FastAPI Series 03 >> Routing and Endpoint Design

Table of Contents

In this blog post, we delve into the essentials of FastAPI routing and endpoint design, discussing best practices like RESTful principles, path parameters, and using the APIRouter class for organizing your endpoints. Master the art of creating clean, maintainable, and scalable FastAPI applications with these proven techniques.

Introduction

Now that you’ve built your first FastAPI API, it’s time to delve deeper into the world of FastAPI and explore one of its most important aspects: routing and endpoint design. In this blog post, we’ll discuss best practices for designing and organizing your API’s routes and endpoints to create a robust, maintainable, and scalable application.

Understanding FastAPI Routing

FastAPI provides a simple and intuitive way to define routes in your application, allowing you to map specific URL patterns to corresponding Python functions, called endpoints. These endpoints are responsible for handling incoming HTTP or HTTPS requests and returning appropriate responses. Let’s recap the basic syntax for defining a route in FastAPI:

@app.<http_method>("/<route_path>")
async def <endpoint_function>(<parameters>):
    <function_body>

In this syntax, <http_method> is the HTTP method (e.g., get, post, put, delete), <route_path> is the URL path, <endpoint_function> is the Python function handling the request, and are the optional parameters passed to the function.

Best Practices for Route Design

When designing routes for your FastAPI application, consider the following best practices to ensure a clean and maintainable codebase:

• Use RESTful principles: Structure your routes and endpoints around resources (e.g., /users, /products) and use standard HTTP methods (e.g., GET, POST, PUT, DELETE) to perform operations on these resources.

• Keep route paths simple and descriptive: Use clear and concise names for your routes to improve readability and maintainability.

• Utilize path parameters: FastAPI allows you to define path parameters within your route paths (e.g., /users/{user_id}) to create dynamic routes that can handle a variety of requests.

Organizing Endpoints with APIRouter

As your FastAPI application grows, managing a large number of routes and endpoints can become challenging. To help with this, FastAPI provides the APIRouter class, which allows you to modularize your endpoints and group them based on their functionality or resources. Here’s an example of how to use APIRouter to organize your endpoints:

1. Import the APIRouter class:

from fastapi import APIRouter

2. Create an instance of APIRouter:

user_router = APIRouter()

3. Define your endpoints using the APIRouter instance:

@user_router.get("/users")
async def get_users():
    <function_body>

@user_router.get("/users/{user_id}")
async def get_user(user_id: int):
    <function_body>

4. Include the APIRouter in your main FastAPI application:

app.include_router(user_router)

Example

from fastapi import FastAPI
from fastapi import APIRouter

app = FastAPI()
user_router = APIRouter()

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

@user_router.get("/users")
async def get_users():
    return {"get": "user"}

@user_router.get("/users/{user_id}")
async def get_user(user_id: int):
    return {"get": f"user{user_id}"}

app.include_router(user_router)

In this example, we use the user_router to manage the user related APIs.

http://127.0.0.1:8000/users

http://127.0.0.1:8000/users/123

Conclusion

In this blog post, we explored best practices for FastAPI routing and endpoint design, covering the fundamentals of route design, RESTful principles, path parameters, and how to use the APIRouter class for organizing your endpoints. By following these best practices, you can create a robust, maintainable, and scalable FastAPI application. Stay tuned for our next blog post, where we’ll dive into creating secure and reliable APIs with FastAPI’s authentication and authorization features.