I still didn't find any documentation on how to use it except in the Phalcon source itself. Will this work?
$session = new \Phalcon\Session\Adapter\Redis(array(
'uniqueId' => 'uniqueId',
'host' => 'localhost',
'auth' => 'secret',
'port' => 6379,
'persistent' => false,
'lifetime' => 1209600,
'prefix' => 'prefix_',
'timeout' => 3,
));