OpenAPI schema customization in FastAPI - Mini Project: Build & Apply

OpenAPI Schema Customization with FastAPI

📖 Scenario: You are building a simple web API using FastAPI. You want to customize the OpenAPI schema to provide a clear title, description, and version for your API documentation. This helps users understand what your API does and its current version.

🎯 Goal: Create a FastAPI app with a customized OpenAPI schema that includes a specific title, description, and version.

📋 What You'll Learn

Create a FastAPI app instance

Set the OpenAPI schema title to 'Book Store API'

Set the OpenAPI schema description to 'API for managing books in a store'

Set the OpenAPI schema version to '1.0.0'

Add a simple GET endpoint at '/' returning a welcome message

💡 Why This Matters

🌍 Real World

Customizing the OpenAPI schema helps API users understand the purpose and version of your API clearly, improving developer experience and documentation quality.

💼 Career

Many backend developer roles require building and documenting APIs. Knowing how to customize OpenAPI schemas with FastAPI is a valuable skill for creating professional APIs.

1

Create a FastAPI app instance

Write code to import FastAPI from fastapi and create a FastAPI app instance called app.

FastAPI

from fastapi import FastAPI

# Create the FastAPI app instance
# Your code here

Need a hint?

Use app = FastAPI() to create the app instance.

2

Customize OpenAPI schema with title, description, and version

Modify the FastAPI app creation to include title='Book Store API', description='API for managing books in a store', and version='1.0.0' as parameters.

FastAPI

from fastapi import FastAPI

# Create the FastAPI app with custom OpenAPI schema info
# Your code here

Need a hint?

Pass title, description, and version as arguments to FastAPI().

3

Add a GET endpoint at '/' returning a welcome message

Add a GET endpoint using @app.get("/") that returns a dictionary with the key message and value 'Welcome to the Book Store API!'.

FastAPI

from fastapi import FastAPI

app = FastAPI(
    title='Book Store API',
    description='API for managing books in a store',
    version='1.0.0'
)

# Add a GET endpoint at '/' returning a welcome message
# Your code here

Need a hint?

Use @app.get("/") decorator and define a function read_root that returns the dictionary.

4

Run the FastAPI app with customized OpenAPI schema

Add the code to run the FastAPI app using if __name__ == "__main__" block with import uvicorn and uvicorn.run(app, host="127.0.0.1", port=8000).

FastAPI

from fastapi import FastAPI

app = FastAPI(
    title='Book Store API',
    description='API for managing books in a store',
    version='1.0.0'
)

@app.get("/")
def read_root():
    return {"message": "Welcome to the Book Store API!"}

# Add code to run the app with uvicorn
# Your code here

Need a hint?

Use the standard Python entry point check and call uvicorn.run() with the app and host/port.