raise HTTPException(status_code=400, detail="X-Token header invalid")


async def get_query_token(token: str):
    if token != "jessica":

import * as fs from 'fs'

async function modifyOpenAPIFile(filePath) {
  try {
    const data = await fs.promises.readFile(filePath)
    const openapiContent = JSON.parse(data)

    const paths = openapiContent.paths
    for (const pathKey of Object.keys(paths)) {
      const pathData = paths[pathKey]
      for (const method of Object.keys(pathData)) {
        const operation = pathData[method]
        if (operation.tags && operation.tags.length > 0) {

    ```

That status code will be used in the response and will be added to the OpenAPI schema.

!!! note "Technical Details"
    You could also use `from starlette import status`.

    **FastAPI** provides the same `starlette.status` as `fastapi.status` just as a convenience for you, the developer. But it comes directly from Starlette.

## Tags

To **deploy** an application means to perform the necessary steps to make it **available to the users**.

For a **web API**, it normally involves putting it in a **remote machine**, with a **server program** that provides good performance, stability, etc, so that your **users** can **access** the application efficiently and without interruptions or problems.

    hashed_password: str


def get_user(db, username: str):
    if username in db:
        user_dict = db[username]
        return UserInDB(**user_dict)


def fake_decode_token(token):
    # This doesn't provide any security at all
    # Check the next version
    user = get_user(fake_users_db, token)
    return user


async def get_current_user(token: Annotated[str, Depends(oauth2_scheme)]):

* <a href="https://tartiflette.io/" class="external-link" target="_blank">Tartiflette</a>
    * With <a href="https://tartiflette.github.io/tartiflette-asgi/" class="external-link" target="_blank">Tartiflette ASGI</a> to provide ASGI integration
* <a href="https://graphene-python.org/" class="external-link" target="_blank">Graphene</a>

开发人员永远都不需要直接调用这些函数，这些函数是由框架（在此为 **FastAPI** ）调用的。

通过依赖注入系统，只要告诉 **FastAPI** *路径操作函数* 还要「依赖」其他在*路径操作函数*之前执行的内容，**FastAPI** 就会执行函数代码，并「注入」函数返回的结果。

其他与「依赖注入」概念相同的术语为：

* 资源（Resource）
* 提供方（Provider）
* 服务（Service）
* 可注入（Injectable）
* 组件（Component）

## **FastAPI** 插件

**依赖注入**系统支持构建集成和「插件」。但实际上，FastAPI 根本**不需要创建「插件」**，因为使用依赖项可以声明不限数量的、可用于*路径操作函数*的集成与交互。

### Dependency Injection

FastAPI bao gồm một hệ thống <abbr title='cũng biết đến như là "components", "resources", "services", "providers"'><strong>Dependency Injection</strong></abbr> vô cùng dễ sử dụng nhưng vô cùng mạnh mẽ.

* Thậm chí, các dependency có thể có các dependency khác, tạo thành một phân cấp hoặc **"một đồ thị" của các dependency**.

def test_users_token_monica_with_no_jessica(client: TestClient):
    response = client.get("/users?token=monica")
    assert response.status_code == 400
    assert response.json() == {"detail": "No Jessica token provided"}


def test_items_token_jessica(client: TestClient):
    response = client.get(
        "/items?token=jessica", headers={"X-Token": "fake-super-secret-token"}
    )
    assert response.status_code == 200

@needs_py39
def test_users_token_monica_with_no_jessica(client: TestClient):
    response = client.get("/users?token=monica")
    assert response.status_code == 400
    assert response.json() == {"detail": "No Jessica token provided"}


@needs_py39
def test_items_token_jessica(client: TestClient):
    response = client.get(
        "/items?token=jessica", headers={"X-Token": "fake-super-secret-token"}
    )