RestAPI Crud - Update Data Before Saving to DB

Hi

I have a CakePHP 3.0 Rest API using CRUD up and running, accepting the JSON being passed and creating new rows in DB w/o issue. I now have a need to add some additional data into the database at time the new row is created into the database. This new data is not passed in the JSON.

Looking for some guidance as to how I can update the data array being passed to the Crud Add action via the API/JSON so that I can manually insert another column/data field.

I have tried adding this data in via the Model’s beforeMarhsal function, but it does not seem to even be called when the API Add action from Crud is executed?

      public function beforeMarshal(\Cake\Event\Event $event, \ArrayObject $data, \ArrayObject $options) {
              if (!isset($data['server'])) {
                  $data['server'] = '<server location>';
              }
    }

Thanks in advance