We describe how to generate a reply to a consumer's query by taking in mind not only the needed information request but also the query constraints. The use of Directory Facilitator helps the consumer's interpreter locating an interface able to answer its demand and so, the supplier services that meet its needs. This interface by using a proxy cache is able, regarding the consumer constraints, to generate information replies to requests from earlier data acquisitions. Applying Multi-Agents System helps creating an effective consumer-supplier's interface with information treatments and data fusion processes. In this paper, we suppose software architecture and we show by an implementation how agents can handle and treat consumer requirements.