aIST-nexus is a F.R.S.-FNRS Mandat d’Impulsion Scientifique programme that rethinks urban social–ecological metabolism through the combined lenses of agency, information and spacetime. Rather than treating cities as passive containers of stocks and flows, it asks how actors, infrastructures, practices and non-human processes actively produce metabolic change.

The programme combines systematic reviews, conceptual modelling, computational text analysis and the characterisation of urban-metabolism models. Its publications develop a framework organised around structures acting as agents, chains of events and different modalities of agency, while semantic-network analysis reveals how industrial ecology, social ecology and urban studies describe systems and agents differently. A complementary model survey examines how resource-use assessments engage with agents and where decision-support tools could become more responsive to situated action.

The project provides a conceptual backbone for the Urban Metabolism Lab’s agency-and-systems research. It also supports a broader methodological shift from descriptive accounting toward models that can explain who or what changes urban resource systems, under which conditions, and with what consequences for planning and collective decision-making.