A big problem with WHMCS is that you don't have any API to manage customfields. With this API you can update all clients, products and support custom fields.

You can use it as a standard WHMCS API. You may want to use it with internal API function. In this case WHMCS documentation is helpful so no more explanations are required. Keep in mind that due to the way WHMCS handles API permissions, you will only be able to use this as internal API.

To use it you have to upload the updatecustomfields.php (all lowercase) into the /includes/api whmcs folder and it's done.

Parameters

Response Parameters

Example request (CURL)

Given the recent changes in WHMCS custom API work only with the Local API function.

Example Request (Local API)

$command = 'UpdateCustomFields';
$postData = array(
    'relid' => 1,
    'customfield' => 12,
    'value' => 'newvalue',
);
$adminUsername = 'ADMIN_USERNAME';

$results = localAPI($command, $postData, $adminUsername);
print_r($results);

Example Response

Array (
 [result] => success,
 [message] => Custom field with id # has been updated with the value: newvalue,
 )

Error Responses

Error response codes are:

• The relid is undefined
• The type you selected does not exists. Please check
• The customfield is undefined
• The customfield could not be found. Please check the 'customfield' and 'type' parameters
• A client with id # does not exists
• A product with id # does not exists
• This product does not own this custom field
• A ticket with id # does not exists
• This support department does not own this custom field

Got questions or problems? Contact us or comment, we'll be happy to help.