AISA: A Unified Architecture for Agentic AI Systems

Recent advances in large language models have enabled the emergence of agentic AI systems capable of autonomous reasoning, planning, tool use, and multi-step interaction with complex environments. However, current agentic systems are often developed in an ad hoc and fragmented manner, lacking a unified architectural framework that integrates reasoning, infrastructure, evaluation, governance, and ethical oversight. This paper introduces \textbf{AISA} (Agentic AI Systems Architecture), a layered conceptual framework that provides a holistic reference architecture for designing, deploying, and governing agentic AI systems. AISA unifies cognitive agent design, tool execution, orchestration infrastructure, continuous evaluation, deployment operations, and governance considerations into a single coherent model. The framework is intended to serve as a shared vocabulary and design blueprint for researchers, practitioners, and policymakers working on next-generation autonomous AI systems. Reference materials, architectural artifacts, and ongoing implementations are made available at https://huggingface.co/AISA-Framework.