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vendor/ruvector/docs/adr/coherence-engine/ADR-CE-017-unified-audit-trail.md

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+# ADR-CE-017: Unified Audit Trail
+
+**Status**: Accepted
+**Date**: 2026-01-22
+**Parent**: ADR-014 Coherence Engine Architecture
+
+## Context
+
+RuvLLM has `WitnessLog` for inference audit. Prime-Radiant has `WitnessRecord` for coherence decisions. Two separate audit trails create:
+- Fragmented compliance story
+- Difficult cross-referencing
+- Duplicate storage
+
+## Decision
+
+**WitnessLog and Prime-Radiant governance share single audit trail.**
+
+Unified structure:
+```rust
+pub struct UnifiedWitnessLog {
+    coherence_witnesses: Vec<WitnessRecord>,
+    inference_witnesses: WitnessLog,
+}
+
+pub struct GenerationWitness {
+    inference: InferenceWitness,
+    coherence: WitnessRecord,
+    hash_chain: Hash,
+}
+```
+
+Every LLM generation links:
+- Inference witness (what was generated)
+- Coherence witness (why it was allowed)
+- Hash chain (tamper-evident ordering)
+
+## Consequences
+
+### Benefits
+- Single audit trail for compliance
+- Cross-reference inference ↔ coherence decisions
+- Reduced storage (shared chain)
+
+### Risks
+- Migration from two systems to one
+- Both systems must agree on witness format
+
+## References
+
+- ADR-014: Coherence Engine Architecture, "RuvLLM Integration"
+- ADR-CE-005: First-Class Governance Objects