This article develops a conceptual framework for linking systems and agencies in urban-metabolism research. It challenges the tendency to represent actors as external drivers of otherwise passive systems and instead asks how agency is embedded in structures, events and relations.

The framework is organised around three analytical axes: structures that operate as actors, chains of events through which change unfolds, and modalities or dimensions of agency. Computational linguistics, text mining and semantic-network analysis are used to compare how research traditions describe systems, actors and action. This makes disciplinary assumptions visible and identifies points where industrial ecology, social ecology and urban studies can be integrated.

The contribution provides a theoretical and methodological foundation for aIST-nexus. It supports models that can distinguish different capacities to act and thereby improve the interpretation of transitions, conflicts and decision-support processes.