fenom-modificator

<?php
/** @var modx $modx */
switch ($modx->event->name) {
    case 'pdoToolsOnFenomInit':
        /** @var Fenom $fenom */
        $fenom->addModifier('modName', function ($input) use ($modx) {
            /** @var modx $modx */
            //here your code
            return;
        });

        break;
}