Six Birds Theory (SBT) treats macroscopic objects as induced closures. The paper argues agency is about control, not persistence, and offers a ledgered interface. It operationalizes the contract with four checkable components: ledger‑gated feasibility, a viability kernel, a greatest fixed‑point calculation, and successor semantics. Practitioners can use SBT to build agentic systems that are provably viable and hard to spoof.