# VEX Consensus Engine

## Module
VexLens

## Status
IMPLEMENTED

## Description
A multi-mode VEX consensus engine is implemented with trust-weighted scoring, conflict resolution, and persistence via dual-write consensus projection stores.

## Implementation Details
- **Consensus engine**: `src/VexLens/StellaOps.VexLens/Consensus/VexConsensusEngine.cs`, `IVexConsensusEngine.cs` -- multi-mode consensus with trust-weighted scoring and conflict resolution
- **Core consensus**: `src/VexLens/StellaOps.VexLens/StellaOps.VexLens.Core/Consensus/VexConsensusEngine.cs`, `IVexConsensusEngine.cs`
- **Dual-write store**: `src/VexLens/StellaOps.VexLens/Storage/DualWriteConsensusProjectionStore.cs` -- writes consensus projections to both in-memory and persistent stores
- **In-memory store**: `src/VexLens/StellaOps.VexLens/Storage/InMemoryConsensusProjectionStore.cs`
- **Postgres store proxy**: `src/VexLens/StellaOps.VexLens/Storage/PostgresConsensusProjectionStoreProxy.cs`
- **Postgres persistence**: `src/VexLens/StellaOps.VexLens.Persistence/Postgres/PostgresConsensusProjectionStore.cs`
- **Persistence repository**: `src/VexLens/StellaOps.VexLens.Persistence/Repositories/ConsensusProjectionRepository.cs`, `IConsensusProjectionRepository.cs`
- **Consensus API models**: `src/VexLens/StellaOps.VexLens/Api/ConsensusApiModels.cs` -- API request/response models
- **Orchestration**: `src/VexLens/StellaOps.VexLens/Orchestration/ConsensusJobTypes.cs`, `IConsensusJobService.cs`, `OrchestratorLedgerEventEmitter.cs`
- **Signal emitter**: `src/VexLens/StellaOps.VexLens/Integration/VexSignalEmitter.cs` -- emits VEX signals to downstream systems
- **Policy integration**: `src/VexLens/StellaOps.VexLens/Integration/PolicyEngineIntegration.cs`, `IPolicyEngineIntegration.cs` -- feeds consensus into policy engine
- **Noise gate**: `src/VexLens/StellaOps.VexLens/NoiseGate/NoiseGateService.cs`, `INoiseGate.cs`, `NoiseGateOptions.cs` -- suppresses low-signal VEX noise
- **Metrics**: `src/VexLens/StellaOps.VexLens/Observability/VexLensMetrics.cs` -- consensus engine metrics
- **WebService API**: `src/VexLens/StellaOps.VexLens.WebService/Program.cs`, `Extensions/VexLensEndpointExtensions.cs`, `ExportEndpointExtensions.cs`
- **Tests**: `src/VexLens/StellaOps.VexLens/__Tests/StellaOps.VexLens.Tests/Storage/DualWriteConsensusProjectionStoreTests.cs`, `PostgresConsensusProjectionStoreProxyTests.cs`, `NoiseGate/NoiseGateServiceTests.cs`
- **Source**: Feature matrix scan

## E2E Test Plan
- [ ] Verify consensus engine produces trust-weighted verdicts from multiple VEX sources
- [ ] Test dual-write store persists to both in-memory and PostgreSQL
- [ ] Verify conflict resolution handles contradictory VEX statements
- [ ] Test noise gate suppresses low-confidence VEX signals
- [ ] Verify policy engine integration receives consensus results
- [ ] Test consensus API endpoints return valid projections