| xlHeaderVersion | msgp uint                   | header version identifier
| xlMetaVersion   | msgp uint                   | metadata version identifier
| versions        | msgp int                    | Number of versions following
| header_1        | msgp bin array              | Header of version 1
| metadata_1      | msgp bin array              | Metadata of version 1
| ...header_n     | msgp bin array              | Header of last version

      '@type': type.googleapis.com/envoy.extensions.filters.http.wasm.v3.Wasm
      config:
        configuration:
          '@type': type.googleapis.com/google.protobuf.StringValue
          value: '{"header_1":"some_value_1","header_2":"another_value"}'
        name: default.display-metadata
        vmConfig:
          code:
            local:

                        },
                        "configuration": {
                            "@type": "type.googleapis.com/google.protobuf.StringValue",
                            "value": "{\"header_1\":\"some_value_1\",\"header_2\":\"another_value\"}"
                        }
                    }
                }
            },
            "lastUpdated": "2022-12-08T11:03:53.225Z"
        },
        {

                                "configuration": {
                                    "@type": "type.googleapis.com/google.protobuf.StringValue",
                                    "value": "{\"header_1\":\"some_value_1\",\"header_2\":\"another_value\"}"
                                }
                            }
                        }
                    },
                    "last_updated": "2022-12-08T11:03:53.225Z"

    val headers1 =
      Headers.Builder()
        .add("Connection", "close")
        .add("Transfer-Encoding", "chunked")
        .build()
    val headers2 =
      Headers.Builder()
        .add("Connection", "keep-alive")
        .add("Transfer-Encoding", "chunked")
        .build()
    assertThat(headers2).isNotEqualTo(headers1)
    assertThat(headers2.hashCode()).isNotEqualTo(headers1.hashCode().toLong())
  }

func setEventStreamHeaders(w http.ResponseWriter) {
	w.Header().Set(xhttp.ContentType, "text/event-stream")
	w.Header().Set(xhttp.CacheControl, "no-cache") // nginx to turn off buffering
	w.Header().Set("X-Accel-Buffering", "no")      // nginx to turn off buffering
}

// Write http common headers
func setCommonHeaders(w http.ResponseWriter) {
	// Set the "Server" http header.
	w.Header().Set(xhttp.ServerInfo, MinioStoreName)

Und da die `Response` häufig zum Setzen von Headern und Cookies verwendet wird, stellt **FastAPI** diese auch unter `fastapi.Response` bereit.

///

## Benutzerdefinierte Header

Beachten Sie, dass benutzerdefinierte proprietäre Header <a href="https://developer.mozilla.org/en-US/docs/Web/HTTP/Headers" class="external-link" target="_blank">mittels des Präfix 'X-'</a> hinzugefügt werden können.

///

## Duplicate headers

It is possible to receive duplicate headers. That means, the same header with multiple values.

You can define those cases using a list in the type declaration.

You will receive all the values from the duplicate header as a Python `list`.

# Header-Parameter

So wie `Query`-, `Path`-, und `Cookie`-Parameter können Sie auch <abbr title='Header – Kopfzeilen, Header, Header-Felder: Schlüssel-Wert-Metadaten, die vom Client beim Request, und vom Server bei der Response gesendet werden'>Header</abbr>-Parameter definieren.

## `Header` importieren

Importieren Sie zuerst `Header`:

//// tab | Python 3.10+

```Python hl_lines="3"
{!> ../../docs_src/header_params/tutorial001_an_py310.py!}
```

// functionality to handle SSE-C copy requests.
var SSECopy = ssecCopy{}

type ssecCopy struct{}

// IsRequested returns true if the HTTP headers contains
// at least one SSE-C copy header. Regular SSE-C headers
// are ignored.
func (ssecCopy) IsRequested(h http.Header) bool {
	if _, ok := h[xhttp.AmzServerSideEncryptionCopyCustomerAlgorithm]; ok {
		return true
	}