Abstract-- Grid middleware needs to adapt to changing resources for a large variety of operations. Currently, information about Grid resources can be retrieved from various monitoring and information systems. However, the available information is rather low level and also dispersed across many individual sources. In this paper, we present the Delphoi service that provides a unified interface to all necessary information, on an abstraction level that matches the adaptation needs of middleware services. Delphoi has been developed as part of the EC-funded GridLab project and is currently being deployed on the project's testbed for adding adaptivity to GridLab's middleware services.