from fastapi import FastAPI, Response

app = FastAPI()


@app.get("/headers-and-object/")
def get_headers(response: Response):
    response.headers["X-Cat-Dog"] = "alone in the world"

* 🌐 Remove translation docs references to aiofiles as it's no longer needed since AnyIO. PR [#3594](https://github.com/tiangolo/fastapi/pull/3594) by [@alonme](https://github.com/alonme).
* ✏ 🌐 Fix typo in Portuguese translation for `docs/pt/docs/tutorial/path-params.md`. PR [#4722](https://github.com/tiangolo/fastapi/pull/4722) by [@CleoMenezesJr](https://github.com/CleoMenezesJr).

By default it will listen on the IP address `127.0.0.1`, which is the IP for your machine to communicate with itself alone (`localhost`).

## `fastapi run`

When you run `fastapi run`, it will run on production mode by default.

It will have **auto-reload disabled** by default.

    ```

!!! note
    Keep in mind that in this case, FastAPI won't check the contents of the list.

    For example, `List[int]` would check (and document) that the contents of the list are integers. But `list` alone wouldn't.

## Declare more metadata

You can add more information about the parameter.

That information will be included in the generated OpenAPI and used by the documentation user interfaces and external tools.

        app = FastAPI()

        @app.head("/items/", status_code=204)
        def get_items_headers(response: Response):
            response.headers["X-Cat-Dog"] = "Alone in the world"
        ```
        """
        return self.router.head(
            path,
            response_model=response_model,
            status_code=status_code,
            tags=tags,

from fastapi import FastAPI
from fastapi.responses import JSONResponse

app = FastAPI()


@app.get("/headers/")
def get_headers():
    content = {"message": "Hello World"}
    headers = {"X-Cat-Dog": "alone in the world", "Content-Language": "en-US"}

def test_path_operation():
    response = client.get("/headers-and-object/")
    assert response.status_code == 200, response.text
    assert response.json() == {"message": "Hello World"}

def test_path_operation():
    response = client.get("/headers/")
    assert response.status_code == 200, response.text
    assert response.json() == {"message": "Hello World"}
    assert response.headers["X-Cat-Dog"] == "alone in the world"

* **WebSocket** desteği.
* **GraphQL** desteği.
* Kullanım halinde arka plan işlevleri.
* Başlatma ve kapatma eventleri(startup and shutdown).
* Test sunucusu HTTPX üzerine kurulu.
* **CORS**, GZip, Static dosyalar, Streaming responseları.
* **Session and Cookie** desteği.

It's still possible to use `BackgroundTask` alone in FastAPI, but you have to create the object in your code and return a Starlette `Response` including it.