PaymentTestGateway

A lightweight Payment Gateway Sandbox built with ASP.NET Core 8, Blazor Server, and Clean Architecture.

The goal of this project is to provide a realistic payment gateway simulator that developers can integrate with during development and testing without requiring access to a real bank or payment service provider.

---

Features

Payment API

• Create Payment
• Update Payment Status
  • Successful
  • Failed
  • Cancelled
• Verify Payment

---

Payment UI

• Payment Page
• Payment Result Page
• Callback Redirect
• Responsive Layout
• CSS Isolation

---

Payment Lifecycle

Application
      │
      ▼
Create Payment
      │
      ▼
Redirect User
      │
      ▼
Payment Gateway
      │
      ▼
User Action
      │
      ├──────── Success
      ├──────── Failed
      └──────── Cancelled
      │
      ▼
Redirect To Callback
      │
      ▼
Verify Payment

---

Current Capabilities

• Clean Architecture
• REST API
• Blazor Server UI
• Swagger
• In-Memory Storage
• Callback Support
• Payment Verification
• Reference Number Generation
• Payment Timestamp
• Payment Status Management

---

Project Structure

PaymentTestGateway
│
├── src
│   ├── PaymentTestGateway.Web
│   │
│   ├── PaymentTestGateway.Application
│   │
│   ├── PaymentTestGateway.Domain
│   │
│   └── PaymentTestGateway.Infrastructure
│
├── docs
│
├── samples
│
└── assets

---

Architecture

Presentation
     │
     ▼
Application
     │
     ▼
Domain
     │
     ▼
Infrastructure

---

API

Create Payment

POST /api/payment/create

Request

{
  "amount": 400,
  "description": "Test Payment",
  "callbackUrl": "https://your-app.com/payment/callback"
}

Response

{
  "paymentId": "xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx",
  "paymentUrl": "/pay/xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx"
}

---

Update Payment Status

Success

POST /api/payment/{paymentId}/success

Failed

POST /api/payment/{paymentId}/failed

Cancelled

POST /api/payment/{paymentId}/cancel

---

Verify Payment

POST /api/payment/verify

Request

{
  "paymentId": "xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx"
}

Successful Response

{
  "paymentId": "...",
  "status": 1,
  "amount": 400,
  "referenceNumber": "204988438307",
  "paidAt": "2026-07-13T12:20:00Z",
  "isSuccessful": true
}

---

User Interface

Payment Page

/pay/{paymentId}

Displays

• Payment Id
• Amount
• Description

Actions

• Successful Payment
• Failed Payment
• Cancel Payment

---

Payment Result

/payment-result/{paymentId}

Displays

• Current Status
• Payment Id
• Amount
• Description
• Return To Application

---

Getting Started

Clone repository

git clone https://github.com/peymanpro/PaymentTestGateway.git

Go to project

cd PaymentTestGateway

Run application

dotnet run --project src/PaymentTestGateway.Web

Swagger

http://localhost:5031/swagger

---

Current Version

v1.0.0

This version provides a complete MVP payment gateway simulation suitable for local development and integration testing.

---

Roadmap

v1.1

Business Rules

• Prevent duplicate payment
• Payment expiration
• Better error codes
• Idempotent payment operations

---

v1.2

Persistence

• Entity Framework Core
• PostgreSQL
• Payment Repository
• Migration Support

---

v1.3

Quality

• Unit Tests
• Integration Tests
• GitHub Actions
• Code Coverage

---

v1.4

Operations

• Docker
• Docker Compose
• Health Checks
• Structured Logging

---

v2.0

Advanced Gateway Features

• Webhook Notifications
• Merchant Management
• JWT Authentication
• Rate Limiting
• OpenTelemetry
• Metrics
• Admin Dashboard

---

Planned Ecosystem

This project is planned to be used by other repositories in this portfolio.

Enterprise Portfolio

PaymentTestGateway
        ▲
        │
        │
Enterprise Microservices Shop
        │
        ├── Identity Service
        ├── Order Service
        ├── Inventory Service
        ├── Payment Service
        └── Notification Service

RabbitMQ Saga Demo

GraphQL API

ML.NET Recommendation Engine

---

Design Goals

• Clean Architecture
• SOLID Principles
• Enterprise-ready Design
• Reusable Components
• Simple Integration
• Developer Friendly

---

License

MIT License

---

Contributing

Issues, discussions, feature requests and pull requests are welcome.

---

Support

If this project helps you, consider giving it a ⭐ on GitHub.