This paper presents an extension of the JADE agent development framework that may be the basis for the realization of flexible agent-based grid systems. In particular, JADE framework has been enriched with two new types of agents that, on the one hand simplify the distribution of tasks inside a grid of agent platforms, and, on the other hand, facilitate the composition of tasks through the use of production rules. Moreover, the paper describes how such kinds of operations are executed through the proper authentication and authorization mechanisms.