FastAPI To-Do List API

A REST API built with FastAPI that allows users to register, log in, and manage their own tasks. Each user can only view and manage tasks they created. Tasks are stored in a local SQLite database using SQLModel.

Features

• User registration and login
• JWT-based authentication
• Per-user task isolation
• Add, view, update, and delete tasks
• SQLite storage via SQLModel
• Input validation using Pydantic
• HTTP error handling

Installation

Clone the repository:

git clone https://github.com/cosmos-creator/Basic-FastAPI-ToDo-List-API.git
cd Basic-FastAPI-ToDo-List-API

Install dependencies:

pip install fastapi uvicorn sqlmodel passlib[bcrypt] python-jose[cryptography] python-dotenv python-multipart

Set up your .env file:

SECRET_KEY=your_secret_key_here

Running the API

uvicorn main:app --reload

Available at http://127.0.0.1:8000 — interactive docs at http://127.0.0.1:8000/docs

API Endpoints

Auth

POST /register — Create a new account

{
    "username": "cosmos-creator",
    "password": "yourpassword"
}

POST /login — Returns a JWT token (use the Authorize button in /docs)

Tasks (require authentication)

GET / — Returns all tasks belonging to the logged-in user

POST /add — Add a new task

{
    "name": "Finish project",
    "description": "Complete FastAPI To-Do API"
}

PUT /update/{id} — Update an existing task by ID

{
    "name": "Updated task name",
    "description": "Updated description"
}

DELETE /delete?id=1 — Delete a task by ID (only if it belongs to you)

Authentication Flow

1. Register via POST /register
2. Log in via the Authorize button in /docs
3. All task routes are protected — requests without a valid token are rejected with 401

Error Handling

Status	Reason
401	Invalid credentials or missing/expired token
403	Attempting to modify another user's task
404	Task not found
409	Username already taken

Technologies Used

• Python
• FastAPI
• SQLModel
• SQLite
• JWT (python-jose)
• passlib (bcrypt)

Purpose

Built as a learning project to practice:

• REST API development
• JWT authentication
• Database integration with SQLModel
• Dependency injection
• Per-user data isolation