Project_25

🔗 Project 25 – URL Shortener API (FastAPI + MongoDB)

A fully functional URL Shortener built with FastAPI and MongoDB.
This API converts long URLs into short, shareable tokens and automatically redirects users when they visit the short link.

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🧰 Tech Stack

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✨ Features

Feature	Description
🧾 Shorten URLs	Converts long URLs into 10-character short tokens
🔁 Redirect	Automatically redirects users to the original link
🔐 Unique Tokens	Uses secure random generator from Python’s secrets
💾 Database	Stores URL-token pairs in MongoDB
⚡ Quick Docs	/ route redirects directly to FastAPI Docs

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🧱 Project Structure

Project_25_URL_Shortener_API/
│
├── main.py
├── requirements.txt
└── .env

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⚙️ Setup Guide

1️⃣ Clone Repository

git clone https://github.com/yourusername/url-shortener-api.git
cd url-shortener-api

2️⃣ Create Virtual Environment

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

3️⃣ Install Dependencies

pip install -r requirements.txt

4️⃣ Setup Environment Variable

Create a .env file:

MONGO_URI=mongodb+srv://your_user:password@cluster-url/

5️⃣ Run Server

uvicorn main:app --reload

Visit 👉 http://127.0.0.1:8000/docs

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🔹 API Endpoints

Method	Route	Description
GET	/	Redirects to API Docs
POST	/short	Shorten a URL
GET	/{token}	Redirects to original URL

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🧩 Usage Examples

➕ Create Short URL

POST /short

{
  "url": "https://www.python.org/downloads/release/python-3110/"
}

✅ Response:

{
  "status": 200,
  "message": "recorded",
  "url": "http://localhost:8000/Zx9AB12kLm"
}

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🔁 Redirect

Open your browser:

http://localhost:8000/Zx9AB12kLm

You’ll be redirected instantly to the original link.

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⚙️ How It Works

┌───────────────┐
│  Long URL     │
└──────┬────────┘
       │
       ▼
[ FastAPI POST /short ]
       │
  Generates Random Token
       │
  Saves {token:url} in MongoDB
       │
       ▼
Returns short link → /{token}
       │
       ▼
[ GET /{token} → Redirects user ]

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🧠 Concepts Practiced

• Working with secrets & string modules for random tokens
• Using MongoDB CRUD with PyMongo
• Redirecting with RedirectResponse
• Input validation using Pydantic
• Safe error handling and try-catch patterns

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📄 requirements.txt

fastapi==0.117.1
uvicorn==0.37.0
pymongo==4.15.1
python-dotenv==1.1.1
pydantic==2.11.9

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🪄 Future Enhancements

• Add analytics (click count, timestamp, IP)
• Add expiration date for short links
• Add custom aliases (user-defined tokens)
• Create web frontend to generate short links

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👨‍💻 Credits

Developed by: Pinaka Course: CodeShiksha – Python Bhasha Mastery Year: © 2025