## 匯入 `Cookie` { #import-cookie }

先匯入 `Cookie`：

{* ../../docs_src/cookie_params/tutorial001_an_py310.py hl[3] *}

## 宣告 `Cookie` 參數 { #declare-cookie-parameters }

然後用與 `Path`、`Query` 相同的結構宣告 `Cookie` 參數。

你可以設定預設值，以及所有額外的驗證或註解參數：

{* ../../docs_src/cookie_params/tutorial001_an_py310.py hl[9] *}

/// note | 技術細節

`Cookie` 是 `Path` 與 `Query` 的「姊妹」類別。它同樣繼承自共同的 `Param` 類別。

<%@page pageEncoding="UTF-8" contentType="text/html; charset=UTF-8"%>
<%-- query did not match any document --%>
<div id="result" class="row">
	<div class="col-md-8">
		<div class="text-center py-4">
			<p class="mb-3"><i class="fa fa-search fa-3x text-muted" aria-hidden="true"></i></p>
			<p class="mb-2"><la:message key="labels.did_not_match" arg0="${displayQuery}" /></p>
			<p class="text-muted"><la:message key="labels.did_not_match_suggestion" /></p>

{* ../../docs_src/openapi_callbacks/tutorial001_py310.py hl[1,23] *}

### 建立回呼的「路徑操作」 { #create-the-callback-path-operation }

要建立回呼的「路徑操作」，就使用你上面建立的同一個 `APIRouter`。

它看起來就像一般的 FastAPI「路徑操作」：

* 可能需要宣告它應該接收的 body，例如 `body: InvoiceEvent`。
* 也可以宣告它應該回傳的 response，例如 `response_model=InvoiceEventReceived`。

{* ../../docs_src/openapi_callbacks/tutorial001_py310.py hl[14:16,19:20,26:30] *}

和一般「路徑操作」相比有兩個主要差異：

             Searching for package file structure from directories with
             <font color="#3465A4">__init__.py</font> files
             Importing from <font color="#75507B">/home/user/code/</font><font color="#AD7FA8">awesomeapp</font>

   <span style="background-color:#007166"><font color="#D3D7CF"> module </font></span>  🐍 main.py

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


/// warning

Notice that `Field` is imported directly from `pydantic`, not from `fastapi` as are all the rest (`Query`, `Path`, `Body`, etc).

///

## Declare model attributes { #declare-model-attributes }

You can then use `Field` with model attributes:

{* ../../docs_src/body_fields/tutorial001_an_py310.py hl[11:14] *}

             Searching for package file structure from directories with
             <font color="#3465A4">__init__.py</font> files
             Importing from <font color="#75507B">/home/user/code/</font><font color="#AD7FA8">awesomeapp</font>

   <span style="background-color:#007166"><font color="#D3D7CF"> module </font></span>  🐍 main.py

同樣的技巧也適用於 `Query`、`Cookie` 與 `Header`。😎

///

## 以 Pydantic 模型宣告 Cookie { #cookies-with-a-pydantic-model }

在 **Pydantic 模型**中宣告所需的 **Cookie** 參數，接著將參數宣告為 `Cookie`：

{* ../../docs_src/cookie_param_models/tutorial001_an_py310.py hl[9:12,16] *}

**FastAPI** 會從請求收到的 **Cookie** 中擷取 **每個欄位** 的資料，並交給你定義的 Pydantic 模型。

## 查看文件 { #check-the-docs }

你可以在 `/docs` 的文件介面中看到已定義的 Cookie：

<div class="screenshot">

For example, you could have a file `config.py` with:

{* ../../docs_src/settings/app01_py310/config.py *}

And then use it in a file `main.py`:

{* ../../docs_src/settings/app01_py310/main.py hl[3,11:13] *}

/// tip

You would also need a file `__init__.py` as you saw in [Bigger Applications - Multiple Files](../tutorial/bigger-applications.md).

///

* Use that `security` with a dependency in your *path operation*.
* It returns an object of type `HTTPBasicCredentials`:
    * It contains the `username` and `password` sent.

{* ../../docs_src/security/tutorial006_an_py310.py hl[4,8,12] *}

When you try to open the URL for the first time (or click the "Execute" button in the docs) the browser will ask you for your username and password:

<img src="/img/tutorial/security/image12.png">

This part is pretty normal, most of the code is probably already familiar to you:

{* ../../docs_src/openapi_callbacks/tutorial001_py310.py hl[7:11,34:51] *}

/// tip

The `callback_url` query parameter uses a Pydantic [Url](https://docs.pydantic.dev/latest/api/networks/) type.

///