In this paper we propose COMPASS, a new decentralized access control architecture for modern WLANs. As traditional centralized access control systems like AAA do not scale well we propose the use of P2P technologies for the distribution of management data directly between the used access points. Leveraging the recent advances in the P2P networking COMPASS does not require any additional equipment or central entities. Using auto-organization and fault recovery mechanisms it is robust and easier to maintain. Standard 802.1X mechanisms on the user link guarantee compatibility to the existing user equipment.