Python Live #185 featuring GraphQL with Strawberry and FastAPI

GraphQL is a query language for APIs that allows clients to request exactly the data they need, making it more flexible than traditional REST APIs. In this tutorial, we will explore how to create a GraphQL API using Strawberry and FastAPI, two popular Python frameworks.

Strawberry is a new GraphQL library for Python that is designed to be easy to use and intuitive. FastAPI is a modern web framework for building APIs with Python that is known for its high performance and ease of use.

Before we dive into the tutorial, make sure you have Python installed on your machine. You can install it by downloading it from the official website or using a package manager like Homebrew on macOS or Chocolatey on Windows.

Once you have Python installed, you can create a new virtual environment for our project by running the following command:

python3 -m venv venv

Next, activate the virtual environment by running the following command:

source venv/bin/activate

Now that we have our virtual environment set up, let’s install the necessary packages for our project:

pip install fastapi uvicorn strawberry-graphql

Now that we have everything installed, let’s create a new file called main.py and add the following code:

from fastapi import FastAPI
from strawberry.asgi import GraphQL

import strawberry

app = FastAPI()

@strawberry.type
class Query:
    hello: str = "Hello, World!"

schema = strawberry.Schema(query=Query)

@app.get("/")
def index():
    return {"message": "Welcome to the GraphQL API"}

app.add_route("/graphql", GraphQL(schema))

In this code, we are creating a simple FastAPI application with a single route that returns a welcome message. We are also defining a GraphQL schema with a single query field called hello that returns a string.

To run the application, simply execute the following command:

uvicorn main:app --reload

This will start the FastAPI server, and you should see a message indicating that the server is running. You can now navigate to http://localhost:8000 in your browser to see the welcome message.

To test the GraphQL API, you can use tools like GraphiQL or GraphQL Playground. Simply navigate to http://localhost:8000/graphql in your browser to access the GraphQL Playground.

In the Playground, you can enter queries to interact with the GraphQL API. For example, you can run the following query to retrieve the value of the hello field:

query {
  hello
}

This should return the response {"data":{"hello":"Hello, World!"}}, indicating that the query was successful.

This is just a simple example of how to create a GraphQL API using Strawberry and FastAPI. You can expand on this example by adding more query fields, mutations, and types to create a more complex API.

I hope this tutorial has been helpful in getting you started with GraphQL and Strawberry. If you have any questions or run into any issues, feel free to reach out for help. Happy coding!