{!../../../docs_src/bigger_applications/app/routers/users.py!}
```

You can think of `APIRouter` as a "mini `FastAPI`" class.

All the same options are supported.

All the same `parameters`, `responses`, `dependencies`, `tags`, etc.

!!! tip
    In this example, the variable is called `router`, but you can name it however you want.

                            },
                        },
                    },
                    "summary": "Read Items",
                    "operationId": "read_items_items__item_id__put",
                    "parameters": [
                        {
                            "required": True,
                            "schema": {
                                "title": "Item Id",
                                "type": "string",

This schema definition includes your API paths, the possible parameters they take, etc.

#### Data "schema"

The term "schema" might also refer to the shape of some data, like a JSON content.

In that case, it would mean the JSON attributes, and data types they have, etc.

# Pfadoperation-Konfiguration

Es gibt mehrere Konfigurations-Parameter, die Sie Ihrem *Pfadoperation-Dekorator* übergeben können.

!!! warning "Achtung"
    Beachten Sie, dass diese Parameter direkt dem *Pfadoperation-Dekorator* übergeben werden, nicht der *Pfadoperation-Funktion*.

## Response-Statuscode

Sie können den (HTTP-)`status_code` definieren, den die Response Ihrer *Pfadoperation* verwenden soll.

                            },
                        },
                    },
                    "summary": "Update Item",
                    "operationId": "update_item_items__item_id__put",
                    "parameters": [
                        {
                            "required": True,
                            "schema": {
                                "title": "The ID of the item to get",

!!! tip
    To declare File bodies, you need to use `File`, because otherwise the parameters would be interpreted as query parameters or body (JSON) parameters.

The files will be uploaded as "form data".

If you declare the type of your *path operation function* parameter as `bytes`, **FastAPI** will read the file for you and you will receive the contents as `bytes`.

    ```

    der wichtigste Teil ist, um einen Parameter optional zu machen, da dieses `None` der Defaultwert ist, und das ist es, was diesen Parameter **nicht erforderlich** macht.

    Der Teil mit `Union[str, None]` erlaubt es Ihrem Editor, Sie besser zu unterstützen, aber er sagt FastAPI nicht, dass dieser Parameter optional ist.

                            },
                        },
                    },
                    "summary": "Update Item",
                    "operationId": "update_item_items__item_id__put",
                    "parameters": [
                        {
                            "required": True,
                            "schema": {"title": "Item Id", "type": "integer"},
                            "name": "item_id",

                            },
                        },
                    },
                    "summary": "Update Item",
                    "operationId": "update_item_items__item_id__put",
                    "parameters": [
                        {
                            "required": True,
                            "schema": {"title": "Item Id", "type": "integer"},
                            "name": "item_id",

        include_in_schema: bool = True,
        json_schema_extra: Union[Dict[str, Any], None] = None,
        **extra: Any,
    ):
        assert default is ..., "Path parameters cannot have a default value"
        self.in_ = self.in_
        super().__init__(
            default=default,
            default_factory=default_factory,
            annotation=annotation,