# Cookie Parameter Models { #cookie-parameter-models }

If you have a group of **cookies** that are related, you can create a **Pydantic model** to declare them. 🍪

This would allow you to **re-use the model** in **multiple places** and also to declare validations and metadata for all the parameters at once. 😎

/// note

This is supported since FastAPI version `0.115.0`. 🤓

///

/// tip

# General - How To - Recipes { #general-how-to-recipes }

Here are several pointers to other places in the docs, for general or frequent questions.

## Filter Data - Security { #filter-data-security }

To ensure that you don't return more data than you should, read the docs for [Tutorial - Response Model - Return Type](../tutorial/response-model.md).

            """
        ),
    ] = _Unset,
    decimal_places: Annotated[
        int | None,
        Doc(
            """
            Maximum number of decimal places allowed for decimal values.
            """
        ),
    ] = _Unset,
    examples: Annotated[
        list[Any] | None,
        Doc(
            """
            Example values for this field.

The content of each of these strings can have any format, but should not contain spaces.

These scopes represent "permissions".

In OpenAPI (e.g. the API docs), you can define "security schemes".

When one of these security schemes uses OAuth2, you can also declare and use scopes.

Each "scope" is just a string (without spaces).

dependencies and the dependencies are solved based on the declared types. So, it's not possible to declare more than one "component" that provides a certain type.

Routes are declared in a single place, using functions declared in other places (instead of using decorators that can be placed right on top of the function that handles the endpoint). This is closer to how Django does it than to how Flask (and Starlette) does it. It separates in the code things that are relatively tightly coupled....

///

## Multiple models { #multiple-models }

Here's a general idea of how the models could look like with their password fields and the places where they are used:

{* ../../docs_src/extra_models/tutorial001_py310.py hl[7,9,14,20,22,27:28,31:33,38:39] *}

### About `**user_in.model_dump()` { #about-user-in-model-dump }

The **default** value of the **function parameter** is the **actual default** value, that's more intuitive with Python in general. 😌

   * it is returned directly. Otherwise, a new array of size {@code minLength + padding} is
   * returned, containing the values of {@code array}, and zeroes in the remaining places.
   *
   * @param array the source array
   * @param minLength the minimum length the returned array must guarantee
   * @param padding an extra amount to "grow" the array by if growth is necessary

The correct place is:

* In the key `content`, that has as value another JSON object (`dict`) that contains:
    * A key with the media type, e.g. `application/json`, that contains as value another JSON object, that contains:
        * A key `schema`, that has as the value the JSON Schema from the model, here's the correct place.

   * it is returned directly. Otherwise, a new array of size {@code minLength + padding} is
   * returned, containing the values of {@code array}, and zeroes in the remaining places.
   *
   * @param array the source array
   * @param minLength the minimum length the returned array must guarantee
   * @param padding an extra amount to "grow" the array by if growth is necessary