}

  @Test
  fun cookie() {
    val cookie: Cookie = Cookie.Builder().build()
    val name: String = cookie.name
    val value: String = cookie.value
    val persistent: Boolean = cookie.persistent
    val expiresAt: Long = cookie.expiresAt
    val hostOnly: Boolean = cookie.hostOnly
    val domain: String = cookie.domain
    val path: String = cookie.path
    val httpOnly: Boolean = cookie.httpOnly

from fastapi import Cookie, Depends, FastAPI

app = FastAPI()


def query_extractor(q: str | None = None):
    return q


def query_or_cookie_extractor(
    q: str = Depends(query_extractor), last_query: str | None = Cookie(default=None)
):
    if not q:
        return last_query
    return q


@app.get("/items/")
async def read_query(query_or_default: str = Depends(query_or_cookie_extractor)):

from typing import Union

from fastapi import Cookie, Depends, FastAPI

app = FastAPI()


def query_extractor(q: Union[str, None] = None):
    return q


def query_or_cookie_extractor(
    q: str = Depends(query_extractor),
    last_query: Union[str, None] = Cookie(default=None),
):
    if not q:
        return last_query
    return q


@app.get("/items/")

from typing import Annotated

from fastapi import Cookie, Depends, FastAPI

app = FastAPI()


def query_extractor(q: str | None = None):
    return q


def query_or_cookie_extractor(
    q: Annotated[str, Depends(query_extractor)],
    last_query: Annotated[str | None, Cookie()] = None,
):
    if not q:
        return last_query
    return q


@app.get("/items/")
async def read_query(

from fastapi import Cookie, FastAPI

app = FastAPI()


@app.get("/items/")
async def read_items(ads_id: str | None = Cookie(default=None)):

from typing import Union

from fastapi import Cookie, FastAPI

app = FastAPI()


@app.get("/items/")
async def read_items(ads_id: Union[str, None] = Cookie(default=None)):

from typing import Annotated

from fastapi import Cookie, FastAPI

app = FastAPI()


@app.get("/items/")
async def read_items(ads_id: Annotated[str | None, Cookie()] = None):

# ヘッダーのパラメータ

ヘッダーのパラメータは、`Query`や`Path`、`Cookie`のパラメータを定義するのと同じように定義できます。

## `Header`をインポート

まず、`Header`をインポートします:

```Python hl_lines="3"
{!../../docs_src/header_params/tutorial001.py!}
```

## `Header`のパラメータの宣言

次に、`Path`や`Query`、`Cookie`と同じ構造を用いてヘッダーのパラメータを宣言します。

最初の値がデフォルト値で、追加の検証パラメータや注釈パラメータをすべて渡すことができます。

```Python hl_lines="9"
{!../../docs_src/header_params/tutorial001.py!}
```

/// note | "技術詳細"

from fastapi import Cookie, FastAPI
from pydantic import BaseModel

app = FastAPI()


class Cookies(BaseModel):
    model_config = {"extra": "forbid"}

    session_id: str
    fatebook_tracker: str | None = None
    googall_tracker: str | None = None


@app.get("/items/")
async def read_items(cookies: Cookies = Cookie()):

from typing import Annotated, Union

from fastapi import Cookie, FastAPI

app = FastAPI()


@app.get("/items/")
async def read_items(ads_id: Annotated[Union[str, None], Cookie()] = None):