Protocol-Governed Systems: A Conceptual Model

Protocol-Governed Systems (PGS) propose a computational architecture in which governance precedes execution. Instead of relying on runtime policies, conventions, or post-hoc validation, PGS defines admissible behavior through governed protocol artifacts that are compiled into deterministic execution structures before runtime begins. This document defines the conceptual model underlying PGS-Protocol. It establishes PGS as a constitutional execution substrate rather than a single application protocol. The model introduces the protocol snapshot as the immutable admissibility boundary between governance and execution, defines a compositional admissibility model spanning compile-time and runtime concerns, formalizes constitutional invariants governing execution behavior, and distinguishes protocol-defined semantics from implementation-defined mechanics. The architecture separates governance from execution through a semantic-agnostic runtime constrained entirely by compiled admissibility structures. Execution produces immutable evidence projections (traces) that provide governance provenance without participating in admissibility decisions themselves. The conceptual model has been validated through the PGS reference implementation (OmniBachi v0.2.0), an open-source ecosystem demonstrating deterministic execution, bounded authority, compile-time admissibility construction, and trace-backed execution evidence. This document provides the semantic foundation for future work including conformance testing, AI governance evidence frameworks, and eventual formal protocol specification