.header("User-Agent", "OkHttp Headers.java")
        .addHeader("Accept", "application/json; q=0.5")
        .addHeader("Accept", "application/vnd.github.v3+json")
        .build()

    client.newCall(request).execute().use { response ->
      if (!response.isSuccessful) throw IOException("Unexpected code $response")

      println("Server: ${response.header("Server")}")

		closeBitrotWriters(writers)
		if err != nil {
			t.Fatalf("Test %d: failed to create random test data: %v", i, err)
		}

		readers := make([]io.ReaderAt, len(disks))
		for i, disk := range disks {
			shardFilesize := erasure.ShardFileSize(test.size)
			readers[i] = newBitrotReader(disk, nil, "testbucket", "testobject", shardFilesize, test.algorithm, bitrotWriterSum(writers[i]), erasure.ShardSize())
		}

            println("onResponseStarted ${info.headers.asMap} ${info.negotiatedProtocol}")
            request.read(ByteBuffer.allocateDirect(4096 * 8))
          }

          override fun onReadCompleted(
            request: UrlRequest,
            info: UrlResponseInfo,
            byteBuffer: ByteBuffer,
          ) {
            println("onReadCompleted ${info.headers.asMap}")
            byteBuffer.flip()

{
    "dynamic_templates": [
      {
        "headers": {
          "path_match": "headers.*",
          "mapping": {
            "type": "keyword"
          }
        }
      },
      {
        "search_fields": {
          "path_match": "searchField.*",
          "mapping": {
            "type": "keyword"
          }
        }
      },
      {
        "documents": {
          "path_match": "documents.*",

**FastAPI** will use that *temporal* response to extract the cookies (also headers and status code), and will put them in the final response that contains the value you returned, filtered by any `response_model`.

You can also declare the `Response` parameter in dependencies, and set cookies (and headers) in them.

## Return a `Response` directly

@app.get("/items/{item_id}")
async def read_item(item_id: str):
    if item_id not in items:
        raise HTTPException(
            status_code=404,
            detail="Item not found",
            headers={"X-Error": "Some custom header"},
        )
    return {"item": items[item_id]}


@app.get("/http-no-body-statuscode-exception")
async def no_body_status_code_exception():
    raise HTTPException(status_code=204)

)

// writeSTSErrorResponse writes error headers
func writeSTSErrorResponse(ctx context.Context, w http.ResponseWriter, errCode STSErrorCode, err error) {
	stsErr := stsErrCodes.ToSTSErr(errCode)

	// Generate error response.
	stsErrorResponse := STSErrorResponse{}
	stsErrorResponse.Error.Code = stsErr.Code
	stsErrorResponse.RequestID = w.Header().Get(xhttp.AmzRequestID)

    val headers =
      Headers.Builder()
        .add("Cache-Control: max-age=120")
    addHeaderLenient(headers, ": A")
    server.enqueue(
      MockResponse.Builder()
        .headers(headers.build())
        .body("body")
        .build(),
    )
    val response = get(server.url("/"))
    assertThat(response.header("")).isEqualTo("A")

def test_get_invalid_one_header(client: TestClient):
    response = client.get("/items/", headers={"X-Token": "invalid"})
    assert response.status_code == 400, response.text
    assert response.json() == {"detail": "X-Token header invalid"}


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

from fastapi import FastAPI, Header
from pydantic import BaseModel

app = FastAPI()


class CommonHeaders(BaseModel):
    host: str
    save_data: bool
    if_modified_since: str | None = None
    traceparent: str | None = None
    x_tag: list[str] = []


@app.get("/items/")
async def read_items(headers: CommonHeaders = Header()):