A RESTful API for managing a library system with Authors and Books, built using TypeScript and Express.
This project demonstrates CRUD operations, input validation, error handling, and basic logging middleware.
- Create, Read, Update, Delete Authors
- Create, Read, Update, Delete Books
- List all books by a specific author (
GET /authors/:id/books) - Input validation (rejects invalid or missing fields)
- Centralized error handling (400, 404, 409, 500)
- Logging middleware (logs HTTP method + URL)
- Optional: filtering, searching, sorting, and pagination for books
library-api/
│
├─ src/
│ ├─ index.ts # Entry point
│ ├─ routes/
│ │ ├─ authors.ts
│ │ └─ books.ts
│ ├─ models/
│ │ ├─ author.ts
│ │ └─ book.ts
│ ├─ middleware/
│ │ ├─ logger.ts
│ │ ├─ validation.ts
│ │ └─ errorHandler.ts
│ └─ utils/
│ └─ ApiError.ts
│
├─ package.json
├─ tsconfig.json
└─ README.md
- Clone the repository:
git clone https://github.com/your-username/library-api.git
cd library-api- Install dependencies:
npm install- Start development server:
npm run devServer will run at http://localhost:3000.
- Build for production:
npm run build
npm start| Method | Endpoint | Description |
|---|---|---|
| POST | /authors |
Create a new author |
| GET | /authors |
List all authors |
| GET | /authors/:id |
Get author by ID |
| PUT | /authors/:id |
Update author by ID |
| DELETE | /authors/:id |
Delete author (also deletes their books) |
| GET | /authors/:id/books |
List all books for an author |
| Method | Endpoint | Description |
|---|---|---|
| POST | /books |
Create a new book |
| GET | /books |
List all books (supports filtering, sorting, pagination) |
| GET | /books/:id |
Get book by ID |
| PUT | /books/:id |
Update book by ID |
| DELETE | /books/:id |
Delete book |
Create Author
POST /authors
{
"name": "Chinua Achebe",
"bio": "Nigerian novelist",
"birthYear": 1930
}Create Book
POST /books
{
"title": "Things Fall Apart",
"authorId": 1,
"year": 1958,
"summary": "Classic novel"
}- 400 Bad Request – Invalid or missing fields
- 404 Not Found – Resource does not exist
- 409 Conflict – Duplicate book for the same author
- 500 Internal Server Error – Unexpected server error
Example response:
{
"error": "Invalid book: 'authorId' is required and must be a number"
}- Test API using Postman or curl.
- Example curl request:
curl -X POST http://localhost:3000/authors \
-H "Content-Type: application/json" \
-d '{"name":"Chinua Achebe","bio":"Nigerian novelist","birthYear":1930}'- Data is stored in-memory, so all authors and books will reset when the server restarts.
- All endpoints are JSON only.
- Logging middleware prints HTTP method + URL + timestamp in console.
MIT License