*   <li>ROBOTS_TXT_ENABLED_PROPERTY: Enable or disable robots.txt parsing.</li>
 *   <li>AUTHENTICATIONS_PROPERTY: Web authentications.</li>
 *   <li>REQUEST_HEADERS_PROPERTY: Custom request headers.</li>
 *   <li>REDIRECTS_ENABLED: Enable or disable HTTP redirects.</li>
 *   <li>COOKIES_PROPERTY: Cookie settings.</li>
 *   <li>AUTH_SCHEME_PROVIDERS_PROPERTY: Authentication scheme providers.</li>

///

## Add custom headers { #add-custom-headers }

There are some situations in where it's useful to be able to add custom headers to the HTTP error. For example, for some types of security.

You probably won't need to use it directly in your code.

But in case you needed it for an advanced scenario, you can add custom headers:

{* ../../docs_src/handling_errors/tutorial002_py310.py hl[14] *}

    private final Map<String, String> headers;
    private final Set<Function<ObjectNode, Boolean>> applyConditions;

    /**
     * @param headers The headers to inject
     * @param applyConditions a set of conditions that has to be satisfied in order to apply headers
     *                        If the Set is empty then headers are always applied.
     */

* [X-Forwarded-Host](https://developer.mozilla.org/en-US/docs/Web/HTTP/Reference/Headers/X-Forwarded-Host)

///

### Habilitar headers reenviados por el Proxy { #enable-proxy-forwarded-headers }

Puedes iniciar FastAPI CLI con la *Opción de CLI* `--forwarded-allow-ips` y pasar las direcciones IP que deberían ser confiables para leer esos headers reenviados.

// has been used.
// The returned reader contains the payload.
func waitForHTTPResponse(respBody io.Reader) (io.Reader, error) {
	reader := bufio.NewReader(respBody)
	for {
		b, err := reader.ReadByte()
		if err != nil {
			return nil, err
		}
		// Check if we have a response ready or a filler byte.
		switch b {
		case 0:
			return reader, nil
		case 1:
			errorText, err := io.ReadAll(reader)

    else:
        authenticate_value = "Bearer"
    credentials_exception = HTTPException(
        status_code=status.HTTP_401_UNAUTHORIZED,
        detail="Could not validate credentials",
        headers={"WWW-Authenticate": authenticate_value},
    )
    try:
        payload = jwt.decode(token, SECRET_KEY, algorithms=[ALGORITHM])
        username = payload.get("sub")
        if username is None:

}

// Set adds the ETag to the HTTP headers. It overwrites any
// existing ETag entry.
//
// Due to legacy S3 clients, that make incorrect assumptions
// about HTTP headers, Set should be used instead of
// http.Header.Set(...). Otherwise, some S3 clients will not
// able to extract the ETag.
func Set(etag ETag, h http.Header) {
	// Some (broken) S3 clients expect the ETag header to

                        .status(ApiResult.Status.OK)
                        .result());
    }

    /**
     * Retrieves a specific request header setting by ID.
     *
     * @param id the ID of the request header setting to retrieve
     * @return JSON response containing the request header setting
     */
    // GET /api/admin/reqheader/setting/{id}
    @Execute
    public JsonResponse<ApiResult> get$setting(final String id) {

        "comment_id": comment_id,
        "body": body,
    }
    response = httpx.post(
        github_graphql_url,
        headers=headers,
        timeout=settings.httpx_timeout,
        json={"query": query, "variables": variables, "operationName": "Q"},
    )
    if response.status_code != 200:
        logging.error(
            f"Response was not 200, after: {after}, category_id: {category_id}"
        )

    assert response.headers["WWW-Authenticate"] == "Digest"


def test_security_http_digest_incorrect_scheme_credentials():
    response = client.get(
        "/users/me", headers={"Authorization": "Other invalidauthorization"}
    )
    assert response.status_code == 401, response.text
    assert response.json() == {"detail": "Not authenticated"}
    assert response.headers["WWW-Authenticate"] == "Digest"