Declara los **parámetros de header** que necesitas en un **modelo Pydantic**, y luego declara el parámetro como `Header`:

{* ../../docs_src/header_param_models/tutorial001_an_py310.py hl[9:14,18] *}

**FastAPI** **extraerá** los datos para **cada campo** de los **headers** en el request y te dará el modelo Pydantic que definiste.

## Revisa la Documentación { #check-the-docs }

    assertThat(connect.headers["Proxy-Connection"]).isEqualTo("Keep-Alive")
    assertThat(connect.headers["Host"]).isEqualTo("android.com:443")
    val get = server.takeRequest()
    assertThat(get.headers["Private"]).isEqualTo("Secret")
    assertThat(get.headers["User-Agent"]).isEqualTo("App 1.0")
    assertThat(hostnameVerifier.calls).containsExactly("verify android.com")
  }

  /**

      Request
        .Builder()
        .url(server.url("/"))
        .header("", "A")
        .build()
    }
  }

  @Test
  fun emptyResponseHeaderNameIsLenient() {
    val headers = Headers.Builder()
    addHeaderLenient(headers, ":A")
    server.enqueue(
      MockResponse(
        headers = headers.build(),
        body = "body",
      ),
    )

    body.writeTo(bodyContent)

    val reader = MultipartReader(bodyContent, "boundary")

    val quickPart = reader.nextPart()!!
    assertThat(quickPart.headers).isEqualTo(
      headersOf(
        "Content-Type",
        "text/plain; charset=utf-8",
      ),
    )
    assertThat(quickPart.body.readUtf8()).isEqualTo("Quick")

    val brownPart = reader.nextPart()!!
    assertThat(brownPart.headers).isEqualTo(

          response.request
            .newBuilder()
            .header("Authorization", "XYZ")
            .build()
        }.build()
    server.enqueue(
      MockResponse(
        code = 401,
        body = "{\"error\":{\"message\":\"No auth credentials found\",\"code\":401}}",
        headers = Headers.headersOf("content-type", "application/json"),
      ),
    )
    server.enqueue(

      }

    /** Removes all headers on this builder and adds [headers]. */
    open fun headers(headers: Headers) =
      apply {
        this.headers = headers.newBuilder()
      }

    /**
     * Sets this request's `Cache-Control` header, replacing any cache control headers already
     * present. If [cacheControl] doesn't define any directives, this clears this request's
     * cache-control headers.

    val headers = headersOf("User-Agent", "RequestTest")
    val request =
      Request(
        url = url,
        headers = headers,
      )
    assertThat(request.url).isEqualTo(url)
    assertThat(request.headers).isEqualTo(headers)
    assertThat(request.method).isEqualTo("GET")
    assertThat(request.body).isNull()
    assertThat(request.tags).isEqualTo(EmptyTags)
  }

  @Test

// getCanonicalHeaders generate a list of request headers with their values
func getCanonicalHeaders(signedHeaders http.Header) string {
	var headers []string
	vals := make(http.Header, len(signedHeaders))
	for k, vv := range signedHeaders {
		k = strings.ToLower(k)
		headers = append(headers, k)
		vals[k] = vv
	}
	sort.Strings(headers)

	var buf bytes.Buffer
	for _, k := range headers {
		buf.WriteString(k)
		buf.WriteByte(':')

      )

    fun http2HeadersList(request: Request): List<Header> {
      val headers = request.headers
      val result = ArrayList<Header>(headers.size + 4)
      result.add(Header(TARGET_METHOD, request.method))
      result.add(Header(TARGET_PATH, RequestLine.requestPath(request.url)))
      val host = request.header("Host")
      if (host != null) {
        result.add(Header(TARGET_AUTHORITY, host)) // Optional.
      }

  }

  /** Accept headers from the network and store them until the client calls [takeHeaders]. */
  fun receiveHeaders(
    headers: Headers,
    inFinished: Boolean,
  ) {
    assertLockNotHeld()

    val open: Boolean
    withLock {
      if (!hasResponseHeaders ||
        headers[Header.RESPONSE_STATUS_UTF8] != null ||
        headers[Header.TARGET_METHOD_UTF8] != null
      ) {