This paper describes SWAT, a Secure Wireless Agent Testbed. Our goal is to create an integrated environment to study information assurance for mobile agent systems on ad hoc wireless networks. The present SWAT consists of dozens of mobile hosts, both PDAs and laptops, and hundreds of both static and mobile software agents. In deploying the testbed, we have developed novel mechanisms for integrating autonomous agent technologies with public-key and symmetric key encryption to support secure communication, at multiple OSI layers, among groups of hosts and agents. The paper describes the architectural technology used in SWAT, the integration challenges, as well as applications for group collaboration, network health monitoring and system security at both the agent and the host level.