10 FastAPI Best Practices

FastAPI is a modern, fast (high-performance), web framework for building APIs with Python 3.6+ based on standard Python type hints. It is one of the fastest Python frameworks available, allowing you to quickly and easily build robust APIs.

However, there are certain best practices that should be followed when using FastAPI. In this article, we will discuss 10 best practices for using FastAPI to ensure that your API is secure, efficient, and easy to use. We will also discuss how to use FastAPI to create a scalable and maintainable API.

1. Use a database

A database allows you to store and retrieve data quickly, which is essential for any application. It also helps keep your code organized and makes it easier to maintain.

Using a database with FastAPI can be done in several ways. You can use an ORM (Object Relational Mapping) library such as SQLAlchemy or Peewee to interact with the database. Alternatively, you can use raw SQL queries if you prefer.

No matter which approach you choose, using a database will help make your application more efficient and reliable.

2. Use dependency injection

Dependency injection allows you to easily inject dependencies into your code, making it easier to test and maintain. It also makes it easier to switch out different implementations of the same dependency without having to rewrite large chunks of code.

For example, if you have a database connection that needs to be used in multiple places throughout your application, you can use dependency injection to make sure that all of those places are using the same instance of the database connection. This way, you don’t have to worry about creating multiple connections or managing them separately.

3. Use an ORM

An ORM (Object Relational Mapper) is a tool that allows you to interact with your database in an object-oriented way. This means that instead of writing SQL queries, you can use objects and methods to query the database.

Using an ORM makes it easier to write code that interacts with the database, as well as making it more secure. It also helps keep your codebase organized and maintainable. Additionally, using an ORM will make it easier for other developers to understand your code.

4. Use automatic docs

Automatic docs allow you to quickly and easily generate documentation for your API, which makes it easier for developers to understand how to use the API. This is especially useful when working with a large team of developers who need to be able to access the same information quickly and efficiently. Additionally, automatic docs can help reduce the amount of time spent on manual documentation, freeing up more time for development.

5. Use automatic validation

When you use automatic validation, FastAPI will automatically validate the data that is sent to your API. This means that it will check if the data is in the correct format and meets any other requirements you have set for it. If the data does not meet these requirements, then FastAPI will return an error message instead of processing the request.

This helps ensure that only valid requests are processed by your API, which can help improve performance and reduce errors. It also makes it easier to debug problems since you know exactly what went wrong when a request fails.

6. Use automatic serialization

Serialization is the process of converting data from one format to another. In FastAPI, this means taking a Python object and turning it into JSON or XML so that it can be sent over the web.

Using automatic serialization makes your code more efficient by eliminating the need for manual coding. It also reduces errors since you don’t have to worry about writing custom serializers. Finally, it’s faster because the serialization happens automatically in the background.

7. Use automatic API docs

When you use automatic API docs, it makes your code easier to read and understand. It also helps other developers quickly get up to speed on how to use your API. This is especially important if you’re working with a team of developers or have an open source project that others can contribute to.

Using automatic API docs also ensures that all the endpoints are documented correctly and consistently. This reduces the amount of time spent manually writing documentation and increases the accuracy of the information provided. Finally, using automatic API docs allows for faster development cycles since changes can be made quickly without having to update the documentation every time.

8. Use automatic OpenAPI schemas

OpenAPI schemas are a great way to document your API and make it easier for developers to understand how to use it. FastAPI automatically generates OpenAPI schemas from the code you write, so you don’t have to manually create them yourself. This saves time and makes sure that your documentation is always up-to-date with your code. Additionally, having an OpenAPI schema can help you generate client libraries in different languages, making it easier for developers to integrate with your API.

9. Use standard Python types for data exchange

When you use standard Python types, such as strings, integers, and floats, for data exchange, it makes your code more readable and easier to debug. It also helps ensure that the data is valid before it’s sent or received. This reduces the risk of errors and makes it easier to maintain your API.

Additionally, using standard Python types allows you to take advantage of FastAPI’s built-in validation features. These features can help you quickly identify any issues with incoming requests and provide helpful error messages when something goes wrong.

10. Use the same type system in your app and your clients

When you use the same type system, it ensures that your app and clients are using the same data types. This makes it easier to debug any issues that may arise from mismatched data types. It also helps ensure that your API is consistent across all of its endpoints.

Using the same type system also allows for better code reuse. If you have a function or class that uses a certain type, you can easily reuse it in both your app and your client without having to worry about compatibility issues.