So, even with the code above that doesn't use Pydantic explicitly, FastAPI is using Pydantic to convert those standard dataclasses to Pydantic's own flavor of dataclasses.

And of course, it supports the same:

* data validation
* data serialization

</div>

It will also auto-sort all your imports.

For it to sort them correctly, you need to have FastAPI installed locally in your environment, with the command in the section above using `-e`.

## Docs

First, make sure you set up your environment as described above, that will install all the requirements.

### Docs live

During local development, there is a script that builds the site and checks for any changes, live-reloading:

## Learn More

You can learn more about **GraphQL** in the <a href="https://graphql.org/" class="external-link" target="_blank">official GraphQL documentation</a>.

In all the docs there are examples compatible with each version of Python (when there's a difference).

For example "**Python 3.6+**" means it's compatible with Python 3.6 or above (including 3.7, 3.8, 3.9, 3.10, etc). And "**Python 3.9+**" means it's compatible with Python 3.9 or above (including 3.10, etc).

### Disable Response Model

Continuing from the example above, you might not want to have the default data validation, documentation, filtering, etc. that is performed by FastAPI.

### Technical Details: `root_path`

When you mount a sub-application as described above, FastAPI will take care of communicating the mount path for the sub-application using a mechanism from the ASGI specification called a `root_path`.

That way, the sub-application will know to use that path prefix for the docs UI.

## Recap

* Import `FastAPI`.
* Create an `app` instance.
* Write a **path operation decorator** (like `@app.get("/")`).
* Write a **path operation function** (like `def root(): ...` above).

The TLS Termination Proxy would have access to one or more **TLS certificates** (HTTPS certificates).

Using the **SNI extension** discussed above, the TLS Termination Proxy would check which of the TLS (HTTPS) certificates available it should use for this connection, using the one that matches the domain expected by the client.

At first, it didn't have an automatic API documentation web UI, but I knew I could add Swagger UI to it.

It had a dependency injection system. It required pre-registration of components, as other tools discussed above. But still, it was a great feature.

=== "Python 3.8 and above"

    ```Python hl_lines="3  17"
    {!> ../../../docs_src/path_operation_configuration/tutorial001.py!}
    ```

=== "Python 3.9 and above"

    ```Python hl_lines="3  17"
    {!> ../../../docs_src/path_operation_configuration/tutorial001_py39.py!}
    ```

=== "Python 3.10 and above"

    ```Python hl_lines="1  15"