A simple Expense Tracking REST API built with FastAPI, SQLAlchemy, and SQLite.
It supports basic CRUD operations for Categories and Expenses, with validation handled by Pydantic schemas.

• Categories: create, list (with filters), get by ID, delete.
• Expenses: create (linked to categories), list (with filters + pagination), get by ID, delete.
• Validation with Pydantic (condecimal, regex, custom validators).
• SQLite + SQLAlchemy ORM integration.
• Pytest-based tests for categories and expenses.

• FastAPI — web framework
• SQLAlchemy — ORM for database
• SQLite — lightweight DB
• Pydantic — validation
• Pytest — testing

# Install dependencies
pip install -r requirements.txt

# Run dev server
uvicorn main:app --reload
Open API docs available at: http://127.0.0.1:8000/docs
pytest -v