# Sub-Volume E: Quantum Proxy Server (QPS)

## Overview

The Quantum Proxy Server (QPS) bridges transactions from non-quantum financial systems to QFS/QNT rails without disruption, providing quantum envelope creation and dimensional harmonization.

## Transaction Path

```
legacy_tx → QPS → quantum_wrap → DBIS_QFS
```

## QPS Functions

### Quantum Envelope Creation

Creates quantum-safe envelopes for legacy transactions with:
- Quantum hash (SHA-3-256)
- Causal-consistency hash (preserves transaction causality)
- Dimensional harmonization hash (ensures consistency across dimensions)

### Causal-Consistency Enforcement

Ensures transaction causality is preserved across quantum systems by:
- Maintaining causal order
- Linking to previous transactions
- Verifying temporal consistency

### Dimensional Harmonization

Ensures transactions are consistent across:
- Classical dimension (traditional ledgers)
- Quantum dimension (quantum ledgers)
- Multiversal dimension (parallel realities)

### FX & Risk Translation

Translates legacy protocol data to quantum-compatible format:
- FX rate conversion
- Risk score calculation
- Protocol-specific field mapping

## Universal Compatibility

QPS is compatible with:

- **SWIFT** - MT103 message format
- **ISO20022** - pacs.008, pain.001 formats
- **ACH** - Automated Clearing House format
- **SEPA** - Single Euro Payments Area format
- **Private Bank Ledgers** - Custom private bank formats

## Services

### QuantumProxyService

Main service for transaction bridging.

**Location**: `src/infrastructure/quantum/proxy/quantum-proxy.service.ts`

**Key Methods**:
- `bridgeTransaction()` - Bridge transaction from legacy to DBIS QFS
- `getProxyTransaction()` - Get proxy transaction by ID
- `getProxyTransactionsForBank()` - Get transactions for a bank

### QuantumEnvelopeService

Service for quantum envelope creation.

**Location**: `src/infrastructure/quantum/proxy/quantum-envelope.service.ts`

**Key Methods**:
- `createQuantumEnvelope()` - Create quantum envelope for legacy transaction
- `getEnvelope()` - Get envelope by ID
- `verifyEnvelopeIntegrity()` - Verify envelope integrity

### QuantumTranslationService

Service for FX & risk translation.

**Location**: `src/infrastructure/quantum/proxy/quantum-translation.service.ts`

**Key Methods**:
- `translateLegacyTransaction()` - Translate legacy transaction to quantum format
- `getTranslation()` - Get translation by ID
- `getTranslationsByProtocol()` - Get translations by protocol

### QuantumCompatibilityService

Service for universal compatibility checking.

**Location**: `src/infrastructure/quantum/proxy/quantum-compatibility.service.ts`

**Key Methods**:
- `checkCompatibility()` - Check compatibility of legacy protocol
- `registerProtocolMapping()` - Register protocol mapping
- `listSupportedProtocols()` - List all supported protocols

## API Endpoints

### Transaction Bridging

- `POST /api/quantum-proxy/bridge` - Bridge transaction from legacy to DBIS QFS
- `GET /api/quantum-proxy/transaction/:proxyTransactionId` - Get proxy transaction by ID
- `GET /api/quantum-proxy/transactions/bank/:sovereignBankId` - Get transactions for a bank
- `GET /api/quantum-proxy/transactions/protocol/:legacyProtocol` - Get transactions by protocol

### Envelope Management

- `GET /api/quantum-proxy/envelope/:envelopeId` - Get quantum envelope by ID
- `POST /api/quantum-proxy/envelope/:envelopeId/verify` - Verify envelope integrity

### Translation

- `POST /api/quantum-proxy/translate` - Translate legacy transaction
- `GET /api/quantum-proxy/translation/:translationId` - Get translation by ID

### Compatibility

- `POST /api/quantum-proxy/compatibility/check` - Check protocol compatibility
- `GET /api/quantum-proxy/compatibility/protocols` - List supported protocols
- `POST /api/quantum-proxy/compatibility/mapping` - Register protocol mapping

## Database Schema

### QuantumProxyTransaction

Main proxy transaction record.

**Fields**:
- `proxyTransactionId` - Unique proxy transaction identifier
- `legacyTransactionId` - Original legacy transaction ID
- `legacyProtocol` - Legacy protocol (SWIFT, ISO20022, etc.)
- `quantumEnvelopeId` - Reference to quantum envelope
- `dbisQfsTransactionId` - Reference to DBIS QFS transaction
- `status` - Transaction status (pending, bridged, failed)

### QuantumEnvelope

Quantum envelope record.

**Fields**:
- `envelopeId` - Unique envelope identifier
- `quantumHash` - Quantum-safe hash (SHA-3-256)
- `causalConsistencyHash` - Causal consistency hash
- `dimensionalHarmonizationHash` - Dimensional harmonization hash
- `transactionData` - Original transaction data

### QuantumTranslation

Translation record.

**Fields**:
- `translationId` - Unique translation identifier
- `legacyAmount` - Original legacy amount
- `quantumAmount` - Translated quantum amount
- `fxRate` - FX conversion rate
- `riskScore` - Risk assessment score
- `protocolMapping` - Protocol-specific mapping configuration

### LegacyProtocolMapping

Protocol mapping configuration.

**Fields**:
- `mappingId` - Unique mapping identifier
- `legacyProtocol` - Legacy protocol name
- `mappingConfig` - Protocol-specific mapping configuration

## Integration Points

- **GQL (Global Quantum Ledger)**: QPS submits transactions to GQL
- **Quantum-Safe Crypto**: Uses quantum-safe cryptographic hashing
- **Legacy Payment Systems**: Bridges SWIFT, ISO20022, ACH, SEPA, private ledgers

## Use Cases

### SWIFT to Quantum Migration

Bridge existing SWIFT transactions to quantum financial rails without disruption.

### ISO20022 Quantum Integration

Seamlessly integrate ISO20022 messages with quantum systems.

### Legacy Bank Integration

Enable private banks with custom protocols to access quantum financial systems.

### Cross-Dimensional Transactions

Ensure transactions are consistent across classical, quantum, and multiversal dimensions.

## Example Usage

```typescript
import { quantumProxyService } from '@/infrastructure/quantum/proxy/quantum-proxy.service';

// Bridge SWIFT transaction to quantum
const result = await quantumProxyService.bridgeTransaction({
  legacyTransactionId: 'SWIFT-12345',
  legacyProtocol: 'SWIFT',
  sourceBankId: 'OMNL',
  destinationBankId: 'USCB',
  amount: '1000000',
  currencyCode: 'USD',
  transactionData: {
    sender: 'OMNL',
    receiver: 'USCB',
    amount: 1000000,
    currency: 'USD',
  },
});

console.log(`Quantum transaction ID: ${result.dbisQfsTransactionId}`);
```

## Status

✅ **Implemented** - Sub-Volume E is fully implemented and integrated with existing DBIS systems.