required: true
        - label: I already searched in Google "How to X in FastAPI" and didn't find any information.
          required: true
        - label: I already read and followed all the tutorial in the docs and didn't find an answer.
          required: true
        - label: I already checked if it is not related to FastAPI but to [Pydantic](https://github.com/pydantic/pydantic).
          required: true

# Extending OpenAPI

There are some cases where you might need to modify the generated OpenAPI schema.

In this section you will see how.

## The normal process

The normal (default) process, is as follows.

A `FastAPI` application (instance) has an `.openapi()` method that is expected to return the OpenAPI schema.

For "synchronous" (contrary to "asynchronous") they commonly also use the term "sequential", because the computer / program follows all the steps in sequence before switching to a different task, even if those steps involve waiting.

### Concurrency and Burgers

Let's now see the file `sql_app/models.py`.

### Create Peewee models for our data

Now create the Peewee models (classes) for `User` and `Item`.

This is the same you would do if you followed the Peewee tutorial and updated the models to have the same data as in the SQLAlchemy tutorial.

!!! tip
    Peewee also uses the term "**model**" to refer to these classes and instances that interact with the database.

                """
            ),
            deprecated(
                """
                "openapi_prefix" has been deprecated in favor of "root_path", which
                follows more closely the ASGI standard, is simpler, and more
                automatic.
                """
            ),
        ] = "",
        root_path: Annotated[
            str,
            Doc(

    ```

=== "Python 3.8+"

    ```Python hl_lines="18"
    {!> ../../../docs_src/body/tutorial004.py!}
    ```

The function parameters will be recognized as follows:

* If the parameter is also declared in the **path**, it will be used as a path parameter.
* If the parameter is of a **singular type** (like `int`, `float`, `str`, `bool`, etc) it will be interpreted as a **query** parameter.

COPY ./requirements.txt /app/requirements.txt

RUN pip install --no-cache-dir --upgrade -r /app/requirements.txt

COPY ./app /app
```

### Bigger Applications

If you followed the section about creating [Bigger Applications with Multiple Files](../tutorial/bigger-applications.md){.internal-link target=_blank}, your `Dockerfile` might instead look like:

```Dockerfile hl_lines="7"

!!! note
    When defining a <a href="https://docs.pydantic.dev/latest/concepts/types/#unions" class="external-link" target="_blank">`Union`</a>, include the most specific type first, followed by the less specific type. In the example below, the more specific `PlaneItem` comes before `CarItem` in `Union[PlaneItem, CarItem]`.

=== "Python 3.10+"

    ```Python hl_lines="1  14-15  18-20  33"

New features are added frequently, bugs are fixed regularly, and the code is still continuously improving.

That's why the current versions are still `0.x.x`, this reflects that each version could potentially have breaking changes. This follows the <a href="https://semver.org/" class="external-link" target="_blank">Semantic Versioning</a> conventions.

A middleware doesn't have to be made for FastAPI or Starlette to work, as long as it follows the ASGI spec.

In general, ASGI middlewares are classes that expect to receive an ASGI app as the first argument.

So, in the documentation for third-party ASGI middlewares they will probably tell you to do something like: