# AI-Assisted Explanation and Classification

## Module
Attestor

## Status
VERIFIED

## Description
AI authority classifier with explanation scoring, citation references, explanation types, and model identifiers. AI artifact verification step integrates into the verification pipeline.

## Implementation Details
- **AIAuthorityClassifier**: `src/Attestor/__Libraries/StellaOps.Attestor.ProofChain/Predicates/AI/AIAuthorityClassifier.cs` (with `.Explanation`, `.ExplanationScore`, `.PolicyDraft`, `.PolicyDraftScore`, `.Remediation`, `.RemediationScore`, `.VexDraft`, `.VexDraftScore` partials) -- classifies AI outputs into `Suggestion`, `EvidenceBacked`, or `AuthorityThreshold` based on citation rate, verified rate, and confidence score.
- **AIAuthorityThresholds**: `AIAuthorityThresholds.cs` -- configurable thresholds: `MinCitationRate` (default 0.8), `MinConfidenceScore` (default 0.7), `MinVerifiedCitationRate` (default 0.9), `AuthorityThresholdScore` (default 0.95).
- **AIArtifactAuthority enum**: `AIArtifactAuthority.cs` -- three levels: Suggestion (no evidence), EvidenceBacked (citations verified), AuthorityThreshold (meets auto-processing score).
- **AIExplanationPredicate**: `AIExplanationPredicate.cs` -- record extending `AIArtifactBasePredicate` with `ExplanationType`, `Content`, `Citations`, `ConfidenceScore`, `CitationRate`, `Subject`, `ContextScope`.
- **AIExplanationCitation**: `AIExplanationCitation.cs` -- links claims to evidence with `ClaimIndex`, `ClaimText`, `EvidenceId` (sha256 format), `EvidenceType`, `Verified` flag.
- **AIExplanationType enum**: `AIExplanationType.cs` -- Exploitability, CodePath, PolicyDecision, RiskFactors, RemediationOptions, PlainLanguageSummary, EvidenceChain.
- **AIModelIdentifier**: `AIModelIdentifier.cs` -- tracks provider/model/version with optional `WeightsDigest` for local models.
- **Verification Step**: `src/Attestor/__Libraries/StellaOps.Attestor.ProofChain/Verification/AIArtifactVerificationStep.cs` (with `.Execute`, `.Classify`, `.Helpers`, `.Summary`, `.VerifyParse`, `.VerifyValidation` partials) -- integrates into `VerificationPipeline` to verify AI artifacts in proof bundles.
- **Tests**: `src/Attestor/__Tests/StellaOps.Attestor.ProofChain.Tests/AI/AIExplanationAndVerificationBehaviorTests.cs`

## E2E Test Plan
- [ ] Create an `AIExplanationPredicate` with citation rate >= 0.8, verified rate >= 0.9, and confidence >= 0.7, classify via `AIAuthorityClassifier`, and verify it returns `EvidenceBacked`
- [ ] Create an explanation with citation rate < 0.8 and verify classifier returns `Suggestion` with appropriate reason messages
- [ ] Create an explanation with quality score >= 0.95 and verify classifier returns `AuthorityThreshold`
- [ ] Submit a proof bundle containing AI artifacts through `AIArtifactVerificationStep.ExecuteAsync` and verify all artifacts are validated (parse, schema, classification)
- [ ] Submit a proof bundle with invalid AI artifacts (malformed predicate) and verify the verification step returns `Passed = false` with error details
- [ ] Create an `AIExplanationCitation` with `Verified = false` and verify it lowers the verified rate below the threshold, causing the classifier to return `Suggestion`
- [ ] Verify `AIModelIdentifier.ToString()` produces the canonical `provider:model:version` format

## Verification
- Verified on 2026-02-11 with `run-001`.
- Tier 0 source checks passed for classifier, predicate, model identifier, and verification-step files.
- Tier 1 build passed and feature-scoped AI behavior tests passed (`7/7`) via xUnit runner class filtering.
- Tier 2 behavioral checks passed for:
  - `EvidenceBacked`, `Suggestion`, and `AuthorityThreshold` classifier outcomes
  - invalid/malformed artifact rejection in `AIArtifactVerificationStep.ExecuteAsync`
  - canonical `AIModelIdentifier.ToString()` format
- Evidence:
  - `docs/qa/feature-checks/runs/attestor/ai-assisted-explanation-and-classification/run-001/tier0-source-check.json`
  - `docs/qa/feature-checks/runs/attestor/ai-assisted-explanation-and-classification/run-001/tier1-build-check.json`
  - `docs/qa/feature-checks/runs/attestor/ai-assisted-explanation-and-classification/run-001/tier2-integration-check.json`