Library Management System – Backend API

A RESTful backend for a Library Management System with role-based authentication for Librarians and Members.

Features

• JWT-based authentication
• Role-based access control (Librarian / Member)
• Book management (CRUD) — Librarian only
• Member management — Librarian only
• Borrow / Return books — Member only
• Input validation using express-validator
• Centralized error handling

Tech Stack

• Node.js + Express.js
• MongoDB + Mongoose
• JWT (jsonwebtoken)
• bcrypt
• express-validator

Project Structure

library-management-system/
├── config/
│   └── db.js
├── controllers/
│   ├── authController.js
│   ├── bookController.js
│   └── memberController.js
├── middleware/
│   ├── authMiddleware.js
│   ├── roleMiddleware.js
│   └── errorMiddleware.js
├── models/
│   ├── User.js
│   ├── Book.js
│   └── Borrow.js
├── routes/
│   ├── authRoutes.js
│   ├── bookRoutes.js
│   └── memberRoutes.js
├── validators/
│   └── validationRules.js
├── .env
├── server.js
└── package.json

Installation & Setup

1. Clone the repository

git clone https://github.com/Pavanakv/Library-Management-System.git
cd library-management-system

2. Install dependencies

npm install

3. Create a .env file in the root with the following variables:

PORT=5000
DATABASE_URL=your_mongodb_connection_string
JWT_SECRET=your_jwt_secret_key

4. Run the server

npm run dev

Server will start on http://localhost:5000

Database Setup

This project uses MongoDB. You can use either:

• A local MongoDB instance, or
• MongoDB Atlas (cloud)

Three collections are created automatically by Mongoose on first use:

• users — stores both members and librarians
• books — stores book inventory
• borrows — stores borrow/return records

Note: Librarian accounts cannot be created via the API. They must be inserted directly into the database with a bcrypt-hashed password and role: "librarian".

API Documentation

Auth Routes

Method	Endpoint	Access	Description
POST	/api/auth/register	Public	Register as a member
POST	/api/auth/login	Public	Login (member or librarian)

Book Routes

Method	Endpoint	Access	Description
POST	/api/books	Librarian	Add a new book
GET	/api/books	Authenticated	Get all books
GET	/api/books/:id	Authenticated	Get book details
PUT	/api/books/:id	Librarian	Update book
DELETE	/api/books/:id	Librarian	Delete book
POST	/api/books/:id/borrow	Member	Borrow a book
POST	/api/books/:id/return	Member	Return a book

Member Routes

Method	Endpoint	Access	Description
GET	/api/members	Librarian	Get all members
DELETE	/api/members/:id	Librarian	Delete a member
GET	/api/members/me/books	Member	Get logged-in member's borrowed books

Authentication Flow

1. Member registers via /api/auth/register (role is always set to member)
2. User logs in via /api/auth/login, receives a JWT token
3. Token must be sent in the Authorization header as Bearer <token> for all protected routes
4. authMiddleware.js verifies the token and attaches the user to req.user
5. roleMiddleware.js checks req.user.role against the allowed roles for that route

Deployment

Live API URL: https://library-management-system-h8xl.onrender.com

Author

Pavana K V