Architectural Invariants
This document defines architectural invariants for Gantral.
Invariants are constraints that guide design and implementation decisions.
They are intended to preserve execution control and auditability.
Invariant 1: Instance-First Semantics
Execution metadata is associated with instances, not agents.
Audit, cost, and accountability attach to a specific execution instance.
Invariant 2: Human Authority Is Explicit
Where human involvement is configured, execution requires an explicit human decision.
Human decisions are modeled within execution, not inferred externally.
Invariant 3: Determinism Over Convenience
Execution behavior should be predictable and reconstructable.
Features that introduce hidden non-determinism are discouraged.
Invariant 4: Declarative Control
Policies, escalation rules, and authority constraints should be expressed declaratively.
Embedding control logic directly in agent code is discouraged.
Invariant 5: Adapters Contain No Business Logic
Integrations should emit events and consume decisions.
Business or governance logic should not be embedded in adapters.
Interpretation
These invariants describe architectural intent.
They are not contractual guarantees and may evolve through documented governance processes.