Invoice API

A simple REST API for managing invoices, built with Python and FastAPI.

Tech Stack

• Backend: FastAPI (Python)
• Database: PostgreSQL
• ORM: SQLAlchemy
• Frontend: HTML, CSS, JavaScript

What I Learned

This project covers the core concepts of web development:

Concept	What It Does
REST API	GET, POST, PUT, DELETE operations
Database	Store data permanently with PostgreSQL
ORM	Talk to database using Python (SQLAlchemy)
Frontend	Display data and handle user interactions

API Endpoints

Method	Endpoint	Description
GET	/invoices	List all invoices
GET	/invoices/{id}	Get one invoice
POST	/invoices	Create new invoice
PUT	/invoices/{id}	Update invoice
DELETE	/invoices/{id}	Delete invoice

Project Structure

invoice-api/
├── main.py       # API endpoints
├── database.py   # Database connection
├── models.py     # Database tables (SQLAlchemy)
├── schemas.py    # Request/Response shapes (Pydantic)
├── index.html    # Frontend UI
└── README.md

How to Run

1. Install dependencies:

pip install fastapi uvicorn sqlalchemy psycopg2-binary

2. Start PostgreSQL and create database:

createdb invoice_db

3. Run the API:

uvicorn main:app --reload

4. Open index.html in browser or visit http://localhost:8000/docs

Screenshots

API Docs: http://localhost:8000/docs