Software agent technology will become a necessity to e-commerce (traditional or wireless) rather than luxury. We propose an agent-based environment, which we call E-Commerce through Wireless Devices (E-CWE), that allows users, stationary or mobile, to submit their requests for services offered by providers. The E-CWE environment consists of a reception platform including a repository of service descriptions. A supervisor-agent is in charge of this repository. Acting on behalf of their users, user-agents are dynamically created in this platform. In the E-CWE environment, security is achieved in two steps: securing service access and securing payment. A prototype of a Travel Planning Agent (TPA) system is proposed to evaluate the performance of the environment.