contactcats/Civi/Api4/Action/ContactCategory/Save.php

<?php
namespace Civi\Api4\Action\ContactCategory;

use Civi\Api4\Generic\Result;
use CRM_Contactcats_ExtensionUtil as E;
use CRM_Core_DAO;

/**
 * Create ContactCategory action
 *
 * This entity's ID is a unique primary key that references
 * contact_id. Here we overwrite the validateValues which normally
 *
 * @see \Civi\Api4\Generic\AbstractAction
 *
 */
class Save extends \Civi\Api4\Generic\DAOSaveAction {

  /**
   * Allow creating records with ids.
   *
   * @inheritDoc
   */
  public function _run(Result $result) {
    $ids = [];
    foreach (array_column($this->records, 'id') as $id) {
      if ($id) {
        $ids[] = (int) $id;
      }
    }
    if ($ids) {
      $idsList = implode(",", array_filter($ids));
      $preExisting = array_column(CRM_Core_DAO::executeQuery(
        "SELECT id FROM civicrm_contact_category WHERE id IN ($idsList)"
        )->fetchAll(), 'id');
      // Any where we were given an ID that doesn't exist are important.
      foreach (array_diff($ids, $preExisting) as $unknownID) {
        CRM_Core_DAO::executeQuery("INSERT INTO civicrm_contact_category (id) VALUES ($unknownID)");
      }
    }

    // Now let it proceed as normal.
    parent::_run($result);
  }

}