每个标签元数据字典的顺序也定义了在文档用户界面显示的顺序。

例如按照字母顺序，即使 `users` 排在 `items` 之后，它也会显示在前面，因为我们将它的元数据添加为列表内的第一个字典。

## OpenAPI URL

默认情况下，OpenAPI 模式服务于 `/openapi.json`。

但是你可以通过参数 `openapi_url` 对其进行配置。

例如，将其设置为服务于 `/api/v1/openapi.json`：

```Python hl_lines="3"
{!../../docs_src/metadata/tutorial002.py!}
```

如果你想完全禁用 OpenAPI 模式，可以将其设置为 `openapi_url=None`，这样也会禁用使用它的文档用户界面。

## 文档 URLs

你可以配置两个文档用户界面，包括：

    assert response.json() == {"detail": "Item not found"}


def test_openapi_schema():
    response = client.get("/openapi.json")
    assert response.status_code == 200, response.text
    assert response.json() == {
        "openapi": "3.1.0",
        "info": {"title": "FastAPI", "version": "0.1.0"},
        "paths": {
            "/items-header/{item_id}": {
                "get": {

        "tax": 10.5,
        "tags": [],
    }


@needs_py39
@needs_pydanticv2
def test_openapi_schema(client: TestClient):
    response = client.get("/openapi.json")
    assert response.status_code == 200, response.text
    assert response.json() == {
        "openapi": "3.1.0",
        "info": {"title": "FastAPI", "version": "0.1.0"},
        "paths": {
            "/items/{item_id}": {
                "get": {

/// warning | "Внимание"

Дополнительные ключи, переданные в функцию `Field`, также будут присутствовать в сгенерированной OpenAPI схеме вашего приложения.
Поскольку эти ключи не являются обязательной частью спецификации OpenAPI, некоторые инструменты OpenAPI, например, [валидатор OpenAPI](https://validator.swagger.io/), могут не работать с вашей сгенерированной схемой.

///

## Резюме

    assert response.status_code == expected_status
    assert response.json() == expected_response


def test_openapi_schema():
    response = client.get("/openapi.json")
    assert response.status_code == 200
    assert response.json() == {
        "openapi": "3.1.0",
        "info": {"title": "FastAPI", "version": "0.1.0"},
        "paths": {
            "/items/": {
                "get": {

* **Robust**: Get production-ready code. With automatic interactive documentation.
* **Standards-based**: Based on (and fully compatible with) the open standards for APIs: <a href="https://github.com/OAI/OpenAPI-Specification" class="external-link" target="_blank">OpenAPI</a> (previously known as Swagger) and <a href="https://json-schema.org/" class="external-link" target="_blank">JSON Schema</a>.

///

/// info | "提示"

当然，实际的 `Content-Type` 头，状态码等等，将来自于你返回的 `Response` 对象。

///

### OpenAPI 中的文档和重载 `Response`

如果你想要在函数内重载响应，但是同时在 OpenAPI 中文档化「媒体类型」，你可以使用 `response_class` 参数并返回一个 `Response` 对象。

接着 `response_class` 参数只会被用来文档化 OpenAPI 的 *路径操作*，你的 `Response` 用来返回响应。

### 直接返回 `HTMLResponse`

比如像这样：

```Python hl_lines="7 23 21"
{!../../docs_src/custom_response/tutorial004.py!}
```

@needs_py310
def test_openapi_schema():
    from docs_src.cookie_params.tutorial001_an_py310 import app

    client = TestClient(app)
    response = client.get("/openapi.json")
    assert response.status_code == 200
    assert response.json() == {
        "openapi": "3.1.0",
        "info": {"title": "FastAPI", "version": "0.1.0"},
        "paths": {
            "/items/": {
                "get": {

    assert response.json() == expected_response


@needs_py310
def test_openapi_schema(client: TestClient):
    response = client.get("/openapi.json")
    assert response.status_code == 200
    assert response.json() == {
        "openapi": "3.1.0",
        "info": {"title": "FastAPI", "version": "0.1.0"},
        "paths": {
            "/items/": {
                "get": {

            }
        ]
    }


@needs_pydanticv2
def test_openapi_schema(client: TestClient):
    response = client.get("/openapi.json")
    assert response.status_code == 200, response.text
    assert response.json() == {
        "openapi": "3.1.0",
        "info": {"title": "FastAPI", "version": "0.1.0"},
        "paths": {
            "/items/": {
                "post": {