* Selbst keine erforderlichen Scopes.
                    * Eine Abhängigkeit, die `oauth2_scheme` verwendet.
                    * Einen `security_scopes`-Parameter vom Typ `SecurityScopes`:
                        * Dieser `security_scopes`-Parameter hat ein Attribut `scopes` mit einer `list`e, die alle oben deklarierten Scopes enthält, sprich:

                    * `security_scopes` 参数的类型是 `SecurityScopes`：
                        * `security_scopes` 参数的属性 `scopes` 是包含上述声明的所有作用域的**列表**，因此：
                            * `security_scopes.scopes` 包含用于*路径操作*的 `["me", "items"]`
                            * `security_scopes.scopes` 包含*路径操作* `read_users_me` 的 `["me"]`，因为它在依赖项里被声明

        data = {}
        data["scopes"] = []
        for scope in form_data.scopes:
            data["scopes"].append(scope)
        if form_data.client_id:
            data["client_id"] = form_data.client_id
        if form_data.client_secret:
            data["client_secret"] = form_data.client_secret
        return data
    ```

    Note that for OAuth2 the scope `items:read` is a single scope in an opaque string.

            raise credentials_exception
        token_scopes = payload.get("scopes", [])
        token_data = TokenData(scopes=token_scopes, username=username)
    except (JWTError, ValidationError):
        raise credentials_exception
    user = get_user(fake_users_db, username=token_data.username)
    if user is None:
        raise credentials_exception
    for scope in security_scopes.scopes:
        if scope not in token_data.scopes:

::: fastapi.Depends

## `Security()`

In vielen Szenarien können Sie die Sicherheit (Autorisierung, Authentifizierung usw.) mit Abhängigkeiten handhaben, indem Sie `Depends()` verwenden.

Wenn Sie jedoch auch OAuth2-Scopes deklarieren möchten, können Sie `Security()` anstelle von `Depends()` verwenden.

Sie können `Security()` direkt von `fastapi` importieren:

```python
from fastapi import Security
```

            directly.
            """
        ),
    ] = None,
    *,
    scopes: Annotated[
        Optional[Sequence[str]],
        Doc(
            """
            OAuth2 scopes required for the *path operation* that uses this Security
            dependency.

            The term "scope" comes from the OAuth2 specification, it seems to be

                        },
                        "username": {"title": "Username", "type": "string"},
                        "password": {"title": "Password", "type": "string"},
                        "scope": {"title": "Scope", "type": "string", "default": ""},
                        "client_id": IsDict(
                            {
                                "title": "Client Id",

    def __init__(
        self,
        dependency: Optional[Callable[..., Any]] = None,
        *,
        scopes: Optional[Sequence[str]] = None,
        use_cache: bool = True,
    ):
        super().__init__(dependency=dependency, use_cache=use_cache)

<img src="/img/tutorial/security/image10.png">

!!! note
    Notice the header `Authorization`, with a value that starts with `Bearer `.

## Advanced usage with `scopes`

OAuth2 has the notion of "scopes".

You can use them to add a specific set of permissions to a JWT token.

Then you can give this token to a user directly or a third party, to interact with your API with a set of restrictions.

            raise credentials_exception
        token_scopes = payload.get("scopes", [])
        token_data = TokenData(scopes=token_scopes, username=username)
    except (JWTError, ValidationError):
        raise credentials_exception
    user = get_user(fake_users_db, username=token_data.username)
    if user is None:
        raise credentials_exception
    for scope in security_scopes.scopes:
        if scope not in token_data.scopes: