Invoice Generation Service

This is a FastAPI application for generating and managing invoices. It allows you to create, read, update, and delete invoices without requiring user signup.

Features

• Generate invoices with automatic invoice number generation
• Store invoice details in SQLite database
• Retrieve invoice information by ID or invoice number
• Update invoice details and status
• Delete invoices
• Health check endpoint

Technical Stack

• Framework: FastAPI
• Database: SQLite with SQLAlchemy ORM
• Migrations: Alembic
• Validation: Pydantic
• Linting: Ruff

Project Structure

.
├── alembic.ini               # Alembic configuration file
├── app                       # Application package
│   ├── api                   # API routes
│   │   └── routes            # API route modules
│   │       ├── __init__.py   # Routes initialization
│   │       └── invoices.py   # Invoice routes
│   ├── core                  # Core functionality
│   │   ├── config.py         # Application settings
│   │   ├── database.py       # Database connection setup
│   │   └── utils.py          # Utility functions
│   ├── models                # SQLAlchemy models
│   │   ├── __init__.py       # Models initialization
│   │   └── invoice.py        # Invoice and InvoiceItem models
│   └── schemas               # Pydantic schemas
│       ├── __init__.py       # Schemas initialization
│       └── invoice.py        # Invoice-related schemas
├── main.py                   # Application entry point
├── migrations                # Alembic migrations
│   ├── env.py                # Alembic environment
│   ├── script.py.mako        # Migration script template
│   └── versions              # Migration scripts
│       └── ef0aaab3a275_initial_database_tables.py  # Initial migration
├── requirements.txt          # Project dependencies
└── pyproject.toml            # Ruff configuration

API Endpoints

Health Check

• GET /health: Check if the service is running

Invoice Management

• POST /api/v1/invoices: Create a new invoice
• GET /api/v1/invoices: List all invoices (with pagination)
• GET /api/v1/invoices/{invoice_id}: Get a specific invoice by ID
• POST /api/v1/invoices/find: Find an invoice by invoice number
• PATCH /api/v1/invoices/{invoice_id}: Update an invoice
• PATCH /api/v1/invoices/{invoice_id}/status: Update invoice status
• DELETE /api/v1/invoices/{invoice_id}: Delete an invoice

Setup and Installation

1. Clone the repository
2. Install dependencies:

   pip install -r requirements.txt
   

3. Run migrations:

   alembic upgrade head
   

4. Start the application:

   uvicorn main:app --reload
   

API Documentation

Once the application is running, you can access:

• Interactive API documentation at /docs (Swagger UI)
• Alternative API documentation at /redoc (ReDoc)

Invoice Number Format

Invoices are automatically assigned a unique invoice number with the format:

• INV-YYYYMM-XXXXXX, where:
  • INV is a fixed prefix
  • YYYYMM is the year and month (e.g., 202307 for July 2023)
  • XXXXXX is a random alphanumeric string