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vendor/ruvector/docs/adr/coherence-engine/ADR-CE-016-ruvllm-coherence-validator.md

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+# ADR-CE-016: RuvLLM CoherenceValidator Uses Sheaf Energy
+
+**Status**: Accepted
+**Date**: 2026-01-22
+**Parent**: ADR-014 Coherence Engine Architecture
+
+## Context
+
+RuvLLM's `CoherenceValidator` currently uses heuristic scoring to detect:
+- Semantic inconsistency
+- Factual contradictions
+- Logical errors
+
+These heuristics are:
+- Pattern-based (can be fooled)
+- Not mathematically grounded
+- Difficult to explain
+
+## Decision
+
+**RuvLLM CoherenceValidator uses sheaf energy, not heuristic scores.**
+
+Integration:
+```rust
+pub struct SheafCoherenceValidator {
+    graph: SheafGraph,
+    gate: CoherenceGate,
+    inner: CoherenceValidator,  // Fallback
+}
+```
+
+Process:
+1. Convert context and response to sheaf nodes
+2. Add edges for semantic implications
+3. Compute coherence energy
+4. Gate decision replaces heuristic score
+
+## Consequences
+
+### Benefits
+- Mathematical proof of inconsistency, not pattern matching
+- Explainable: can show which edges have high residuals
+- Unified with Prime-Radiant governance
+
+### Risks
+- Requires embedding quality for node states
+- Edge creation logic needs domain expertise
+
+## References
+
+- ADR-014: Coherence Engine Architecture, "RuvLLM Integration"
+- ruvllm/src/quality/coherence.rs