Custom session driver

Hello.

Currently trying to create custom session driver for Lumen. System as it is from latest docs in laravel tells me a lot and main implementation pretty much works. Problem starts that i want to set custom session id wich is actually session_id() php function. I got 2 applications and i am trying to share sessions between them. We are using memcache for session storage but problem starts that i need to get session id in Lumen same as session_id() Memcache connects and i can get data from it. If i return it then it does not give anything. If i try to force set and save it gives me _sf2_meta data error (undefined index) and that is because data bag is an empty array.

Anyone can suggest me something?