C₂ – Contextual Co-Agency: Policy Brief v1.0

This policy brief introduces C₂ (Contextual Co-Agency), a structural Human–AI decision architecture designed to localize human authority at the point of irreversibility in AI-enabled systems. The document identifies responsibility diffusion — not model error — as the central governance risk in scaled AI deployment across public administration, defense, financial regulation, healthcare, and critical infrastructure. C₂ formalizes a runtime authorization layer prior to execution, ensuring that consequence attaches to a designated human authority before structural binding occurs. The architecture does not propose AI personhood or new constitutional categories. It introduces decision-boundary mapping, explicit commit-point definition, and reconstructable authority localization within existing legal frameworks. This policy brief constitutes part of the broader C₂ framework series, including executive summaries, operational annexes, and field notes. DOI-linked publication ensures timestamped structural authorship and open scholarly reference.