Router prefix and tags in FastAPI - Mini Project: Build & Apply

FastAPI Router Prefix and Tags

📖 Scenario: You are building a simple web API for a bookstore. You want to organize your routes using FastAPI routers. This helps keep your code clean and easy to manage.

🎯 Goal: Create a FastAPI router with a prefix and tags to group book-related endpoints. This will help users and developers understand the API structure better.

📋 What You'll Learn

Create a FastAPI router named book_router.

Set the router prefix to /books.

Add the tag Books to the router.

Define a GET endpoint / inside the router that returns a list of book titles.

Include the router in the main FastAPI app.

💡 Why This Matters

🌍 Real World

Organizing API routes with routers is common in real-world web applications to keep code clean and maintainable.

💼 Career

Understanding FastAPI routers, prefixes, and tags is essential for backend developers building scalable APIs.

1

Create the initial FastAPI app and router

Import FastAPI and APIRouter from fastapi. Create a FastAPI app called app and a router called book_router.

FastAPI

from fastapi import FastAPI, APIRouter

# Create the FastAPI app and router
# Your code here

Need a hint?

Use app = FastAPI() to create the app and book_router = APIRouter() to create the router.

2

Add prefix and tags to the router

Modify the book_router to have the prefix /books and the tags list containing Books.

FastAPI

from fastapi import FastAPI, APIRouter

app = FastAPI()
book_router = APIRouter()
# Add prefix '/books' and tags ['Books'] to book_router
# Your code here

Need a hint?

Pass prefix='/books' and tags=['Books'] as arguments when creating book_router.

3

Add a GET endpoint to the router

Inside book_router, define a GET endpoint at / that returns the list ["The Hobbit", "1984", "Python 101"]. Use the function name get_books.

FastAPI

from fastapi import FastAPI, APIRouter

app = FastAPI()
book_router = APIRouter(prefix='/books', tags=['Books'])

# Define GET endpoint '/' inside book_router
# Your code here

Need a hint?

Use @book_router.get('/') decorator and define def get_books(): that returns the list.

4

Include the router in the main app

Add the book_router to the main app using app.include_router(book_router).

FastAPI

from fastapi import FastAPI, APIRouter

app = FastAPI()
book_router = APIRouter(prefix='/books', tags=['Books'])

@book_router.get('/')
def get_books():
    return ["The Hobbit", "1984", "Python 101"]

# Include book_router in app
# Your code here

Need a hint?

Use app.include_router(book_router) to add the router to the app.