🏦 SECUREBANK — Bulletproof Core Banking API

SECUREBANK is a high-integrity, ledger-based core banking API designed for a 2-day hackathon. The system guarantees that money is never lost, duplicated, or partially applied—even under server crashes, malicious input, and extreme concurrency.

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🚀 Key Features

• Pure Ledger Architecture: Every balance change is backed by immutable Debit or Credit entries.
• Atomic Transfers: All-or-nothing transfers ensuring sender debit and receiver credit are perfectly synchronized.
• Idempotency Guards: Prevents duplicate processing via both header-based (Idempotency-Key) and intent-based workflows.
• Zero-Trust Security: Robust authentication using JWT and Refresh Tokens, with role-based access control (Admin/User).
• Concurrency Safety: Optimistic locking (RowVersion) prevents race conditions and double-spending.
• Automated Interest: Background jobs (Hangfire) to apply periodic interest to savings accounts.
• Full Auditability: Transparent transaction history allowing for full balance reconstruction.

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🏗️ Technical Architecture

The project follows Clean Architecture principles to ensure separation of concerns and maintainability:

• API: Entry point, middleware (Rate Limiting, Exception Handling), and controllers.
• Application: Core business logic, DTOs, interfaces, and service implementations.
• Domain: Pure entities, enums, and business invariants.
• Infrastructure: Persistence (EF Core), background jobs (Hangfire), and external services (CSV, Identity).

Technology Stack

• Framework: .NET 8.0
• Database: PostgreSQL (via EF Core)
• Background Jobs: Hangfire
• Authentication: JWT Bearer + Identity
• Documentation: Swagger/OpenAPI

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🛠️ Getting Started

Prerequisites

• .NET 8 SDK
• PostgreSQL

Setup

1. Clone the repository:

   git clone https://github.com/karar-hayder/ITS-SecureBank.git
   cd ITS-SecureBank

2. Configure Database: Update the DefaultConnection in API/appsettings.Development.json:

   "ConnectionStrings": {
     "DefaultConnection": "Host=localhost;Database=bank_db;Username=postgres;Password=your_password"
   }

3. Run Migrations:

   dotnet ef database update --project Infrastructure --startup-project API

4. Run the Application:

   dotnet run --project API

   The API will be available at http://localhost:5202 (or as configured). Swagger UI can be accessed at /swagger.

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📜 Documentation

For deeper architectural details, refer to:

• 📑 Workflow Documentation: Operational flows and sequence diagrams.
• 🗺️ Request Flow: Detailed pipeline and layer interaction.
• 🗄️ Database Schema: Entity Relationships and table definitions.

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👥 Core Team

This project, This Backend was developed for the hackathon by:

• Karar Haider - @karar-hayder
• Ali Mohammed - @NOT-Ali0

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🛡️ Core Banking Invariants

1. Money Conservation: Transfers have a net-zero effect.
2. Atomicity: Operations are all-or-nothing.
3. Consistency: Balances never go negative.
4. Isolation: Double spending is impossible.
5. Durability: Committed transactions survive any crash.

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Built for the ITS (Iraq Tech School) SecureBank Hackathon — Focused on Correctness, Resilience, and Clarity.