# Replay Fidelity Verification

## Module
Attestor

## Status
VERIFIED

## Description
Replay result and verification models, AI artifact replayer interface, SBOM replay verification service, and CLI replay commands for deterministic replay verification.

## Implementation Details
- **AI Artifact Replay Manifest**: `src/Attestor/__Libraries/StellaOps.Attestor.ProofChain/Replay/AIArtifactReplayManifest.cs` -- manifest capturing all inputs (prompts, evidence, model parameters) for deterministic replay.
- **Replay Input Artifact**: `Replay/ReplayInputArtifact.cs` -- individual input artifact with content hash.
- **Replay Prompt Template**: `Replay/ReplayPromptTemplate.cs` -- exact prompt template with parameter bindings.
- **Replay Result**: `Replay/ReplayResult.cs` -- result of a replay attempt with fidelity metrics (semantic similarity, structural match, hash match).
- **Replay Status**: `Replay/ReplayStatus.cs` -- enum tracking replay outcome (Identical, Semantically Equivalent, Divergent, Failed).
- **Replay Verification Result**: `Replay/ReplayVerificationResult.cs` -- verification comparing replayed output to original output.
- **AI Artifact Replayer**: `Replay/IAIArtifactReplayer.cs` -- interface for executing replays.
- **Verification Replay Log**: `__Libraries/StellaOps.Attestor.EvidencePack/Models/VerificationReplayLog.cs` -- log of replay verification steps.
- **Verification Replay Log Builder**: `__Libraries/StellaOps.Attestor.EvidencePack/Services/VerificationReplayLogBuilder.cs` -- builds replay logs.
- **Tests**: `__Tests/StellaOps.Attestor.ProofChain.Tests/ReplayManifestTests.cs`

## E2E Test Plan
- [ ] Create an `AIArtifactReplayManifest` with input artifacts, prompt template, and model parameters; verify all inputs are captured
- [ ] Execute a replay via `IAIArtifactReplayer` and verify `ReplayResult` contains fidelity metrics
- [ ] Verify `ReplayStatus.Identical` when the replayed output exactly matches the original
- [ ] Verify `ReplayStatus.SemanticallyEquivalent` when outputs differ in formatting but are semantically equivalent
- [ ] Verify `ReplayStatus.Divergent` when the replayed output significantly differs from the original
- [ ] Compare original and replayed outputs via `ReplayVerificationResult` and verify detailed comparison metrics
- [ ] Build a `VerificationReplayLog` capturing all replay steps and verify the log is complete
- [ ] Verify replay determinism: replay the same manifest twice and confirm identical `ReplayResult`

## Verification

| Check | Result |
|-------|--------|
| Tier 0 - Source Verification | PASS |
| Tier 1 - Build + Code Review | PASS |
| Tier 2 - Behavioral Verification | PASS |
| Verified Date | 2026-02-13 |
| Run ID | run-001 |