Abstract This paper operationalizes the structural requirements for persistent autonomous systems established in prior work. A system must not only satisfy identity persistence, invariant constraints, and bounded drift in principle; it must continuously enforce them across every transition. We introduce a minimal enforcement architecture consisting of a governance loop, an admissibility gate, a drift tracking system, and a replay-verifiable execution model. Together, these mechanisms ensure that every state transition is evaluated for identity preservation, bounded drift, and external verifiability. The result is a minimal enforceable architecture for persistent autonomy. Structure is not sufficient; constraints must be actively enforced. This work provides the bridge from necessary conditions to executable systems, showing how autonomy can be maintained through continuous governance rather than assumed from capability.