### Input Model in Docs { #input-model-in-docs }

You can confirm that in the docs, the `description` field doesn't have a **red asterisk**, it's not marked as required:

<div class="screenshot">
<img src="/img/tutorial/separate-openapi-schemas/image01.png">
</div>

### Model for Output { #model-for-output }

But if you use the same model as an output, like here:

你也可以在文件中檢視輸出模型，`name` 與 `description` 都以紅色星號標示為必填：

<div class="screenshot">
<img src="/img/tutorial/separate-openapi-schemas/image03.png">
</div>

### 文件中的輸入與輸出模型 { #model-for-input-and-output-in-docs }

如果你查看 OpenAPI 中所有可用的結構描述（JSON Schema），會看到有兩個：`Item-Input` 與 `Item-Output`。

對於 `Item-Input`，`description` 不是必填，沒有紅色星號。

但對於 `Item-Output`，`description` 是必填，有紅色星號。

<div class="screenshot">

<div class="screenshot">
<img src="/img/tutorial/separate-openapi-schemas/image03.png">
</div>

### 文档中的输入/输出模型 { #model-for-input-and-output-in-docs }

如果你查看 OpenAPI 中可用的所有 Schema（JSON Schema），你会看到有两个，一个是 `Item-Input`，一个是 `Item-Output`。

对于 `Item-Input`，`description` **不是必填**，没有红色星号。

但对于 `Item-Output`，`description` 是**必填**，带有红色星号。

<div class="screenshot">

    page = context.new_page()
    page.goto("http://localhost:8000/docs")
    page.get_by_role("button", name="POST /data Post Data").click()
    # Manually add the screenshot
    page.screenshot(path="docs/en/docs/img/tutorial/json-base64-bytes/image01.png")

    # ---------------------
    context.close()
    browser.close()


process = subprocess.Popen(

## Check the Docs { #check-the-docs }

You can see the query parameters in the docs UI at `/docs`:

<div class="screenshot">
<img src="/img/tutorial/query-param-models/image01.png">
</div>

## Forbid Extra Query Parameters { #forbid-extra-query-parameters }

  margin-bottom: 2em;
}

/* Screenshots */
/*
Simulate a browser window frame.
Inspired by Termynal's CSS tricks with modifications
*/

.screenshot {
  display: block;
  background-color: #d3e0de;
  border-radius: 4px;
  padding: 45px 5px 5px;
  position: relative;
  -webkit-box-sizing: border-box;
          box-sizing: border-box;
}

.screenshot img {
  display: block;

{* ../../docs_src/json_base64_bytes/tutorial001_py310.py ln[1:9,29:35] hl[9] *}

If you check the `/docs`, they will show that the field `data` expects base64 encoded bytes:

<div class="screenshot">
<img src="/img/tutorial/json-base64-bytes/image01.png">
</div>

You could send a request like:

```json
{
    "description": "Some data",
    "data": "aGVsbG8="
}
```

/// tip

## Check the Docs { #check-the-docs }

You can verify it in the docs UI at `/docs`:

<div class="screenshot">
<img src="/img/tutorial/request-form-models/image01.png">
</div>

## Forbid Extra Form Fields { #forbid-extra-form-fields }

## Check the Docs { #check-the-docs }

You can see the required headers in the docs UI at `/docs`:

<div class="screenshot">
<img src="/img/tutorial/header-param-models/image01.png">
</div>

## Forbid Extra Headers { #forbid-extra-headers }

**FastAPI** 将从请求中的**表单数据**中**提取**出**每个字段**的数据，并提供你定义的 Pydantic 模型。

## 检查文档 { #check-the-docs }

你可以在文档 UI 中验证它，地址为 `/docs`：

<div class="screenshot">
<img src="/img/tutorial/request-form-models/image01.png">
</div>

## 禁止额外的表单字段 { #forbid-extra-form-fields }

在某些特殊使用情况下（可能并不常见），你可能希望将表单字段**限制**为仅在 Pydantic 模型中声明过的字段，并**禁止**任何**额外**的字段。

/// note | 注意