Todo API

A scalable RESTful API built with FastAPI and PostgreSQL. This project demonstrates backend architecture using standard CRUD operations, database migrations and strict data validation.

Key Features

• Full CRUD Operations: Create, Read (All & By ID), Update and Delete tasks.
• Smart Updates: Implementation of PATCH method for partial updates (specifically for toggling the is_complete status).
• Due Dates: Implementation of datetime sorting to prioritize tasks.
• Subtasks: Relational mapping to allow nested tasks (One-to-Many).
• Data Validation: Strict schema validation using Pydantic V2.
• Database Persistence: robust data storage using PostgreSQL.
• ORM Layer: Clean database interaction using SQLAlchemy.
• Migrations: Database schema version control using Alembic.
• Modular Architecture: Codebase organized into distinct layers (Routers, CRUD, Models, Schemas) for maintainability.

Tech Stack

• Framework: FastAPI
• Database: PostgreSQL
• ORM: SQLAlchemy
• Migrations: Alembic
• Serialization/Validation: Pydantic
• Server: Uvicorn (ASGI)

Project Structure

This project follows a modular pattern to ensure scalability and separation of concerns:

├── alembic/                # Database migration scripts
├── crud/
│   └── todo_crud.py        # Database interaction logic (Create, Read, Update, Delete)
├── database/
│   └── connections.py      # Database session and connection setup
├── models/
│   └── todo_model.py       # SQLAlchemy database models
├── schema/
│   └── todo_schema.py      # Pydantic models for request/response validation
├── routers/
│   └── todo_router.py      # API Endpoint definitions
├── main.py                 # Application entry point
├── .env                    # Environment variables (Database credentials)
└── alembic.ini             # Alembic configuration

Getting Started

Follow these steps to set up the project locally.

Prerequisites

• Python 3.10+
• PostgreSQL installed and running

1. Clone the repository

git clone https://github.com/rhoda-lee/Todo-App.git
cd your-repo-name

2. Create a Virtual Environment

python -m venv venv
# Windows
venv\Scripts\activate
# Mac/Linux
source venv/bin/activate

3. Install Dependencies

pip install -r requirements.txt

4. Configure Environment Variables

Create a .env file in the root directory and add your PostgreSQL credentials:

DATABASE_URL=postgresql://username:password@localhost:5432/your_database_name

Note: Make sure to create the database in PostgreSQL before running migrations.

5. Run Database Migrations

Use Alembic to create the tables in your database:

alembic upgrade head

6. Run the Server

uvicorn main:app --reload

The API will be available at http://127.0.0.1:8000.

API Documentation

FastAPI provides automatic, interactive documentation. Once the server is running, visit:

• Swagger UI: http://127.0.0.1:8000/docs
• ReDoc: http://127.0.0.1:8000/redoc

Endpoints Overview

Method	Endpoint	Description
GET	/todos/	Retrieve all todo items
POST	/todos/	Create a new todo item
GET	/todos/{id}	Retrieve a specific item by ID
PATCH	/todos/{id}	Update an item (e.g., mark as done)
DELETE	/todos/{id}	Delete an item

Future Improvements

This project is currently in active development. Upcoming features include:

• Tagging System: Many-to-Many relationships for task categorization.

Author

Rhoda Oduro-Nyarko

• GitHub Profile
• LinkedIn Profile

Built with ❤️ using Python and FastAPI.