RedisMonitor.php

class RedisMonitor
{
    private $redis;

    public function __construct(Client $redis)
    {
        $this->redis = $redis;
    }

    public function __invoke()
    {
        $this->redis
            ->connect()
            ->then(function($client) {
                $client->monitor(function ($event) {
                    echo $event->payload;
                });
            });
    }
}