Abstract: Agent-based models are inherently microstructures–with their attention to agent behavior in a field context– and only aggregate up to systems with recognizable macroeconomic characteristics. One might ask why the traditional Keynes-Kalecki or structuralist (KKS) model would bear any relationship to the multi-agent modeling approach. This paper shows how KKS models might benefit from agent-based microfoundations, without sacrificing traditional macroeconomic themes, such as aggregate demand, animal spirits and endogenous money. Above all, the integration of the two approaches gives rise to the possibility that a KKS system–stable over many consecutive time periods–might lurch into an uncontrollable downturn, from which a recovery would require outside intervention. As a by-product of the integration of these two popular approaches, there emerges a cogent analysis of the network structure necessary to bind real and financial agents into a integrated whole. It is seen, contrary to much of the existing literature, that a highly connected financial system does not necessarily lead to more crashes of the integrated system.