@app.get("/cookie_example/")
        def cookie_example(
            data: str | None = Cookie(
                default=None,
                example="cookie1",
            ),
        ):
            return data

    @app.get("/cookie_examples/")
    def cookie_examples(
        data: str | None = Cookie(
            default=None,
            examples=["cookie1", "cookie2"],
        ),
    ):

                                    "Stored search parameters in cookie: name={}, size={}, maxAge={}, path={}, domain={}, secure={}, httpOnly={}, sameSite={}",
                                    cookie.getName(), encoded.length(), cookie.getMaxAge(), cookie.getPath(), cookie.getDomain(),
                                    cookie.getSecure(), cookie.isHttpOnly(), fessConfig.getCookieSearchParameterSameSite());
                        }

internal fun parseCookie(
  currentTimeMillis: Long,
  url: HttpUrl,
  setCookie: String,
): Cookie? = Cookie.parse(currentTimeMillis, url, setCookie)

internal fun cookieToString(
  cookie: Cookie,
  forObsoleteRfc2965: Boolean,
): String = cookie.toString(forObsoleteRfc2965)

internal fun addHeaderLenient(
  builder: Headers.Builder,
  line: String,

import pytest
from fastapi import Cookie, FastAPI
from fastapi.testclient import TestClient
from inline_snapshot import snapshot
from pydantic import BaseModel, Field

app = FastAPI()

# =====================================================================================
# Without aliases


@app.get("/optional-str")
async def read_optional_str(p: Annotated[str | None, Cookie()] = None):
    return {"p": p}

    url: HttpUrl,
    cookies: List<Cookie>,
  )

  /**
   * Load cookies from the jar for an HTTP request to [url]. This method returns a possibly
   * empty list of cookies for the network request.
   *
   * Simple implementations will return the accepted cookies that have not yet expired and that
   * [match][Cookie.matches] [url].
   */
  fun loadForRequest(url: HttpUrl): List<Cookie>

  companion object {

import org.apache.http.impl.conn.PoolingHttpClientConnectionManager;
import org.apache.http.impl.cookie.DefaultCookieSpecProvider;
import org.apache.http.impl.cookie.DefaultCookieSpecProvider.CompatibilityLevel;
import org.apache.http.impl.cookie.IgnoreSpecProvider;
import org.apache.http.impl.cookie.NetscapeDraftSpecProvider;
import org.apache.http.impl.cookie.RFC6265CookieSpecProvider;
import org.apache.http.message.BasicHeader;

You can define Header parameters the same way you define `Query`, `Path` and `Cookie` parameters.

## Import `Header` { #import-header }

First import `Header`:

{* ../../docs_src/header_params/tutorial001_an_py310.py hl[3] *}

## Declare `Header` parameters { #declare-header-parameters }

Then declare the header parameters using the same structure as with `Path`, `Query` and `Cookie`.

from typing import Annotated

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: Annotated[Cookies, Cookie()]):

        .clearHeaders()
        .addHeader("Cookie: s=square")
        .addHeader("Cookie", "a=android")
    assertThat(headersToList(response))
      .containsExactly("Cookie: s=square", "Cookie: a=android")
  }

  @Test
  fun mockResponseSetHeader() {
    val response =
      MockResponse()
        .clearHeaders()
        .addHeader("Cookie: s=square")
        .addHeader("Cookie: a=android")

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(