user-blacklist.md).

# Enroll User Blacklist

Registers the face of a new user in the shared blacklist. The userId must be unique within the collection. Only the client that registered the face will be able to retrieve the full userId in search results and delete this entry.

### Endpoint

```
PUT /users/blacklist/{userId}
```

### Authentication

| Type    | Location | Name          |
| ------- | -------- | ------------- |
| API Key | Header   | **x-api-key** |

### Request body

**Content-Type:** `application/json`

#### Route parameters

| Parameter | Type   | Required | Description                                                                     |
| --------- | ------ | -------- | ------------------------------------------------------------------------------- |
| `userId`  | string | **Yes**  | Unique user identifier. This ID must be unique within the blacklist collection. |

#### Parameters

| Parameter | Type   | Required | Description                                                                                                              |
| --------- | ------ | -------- | ------------------------------------------------------------------------------------------------------------------------ |
| `face`    | string | **Yes**  | Image of the user's face **encoded in Base64**. Supported formats are **JPEG** and **PNG**. Maximum supported size: 5MB. |

#### Request example

```json
{
  "face": "iVBORw0KGgoAAAANSUhEUgAAAAEAAAABCAYAAAAfFcSJAAAADUlEQVR42mNk+M9QDwADhgGAWjR9awAAAABJRU5ErkJggg=="
}
```

### Responses

#### `200` Success

User successfully registered in the blacklist. This response does not include a body.

#### `400` Bad Request

#### Response example: duplicate userId

```json
{
  "status": 400,
  "title": "Bad Request",
  "detail": "Invalid request.",
  "type": "https://developer.mozilla.org/en-US/docs/Web/HTTP/Status/400",
  "errors": ["the provided userId already exists"]
}
```

#### Response example: invalid face image

```json
{
  "status": 400,
  "title": "Bad Request",
  "detail": "Invalid request.",
  "type": "https://developer.mozilla.org/en-US/docs/Web/HTTP/Status/400",
  "errors": ["no face was detected in the provided image"]
}
```

#### `401` Unauthorized

```json
{
  "message": "Unauthorized"
}
```

#### `403` Forbidden

```json
{
  "Message": "User is not authorized to access this resource with an explicit deny"
}
```

#### `404` Not Found

```json
{
  "status": 404,
  "title": "Not Found",
  "detail": "The server can't find the requested resource.",
  "type": "https://developer.mozilla.org/en-US/docs/Web/HTTP/Status/404"
}
```