# Update a custom field key

Update the matching custom field key.

> Warning: It is NOT recommended to update keys that are currently in
use. Changing allowed values or whether they are restricted after other
values have already been used can lead to undesirable results.

Endpoint: PUT /custom_field_keys/{custom_field_key_id}
Version: v4
Security: APIToken

## Path parameters:

  - `custom_field_key_id` (string, required)
    Unique identifier for the resource instance.
    Example: "plqlkk-22rw6g-3dqgx0"

## Header parameters:

  - `Content-Type` (string, required)
    Enum: "application/json"

  - `Authorization` (string, required)
    Bearer token for authentication

  - `Accept` (string, required)
    Enum: "application/json"

## Request fields (application/json):

  - `data` (object, required)

  - `data.attributes` (object, required)

  - `data.attributes.name` (string)
    The key name.
    Example: "color"

  - `data.attributes.allowed_values` (array)
    The value that can be used with this key when creating or updating any Custom Field on an Asset must be one of these strings. If not included or empty array [], the values are unrestricted.
    Example: ["orange","gray","green"]

## Response 200 fields (application/json):

  - `data` (object, required)

  - `data.id` (string, required)
    Unique identifier for the resource instance.
    Example: "plqlkk-22rw6g-3dqgx0"

  - `data.type` (string, required)
    The type of the resource.
    Enum: "custom_field_keys"

  - `data.attributes` (object, required)

  - `data.attributes.name` (string)
    The key name.
    Example: "color"

  - `data.attributes.allowed_values` (array)
    The value that can be used with this key when creating or updating any Custom Field on an Asset must be one of these strings. If not included or empty array [], the values are unrestricted.
    Example: ["orange","gray","green"]

  - `data.attributes.position` (integer)
    Sets the location of the custom field among other custom fields in the Brandfolder UI.

  - `data.attributes.prioritized` (boolean)
    Set to true to display the custom field in asset previews. A Brandfolder can have up to five prioritized custom fields.

  - `data.attributes.required` (boolean)
    If set to true, users uploading an asset must input the custom field before uploading the asset. Children of dependent custom fields can also be marked as required.

  - `data.attributes.restricted` (boolean)
    If set to true, the field value is restricted to a set of allowed values (see allowed_values); otherwise, the field value is unrestricted.
    Example: true