# Path Explanation Service with Multi-Format Rendering

## Module
Scanner

## Status
VERIFIED

## Description
Service that converts raw reachability graph paths (entrypoint-to-sink) into human-readable explanations with gate annotations, supporting text, markdown, and JSON output formats for display in CLI, UI, and API responses.

## Implementation Details
- **Path Explanation Service**:
  - `src/Scanner/__Libraries/StellaOps.Scanner.Reachability/Explanation/PathExplanationService.cs` - `PathExplanationService` converts raw reachability graph paths into human-readable explanations with gate annotations
  - `src/Scanner/__Libraries/StellaOps.Scanner.Reachability/Explanation/PathExplanationModels.cs` - Models for path explanation data including node descriptions, gate annotations, and confidence levels
- **Multi-Format Rendering**:
  - `src/Scanner/__Libraries/StellaOps.Scanner.Reachability/Explanation/PathRenderer.cs` - `PathRenderer` renders path explanations in multiple formats: plain text, markdown, and JSON for CLI, UI, and API consumption

## E2E Test Plan
- [ ] Generate a reachability path from an entrypoint to a vulnerable sink and verify the explanation service produces a human-readable description
- [ ] Verify gate annotations (auth, admin-only, feature flags) appear in the path explanation
- [ ] Verify text format rendering produces a clean CLI-readable output
- [ ] Verify markdown format rendering produces properly formatted markdown with code blocks and links
- [ ] Verify JSON format rendering produces structured data suitable for API responses and UI consumption
- [ ] Verify multi-hop paths (entrypoint -> intermediate -> sink) include all intermediate nodes with descriptions

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## Verification

| Check | Result |
|-------|--------|
| Tier 0 - Source files exist | PASS |
| Tier 1 - Build + code review | PASS |
| Tier 2 - Integration tests | PASS |
| Verified | 2026-02-13T18:10:00Z |