### 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

                return None
        return HTTPAuthorizationCredentials(scheme=scheme, credentials=credentials)


class HTTPBasic(HTTPBase):
    """
    HTTP Basic authentication.

    ## Usage

    Create an instance object and use that object as the dependency in `Depends()`.

    The dependency result will be an `HTTPBasicCredentials` object containing the
    `username` and the `password`.

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`.

    assert verify_password("secret", fake_users_db["johndoe"]["hashed_password"])


def test_get_password_hash():
    assert get_password_hash("secretalice")


def test_create_access_token():
    access_token = create_access_token(data={"data": "foo"})
    assert access_token


def test_token_no_sub():
    response = client.get(
        "/users/me",
        headers={

### Virtual environment with `venv`

You can create an isolated virtual local environment in a directory using Python's `venv` module. Let's do this in the cloned repository (where the `requirements.txt` is):

<div class="termy">

```console
$ python -m venv env
```

</div>

                                    }
                                }
                            },
                        },
                    },
                    "summary": "Create Item",
                    "operationId": "create_item_items__post",
                    "requestBody": {
                        "content": {
                            "application/json": {

                                    }
                                }
                            },
                        },
                    },
                    "summary": "Create Item",
                    "operationId": "create_item_items__post",
                    "requestBody": {
                        "content": {
                            "application/json": {

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!}
    ```

---

Bei der Erstellung von APIs verwenden Sie normalerweise diese spezifischen HTTP-Methoden, um eine bestimmte Aktion durchzuführen.

Normalerweise verwenden Sie:

* `POST`: um Daten zu erzeugen (create).
* `GET`: um Daten zu lesen (read).
* `PUT`: um Daten zu aktualisieren (update).
* `DELETE`: um Daten zu löschen (delete).

In OpenAPI wird folglich jede dieser HTTP-Methoden als „Operation“ bezeichnet.