// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.

TEXT foo(SB), 0, $0
	RET
TEXT foo(SB), 0, $0 // ERROR "symbol foo redeclared"
	RET

GLOBL bar(SB), 0, $8
GLOBL bar(SB), 0, $8 // ERROR "symbol bar redeclared"

DATA bar+0(SB)/8, $0

# Body - Fields

The same way you can declare additional validation and metadata in *path operation function* parameters with `Query`, `Path` and `Body`, you can declare validation and metadata inside of Pydantic models using Pydantic's `Field`.

## Import `Field`

First, you have to import it:

{* ../../docs_src/body_fields/tutorial001_an_py310.py hl[4] *}


/// warning

```

////

This will make `tags` be a list, although it doesn't declare the type of the elements of the list.

## List fields with type parameter

But Python has a specific way to declare lists with internal types, or "type parameters":

### Import typing's `List`

In Python 3.9 and above you can use the standard `list` to declare these type annotations as we'll see below. 💡

/// note

This is supported since FastAPI version `0.113.0`. 🤓

///

## Pydantic Models for Forms

You just need to declare a **Pydantic model** with the fields you want to receive as **form fields**, and then declare the parameter as `Form`:

//// tab | Python 3.9+

```Python hl_lines="9-11  15"
{!> ../../docs_src/request_form_models/tutorial001_an_py39.py!}
```

////

//// tab | Python 3.8+

///

## Declare metadata

You can declare all the same parameters as for `Query`.

For example, to declare a `title` metadata value for the path parameter `item_id` you can type:

//// tab | Python 3.10+

```Python hl_lines="10"

///

{* ../../docs_src/security/tutorial005_an_py310.py hl[156] *}

## Declare scopes in *path operations* and dependencies

Now we declare that the *path operation* for `/users/me/items/` requires the scope `items`.

For this, we import and use `Security` from `fastapi`.

You can declare a `response_model`, using the default status code `200` (or a custom one if you need), and then declare additional information for that same response in `responses`, directly in the OpenAPI schema.

**FastAPI** will keep the additional information from `responses`, and combine it with the JSON Schema from your model.

/// tip | Dica

Prefira utilizar a versão `Annotated` se possível.

///

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

////

## Declare parâmetros de `Cookie`

Então declare os paramêtros de cookie usando a mesma estrutura que em `Path` e `Query`.

Você pode definir o valor padrão, assim como todas as validações extras ou parâmetros de anotação:


//// tab | Python 3.10+

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`. 🤓

///

## Query Parameters with a Pydantic Model

## Multiple path and query parameters

You can declare multiple path parameters and query parameters at the same time, **FastAPI** knows which is which.

And you don't have to declare them in any specific order.

They will be detected by name:

//// tab | Python 3.10+

```Python hl_lines="6  8"