messagedisappearing.php

См. документацию.

<?php
namespace Bitrix\Im\Update;
 
use Bitrix\Im\V2\Message;
use Bitrix\Main\Application;
use Bitrix\Main\Type\DateTime;
 
class MessageDisappearing
{
    public static function disappearMessagesAgent(): string
    {
        $connection = Application::getConnection();
 
        $messagesQuery = $connection->query("
            SELECT MESSAGE_ID
            FROM b_im_message_disappearing
            WHERE DATE_REMOVE < '" . (new DateTime())->format('Y-m-d H:i:s') . "'
        ");
 
        $messages = $messagesQuery->fetchAll();
 
        foreach ($messages as $message)
        {
            $message = new Message($message['MESSAGE_ID']);
            if ($message->getId())
            {
                $message->deleteComplete();
            }
        }
 
        return __METHOD__ . '();';
    }
}