💰 Expense Tracker API (SaaS MVP)

A professional, scalable Expense Tracking SaaS Backend built with .NET 9, following the principles of Clean Architecture and Domain-Driven Design (DDD). Designed to be the robust core for a modern financial management dashboard.

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🏗️ Architecture

This project is structured around the Dependency inversion principle, ensuring the core domain logic is decoupled from external frameworks and UI.

graph TD;
    API[Presentation Layer (API)] --> Application;
    Infrastructure --> Application;
    Application --> Domain;
    Infrastructure --> Domain;

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Layers Breakdown

• ExpenseTracker.Domain: The heart of the system. Contains Entities, Enums, and Repository Interfaces. No dependencies.
• ExpenseTracker.Application: Business logic, DTOs, Validators, and Service Interfaces. Orchestrates data flow.
• ExpenseTracker.Infrastructure: Implementation of data access (EF Core), external services, and repositories.
• ExpenseTracker.API: The entry point. Controllers, Middleware, and Dependency Injection configuration.

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🚀 Tech Stack & Features

• Core: .NET 9.0, C# 12
• Data Access: Entity Framework Core, Repository Pattern
• Database: MySQL 8.0
• Validation: FluentValidation
• Mapping: AutoMapper
• Logging: Serilog (Structured Logging)
• Documentation: Swagger / OpenAPI (with JWT Auth support)
• Authentication: JWT (JSON Web Tokens) with Refresh Tokens
• Security: BCrypt hashing, CORS policies, Exception Handling Middleware

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🛠️ Getting Started

Prerequisites

• .NET 9.0 SDK
• MySQL Server

Installation (The Easy Way 🐳)

Pre-requisite: Make sure you have Docker and Docker Compose installed.

1. Clone the repository

   git clone https://github.com/your-username/ExpenseTracker.git
   cd ExpenseTracker

2. Run with Docker Compose

   docker-compose up --build

3. Access the App

   • Frontend: http://localhost:3000
   • API Swagger: http://localhost:5062/swagger

   Note: If running for the first time, you may need to apply migrations manually or simply let the API initialize.

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Installation (Manual Way)

1. Configure Database Update appsettings.json or preferably use User Secrets:

   "ConnectionStrings": {
     "DefaultConnection": "Server=localhost;Port=3306;Database=ExpenseTrackerDb;User=root;Password=YOUR_STRONG_PASSWORD;"
   }

2. Run Migrations

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

3. Run the API

   dotnet run --project ExpenseTracker.API

4. Explore Navigate to https://localhost:7139/swagger to view the interactive API documentation.

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🧪 Testing

The solution includes a dedicated test project ExpenseTracker.Tests using xUnit and FluentAssertions.

dotnet test

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🔮 Future Roadmap

• Docker Support: Containerize the API and Database.
• CI/CD Pipeline: GitHub Actions for automated testing and deployment.
• Role-Based Access Control (RBAC): Admin vs User roles.
• Reporting Service: Background jobs for generating monthly PDF reports.

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Developed by Adham - Backend Engineer