🔗 Node.js URL Shortener

A URL shortening service built with Node.js, Express, and MongoDB. It generates short links that redirect to the original long URLs, tracks visit history per link, and supports authenticated, role-based link management (Normal / Admin).

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✨ Features

• 🔐 Authentication — JWT-based signup, login, and logout
• ✂️ Short Link Generation — Unique short IDs via nanoid
• 🔁 Redirection — Fast redirects from short link to original URL
• 📊 Visit Tracking — Timestamp, IP, and user recorded per visit
• 👤 Per-User Management — Users manage only the links they created
• 🛡️ Role-Based Access — Separate NORMAL and ADMIN views
• 🎨 Server-Rendered UI — EJS templates with custom CSS

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🛠️ Tech Stack

Layer	Technology
Runtime	Node.js
Framework	Express.js
Database	MongoDB (Mongoose)
Auth	JWT + cookie-parser
Templating	EJS
Short ID	nanoid
Config	dotenv

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📁 Project Structure

Public/          # Static assets (CSS, JS, images)
controller/      # Route handler / business logic
middleware/      # Auth & request middleware
model/           # Mongoose schemas (Url, User)
routes/          # Express route definitions
service/         # Supporting business logic
views/           # EJS templates
index.js         # App entry point — wires middleware, DB, routes
connection.js    # MongoDB connection helper
.env.example     # Sample environment variables

index.js initializes the database connection and middleware, then mounts routes; routes/ map paths to controller/ handlers, which use the model/ schemas and render views/.

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⚙️ Getting Started

Prerequisites

• Node.js (v16+)
• A MongoDB instance (local or Atlas)

Installation

git clone https://github.com/Aman-20/nodejs-url-shortener.git
cd nodejs-url-shortener
npm install
cp .env.example .env   # then fill in the values below
npm start

The server runs on PORT (default 3000) — visit http://localhost:3000 or your configured DOMAIN_NAME.

Environment Variables

Variable	Description
MONGO_URL	MongoDB connection string
JWT_SECRET	Secret used to sign/verify auth tokens
DOMAIN_NAME	Base URL used to build/display short links
PORT	Server port (optional, default 3000)

The MongoDB connection uses database name Auth1 (set in connection.js) unless overridden.

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🔌 API Routes

Authentication middleware runs globally; /url requires NORMAL or ADMIN, and /admin requires ADMIN.

Method	Endpoint	Access	Description
POST	/user/signup	Public	Register a new user
POST	/user/login	Public	Authenticate a user
GET	/user/logout	Authenticated	Log out the current user
GET	/url	Normal/Admin	List short URLs created by the logged-in user
POST	/url	Normal/Admin	Create a short URL from a submitted long URL
POST	/url/delete/:id	Normal/Admin	Delete a short URL (only if owned by the user)
GET	/u/:id	Public	Redirect to the long URL; logs a visit record
GET	/admin	Admin	View all shortened URLs across users

Example — create a short URL

curl -X POST -d "url=https://example.com" http://localhost:3000/url

On success, the app redirects to /url/?id=<short> to display the newly created link.

Example — visit a short URL

curl -L http://localhost:3000/u/<short>

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🗃️ Data Model — Url

Field	Type	Description
short	String	Unique short code
long	String	Original long URL
history	[{ timestamp, ip, user }]	Visit log per short link
createdBy	ObjectId (ref: User)	Owner of the link
timestamps	—	createdAt / updatedAt auto-managed

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⚠️ Known Limitations

• Short IDs (nanoid(6)) aren't retried on collision — a duplicate ID could throw a uniqueness error under rare conditions.
• Submitted URLs aren't validated/sanitized (e.g., no scheme check or SSRF protection).
• Most endpoints render EJS views/redirects rather than returning JSON.

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🚀 Potential Improvements

• Retry logic for short ID collisions
• Input validation & URL sanitization
• Optional JSON API mode for external consumers
• Click analytics dashboard (referrer, device, location)
• Link expiration & custom aliases

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📄 License

ISC

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👤 Author

Aman GitHub: @Aman-20