# DBIS Global Payments Network (GPN)

## Overview

The DBIS Global Payments Network (GPN) is the universal, sovereign-grade payment network connecting 33 Sovereign Central Banks, private banks, CBDC wallets, commodity token networks, and security token infrastructures.

## Architecture

### Layer 1 – Sovereign Access Layer

- SCB nodes authenticate via SDIP (Sovereign Digital Identity Passport)
- Sovereign traffic segmented by identity
- Zero-trust authentication

**Service**: `gpn-sovereign-access.service.ts`

**API Endpoint**: `POST /api/v1/gpn/authenticate`

### Layer 2 – Global Switching Layer

- DBIS switch routes payments using:
  - FX cost optimization
  - Liquidity availability
  - SRI-based risk weighting

**Service**: `gpn-switching.service.ts`

**API Endpoint**: `POST /api/v1/gpn/route`

### Layer 3 – Finality Layer

- Atomic settlement achieved when:
  - SCB ledger posts
  - DBIS Master Ledger posts
  - Hash-lock matches

**Service**: `gpn-finality.service.ts`

**API Endpoints**:
- `POST /api/v1/gpn/finality` - Verify finality
- `POST /api/v1/gpn/hash-lock` - Create hash-lock

## Supported Payment Types

- Person → Person (rCBDC)
- Bank → Bank (wCBDC)
- SCB → SCB (institutional payments)
- Commodity-backed payments (CDT → CBDC)
- Security-linked payments
- Cross-chain payments (multi-ledger)

## Messaging Standards

GPN uses ISO 20022 messages wrapped in Sovereign Message Envelope (SME):

- PACS.008 - FI to FI Credit Transfer
- PACS.002 - Payment Status Report
- FXMT.003 - FX Trade Execution Report
- CBDC_TX - CBDC transaction messages
- SCB_NOTIFY - SCB notification messages
- DBIS_COMMIT - DBIS commitment messages

**Service**: `gpn-message-handler.service.ts`

**API Endpoint**: `POST /api/v1/gpn/message/pacs008`

## Database Models

- `GpnPayment` - Payment routing records
- `GpnRoute` - Routing paths with cost/risk metrics
- `GpnSettlementLock` - Hash-lock records for finality

## Integration Points

- ISO 20022 service (existing)
- SIRE routing (existing)
- GSS Master Ledger (existing)
- SDIP identity (Volume V)