FastAPI Tutorial: Build a REST API from scratch in 3 minutes

FastAPI is a modern, fast (high-performance), web framework for building APIs with Python 3.7+ based on standard Python type hints. It’s easy to use, simple, and very fast. In this tutorial, we will learn how to build a REST API from scratch using FastAPI in just 3 minutes!

Step 1: Install FastAPI

First, we need to install FastAPI using pip:

pip install fastapi

Step 2: Create a FastAPI Application

Now, let’s create a simple FastAPI application:


import fastapi
app = fastapi.FastAPI()


Step 3: Define an API Endpoint

Let’s define a simple API endpoint that returns “Hello, World!” when accessed:


@app.get("/")
def read_root():
return {"Hello": "World"}


Step 4: Run the FastAPI Application

Finally, let’s run our FastAPI application:


import uvicorn
uvicorn.run(app, host="0.0.0.0", port=8000)


Step 5: Test the API

Now, open your web browser and go to http://localhost:8000. You should see the following output:


{"Hello": "World"}


Congratulations! You have successfully built a REST API using FastAPI in just 3 minutes!

FastAPI is an amazing framework that makes it incredibly easy to build high-performance APIs with Python. I hope this tutorial has been helpful in getting you started with FastAPI. Happy coding!