SAMPARK: Seamless And Modern Payment Architecture for Rapid Transactions and Knowledge

Overview

SAMPARK is an open-source project that simulates the architectural patterns and event flows of India's digital payment ecosystem. It provides a realistic reference model without replicating actual internal operations of real payment networks, serving as a practical blueprint for engineers exploring financial technology architectures and distributed system design.

Architecture

SAMPARK implements a multi-layered architecture mirroring real-world payment ecosystems:

Core Components

• National Transaction Hub (NTH): Central payment switch similar to NPCI's role
• Payment Service Providers (PSPs): Banks providing backend services
• Third Party Payment Applications (TPAP): Consumer-facing payment interfaces

Supported Transaction Types

• UPI: Unified Payments Interface
• IMPS: Immediate Payment Service

System Architecture

UPI Transaction Flow

[BazzarPe] → [PSP: Paisa Vasool Bank] → [NTH] → [PSP: Babu Rao Ganpatrao Bank] → [ChillarPay]

IMPS Transaction Flow

[Remitter Bank] → [NTH] → [Beneficiary Bank]

Transaction Journey

1. Initiation: User initiates payment through TPAP
2. PSP Processing: Sponsoring bank validates and processes
3. Central Routing: NTH routes transaction to destination PSP
4. Settlement: Destination PSP credits beneficiary account
5. Confirmation: End-to-end transaction confirmation

Network Participants

Banks and Sponsored TPAPs

Bank Name	IFSC Code	IIN	Port	Sponsored TPAP	Specialty Focus
Paisa Vasool Bank	PVB	321987	3004	BazzarPe	Merchant payments & marketplace solutions
Babu Rao Ganpatrao Bank	BRG	654321	3001	ChillarPay	P2P transfers & micro-payments
Chinta Mat Karo Bank	CMK	456123	3003	Available	Worry-free banking solutions
Chai Pani Bank	CPB	789456	3002	Available	Micro-transaction specialists

Third Party Applications

TPAP Name	Port	Sponsor PSP	Description
BazzarPe	6001	Paisa Vasool Bank	UPI merchant payment solution
ChillarPay	6002	Chinta Mat Karo Bank	UPI P2P transfer application

Core Services

Service	Port	Description
NTH Switch	3005	National Transaction Hub
Redis Stack	6379/8001	Shared caching and session management
Kafka	9092	Message broker for event streaming
Zookeeper	2181	Kafka cluster coordination

Technology Stack

• Message Broker: Apache Kafka + Zookeeper
• Containerization: Docker & Docker Compose
• Caching: Redis Stack
• Database: PostgreSQL with Prisma ORM
• Runtime: Bun (Node.js)
• Language: TypeScript
• Framework: Express.js
• Testing: Jest
• Monitoring: Grafana + Prometheus (Optional)

Quick Start

Prerequisites

• Docker and Docker Compose
• Git

Installation

1. Clone the repository:

git clone https://github.com/Gajjar-Mohit/Sampark.git
cd sampark

2. Start all services:

docker-compose up -d

3. Verify services are running:

docker-compose ps

Service URLs

• NTH Switch: http://localhost:3005
• Paisa Vasool Bank: http://localhost:3004
• Babu Rao Ganpatrao Bank: http://localhost:3001
• Chinta Mat Karo Bank: http://localhost:3003
• Chai Pani Bank: http://localhost:3002
• BazzarPe: http://localhost:6001
• ChillarPay: http://localhost:6002
• Redis Insight: http://localhost:8001

Project Structure

SAMPARK/
├── banks/                    # Payment Service Providers
│   ├── babu-rao-ganpatrao-bank/
│   ├── chai-pani-bank/
│   ├── chinta-mat-karo-bank/
│   └── paisa-vasool-bank/
├── nth/                      # National Transaction Hub
├── tpap/                     # Third Party Applications
│   ├── BazaarPe/
│   └── ChillarPay/
├── k8s/                      # Kubernetes configurations
├── tests/                    # Test suites
├── assets/                   # Static assets
├── docker-compose.yml        # Container orchestration
└── README.md                # This file

Development

Environment Setup

Each service uses environment variables for configuration. Key variables include:

• NODE_ENV: Environment (development/production)
• DATABASE_URL: PostgreSQL connection string
• KAFKA_BASEURL: Kafka broker URL
• REDIS_URL: Redis connection string
• PORT: Service port

Database Management

Services use Prisma for database operations:

# Run migrations
docker-compose exec <service> bun prisma migrate deploy

# Seed data
docker-compose exec <service> bun run seed

Logs and Monitoring

To reduce log noise, most services have logging disabled. Enable logging by removing logging: driver: "none" from docker-compose.yml.

API Documentation

Detailed API documentation is available in each module's README:

• Banks APIs
• TPAP APIs
• NTH APIs

Testing

Run tests for specific services:

# Run all tests
docker-compose exec <service> bun test

# Run with coverage
docker-compose exec <service> bun test --coverage

Contributing

1. Fork the repository
2. Create a feature branch
3. Make your changes
4. Add tests
5. Submit a pull request

License

This project is open-source. See LICENSE file for details.

Disclaimer

This project is for educational and research purposes. It simulates payment system architectures and should not be used in production environments without proper security audits and compliance reviews.