# Evidence Subgraph UI Visualization

## Module
Attestor

## Status
VERIFIED

## Description
Backend proof graph model is implemented (nodes, edges, subgraphs, paths). Evidence panel e2e tests exist. Full frontend visualization component status unclear from source search alone.

## What's Implemented
- **Proof Graph Model**: `src/Attestor/__Libraries/StellaOps.Attestor.ProofChain/Graph/InMemoryProofGraphService.cs` (with `.Mutation`, `.Queries`, `.Subgraph`) -- graph service with node/edge management, subgraph extraction, and path queries.
- **Graph Node**: `Graph/ProofGraphNode.cs` -- node model with type and metadata.
- **Graph Edge**: `Graph/ProofGraphEdge.cs` -- edge model with type linking nodes.
- **Graph Node/Edge Types**: `Graph/ProofGraphNodeType.cs`, `Graph/ProofGraphEdgeType.cs` -- typed node and edge enumerations.
- **Graph Path**: `Graph/ProofGraphPath.cs` -- path through the proof graph.
- **Graph Subgraph**: `Graph/ProofGraphSubgraph.cs` -- extracted subgraph for a specific subject.

## What's Missing
- **Frontend graph visualization component**: No Angular component rendering the proof graph as an interactive visualization (nodes as circles/rectangles, edges as arrows).
- **Interactive exploration**: No click-to-expand, zoom, pan, or filter functionality for graph navigation in the UI.
- **Subgraph API endpoint**: The WebService controllers do not expose a dedicated endpoint for fetching proof graph subgraphs for a given subject.
- **Graph layout algorithm**: No force-directed or hierarchical layout algorithm for rendering the graph in 2D.
- **Evidence node detail panel**: No side panel showing node details (attestation content, verification status) when a node is selected.

## Implementation Plan
- Add a REST endpoint in `ProofChainController` for subgraph queries by subject
- Create an Angular component using a graph visualization library (e.g., D3.js or Cytoscape.js)
- Implement interactive exploration (zoom, pan, click-to-expand, filtering by node/edge type)
- Add a node detail panel showing attestation content and verification status
- Implement graph layout algorithm (hierarchical for proof chains, force-directed for evidence graphs)
- Add e2e tests for graph rendering and interaction

## Related Documentation
- Source: See feature catalog

## 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 |