Originally Posted by
SirToby
The lounge in OSL is before passport control so one needs to be plan some extra time for queuing if your passport cannot be used at the auto machines.
It is a 3rd party lounge, so not sure if they follow rules as per oneworld (C inbound + Y "connecting" outbound), they might only care for your departing booked class but probably worth a try to ask.
Assuming OP's AA flight is to NA then it's not a short haul connecting from long haul that is required to give lounge access at OSL...