app = FastAPI()
    router = APIRouter()

    @router.get("/hello/")
    def hello_page() -> str:
        return "Hello, World!"

    app.include_router(router)

    client = TestClient(app)

    response = client.get("/hello/", follow_redirects=False)
    assert response.status_code == 200

    response = client.get("/hello", follow_redirects=False)
    assert response.status_code == 307

```txt
Hello, World from Flask!
```

并且如果您访问 <a href="http://localhost:8000/v2" class="external-link" target="_blank">http://localhost:8000/v2</a>，您将会看到由 FastAPI 返回的响应：

```JSON
{
    "message": "Hello World"
}

```

👈 ⏸ 🎦 📛 🌐❔ 👆 📱 ➖ 🍦, 👆 🇧🇿 🎰.

### ✅ ⚫️

📂 👆 🖥 <a href="http://127.0.0.1:8000" class="external-link" target="_blank">http://127.0.0.1:8000</a>.

👆 🔜 👀 🎻 📨:

```JSON
{"message": "Hello World"}
```

### 🎓 🛠️ 🩺

🔜 🚶 <a href="http://127.0.0.1:8000/docs" class="external-link" target="_blank">http://127.0.0.1:8000/docs</a>.

@app.websocket_route("/")
async def index(websocket: WebSocket):
    await websocket.accept()
    await websocket.send_text("Hello, world!")
    await websocket.close()


@router.websocket_route("/router")
async def routerindex(websocket: WebSocket):
    await websocket.accept()
    await websocket.send_text("Hello, router!")
    await websocket.close()


@prefix_router.websocket_route("/")

```txt
Hello, World from Flask!
```

&amp; 🚥 👆 🚶 <a href="http://localhost:8000/v2" class="external-link" target="_blank">http://localhost:8000/v2</a> 👆 🔜 👀 📨 ⚪️➡️ FastAPI:

```JSON
{
    "message": "Hello World"
}

    ), "default configs should be preserved"


def test_get_users():
    response = client.get("/users/foo")
    assert response.status_code == 200, response.text

from docs_src.behind_a_proxy.tutorial003 import app

client = TestClient(app)


def test_main():
    response = client.get("/app")
    assert response.status_code == 200
    assert response.json() == {"message": "Hello World", "root_path": "/api/v1"}


def test_openapi_schema():
    response = client.get("/openapi.json")
    assert response.status_code == 200
    assert response.json() == {
        "openapi": "3.1.0",

        title=app.title + " - ReDoc",
        redoc_js_url="https://unpkg.com/redoc@next/bundles/redoc.standalone.js",
    )


@app.get("/users/{username}")
async def read_user(username: str):

        title=app.title + " - ReDoc",
        redoc_js_url="/static/redoc.standalone.js",
    )


@app.get("/users/{username}")
async def read_user(username: str):

```txt
Hello, World from Flask!
```

Und wenn Sie auf <a href="http://localhost:8000/v2" class="external-link" target="_blank">http://localhost:8000/v2</a> gehen, sehen Sie die Response von FastAPI:

```JSON
{
    "message": "Hello World"
}