Agent-oriented design relies on key abstractions: goals, plans and actions. These abstractions are used by several agent modeling languages and methodologies to specify the many different multi-agent system (MAS) features. Nevertheless, there are some agency features that cannot be properly modularized using only these abstractions. The Aspect-Oriented Programming paradigm allows the modularization of agency concerns, preventing scattered and tangled code through a development methodology. This paper presents AgentCross, an agent methodology independent platform that allows the implementation of crosscutting concerns in MAS. AgentCross proposes the inclusion of aspect-oriented abstractions into the agent platform specified by FIPA. This is achieved by the integration of JADE agent platform and AspectJ. We describe the new agent crosscutting abstractions, the platform integration and we also show a simple example of the implementation of crosscutting concerns in a MAS.