Abstract: Automatic specification of semantic services in response to declarative queries of sensor networks is described herein. Declarative Queries from users are received, and a set of sensors and related semantic services are automatically planned that prove or solve the input query against a network of sensors deployed to monitor one or more regions of interest. The plan is further analyzed to determine whether any pre-existing services provide event streams that may be useful in proving the query. If so, these existing event streams are utilized in proving the input query, thereby minimizing the creation of redundant or duplicated semantic services and reusing existing services where possible. This analysis also contributes to compact service graphs that prove queries efficiently. The architecture also enables users to specify constraints or ranges of constraints applicable to queries.