File responses in FastAPI - Mini Project: Build & Apply

Serving a File with FastAPI

📖 Scenario: You are building a simple web service that sends a file to users when they visit a specific URL. This is useful for sharing documents, images, or any downloadable content.

🎯 Goal: Create a FastAPI app that serves a file called example.txt located in the project folder when a user visits the /download URL.

📋 What You'll Learn

Create a FastAPI app instance named app

Create a file named example.txt with the exact content: Hello, FastAPI file response!

Add a route /download that returns the file example.txt using FastAPI's FileResponse

Ensure the file is served with the correct media type and filename

💡 Why This Matters

🌍 Real World

Web services often need to send files like reports, images, or documents to users. FastAPI's FileResponse makes this easy and efficient.

💼 Career

Backend developers use FastAPI to build APIs that serve files securely and quickly. Knowing how to serve files is a common task in web development jobs.

1

Create the file example.txt

Create a file named example.txt in your project folder with the exact content: Hello, FastAPI file response!

FastAPI

# Create the file example.txt with the specified content

Need a hint?

Use a text editor or Python code to create example.txt with the exact text inside.

2

Create a FastAPI app instance

Write code to import FastAPI from fastapi and create an app instance named app.

FastAPI

from fastapi import FastAPI

# Create the FastAPI app instance named app
# Your code here

Need a hint?

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

3

Import FileResponse and add the /download route

Import FileResponse from fastapi.responses. Then add a route /download using @app.get("/download") that returns FileResponse("example.txt").

FastAPI

from fastapi.responses import FileResponse

# Add the /download route below
# Your code here

Need a hint?

Use FileResponse to send the file with correct media type text/plain and filename example.txt.

4

Complete the FastAPI file response setup

Ensure the route function download_file is async and returns FileResponse with media_type="text/plain" and filename="example.txt".

FastAPI

# Verify the route function is async and returns FileResponse with correct parameters
# Your code here

Need a hint?

The function must be async and return the file response with the exact parameters.