TransactionAnalysis

A full-stack demo banking application that simulates core financial operations: user registration, secure login, account creation, deposits, withdrawals, transfers and transaction history. It was built to practise layered backend design (controllers, services, repositories, EF Core migrations) alongside a typed React front end. It uses a local SQLite database and holds no real financial data.

Stack

• Backend: ASP.NET Core Web API on .NET 9, Entity Framework Core 9 with SQLite and migrations, JWT bearer authentication, DotNetEnv for .env loading
• Frontend: React 19, TypeScript, Vite, Tailwind CSS, React Router, TanStack Query, Axios
• Tests: xUnit with Microsoft.AspNetCore.Mvc.Testing integration tests (backend/test)

Running

You need the .NET 9 SDK and Node.js. Use two terminals from the repository root.

Backend (applies migrations and creates backend/bank.db on first start):

cd backend
dotnet run

Frontend:

cd frontend
npm install
npm run dev

Create frontend/.env so the app knows where the API lives:

VITE_API_BASE_URL=http://localhost:5000
VITE_FRONTEND_URL=http://localhost:5173

The backend allows CORS from http://localhost:5173. JWT settings come from the Jwt section of backend/appsettings.json; the key there is a placeholder, so override it with a long random value through the Jwt__Key environment variable (or a git-ignored .env) for anything beyond local use. EnableDetailedLogging in .env toggles verbose logging.

Run the tests:

cd backend/test
dotnet test

API overview

Area	Routes
Auth	POST /api/auth/register, POST /api/auth/login
Users	/api/users (create, update, delete, get by id, info by username, list)
Accounts	/api/accounts (new, get, list, delete, {id}/deposit, {id}/withdraw, transfer)
Transactions	/api/transactions (new, get, list, delete, per-account history)

Project layout

backend/
  api/          controllers, DTOs, options
  service/      business logic (interfaces + impl)
  repository/   data access (interfaces + impl)
  domain/ data/ domain models, EF Core context and entities
  Migrations/   EF Core migrations
  test/         integration tests
frontend/src/   pages, components, contexts, API service
Bank.sln