### Create an `Enum` class

Import `Enum` and create a sub-class that inherits from `str` and from `Enum`.

By inheriting from `str` the API docs will be able to know that the values must be of type `string` and will be able to render correctly.

Then create class attributes with fixed values, which will be the available valid values:

### Step 2: create a `FastAPI` "instance"

```Python hl_lines="3"
{!../../../docs_src/first_steps/tutorial001.py!}
```

Here the `app` variable will be an "instance" of the class `FastAPI`.

This will be the main point of interaction to create all your API.

### Step 3: create a *path operation*

#### Path

Right as we wanted it. ✔️

This is because FastAPI uses this `root_path` to create the default `server` in OpenAPI with the URL provided by `root_path`.

## Additional servers

!!! warning
    This is a more advanced use case. Feel free to skip it.

By default, **FastAPI** will create a `server` in the OpenAPI schema with the URL for the `root_path`.

Bu insanlar:

* [GitHub-da başqalarının suallarına kömək edirlər](help-fastapi.md#help-others-with-questions-in-github){.internal-link target=_blank}.
* [Pull Request-lər yaradırlar](help-fastapi.md#create-a-pull-request){.internal-link target=_blank}.
* Pull Request-ləri ([xüsusilə tərcümələr üçün vacib olan](contributing.md#translations){.internal-link target=_blank}.) nəzərdən keçirirlər.

Bu insanlara təşəkkür edirəm. 👏 🙇

    To use `TestClient`, first install <a href="https://www.python-httpx.org" class="external-link" target="_blank">`httpx`</a>.

    E.g. `pip install httpx`.

Import `TestClient`.

Create a `TestClient` by passing your **FastAPI** application to it.

Create functions with a name that starts with `test_` (this is standard `pytest` conventions).

Use the `TestClient` object the same way as you do with `httpx`.

Bu insanlar:

* [GitHubdaki soruları cevaplayarak diğerlerine yardım ediyor](help-fastapi.md#help-others-with-questions-in-github){.internal-link target=_blank}.
* [Pull Request'ler oluşturuyor](help-fastapi.md#create-a-pull-request){.internal-link target=_blank}.
* Pull Request'leri gözden geçiriyorlar, [özellikle çeviriler için bu çok önemli](contributing.md#translations){.internal-link target=_blank}.

Onları bir alkışlayalım. 👏 🙇

It was created to generate the HTML in the backend, not to create APIs used by a modern frontend (like React, Vue.js and Angular) or by other systems (like <abbr title="Internet of Things">IoT</abbr> devices) communicating with it.

!!! danger
    Never store the plain password of a user or send it in a response like this, unless you know all the caveats and you know what you are doing.

## Add an output model

We can instead create an input model with the plaintext password and an output model without it:

=== "Python 3.10+"

    ```Python hl_lines="9  11  16"
    {!> ../../../docs_src/response_model/tutorial003_py310.py!}
    ```

Here, this section would run directly, right before starting your **FastAPI** application.

* Create an `engine`.
* Create all the tables from the `metadata` object.

```Python hl_lines="25-28"
{!../../../docs_src/async_sql_databases/tutorial001.py!}
```

## Create models

Create Pydantic models for:

* Notes to be created (`NoteIn`).

```

### Create a custom `GzipRoute` class

Next, we create a custom subclass of `fastapi.routing.APIRoute` that will make use of the `GzipRequest`.

This time, it will overwrite the method `APIRoute.get_route_handler()`.

This method returns a function. And that function is what will receive a request and return a response.

Here we use it to create a `GzipRequest` from the original request.