Smart spaces are open complex computing systems, consisting of a large variety of cooperative smart things. Central to building smart spaces is the support for sophisticated coordination among diverse smart things collaborating to accomplish specified tasks. Multi-agent systems are often used as the software infrastructures to address the coordination in smart spaces. However, since agents in smart spaces are dynamic, resource-bounded and have complicated service dependencies, current approaches to coordination in multi-agent systems encounter new challenges when applied in smart spaces. In this paper, we present Baton, a service management system to explicitly resolve the particular issues stemming from smart spaces while coordinating agents (delegating smart things in smart spaces). Baton is designed as a complement to coordination approaches in multi-agent systems with a focus on mechanisms for service discovery, service composition, request arbitration and dependency maintenance. B...