# Graph Analytics Engine

## Module
Graph

## Status
VERIFIED

## Description
Graph analytics with engine, pipeline, DI extensions, and Postgres persistence for analytics results.

## Implementation Details
- **Analytics engine**: `src/Graph/StellaOps.Graph.Indexer/Analytics/GraphAnalyticsEngine.cs` -- core graph analytics computation engine
- **Analytics pipeline**: `src/Graph/StellaOps.Graph.Indexer/Analytics/GraphAnalyticsPipeline.cs` -- multi-stage analytics pipeline orchestration
- **Hosted service**: `src/Graph/StellaOps.Graph.Indexer/Analytics/GraphAnalyticsHostedService.cs` -- background service running analytics on schedule
- **Analytics types**: `src/Graph/StellaOps.Graph.Indexer/Analytics/GraphAnalyticsTypes.cs` -- clustering, centrality, and analytics result types
- **Metrics**: `src/Graph/StellaOps.Graph.Indexer/Analytics/GraphAnalyticsMetrics.cs` -- Prometheus-compatible analytics execution metrics
- **Options**: `src/Graph/StellaOps.Graph.Indexer/Analytics/GraphAnalyticsOptions.cs` -- configurable analytics parameters
- **Writer options**: `src/Graph/StellaOps.Graph.Indexer/Analytics/GraphAnalyticsWriterOptions.cs` -- result persistence configuration
- **Overlay exporter**: `src/Graph/StellaOps.Graph.Indexer/Analytics/GraphOverlayExporter.cs` -- exports analytics results as graph overlays
- **In-memory writer**: `src/Graph/StellaOps.Graph.Indexer/Analytics/InMemoryGraphAnalyticsWriter.cs` -- test analytics writer
- **In-memory snapshot**: `src/Graph/StellaOps.Graph.Indexer/Analytics/InMemoryGraphSnapshotProvider.cs` -- test snapshot provider
- **DI extensions**: `src/Graph/StellaOps.Graph.Indexer/Analytics/GraphAnalyticsServiceCollectionExtensions.cs` -- DI registration
- **Postgres persistence**: `src/Graph/__Libraries/StellaOps.Graph.Indexer.Persistence/Postgres/Repositories/PostgresGraphAnalyticsWriter.cs` -- PostgreSQL analytics result storage
- **Tests**: `src/Graph/__Tests/StellaOps.Graph.Indexer.Tests/GraphAnalyticsEngineTests.cs`, `GraphAnalyticsPipelineTests.cs`, `GraphOverlayExporterTests.cs`, `GraphAnalyticsTestData.cs`
- **Source**: Feature matrix scan

## E2E Test Plan
- [x] Verify analytics engine computes clustering and centrality scores
- [x] Test pipeline executes multi-stage analytics in correct order
- [x] Verify hosted service runs analytics on configured schedule
- [ ] Test Postgres persistence stores analytics results correctly (skipped: Docker unavailable)
- [x] Verify overlay exporter generates valid overlay data from analytics

## Verification
- **Run ID**: run-001
- **Date**: 2026-02-09T16:00:00Z
- **Tier**: 1 (Build + Test)
- **Result**: PASS
- **Evidence**: Graph.Indexer.Tests 37/37 pass, Graph.Core.Tests 19/19 pass. Persistence tests skipped (Docker unavailable, env_issue). All source files verified (16/16).