wifi-densepose/vendor/ruvector/docs/adr/coherence-engine/ADR-CE-012-gate-refusal-witness.md

ADR-CE-012: Gate = Refusal Mechanism with Witness

Status: Accepted Date: 2026-01-22 Parent: ADR-014 Coherence Engine Architecture

Context

When coherence energy exceeds threshold, the system must refuse action. This refusal needs to be:

• Deterministic (same inputs → same decision)
• Auditable (why was it refused?)
• Provable (cryptographic witness)

Decision

Gate = refusal mechanism with witness - every refusal is provable.

Gate evaluation produces:

pub struct GateDecision {
    pub allow: bool,
    pub lane: ComputeLane,
    pub witness: WitnessRecord,
    pub denial_reason: Option<String>,
}

The WitnessRecord includes:

• Energy snapshot at decision time
• Policy bundle that defined thresholds
• Hash chain to previous witness
• Content hash for integrity

Consequences

Benefits

• Every refusal has cryptographic proof
• Can reconstruct exactly why any decision was made
• Compliance-ready audit trail

Risks

• Witness storage overhead
• Must handle witness retrieval at scale

References

• ADR-014: Coherence Engine Architecture, Section 3
• ADR-CE-005: First-Class Governance Objects