Cognitive Admission Control makes an agent produce a witness certificate before it can mutate infrastructure.

CAC maps a typed action and its modeled risk to obligations naming predicates, evidence classes, scope, freshness and witness-set constraints. A deterministic evaluator returns satisfied, violated or unresolved, where unresolved emits a targeted evidence-acquisition request, and admission yields a certificate binding the action to its witness manifest. In 390 CAC trials, 120 effects completed with no harmful effects, while a live-policy baseline matched the completion count but admitted a constructed correlated-witness failure. The authors are explicit these are implementation behaviors, not production failure rates.