Title: WP_REST_Server
Published: December 9, 2015
Last modified: February 24, 2026

---

# class WP_REST_Server {}

## In this article

 * [Methods](https://developer.wordpress.org/reference/classes/WP_REST_Server/?output_format=md#methods)
 * [Source](https://developer.wordpress.org/reference/classes/WP_REST_Server/?output_format=md#source)
 * [Changelog](https://developer.wordpress.org/reference/classes/WP_REST_Server/?output_format=md#changelog)
 * [User Contributed Notes](https://developer.wordpress.org/reference/classes/WP_REST_Server/?output_format=md#user-contributed-notes)

[ Back to top](https://developer.wordpress.org/reference/classes/WP_REST_Server/?output_format=md#wp--skip-link--target)

Core class used to implement the WordPress REST API server.

## 󠀁[Methods](https://developer.wordpress.org/reference/classes/WP_REST_Server/?output_format=md#methods)󠁿

| Name | Description | 
| [WP_REST_Server::__construct](https://developer.wordpress.org/reference/classes/wp_rest_server/__construct/) | Instantiates the REST server. | 
| [WP_REST_Server::add_active_theme_link_to_index](https://developer.wordpress.org/reference/classes/wp_rest_server/add_active_theme_link_to_index/) | Adds a link to the active theme for users who have proper permissions. | 
| [WP_REST_Server::add_image_to_index](https://developer.wordpress.org/reference/classes/wp_rest_server/add_image_to_index/) | Exposes an image through the WordPress REST API. | 
| [WP_REST_Server::add_site_icon_to_index](https://developer.wordpress.org/reference/classes/wp_rest_server/add_site_icon_to_index/) | Exposes the site icon through the WordPress REST API. | 
| [WP_REST_Server::add_site_logo_to_index](https://developer.wordpress.org/reference/classes/wp_rest_server/add_site_logo_to_index/) | Exposes the site logo through the WordPress REST API. | 
| [WP_REST_Server::check_authentication](https://developer.wordpress.org/reference/classes/wp_rest_server/check_authentication/) | Checks the authentication headers if supplied. | 
| [WP_REST_Server::dispatch](https://developer.wordpress.org/reference/classes/wp_rest_server/dispatch/) | Matches the request to a callback and call it. | 
| [WP_REST_Server::embed_links](https://developer.wordpress.org/reference/classes/wp_rest_server/embed_links/) | Embeds the links from the data into the request. | 
| [WP_REST_Server::envelope_response](https://developer.wordpress.org/reference/classes/wp_rest_server/envelope_response/) | Wraps the response in an envelope. | 
| [WP_REST_Server::error_to_response](https://developer.wordpress.org/reference/classes/wp_rest_server/error_to_response/) | Converts an error to a response object. | 
| [WP_REST_Server::get_compact_response_links](https://developer.wordpress.org/reference/classes/wp_rest_server/get_compact_response_links/) | Retrieves the CURIEs (compact URIs) used for relations. | 
| [WP_REST_Server::get_data_for_route](https://developer.wordpress.org/reference/classes/wp_rest_server/get_data_for_route/) | Retrieves publicly-visible data for the route. | 
| [WP_REST_Server::get_data_for_routes](https://developer.wordpress.org/reference/classes/wp_rest_server/get_data_for_routes/) | Retrieves the publicly-visible data for routes. | 
| [WP_REST_Server::get_headers](https://developer.wordpress.org/reference/classes/wp_rest_server/get_headers/) | Extracts headers from a PHP-style $_SERVER array. | 
| [WP_REST_Server::get_index](https://developer.wordpress.org/reference/classes/wp_rest_server/get_index/) | Retrieves the site index. | 
| [WP_REST_Server::get_json_encode_options](https://developer.wordpress.org/reference/classes/wp_rest_server/get_json_encode_options/) | Gets the encoding options passed to wp_json_encode. | 
| [WP_REST_Server::get_json_last_error](https://developer.wordpress.org/reference/classes/wp_rest_server/get_json_last_error/) | Returns if an error occurred during most recent JSON encode/decode. | 
| [WP_REST_Server::get_max_batch_size](https://developer.wordpress.org/reference/classes/wp_rest_server/get_max_batch_size/) | Gets the maximum number of requests that can be included in a batch. | 
| [WP_REST_Server::get_namespace_index](https://developer.wordpress.org/reference/classes/wp_rest_server/get_namespace_index/) | Retrieves the index for a namespace. | 
| [WP_REST_Server::get_namespaces](https://developer.wordpress.org/reference/classes/wp_rest_server/get_namespaces/) | Retrieves namespaces registered on the server. | 
| [WP_REST_Server::get_raw_data](https://developer.wordpress.org/reference/classes/wp_rest_server/get_raw_data/) | Retrieves the raw request entity (body). | 
| [WP_REST_Server::get_response_links](https://developer.wordpress.org/reference/classes/wp_rest_server/get_response_links/) | Retrieves links from a response. | 
| [WP_REST_Server::get_route_options](https://developer.wordpress.org/reference/classes/wp_rest_server/get_route_options/) | Retrieves specified options for a route. | 
| [WP_REST_Server::get_routes](https://developer.wordpress.org/reference/classes/wp_rest_server/get_routes/) | Retrieves the route map. | 
| [WP_REST_Server::get_target_hints_for_link](https://developer.wordpress.org/reference/classes/wp_rest_server/get_target_hints_for_link/) | Gets the target hints for a REST API Link. | 
| [WP_REST_Server::is_dispatching](https://developer.wordpress.org/reference/classes/wp_rest_server/is_dispatching/) | Returns whether the REST server is currently dispatching / responding to a request. | 
| [WP_REST_Server::json_error](https://developer.wordpress.org/reference/classes/wp_rest_server/json_error/) | Retrieves an appropriate error representation in JSON. | 
| [WP_REST_Server::match_request_to_handler](https://developer.wordpress.org/reference/classes/wp_rest_server/match_request_to_handler/) | Matches a request object to its handler. | 
| [WP_REST_Server::register_route](https://developer.wordpress.org/reference/classes/wp_rest_server/register_route/) | Registers a route to the server. | 
| [WP_REST_Server::remove_header](https://developer.wordpress.org/reference/classes/wp_rest_server/remove_header/) | Removes an HTTP header from the current response. | 
| [WP_REST_Server::respond_to_request](https://developer.wordpress.org/reference/classes/wp_rest_server/respond_to_request/) | Dispatches the request to the callback handler. | 
| [WP_REST_Server::response_to_data](https://developer.wordpress.org/reference/classes/wp_rest_server/response_to_data/) | Converts a response to data to send. | 
| [WP_REST_Server::send_header](https://developer.wordpress.org/reference/classes/wp_rest_server/send_header/) | Sends an HTTP header. | 
| [WP_REST_Server::send_headers](https://developer.wordpress.org/reference/classes/wp_rest_server/send_headers/) | Sends multiple HTTP headers. | 
| [WP_REST_Server::serve_batch_request_v1](https://developer.wordpress.org/reference/classes/wp_rest_server/serve_batch_request_v1/) | Serves the batch/v1 request. | 
| [WP_REST_Server::serve_request](https://developer.wordpress.org/reference/classes/wp_rest_server/serve_request/) | Handles serving a REST API request. | 
| [WP_REST_Server::set_status](https://developer.wordpress.org/reference/classes/wp_rest_server/set_status/) | Sends an HTTP status code. |

## 󠀁[Source](https://developer.wordpress.org/reference/classes/WP_REST_Server/?output_format=md#source)󠁿

    ```php
    class WP_REST_Server {

    	/**
    	 * Alias for GET transport method.
    	 *
    	 * @since 4.4.0
    	 * @var string
    	 */
    	const READABLE = 'GET';

    	/**
    	 * Alias for POST transport method.
    	 *
    	 * @since 4.4.0
    	 * @var string
    	 */
    	const CREATABLE = 'POST';

    	/**
    	 * Alias for POST, PUT, PATCH transport methods together.
    	 *
    	 * @since 4.4.0
    	 * @var string
    	 */
    	const EDITABLE = 'POST, PUT, PATCH';

    	/**
    	 * Alias for DELETE transport method.
    	 *
    	 * @since 4.4.0
    	 * @var string
    	 */
    	const DELETABLE = 'DELETE';

    	/**
    	 * Alias for GET, POST, PUT, PATCH & DELETE transport methods together.
    	 *
    	 * @since 4.4.0
    	 * @var string
    	 */
    	const ALLMETHODS = 'GET, POST, PUT, PATCH, DELETE';

    	/**
    	 * Namespaces registered to the server.
    	 *
    	 * @since 4.4.0
    	 * @var array
    	 */
    	protected $namespaces = array();

    	/**
    	 * Endpoints registered to the server.
    	 *
    	 * @since 4.4.0
    	 * @var array
    	 */
    	protected $endpoints = array();

    	/**
    	 * Options defined for the routes.
    	 *
    	 * @since 4.4.0
    	 * @var array
    	 */
    	protected $route_options = array();

    	/**
    	 * Caches embedded requests.
    	 *
    	 * @since 5.4.0
    	 * @var array
    	 */
    	protected $embed_cache = array();

    	/**
    	 * Stores request objects that are currently being handled.
    	 *
    	 * @since 6.5.0
    	 * @var array
    	 */
    	protected $dispatching_requests = array();

    	/**
    	 * Instantiates the REST server.
    	 *
    	 * @since 4.4.0
    	 */
    	public function __construct() {
    		$this->endpoints = array(
    			// Meta endpoints.
    			'/'         => array(
    				'callback' => array( $this, 'get_index' ),
    				'methods'  => 'GET',
    				'args'     => array(
    					'context' => array(
    						'default' => 'view',
    					),
    				),
    			),
    			'/batch/v1' => array(
    				'callback' => array( $this, 'serve_batch_request_v1' ),
    				'methods'  => 'POST',
    				'args'     => array(
    					'validation' => array(
    						'type'    => 'string',
    						'enum'    => array( 'require-all-validate', 'normal' ),
    						'default' => 'normal',
    					),
    					'requests'   => array(
    						'required' => true,
    						'type'     => 'array',
    						'maxItems' => $this->get_max_batch_size(),
    						'items'    => array(
    							'type'       => 'object',
    							'properties' => array(
    								'method'  => array(
    									'type'    => 'string',
    									'enum'    => array( 'POST', 'PUT', 'PATCH', 'DELETE' ),
    									'default' => 'POST',
    								),
    								'path'    => array(
    									'type'     => 'string',
    									'required' => true,
    								),
    								'body'    => array(
    									'type'                 => 'object',
    									'properties'           => array(),
    									'additionalProperties' => true,
    								),
    								'headers' => array(
    									'type'                 => 'object',
    									'properties'           => array(),
    									'additionalProperties' => array(
    										'type'  => array( 'string', 'array' ),
    										'items' => array(
    											'type' => 'string',
    										),
    									),
    								),
    							),
    						),
    					),
    				),
    			),
    		);
    	}


    	/**
    	 * Checks the authentication headers if supplied.
    	 *
    	 * @since 4.4.0
    	 *
    	 * @return WP_Error|null|true WP_Error if authentication error occurred, null if authentication
    	 *                            method wasn't used, true if authentication succeeded.
    	 */
    	public function check_authentication() {
    		/**
    		 * Filters REST API authentication errors.
    		 *
    		 * This is used to pass a WP_Error from an authentication method back to
    		 * the API.
    		 *
    		 * Authentication methods should check first if they're being used, as
    		 * multiple authentication methods can be enabled on a site (cookies,
    		 * HTTP basic auth, OAuth). If the authentication method hooked in is
    		 * not actually being attempted, null should be returned to indicate
    		 * another authentication method should check instead. Similarly,
    		 * callbacks should ensure the value is `null` before checking for
    		 * errors.
    		 *
    		 * A WP_Error instance can be returned if an error occurs, and this should
    		 * match the format used by API methods internally (that is, the `status`
    		 * data should be used). A callback can return `true` to indicate that
    		 * the authentication method was used, and it succeeded.
    		 *
    		 * @since 4.4.0
    		 *
    		 * @param WP_Error|null|true $errors WP_Error if authentication error occurred, null if authentication
    		 *                                   method wasn't used, true if authentication succeeded.
    		 */
    		return apply_filters( 'rest_authentication_errors', null );
    	}

    	/**
    	 * Converts an error to a response object.
    	 *
    	 * This iterates over all error codes and messages to change it into a flat
    	 * array. This enables simpler client behavior, as it is represented as a
    	 * list in JSON rather than an object/map.
    	 *
    	 * @since 4.4.0
    	 * @since 5.7.0 Converted to a wrapper of rest_convert_error_to_response().
    	 *
    	 * @param WP_Error $error WP_Error instance.
    	 * @return WP_REST_Response List of associative arrays with code and message keys.
    	 */
    	protected function error_to_response( $error ) {
    		return rest_convert_error_to_response( $error );
    	}

    	/**
    	 * Retrieves an appropriate error representation in JSON.
    	 *
    	 * Note: This should only be used in WP_REST_Server::serve_request(), as it
    	 * cannot handle WP_Error internally. All callbacks and other internal methods
    	 * should instead return a WP_Error with the data set to an array that includes
    	 * a 'status' key, with the value being the HTTP status to send.
    	 *
    	 * @since 4.4.0
    	 *
    	 * @param string   $code    WP_Error-style code.
    	 * @param string   $message Human-readable message.
    	 * @param int|null $status  Optional. HTTP status code to send. Default null.
    	 * @return string JSON representation of the error.
    	 */
    	protected function json_error( $code, $message, $status = null ) {
    		if ( $status ) {
    			$this->set_status( $status );
    		}

    		$error = compact( 'code', 'message' );

    		return wp_json_encode( $error );
    	}

    	/**
    	 * Gets the encoding options passed to wp_json_encode.
    	 *
    	 * @since 6.1.0
    	 *
    	 * @param \WP_REST_Request $request The current request object.
    	 *
    	 * @return int The JSON encode options.
    	 */
    	protected function get_json_encode_options( WP_REST_Request $request ) {
    		$options = 0;

    		if ( $request->has_param( '_pretty' ) ) {
    			$options |= JSON_PRETTY_PRINT;
    		}

    		/**
    		 * Filters the JSON encoding options used to send the REST API response.
    		 *
    		 * @since 6.1.0
    		 *
    		 * @param int $options             JSON encoding options json_encode().
    		 * @param WP_REST_Request $request Current request object.
    		 */
    		return apply_filters( 'rest_json_encode_options', $options, $request );
    	}

    	/**
    	 * Handles serving a REST API request.
    	 *
    	 * Matches the current server URI to a route and runs the first matching
    	 * callback then outputs a JSON representation of the returned value.
    	 *
    	 * @since 4.4.0
    	 *
    	 * @see WP_REST_Server::dispatch()
    	 *
    	 * @global WP_User $current_user The currently authenticated user.
    	 *
    	 * @param string|null $path Optional. The request route. If not set, `$_SERVER['PATH_INFO']` will be used.
    	 *                          Default null.
    	 * @return null|false Null if not served and a HEAD request, false otherwise.
    	 */
    	public function serve_request( $path = null ) {
    		/* @var WP_User|null $current_user */
    		global $current_user;

    		if ( $current_user instanceof WP_User && ! $current_user->exists() ) {
    			/*
    			 * If there is no current user authenticated via other means, clear
    			 * the cached lack of user, so that an authenticate check can set it
    			 * properly.
    			 *
    			 * This is done because for authentications such as Application
    			 * Passwords, we don't want it to be accepted unless the current HTTP
    			 * request is a REST API request, which can't always be identified early
    			 * enough in evaluation.
    			 */
    			$current_user = null;
    		}

    		/**
    		 * Filters whether JSONP is enabled for the REST API.
    		 *
    		 * @since 4.4.0
    		 *
    		 * @param bool $jsonp_enabled Whether JSONP is enabled. Default true.
    		 */
    		$jsonp_enabled = apply_filters( 'rest_jsonp_enabled', true );

    		$jsonp_callback = false;
    		if ( isset( $_GET['_jsonp'] ) ) {
    			$jsonp_callback = $_GET['_jsonp'];
    		}

    		$content_type = ( $jsonp_callback && $jsonp_enabled ) ? 'application/javascript' : 'application/json';
    		$this->send_header( 'Content-Type', $content_type . '; charset=' . get_option( 'blog_charset' ) );
    		$this->send_header( 'X-Robots-Tag', 'noindex' );

    		$api_root = get_rest_url();
    		if ( ! empty( $api_root ) ) {
    			$this->send_header( 'Link', '<' . sanitize_url( $api_root ) . '>; rel="https://api.w.org/"' );
    		}

    		/*
    		 * Mitigate possible JSONP Flash attacks.
    		 *
    		 * https://miki.it/blog/2014/7/8/abusing-jsonp-with-rosetta-flash/
    		 */
    		$this->send_header( 'X-Content-Type-Options', 'nosniff' );

    		/**
    		 * Filters whether the REST API is enabled.
    		 *
    		 * @since 4.4.0
    		 * @deprecated 4.7.0 Use the 'rest_authentication_errors' filter to
    		 *                   restrict access to the REST API.
    		 *
    		 * @param bool $rest_enabled Whether the REST API is enabled. Default true.
    		 */
    		apply_filters_deprecated(
    			'rest_enabled',
    			array( true ),
    			'4.7.0',
    			'rest_authentication_errors',
    			sprintf(
    				/* translators: %s: rest_authentication_errors */
    				__( 'The REST API can no longer be completely disabled, the %s filter can be used to restrict access to the API, instead.' ),
    				'rest_authentication_errors'
    			)
    		);

    		if ( $jsonp_callback ) {
    			if ( ! $jsonp_enabled ) {
    				echo $this->json_error( 'rest_callback_disabled', __( 'JSONP support is disabled on this site.' ), 400 );
    				return false;
    			}

    			if ( ! wp_check_jsonp_callback( $jsonp_callback ) ) {
    				echo $this->json_error( 'rest_callback_invalid', __( 'Invalid JSONP callback function.' ), 400 );
    				return false;
    			}
    		}

    		if ( empty( $path ) ) {
    			if ( isset( $_SERVER['PATH_INFO'] ) ) {
    				$path = $_SERVER['PATH_INFO'];
    			} else {
    				$path = '/';
    			}
    		}

    		$request = new WP_REST_Request( $_SERVER['REQUEST_METHOD'], $path );

    		$request->set_query_params( wp_unslash( $_GET ) );
    		$request->set_body_params( wp_unslash( $_POST ) );
    		$request->set_file_params( $_FILES );
    		$request->set_headers( $this->get_headers( wp_unslash( $_SERVER ) ) );
    		$request->set_body( self::get_raw_data() );

    		/*
    		 * HTTP method override for clients that can't use PUT/PATCH/DELETE. First, we check
    		 * $_GET['_method']. If that is not set, we check for the HTTP_X_HTTP_METHOD_OVERRIDE
    		 * header.
    		 */
    		$method_overridden = false;
    		if ( isset( $_GET['_method'] ) ) {
    			$request->set_method( $_GET['_method'] );
    		} elseif ( isset( $_SERVER['HTTP_X_HTTP_METHOD_OVERRIDE'] ) ) {
    			$request->set_method( $_SERVER['HTTP_X_HTTP_METHOD_OVERRIDE'] );
    			$method_overridden = true;
    		}

    		$expose_headers = array( 'X-WP-Total', 'X-WP-TotalPages', 'Link' );

    		/**
    		 * Filters the list of response headers that are exposed to REST API CORS requests.
    		 *
    		 * @since 5.5.0
    		 * @since 6.3.0 The `$request` parameter was added.
    		 *
    		 * @param string[]        $expose_headers The list of response headers to expose.
    		 * @param WP_REST_Request $request        The request in context.
    		 */
    		$expose_headers = apply_filters( 'rest_exposed_cors_headers', $expose_headers, $request );

    		$this->send_header( 'Access-Control-Expose-Headers', implode( ', ', $expose_headers ) );

    		$allow_headers = array(
    			'Authorization',
    			'X-WP-Nonce',
    			'Content-Disposition',
    			'Content-MD5',
    			'Content-Type',
    		);

    		/**
    		 * Filters the list of request headers that are allowed for REST API CORS requests.
    		 *
    		 * The allowed headers are passed to the browser to specify which
    		 * headers can be passed to the REST API. By default, we allow the
    		 * Content-* headers needed to upload files to the media endpoints.
    		 * As well as the Authorization and Nonce headers for allowing authentication.
    		 *
    		 * @since 5.5.0
    		 * @since 6.3.0 The `$request` parameter was added.
    		 *
    		 * @param string[]        $allow_headers The list of request headers to allow.
    		 * @param WP_REST_Request $request       The request in context.
    		 */
    		$allow_headers = apply_filters( 'rest_allowed_cors_headers', $allow_headers, $request );

    		$this->send_header( 'Access-Control-Allow-Headers', implode( ', ', $allow_headers ) );

    		$result = $this->check_authentication();

    		if ( ! is_wp_error( $result ) ) {
    			$result = $this->dispatch( $request );
    		}

    		// Normalize to either WP_Error or WP_REST_Response...
    		$result = rest_ensure_response( $result );

    		// ...then convert WP_Error across.
    		if ( is_wp_error( $result ) ) {
    			$result = $this->error_to_response( $result );
    		}

    		/**
    		 * Filters the REST API response.
    		 *
    		 * Allows modification of the response before returning.
    		 *
    		 * @since 4.4.0
    		 * @since 4.5.0 Applied to embedded responses.
    		 *
    		 * @param WP_HTTP_Response $result  Result to send to the client. Usually a `WP_REST_Response`.
    		 * @param WP_REST_Server   $server  Server instance.
    		 * @param WP_REST_Request  $request Request used to generate the response.
    		 */
    		$result = apply_filters( 'rest_post_dispatch', rest_ensure_response( $result ), $this, $request );

    		// Wrap the response in an envelope if asked for.
    		if ( isset( $_GET['_envelope'] ) ) {
    			$embed  = isset( $_GET['_embed'] ) ? rest_parse_embed_param( $_GET['_embed'] ) : false;
    			$result = $this->envelope_response( $result, $embed );
    		}

    		// Send extra data from response objects.
    		$headers = $result->get_headers();
    		$this->send_headers( $headers );

    		$code = $result->get_status();
    		$this->set_status( $code );

    		/**
    		 * Filters whether to send no-cache headers on a REST API request.
    		 *
    		 * @since 4.4.0
    		 * @since 6.3.2 Moved the block to catch the filter added on rest_cookie_check_errors() from wp-includes/rest-api.php.
    		 *
    		 * @param bool $rest_send_nocache_headers Whether to send no-cache headers.
    		 */
    		$send_no_cache_headers = apply_filters( 'rest_send_nocache_headers', is_user_logged_in() );

    		/*
    		 * Send no-cache headers if $send_no_cache_headers is true,
    		 * OR if the HTTP_X_HTTP_METHOD_OVERRIDE is used but resulted a 4xx response code.
    		 */
    		if ( $send_no_cache_headers || ( true === $method_overridden && str_starts_with( $code, '4' ) ) ) {
    			foreach ( wp_get_nocache_headers() as $header => $header_value ) {
    				if ( empty( $header_value ) ) {
    					$this->remove_header( $header );
    				} else {
    					$this->send_header( $header, $header_value );
    				}
    			}
    		}

    		/**
    		 * Filters whether the REST API request has already been served.
    		 *
    		 * Allow sending the request manually - by returning true, the API result
    		 * will not be sent to the client.
    		 *
    		 * @since 4.4.0
    		 *
    		 * @param bool             $served  Whether the request has already been served.
    		 *                                           Default false.
    		 * @param WP_HTTP_Response $result  Result to send to the client. Usually a `WP_REST_Response`.
    		 * @param WP_REST_Request  $request Request used to generate the response.
    		 * @param WP_REST_Server   $server  Server instance.
    		 */
    		$served = apply_filters( 'rest_pre_serve_request', false, $result, $request, $this );

    		if ( ! $served ) {
    			if ( 'HEAD' === $request->get_method() ) {
    				return null;
    			}

    			// Embed links inside the request.
    			$embed  = isset( $_GET['_embed'] ) ? rest_parse_embed_param( $_GET['_embed'] ) : false;
    			$result = $this->response_to_data( $result, $embed );

    			/**
    			 * Filters the REST API response.
    			 *
    			 * Allows modification of the response data after inserting
    			 * embedded data (if any) and before echoing the response data.
    			 *
    			 * @since 4.8.1
    			 *
    			 * @param array            $result  Response data to send to the client.
    			 * @param WP_REST_Server   $server  Server instance.
    			 * @param WP_REST_Request  $request Request used to generate the response.
    			 */
    			$result = apply_filters( 'rest_pre_echo_response', $result, $this, $request );

    			// The 204 response shouldn't have a body.
    			if ( 204 === $code || null === $result ) {
    				return null;
    			}

    			$result = wp_json_encode( $result, $this->get_json_encode_options( $request ) );

    			$json_error_message = $this->get_json_last_error();

    			if ( $json_error_message ) {
    				$this->set_status( 500 );
    				$json_error_obj = new WP_Error(
    					'rest_encode_error',
    					$json_error_message,
    					array( 'status' => 500 )
    				);

    				$result = $this->error_to_response( $json_error_obj );
    				$result = wp_json_encode( $result->data, $this->get_json_encode_options( $request ) );
    			}

    			if ( $jsonp_callback ) {
    				// Prepend '/**/' to mitigate possible JSONP Flash attacks.
    				// https://miki.it/blog/2014/7/8/abusing-jsonp-with-rosetta-flash/
    				echo '/**/' . $jsonp_callback . '(' . $result . ')';
    			} else {
    				echo $result;
    			}
    		}

    		return null;
    	}

    	/**
    	 * Converts a response to data to send.
    	 *
    	 * @since 4.4.0
    	 * @since 5.4.0 The `$embed` parameter can now contain a list of link relations to include.
    	 *
    	 * @param WP_REST_Response $response Response object.
    	 * @param bool|string[]    $embed    Whether to embed all links, a filtered list of link relations, or no links.
    	 * @return array {
    	 *     Data with sub-requests embedded.
    	 *
    	 *     @type array $_links    Links.
    	 *     @type array $_embedded Embedded objects.
    	 * }
    	 */
    	public function response_to_data( $response, $embed ) {
    		$data  = $response->get_data();
    		$links = self::get_compact_response_links( $response );

    		if ( ! empty( $links ) ) {
    			// Convert links to part of the data.
    			$data['_links'] = $links;
    		}

    		if ( $embed ) {
    			$this->embed_cache = array();
    			// Determine if this is a numeric array.
    			if ( wp_is_numeric_array( $data ) ) {
    				foreach ( $data as $key => $item ) {
    					$data[ $key ] = $this->embed_links( $item, $embed );
    				}
    			} else {
    				$data = $this->embed_links( $data, $embed );
    			}
    			$this->embed_cache = array();
    		}

    		return $data;
    	}

    	/**
    	 * Retrieves links from a response.
    	 *
    	 * Extracts the links from a response into a structured hash, suitable for
    	 * direct output.
    	 *
    	 * @since 4.4.0
    	 *
    	 * @param WP_REST_Response $response Response to extract links from.
    	 * @return array Map of link relation to list of link hashes.
    	 */
    	public static function get_response_links( $response ) {
    		$links = $response->get_links();

    		if ( empty( $links ) ) {
    			return array();
    		}

    		// Convert links to part of the data.
    		$data = array();
    		foreach ( $links as $rel => $items ) {
    			$data[ $rel ] = array();

    			foreach ( $items as $item ) {
    				$attributes         = $item['attributes'];
    				$attributes['href'] = $item['href'];

    				if ( 'self' !== $rel ) {
    					$data[ $rel ][] = $attributes;
    					continue;
    				}

    				$target_hints = self::get_target_hints_for_link( $attributes );
    				if ( $target_hints ) {
    					$attributes['targetHints'] = $target_hints;
    				}

    				$data[ $rel ][] = $attributes;
    			}
    		}

    		return $data;
    	}

    	/**
    	 * Gets the target hints for a REST API Link.
    	 *
    	 * @since 6.7.0
    	 *
    	 * @param array $link The link to get target hints for.
    	 * @return array|null
    	 */
    	protected static function get_target_hints_for_link( $link ) {
    		// Prefer targetHints that were specifically designated by the developer.
    		if ( isset( $link['targetHints']['allow'] ) ) {
    			return null;
    		}

    		$request = WP_REST_Request::from_url( $link['href'] );
    		if ( ! $request ) {
    			return null;
    		}

    		$server = rest_get_server();
    		$match  = $server->match_request_to_handler( $request );

    		if ( is_wp_error( $match ) ) {
    			return null;
    		}

    		if ( is_wp_error( $request->has_valid_params() ) ) {
    			return null;
    		}

    		if ( is_wp_error( $request->sanitize_params() ) ) {
    			return null;
    		}

    		$target_hints = array();

    		$response = new WP_REST_Response();
    		$response->set_matched_route( $match[0] );
    		$response->set_matched_handler( $match[1] );
    		$headers = rest_send_allow_header( $response, $server, $request )->get_headers();

    		foreach ( $headers as $name => $value ) {
    			$name = WP_REST_Request::canonicalize_header_name( $name );

    			$target_hints[ $name ] = array_map( 'trim', explode( ',', $value ) );
    		}

    		return $target_hints;
    	}

    	/**
    	 * Retrieves the CURIEs (compact URIs) used for relations.
    	 *
    	 * Extracts the links from a response into a structured hash, suitable for
    	 * direct output.
    	 *
    	 * @since 4.5.0
    	 *
    	 * @param WP_REST_Response $response Response to extract links from.
    	 * @return array Map of link relation to list of link hashes.
    	 */
    	public static function get_compact_response_links( $response ) {
    		$links = self::get_response_links( $response );

    		if ( empty( $links ) ) {
    			return array();
    		}

    		$curies      = $response->get_curies();
    		$used_curies = array();

    		foreach ( $links as $rel => $items ) {

    			// Convert $rel URIs to their compact versions if they exist.
    			foreach ( $curies as $curie ) {
    				$href_prefix = substr( $curie['href'], 0, strpos( $curie['href'], '{rel}' ) );
    				if ( ! str_starts_with( $rel, $href_prefix ) ) {
    					continue;
    				}

    				// Relation now changes from '$uri' to '$curie:$relation'.
    				$rel_regex = str_replace( '\{rel\}', '(.+)', preg_quote( $curie['href'], '!' ) );
    				preg_match( '!' . $rel_regex . '!', $rel, $matches );
    				if ( $matches ) {
    					$new_rel                       = $curie['name'] . ':' . $matches[1];
    					$used_curies[ $curie['name'] ] = $curie;
    					$links[ $new_rel ]             = $items;
    					unset( $links[ $rel ] );
    					break;
    				}
    			}
    		}

    		// Push the curies onto the start of the links array.
    		if ( $used_curies ) {
    			$links['curies'] = array_values( $used_curies );
    		}

    		return $links;
    	}

    	/**
    	 * Embeds the links from the data into the request.
    	 *
    	 * @since 4.4.0
    	 * @since 5.4.0 The `$embed` parameter can now contain a list of link relations to include.
    	 *
    	 * @param array         $data  Data from the request.
    	 * @param bool|string[] $embed Whether to embed all links or a filtered list of link relations.
    	 *                             Default true.
    	 * @return array {
    	 *     Data with sub-requests embedded.
    	 *
    	 *     @type array $_links    Links.
    	 *     @type array $_embedded Embedded objects.
    	 * }
    	 */
    	protected function embed_links( $data, $embed = true ) {
    		if ( empty( $data['_links'] ) ) {
    			return $data;
    		}

    		$embedded = array();

    		foreach ( $data['_links'] as $rel => $links ) {
    			/*
    			 * If a list of relations was specified, and the link relation
    			 * is not in the list of allowed relations, don't process the link.
    			 */
    			if ( is_array( $embed ) && ! in_array( $rel, $embed, true ) ) {
    				continue;
    			}

    			$embeds = array();

    			foreach ( $links as $item ) {
    				// Determine if the link is embeddable.
    				if ( empty( $item['embeddable'] ) ) {
    					// Ensure we keep the same order.
    					$embeds[] = array();
    					continue;
    				}

    				if ( ! array_key_exists( $item['href'], $this->embed_cache ) ) {
    					// Run through our internal routing and serve.
    					$request = WP_REST_Request::from_url( $item['href'] );
    					if ( ! $request ) {
    						$embeds[] = array();
    						continue;
    					}

    					// Embedded resources get passed context=embed.
    					if ( empty( $request['context'] ) ) {
    						$request['context'] = 'embed';
    					}

    					if ( empty( $request['per_page'] ) ) {
    						$matched = $this->match_request_to_handler( $request );
    						if ( ! is_wp_error( $matched ) && isset( $matched[1]['args']['per_page']['maximum'] ) ) {
    							$request['per_page'] = (int) $matched[1]['args']['per_page']['maximum'];
    						}
    					}

    					$response = $this->dispatch( $request );

    					/** This filter is documented in wp-includes/rest-api/class-wp-rest-server.php */
    					$response = apply_filters( 'rest_post_dispatch', rest_ensure_response( $response ), $this, $request );

    					$this->embed_cache[ $item['href'] ] = $this->response_to_data( $response, false );
    				}

    				$embeds[] = $this->embed_cache[ $item['href'] ];
    			}

    			// Determine if any real links were found.
    			$has_links = count( array_filter( $embeds ) );

    			if ( $has_links ) {
    				$embedded[ $rel ] = $embeds;
    			}
    		}

    		if ( ! empty( $embedded ) ) {
    			$data['_embedded'] = $embedded;
    		}

    		return $data;
    	}

    	/**
    	 * Wraps the response in an envelope.
    	 *
    	 * The enveloping technique is used to work around browser/client
    	 * compatibility issues. Essentially, it converts the full HTTP response to
    	 * data instead.
    	 *
    	 * @since 4.4.0
    	 * @since 6.0.0 The `$embed` parameter can now contain a list of link relations to include.
    	 *
    	 * @param WP_REST_Response $response Response object.
    	 * @param bool|string[]    $embed    Whether to embed all links, a filtered list of link relations, or no links.
    	 * @return WP_REST_Response New response with wrapped data
    	 */
    	public function envelope_response( $response, $embed ) {
    		$envelope = array(
    			'body'    => $this->response_to_data( $response, $embed ),
    			'status'  => $response->get_status(),
    			'headers' => $response->get_headers(),
    		);

    		/**
    		 * Filters the enveloped form of a REST API response.
    		 *
    		 * @since 4.4.0
    		 *
    		 * @param array            $envelope {
    		 *     Envelope data.
    		 *
    		 *     @type array $body    Response data.
    		 *     @type int   $status  The 3-digit HTTP status code.
    		 *     @type array $headers Map of header name to header value.
    		 * }
    		 * @param WP_REST_Response $response Original response data.
    		 */
    		$envelope = apply_filters( 'rest_envelope_response', $envelope, $response );

    		// Ensure it's still a response and return.
    		return rest_ensure_response( $envelope );
    	}

    	/**
    	 * Registers a route to the server.
    	 *
    	 * @since 4.4.0
    	 *
    	 * @param string $route_namespace Namespace.
    	 * @param string $route           The REST route.
    	 * @param array  $route_args      Route arguments.
    	 * @param bool   $override        Optional. Whether the route should be overridden if it already exists.
    	 *                                Default false.
    	 */
    	public function register_route( $route_namespace, $route, $route_args, $override = false ) {
    		if ( ! isset( $this->namespaces[ $route_namespace ] ) ) {
    			$this->namespaces[ $route_namespace ] = array();

    			$this->register_route(
    				$route_namespace,
    				'/' . $route_namespace,
    				array(
    					array(
    						'methods'  => self::READABLE,
    						'callback' => array( $this, 'get_namespace_index' ),
    						'args'     => array(
    							'namespace' => array(
    								'default' => $route_namespace,
    							),
    							'context'   => array(
    								'default' => 'view',
    							),
    						),
    					),
    				)
    			);
    		}

    		// Associative to avoid double-registration.
    		$this->namespaces[ $route_namespace ][ $route ] = true;

    		$route_args['namespace'] = $route_namespace;

    		if ( $override || empty( $this->endpoints[ $route ] ) ) {
    			$this->endpoints[ $route ] = $route_args;
    		} else {
    			$this->endpoints[ $route ] = array_merge( $this->endpoints[ $route ], $route_args );
    		}
    	}

    	/**
    	 * Retrieves the route map.
    	 *
    	 * The route map is an associative array with path regexes as the keys. The
    	 * value is an indexed array with the callback function/method as the first
    	 * item, and a bitmask of HTTP methods as the second item (see the class
    	 * constants).
    	 *
    	 * Each route can be mapped to more than one callback by using an array of
    	 * the indexed arrays. This allows mapping e.g. GET requests to one callback
    	 * and POST requests to another.
    	 *
    	 * Note that the path regexes (array keys) must have @ escaped, as this is
    	 * used as the delimiter with preg_match()
    	 *
    	 * @since 4.4.0
    	 * @since 5.4.0 Added `$route_namespace` parameter.
    	 *
    	 * @param string $route_namespace Optionally, only return routes in the given namespace.
    	 * @return array `'/path/regex' => array( $callback, $bitmask )` or
    	 *               `'/path/regex' => array( array( $callback, $bitmask ), ...)`.
    	 */
    	public function get_routes( $route_namespace = '' ) {
    		$endpoints = $this->endpoints;

    		if ( $route_namespace ) {
    			$endpoints = wp_list_filter( $endpoints, array( 'namespace' => $route_namespace ) );
    		}

    		/**
    		 * Filters the array of available REST API endpoints.
    		 *
    		 * @since 4.4.0
    		 *
    		 * @param array $endpoints The available endpoints. An array of matching regex patterns, each mapped
    		 *                         to an array of callbacks for the endpoint. These take the format
    		 *                         `'/path/regex' => array( $callback, $bitmask )` or
    		 *                         `'/path/regex' => array( array( $callback, $bitmask ).
    		 */
    		$endpoints = apply_filters( 'rest_endpoints', $endpoints );

    		// Normalize the endpoints.
    		$defaults = array(
    			'methods'       => '',
    			'accept_json'   => false,
    			'accept_raw'    => false,
    			'show_in_index' => true,
    			'args'          => array(),
    		);

    		foreach ( $endpoints as $route => &$handlers ) {

    			if ( isset( $handlers['callback'] ) ) {
    				// Single endpoint, add one deeper.
    				$handlers = array( $handlers );
    			}

    			if ( ! isset( $this->route_options[ $route ] ) ) {
    				$this->route_options[ $route ] = array();
    			}

    			foreach ( $handlers as $key => &$handler ) {

    				if ( ! is_numeric( $key ) ) {
    					// Route option, move it to the options.
    					$this->route_options[ $route ][ $key ] = $handler;
    					unset( $handlers[ $key ] );
    					continue;
    				}

    				$handler = wp_parse_args( $handler, $defaults );

    				// Allow comma-separated HTTP methods.
    				if ( is_string( $handler['methods'] ) ) {
    					$methods = explode( ',', $handler['methods'] );
    				} elseif ( is_array( $handler['methods'] ) ) {
    					$methods = $handler['methods'];
    				} else {
    					$methods = array();
    				}

    				$handler['methods'] = array();

    				foreach ( $methods as $method ) {
    					$method                        = strtoupper( trim( $method ) );
    					$handler['methods'][ $method ] = true;
    				}
    			}
    		}

    		return $endpoints;
    	}

    	/**
    	 * Retrieves namespaces registered on the server.
    	 *
    	 * @since 4.4.0
    	 *
    	 * @return string[] List of registered namespaces.
    	 */
    	public function get_namespaces() {
    		return array_keys( $this->namespaces );
    	}

    	/**
    	 * Retrieves specified options for a route.
    	 *
    	 * @since 4.4.0
    	 *
    	 * @param string $route Route pattern to fetch options for.
    	 * @return array|null Data as an associative array if found, or null if not found.
    	 */
    	public function get_route_options( $route ) {
    		if ( ! isset( $this->route_options[ $route ] ) ) {
    			return null;
    		}

    		return $this->route_options[ $route ];
    	}

    	/**
    	 * Matches the request to a callback and call it.
    	 *
    	 * @since 4.4.0
    	 *
    	 * @param WP_REST_Request $request Request to attempt dispatching.
    	 * @return WP_REST_Response Response returned by the callback.
    	 */
    	public function dispatch( $request ) {
    		$this->dispatching_requests[] = $request;

    		/**
    		 * Filters the pre-calculated result of a REST API dispatch request.
    		 *
    		 * Allow hijacking the request before dispatching by returning a non-empty. The returned value
    		 * will be used to serve the request instead.
    		 *
    		 * @since 4.4.0
    		 *
    		 * @param mixed           $result  Response to replace the requested version with. Can be anything
    		 *                                 a normal endpoint can return, or null to not hijack the request.
    		 * @param WP_REST_Server  $server  Server instance.
    		 * @param WP_REST_Request $request Request used to generate the response.
    		 */
    		$result = apply_filters( 'rest_pre_dispatch', null, $this, $request );

    		if ( ! empty( $result ) ) {

    			// Normalize to either WP_Error or WP_REST_Response...
    			$result = rest_ensure_response( $result );

    			// ...then convert WP_Error across.
    			if ( is_wp_error( $result ) ) {
    				$result = $this->error_to_response( $result );
    			}

    			array_pop( $this->dispatching_requests );
    			return $result;
    		}

    		$error   = null;
    		$matched = $this->match_request_to_handler( $request );

    		if ( is_wp_error( $matched ) ) {
    			$response = $this->error_to_response( $matched );
    			array_pop( $this->dispatching_requests );
    			return $response;
    		}

    		list( $route, $handler ) = $matched;

    		if ( ! is_callable( $handler['callback'] ) ) {
    			$error = new WP_Error(
    				'rest_invalid_handler',
    				__( 'The handler for the route is invalid.' ),
    				array( 'status' => 500 )
    			);
    		}

    		if ( ! is_wp_error( $error ) ) {
    			$check_required = $request->has_valid_params();
    			if ( is_wp_error( $check_required ) ) {
    				$error = $check_required;
    			} else {
    				$check_sanitized = $request->sanitize_params();
    				if ( is_wp_error( $check_sanitized ) ) {
    					$error = $check_sanitized;
    				}
    			}
    		}

    		$response = $this->respond_to_request( $request, $route, $handler, $error );
    		array_pop( $this->dispatching_requests );
    		return $response;
    	}

    	/**
    	 * Returns whether the REST server is currently dispatching / responding to a request.
    	 *
    	 * This may be a standalone REST API request, or an internal request dispatched from within a regular page load.
    	 *
    	 * @since 6.5.0
    	 *
    	 * @return bool Whether the REST server is currently handling a request.
    	 */
    	public function is_dispatching() {
    		return (bool) $this->dispatching_requests;
    	}

    	/**
    	 * Matches a request object to its handler.
    	 *
    	 * @access private
    	 * @since 5.6.0
    	 *
    	 * @param WP_REST_Request $request The request object.
    	 * @return array|WP_Error The route and request handler on success or a WP_Error instance if no handler was found.
    	 */
    	protected function match_request_to_handler( $request ) {
    		$method = $request->get_method();
    		$path   = $request->get_route();

    		$with_namespace = array();

    		foreach ( $this->get_namespaces() as $namespace ) {
    			if ( str_starts_with( trailingslashit( ltrim( $path, '/' ) ), $namespace ) ) {
    				$with_namespace[] = $this->get_routes( $namespace );
    			}
    		}

    		if ( $with_namespace ) {
    			$routes = array_merge( ...$with_namespace );
    		} else {
    			$routes = $this->get_routes();
    		}

    		foreach ( $routes as $route => $handlers ) {
    			$match = preg_match( '@^' . $route . '$@i', $path, $matches );

    			if ( ! $match ) {
    				continue;
    			}

    			$args = array();

    			foreach ( $matches as $param => $value ) {
    				if ( ! is_int( $param ) ) {
    					$args[ $param ] = $value;
    				}
    			}

    			foreach ( $handlers as $handler ) {
    				$callback = $handler['callback'];

    				// Fallback to GET method if no HEAD method is registered.
    				$checked_method = $method;
    				if ( 'HEAD' === $method && empty( $handler['methods']['HEAD'] ) ) {
    					$checked_method = 'GET';
    				}
    				if ( empty( $handler['methods'][ $checked_method ] ) ) {
    					continue;
    				}

    				if ( ! is_callable( $callback ) ) {
    					return array( $route, $handler );
    				}

    				$request->set_url_params( $args );
    				$request->set_attributes( $handler );

    				$defaults = array();

    				foreach ( $handler['args'] as $arg => $options ) {
    					if ( isset( $options['default'] ) ) {
    						$defaults[ $arg ] = $options['default'];
    					}
    				}

    				$request->set_default_params( $defaults );

    				return array( $route, $handler );
    			}
    		}

    		return new WP_Error(
    			'rest_no_route',
    			__( 'No route was found matching the URL and request method.' ),
    			array( 'status' => 404 )
    		);
    	}

    	/**
    	 * Dispatches the request to the callback handler.
    	 *
    	 * @access private
    	 * @since 5.6.0
    	 *
    	 * @param WP_REST_Request $request  The request object.
    	 * @param string          $route    The matched route regex.
    	 * @param array           $handler  The matched route handler.
    	 * @param WP_Error|null   $response The current error object if any.
    	 * @return WP_REST_Response
    	 */
    	protected function respond_to_request( $request, $route, $handler, $response ) {
    		/**
    		 * Filters the response before executing any REST API callbacks.
    		 *
    		 * Allows plugins to perform additional validation after a
    		 * request is initialized and matched to a registered route,
    		 * but before it is executed.
    		 *
    		 * Note that this filter will not be called for requests that
    		 * fail to authenticate or match to a registered route.
    		 *
    		 * @since 4.7.0
    		 *
    		 * @param WP_REST_Response|WP_HTTP_Response|WP_Error|mixed $response Result to send to the client.
    		 *                                                                   Usually a WP_REST_Response or WP_Error.
    		 * @param array                                            $handler  Route handler used for the request.
    		 * @param WP_REST_Request                                  $request  Request used to generate the response.
    		 */
    		$response = apply_filters( 'rest_request_before_callbacks', $response, $handler, $request );

    		// Check permission specified on the route.
    		if ( ! is_wp_error( $response ) && ! empty( $handler['permission_callback'] ) ) {
    			$permission = call_user_func( $handler['permission_callback'], $request );

    			if ( is_wp_error( $permission ) ) {
    				$response = $permission;
    			} elseif ( false === $permission || null === $permission ) {
    				$response = new WP_Error(
    					'rest_forbidden',
    					__( 'Sorry, you are not allowed to do that.' ),
    					array( 'status' => rest_authorization_required_code() )
    				);
    			}
    		}

    		if ( ! is_wp_error( $response ) ) {
    			/**
    			 * Filters the REST API dispatch request result.
    			 *
    			 * Allow plugins to override dispatching the request.
    			 *
    			 * @since 4.4.0
    			 * @since 4.5.0 Added `$route` and `$handler` parameters.
    			 *
    			 * @param mixed           $dispatch_result Dispatch result, will be used if not empty.
    			 * @param WP_REST_Request $request         Request used to generate the response.
    			 * @param string          $route           Route matched for the request.
    			 * @param array           $handler         Route handler used for the request.
    			 */
    			$dispatch_result = apply_filters( 'rest_dispatch_request', null, $request, $route, $handler );

    			// Allow plugins to halt the request via this filter.
    			if ( null !== $dispatch_result ) {
    				$response = $dispatch_result;
    			} else {
    				$response = call_user_func( $handler['callback'], $request );
    			}
    		}

    		/**
    		 * Filters the response immediately after executing any REST API
    		 * callbacks.
    		 *
    		 * Allows plugins to perform any needed cleanup, for example,
    		 * to undo changes made during the 'rest_request_before_callbacks'
    		 * filter.
    		 *
    		 * Note that this filter will not be called for requests that
    		 * fail to authenticate or match to a registered route.
    		 *
    		 * Note that an endpoint's `permission_callback` can still be
    		 * called after this filter - see `rest_send_allow_header()`.
    		 *
    		 * @since 4.7.0
    		 *
    		 * @param WP_REST_Response|WP_HTTP_Response|WP_Error|mixed $response Result to send to the client.
    		 *                                                                   Usually a WP_REST_Response or WP_Error.
    		 * @param array                                            $handler  Route handler used for the request.
    		 * @param WP_REST_Request                                  $request  Request used to generate the response.
    		 */
    		$response = apply_filters( 'rest_request_after_callbacks', $response, $handler, $request );

    		if ( is_wp_error( $response ) ) {
    			$response = $this->error_to_response( $response );
    		} else {
    			$response = rest_ensure_response( $response );
    		}

    		$response->set_matched_route( $route );
    		$response->set_matched_handler( $handler );

    		return $response;
    	}

    	/**
    	 * Returns if an error occurred during most recent JSON encode/decode.
    	 *
    	 * Strings to be translated will be in format like
    	 * "Encoding error: Maximum stack depth exceeded".
    	 *
    	 * @since 4.4.0
    	 *
    	 * @return false|string Boolean false or string error message.
    	 */
    	protected function get_json_last_error() {
    		if ( JSON_ERROR_NONE === json_last_error() ) {
    			return false;
    		}

    		return json_last_error_msg();
    	}

    	/**
    	 * Retrieves the site index.
    	 *
    	 * This endpoint describes the capabilities of the site.
    	 *
    	 * @since 4.4.0
    	 *
    	 * @param WP_REST_Request $request Request data.
    	 * @return WP_REST_Response The API root index data.
    	 */
    	public function get_index( $request ) {
    		// General site data.
    		$available = array(
    			'name'            => get_option( 'blogname' ),
    			'description'     => get_option( 'blogdescription' ),
    			'url'             => get_option( 'siteurl' ),
    			'home'            => home_url(),
    			'gmt_offset'      => get_option( 'gmt_offset' ),
    			'timezone_string' => get_option( 'timezone_string' ),
    			'page_for_posts'  => (int) get_option( 'page_for_posts' ),
    			'page_on_front'   => (int) get_option( 'page_on_front' ),
    			'show_on_front'   => get_option( 'show_on_front' ),
    			'namespaces'      => array_keys( $this->namespaces ),
    			'authentication'  => array(),
    			'routes'          => $this->get_data_for_routes( $this->get_routes(), $request['context'] ),
    		);

    		$response = new WP_REST_Response( $available );

    		$fields = isset( $request['_fields'] ) ? $request['_fields'] : '';
    		$fields = wp_parse_list( $fields );
    		if ( empty( $fields ) ) {
    			$fields[] = '_links';
    		}

    		if ( $request->has_param( '_embed' ) ) {
    			$fields[] = '_embedded';
    		}

    		if ( rest_is_field_included( '_links', $fields ) || rest_is_field_included( '_embedded', $fields ) ) {
    			$response->add_link( 'help', 'https://developer.wordpress.org/rest-api/' );
    			$this->add_active_theme_link_to_index( $response );
    			$this->add_site_logo_to_index( $response );
    			$this->add_site_icon_to_index( $response );
    		} else {
    			if ( rest_is_field_included( 'site_logo', $fields ) ) {
    				$this->add_site_logo_to_index( $response );
    			}
    			if ( rest_is_field_included( 'site_icon', $fields ) || rest_is_field_included( 'site_icon_url', $fields ) ) {
    				$this->add_site_icon_to_index( $response );
    			}
    		}

    		/**
    		 * Filters the REST API root index data.
    		 *
    		 * This contains the data describing the API. This includes information
    		 * about supported authentication schemes, supported namespaces, routes
    		 * available on the API, and a small amount of data about the site.
    		 *
    		 * @since 4.4.0
    		 * @since 6.0.0 Added `$request` parameter.
    		 *
    		 * @param WP_REST_Response $response Response data.
    		 * @param WP_REST_Request  $request  Request data.
    		 */
    		return apply_filters( 'rest_index', $response, $request );
    	}

    	/**
    	 * Adds a link to the active theme for users who have proper permissions.
    	 *
    	 * @since 5.7.0
    	 *
    	 * @param WP_REST_Response $response REST API response.
    	 */
    	protected function add_active_theme_link_to_index( WP_REST_Response $response ) {
    		$should_add = current_user_can( 'switch_themes' ) || current_user_can( 'manage_network_themes' );

    		if ( ! $should_add && current_user_can( 'edit_posts' ) ) {
    			$should_add = true;
    		}

    		if ( ! $should_add ) {
    			foreach ( get_post_types( array( 'show_in_rest' => true ), 'objects' ) as $post_type ) {
    				if ( current_user_can( $post_type->cap->edit_posts ) ) {
    					$should_add = true;
    					break;
    				}
    			}
    		}

    		if ( $should_add ) {
    			$theme = wp_get_theme();
    			$response->add_link( 'https://api.w.org/active-theme', rest_url( 'wp/v2/themes/' . $theme->get_stylesheet() ) );
    		}
    	}

    	/**
    	 * Exposes the site logo through the WordPress REST API.
    	 *
    	 * This is used for fetching this information when user has no rights
    	 * to update settings.
    	 *
    	 * @since 5.8.0
    	 *
    	 * @param WP_REST_Response $response REST API response.
    	 */
    	protected function add_site_logo_to_index( WP_REST_Response $response ) {
    		$site_logo_id = get_theme_mod( 'custom_logo', 0 );

    		$this->add_image_to_index( $response, $site_logo_id, 'site_logo' );
    	}

    	/**
    	 * Exposes the site icon through the WordPress REST API.
    	 *
    	 * This is used for fetching this information when user has no rights
    	 * to update settings.
    	 *
    	 * @since 5.9.0
    	 *
    	 * @param WP_REST_Response $response REST API response.
    	 */
    	protected function add_site_icon_to_index( WP_REST_Response $response ) {
    		$site_icon_id = get_option( 'site_icon', 0 );

    		$this->add_image_to_index( $response, $site_icon_id, 'site_icon' );

    		$response->data['site_icon_url'] = get_site_icon_url();
    	}

    	/**
    	 * Exposes an image through the WordPress REST API.
    	 * This is used for fetching this information when user has no rights
    	 * to update settings.
    	 *
    	 * @since 5.9.0
    	 *
    	 * @param WP_REST_Response $response REST API response.
    	 * @param int              $image_id Image attachment ID.
    	 * @param string           $type     Type of Image.
    	 */
    	protected function add_image_to_index( WP_REST_Response $response, $image_id, $type ) {
    		$response->data[ $type ] = (int) $image_id;
    		if ( $image_id ) {
    			$response->add_link(
    				'https://api.w.org/featuredmedia',
    				rest_url( rest_get_route_for_post( $image_id ) ),
    				array(
    					'embeddable' => true,
    					'type'       => $type,
    				)
    			);
    		}
    	}

    	/**
    	 * Retrieves the index for a namespace.
    	 *
    	 * @since 4.4.0
    	 *
    	 * @param WP_REST_Request $request REST request instance.
    	 * @return WP_REST_Response|WP_Error WP_REST_Response instance if the index was found,
    	 *                                   WP_Error if the namespace isn't set.
    	 */
    	public function get_namespace_index( $request ) {
    		$namespace = $request['namespace'];

    		if ( ! isset( $this->namespaces[ $namespace ] ) ) {
    			return new WP_Error(
    				'rest_invalid_namespace',
    				__( 'The specified namespace could not be found.' ),
    				array( 'status' => 404 )
    			);
    		}

    		$routes    = $this->namespaces[ $namespace ];
    		$endpoints = array_intersect_key( $this->get_routes(), $routes );

    		$data     = array(
    			'namespace' => $namespace,
    			'routes'    => $this->get_data_for_routes( $endpoints, $request['context'] ),
    		);
    		$response = rest_ensure_response( $data );

    		// Link to the root index.
    		$response->add_link( 'up', rest_url( '/' ) );

    		/**
    		 * Filters the REST API namespace index data.
    		 *
    		 * This typically is just the route data for the namespace, but you can
    		 * add any data you'd like here.
    		 *
    		 * @since 4.4.0
    		 *
    		 * @param WP_REST_Response $response Response data.
    		 * @param WP_REST_Request  $request  Request data. The namespace is passed as the 'namespace' parameter.
    		 */
    		return apply_filters( 'rest_namespace_index', $response, $request );
    	}

    	/**
    	 * Retrieves the publicly-visible data for routes.
    	 *
    	 * @since 4.4.0
    	 *
    	 * @param array  $routes  Routes to get data for.
    	 * @param string $context Optional. Context for data. Accepts 'view' or 'help'. Default 'view'.
    	 * @return array[] Route data to expose in indexes, keyed by route.
    	 */
    	public function get_data_for_routes( $routes, $context = 'view' ) {
    		$available = array();

    		// Find the available routes.
    		foreach ( $routes as $route => $callbacks ) {
    			$data = $this->get_data_for_route( $route, $callbacks, $context );
    			if ( empty( $data ) ) {
    				continue;
    			}

    			/**
    			 * Filters the publicly-visible data for a single REST API route.
    			 *
    			 * @since 4.4.0
    			 *
    			 * @param array $data Publicly-visible data for the route.
    			 */
    			$available[ $route ] = apply_filters( 'rest_endpoints_description', $data );
    		}

    		/**
    		 * Filters the publicly-visible data for REST API routes.
    		 *
    		 * This data is exposed on indexes and can be used by clients or
    		 * developers to investigate the site and find out how to use it. It
    		 * acts as a form of self-documentation.
    		 *
    		 * @since 4.4.0
    		 *
    		 * @param array[] $available Route data to expose in indexes, keyed by route.
    		 * @param array   $routes    Internal route data as an associative array.
    		 */
    		return apply_filters( 'rest_route_data', $available, $routes );
    	}

    	/**
    	 * Retrieves publicly-visible data for the route.
    	 *
    	 * @since 4.4.0
    	 *
    	 * @param string $route     Route to get data for.
    	 * @param array  $callbacks Callbacks to convert to data.
    	 * @param string $context   Optional. Context for the data. Accepts 'view' or 'help'. Default 'view'.
    	 * @return array|null Data for the route, or null if no publicly-visible data.
    	 */
    	public function get_data_for_route( $route, $callbacks, $context = 'view' ) {
    		$data = array(
    			'namespace' => '',
    			'methods'   => array(),
    			'endpoints' => array(),
    		);

    		$allow_batch = false;

    		if ( isset( $this->route_options[ $route ] ) ) {
    			$options = $this->route_options[ $route ];

    			if ( isset( $options['namespace'] ) ) {
    				$data['namespace'] = $options['namespace'];
    			}

    			$allow_batch = isset( $options['allow_batch'] ) ? $options['allow_batch'] : false;

    			if ( isset( $options['schema'] ) && 'help' === $context ) {
    				$data['schema'] = call_user_func( $options['schema'] );
    			}
    		}

    		$allowed_schema_keywords = array_flip( rest_get_allowed_schema_keywords() );

    		$route = preg_replace( '#\(\?P<(\w+?)>.*?\)#', '{$1}', $route );

    		foreach ( $callbacks as $callback ) {
    			// Skip to the next route if any callback is hidden.
    			if ( empty( $callback['show_in_index'] ) ) {
    				continue;
    			}

    			$data['methods'] = array_merge( $data['methods'], array_keys( $callback['methods'] ) );
    			$endpoint_data   = array(
    				'methods' => array_keys( $callback['methods'] ),
    			);

    			$callback_batch = isset( $callback['allow_batch'] ) ? $callback['allow_batch'] : $allow_batch;

    			if ( $callback_batch ) {
    				$endpoint_data['allow_batch'] = $callback_batch;
    			}

    			if ( isset( $callback['args'] ) ) {
    				$endpoint_data['args'] = array();

    				foreach ( $callback['args'] as $key => $opts ) {
    					if ( is_string( $opts ) ) {
    						$opts = array( $opts => 0 );
    					} elseif ( ! is_array( $opts ) ) {
    						$opts = array();
    					}
    					$arg_data             = array_intersect_key( $opts, $allowed_schema_keywords );
    					$arg_data['required'] = ! empty( $opts['required'] );

    					$endpoint_data['args'][ $key ] = $arg_data;
    				}
    			}

    			$data['endpoints'][] = $endpoint_data;

    			// For non-variable routes, generate links.
    			if ( ! str_contains( $route, '{' ) ) {
    				$data['_links'] = array(
    					'self' => array(
    						array(
    							'href' => rest_url( $route ),
    						),
    					),
    				);
    			}
    		}

    		if ( empty( $data['methods'] ) ) {
    			// No methods supported, hide the route.
    			return null;
    		}

    		return $data;
    	}

    	/**
    	 * Gets the maximum number of requests that can be included in a batch.
    	 *
    	 * @since 5.6.0
    	 *
    	 * @return int The maximum requests.
    	 */
    	protected function get_max_batch_size() {
    		/**
    		 * Filters the maximum number of REST API requests that can be included in a batch.
    		 *
    		 * @since 5.6.0
    		 *
    		 * @param int $max_size The maximum size.
    		 */
    		return apply_filters( 'rest_get_max_batch_size', 25 );
    	}

    	/**
    	 * Serves the batch/v1 request.
    	 *
    	 * @since 5.6.0
    	 *
    	 * @param WP_REST_Request $batch_request The batch request object.
    	 * @return WP_REST_Response The generated response object.
    	 */
    	public function serve_batch_request_v1( WP_REST_Request $batch_request ) {
    		$requests = array();

    		foreach ( $batch_request['requests'] as $args ) {
    			$parsed_url = wp_parse_url( $args['path'] );

    			if ( false === $parsed_url ) {
    				$requests[] = new WP_Error( 'parse_path_failed', __( 'Could not parse the path.' ), array( 'status' => 400 ) );

    				continue;
    			}

    			$single_request = new WP_REST_Request( isset( $args['method'] ) ? $args['method'] : 'POST', $parsed_url['path'] );

    			if ( ! empty( $parsed_url['query'] ) ) {
    				$query_args = array();
    				wp_parse_str( $parsed_url['query'], $query_args );
    				$single_request->set_query_params( $query_args );
    			}

    			if ( ! empty( $args['body'] ) ) {
    				$single_request->set_body_params( $args['body'] );
    			}

    			if ( ! empty( $args['headers'] ) ) {
    				$single_request->set_headers( $args['headers'] );
    			}

    			$requests[] = $single_request;
    		}

    		$matches    = array();
    		$validation = array();
    		$has_error  = false;

    		foreach ( $requests as $single_request ) {
    			if ( is_wp_error( $single_request ) ) {
    				$has_error    = true;
    				$validation[] = $single_request;
    				continue;
    			}

    			$match     = $this->match_request_to_handler( $single_request );
    			$matches[] = $match;
    			$error     = null;

    			if ( is_wp_error( $match ) ) {
    				$error = $match;
    			}

    			if ( ! $error ) {
    				list( $route, $handler ) = $match;

    				if ( isset( $handler['allow_batch'] ) ) {
    					$allow_batch = $handler['allow_batch'];
    				} else {
    					$route_options = $this->get_route_options( $route );
    					$allow_batch   = isset( $route_options['allow_batch'] ) ? $route_options['allow_batch'] : false;
    				}

    				if ( ! is_array( $allow_batch ) || empty( $allow_batch['v1'] ) ) {
    					$error = new WP_Error(
    						'rest_batch_not_allowed',
    						__( 'The requested route does not support batch requests.' ),
    						array( 'status' => 400 )
    					);
    				}
    			}

    			if ( ! $error ) {
    				$check_required = $single_request->has_valid_params();
    				if ( is_wp_error( $check_required ) ) {
    					$error = $check_required;
    				}
    			}

    			if ( ! $error ) {
    				$check_sanitized = $single_request->sanitize_params();
    				if ( is_wp_error( $check_sanitized ) ) {
    					$error = $check_sanitized;
    				}
    			}

    			if ( $error ) {
    				$has_error    = true;
    				$validation[] = $error;
    			} else {
    				$validation[] = true;
    			}
    		}

    		$responses = array();

    		if ( $has_error && 'require-all-validate' === $batch_request['validation'] ) {
    			foreach ( $validation as $valid ) {
    				if ( is_wp_error( $valid ) ) {
    					$responses[] = $this->envelope_response( $this->error_to_response( $valid ), false )->get_data();
    				} else {
    					$responses[] = null;
    				}
    			}

    			return new WP_REST_Response(
    				array(
    					'failed'    => 'validation',
    					'responses' => $responses,
    				),
    				WP_Http::MULTI_STATUS
    			);
    		}

    		foreach ( $requests as $i => $single_request ) {
    			if ( is_wp_error( $single_request ) ) {
    				$result      = $this->error_to_response( $single_request );
    				$responses[] = $this->envelope_response( $result, false )->get_data();
    				continue;
    			}

    			$clean_request = clone $single_request;
    			$clean_request->set_url_params( array() );
    			$clean_request->set_attributes( array() );
    			$clean_request->set_default_params( array() );

    			/** This filter is documented in wp-includes/rest-api/class-wp-rest-server.php */
    			$result = apply_filters( 'rest_pre_dispatch', null, $this, $clean_request );

    			if ( empty( $result ) ) {
    				$match = $matches[ $i ];
    				$error = null;

    				if ( is_wp_error( $validation[ $i ] ) ) {
    					$error = $validation[ $i ];
    				}

    				if ( is_wp_error( $match ) ) {
    					$result = $this->error_to_response( $match );
    				} else {
    					list( $route, $handler ) = $match;

    					if ( ! $error && ! is_callable( $handler['callback'] ) ) {
    						$error = new WP_Error(
    							'rest_invalid_handler',
    							__( 'The handler for the route is invalid' ),
    							array( 'status' => 500 )
    						);
    					}

    					$result = $this->respond_to_request( $single_request, $route, $handler, $error );
    				}
    			}

    			/** This filter is documented in wp-includes/rest-api/class-wp-rest-server.php */
    			$result = apply_filters( 'rest_post_dispatch', rest_ensure_response( $result ), $this, $single_request );

    			$responses[] = $this->envelope_response( $result, false )->get_data();
    		}

    		return new WP_REST_Response( array( 'responses' => $responses ), WP_Http::MULTI_STATUS );
    	}

    	/**
    	 * Sends an HTTP status code.
    	 *
    	 * @since 4.4.0
    	 *
    	 * @param int $code HTTP status.
    	 */
    	protected function set_status( $code ) {
    		status_header( $code );
    	}

    	/**
    	 * Sends an HTTP header.
    	 *
    	 * @since 4.4.0
    	 *
    	 * @param string $key Header key.
    	 * @param string $value Header value.
    	 */
    	public function send_header( $key, $value ) {
    		/*
    		 * Sanitize as per RFC2616 (Section 4.2):
    		 *
    		 * Any LWS that occurs between field-content MAY be replaced with a
    		 * single SP before interpreting the field value or forwarding the
    		 * message downstream.
    		 */
    		$value = preg_replace( '/\s+/', ' ', $value );
    		header( sprintf( '%s: %s', $key, $value ) );
    	}

    	/**
    	 * Sends multiple HTTP headers.
    	 *
    	 * @since 4.4.0
    	 *
    	 * @param array $headers Map of header name to header value.
    	 */
    	public function send_headers( $headers ) {
    		foreach ( $headers as $key => $value ) {
    			$this->send_header( $key, $value );
    		}
    	}

    	/**
    	 * Removes an HTTP header from the current response.
    	 *
    	 * @since 4.8.0
    	 *
    	 * @param string $key Header key.
    	 */
    	public function remove_header( $key ) {
    		header_remove( $key );
    	}

    	/**
    	 * Retrieves the raw request entity (body).
    	 *
    	 * @since 4.4.0
    	 *
    	 * @global string $HTTP_RAW_POST_DATA Raw post data.
    	 *
    	 * @return string Raw request data.
    	 */
    	public static function get_raw_data() {
    		// phpcs:disable PHPCompatibility.Variables.RemovedPredefinedGlobalVariables.http_raw_post_dataDeprecatedRemoved
    		global $HTTP_RAW_POST_DATA;

    		// $HTTP_RAW_POST_DATA was deprecated in PHP 5.6 and removed in PHP 7.0.
    		if ( ! isset( $HTTP_RAW_POST_DATA ) ) {
    			$HTTP_RAW_POST_DATA = file_get_contents( 'php://input' );
    		}

    		return $HTTP_RAW_POST_DATA;
    		// phpcs:enable
    	}

    	/**
    	 * Extracts headers from a PHP-style $_SERVER array.
    	 *
    	 * @since 4.4.0
    	 *
    	 * @param array $server Associative array similar to `$_SERVER`.
    	 * @return array Headers extracted from the input.
    	 */
    	public function get_headers( $server ) {
    		$headers = array();

    		// CONTENT_* headers are not prefixed with HTTP_.
    		$additional = array(
    			'CONTENT_LENGTH' => true,
    			'CONTENT_MD5'    => true,
    			'CONTENT_TYPE'   => true,
    		);

    		foreach ( $server as $key => $value ) {
    			if ( str_starts_with( $key, 'HTTP_' ) ) {
    				$headers[ substr( $key, 5 ) ] = $value;
    			} elseif ( 'REDIRECT_HTTP_AUTHORIZATION' === $key && empty( $server['HTTP_AUTHORIZATION'] ) ) {
    				/*
    				 * In some server configurations, the authorization header is passed in this alternate location.
    				 * Since it would not be passed in in both places we do not check for both headers and resolve.
    				 */
    				$headers['AUTHORIZATION'] = $value;
    			} elseif ( isset( $additional[ $key ] ) ) {
    				$headers[ $key ] = $value;
    			}
    		}

    		return $headers;
    	}
    }
    ```

[View all references](https://developer.wordpress.org/reference/files/wp-includes/rest-api/class-wp-rest-server.php/)
[View on Trac](https://core.trac.wordpress.org/browser/tags/6.9.4/src/wp-includes/rest-api/class-wp-rest-server.php#L16)
[View on GitHub](https://github.com/WordPress/wordpress-develop/blob/6.9.4/src/wp-includes/rest-api/class-wp-rest-server.php#L16-L1985)

## 󠀁[Changelog](https://developer.wordpress.org/reference/classes/WP_REST_Server/?output_format=md#changelog)󠁿

| Version | Description | 
| [4.4.0](https://developer.wordpress.org/reference/since/4.4.0/) | Introduced. |

## 󠀁[User Contributed Notes](https://developer.wordpress.org/reference/classes/WP_REST_Server/?output_format=md#user-contributed-notes)󠁿

 1.  [Skip to note 2 content](https://developer.wordpress.org/reference/classes/WP_REST_Server/?output_format=md#comment-content-5890)
 2.   [Sajjad Hussain](https://profiles.wordpress.org/sajjadhussain2509/)  [  4 years ago  ](https://developer.wordpress.org/reference/classes/wp_rest_server/#comment-5890)
 3. [You must log in to vote on the helpfulness of this note](https://login.wordpress.org?redirect_to=https%3A%2F%2Fdeveloper.wordpress.org%2Freference%2Fclasses%2Fwp_rest_server%2F%23comment-5890)
    Vote results for this note: -1[You must log in to vote on the helpfulness of this note](https://login.wordpress.org?redirect_to=https%3A%2F%2Fdeveloper.wordpress.org%2Freference%2Fclasses%2Fwp_rest_server%2F%23comment-5890)
 4. // To get all methods at onces
 5.     ```php
        public function my_custom_rest_route_init() {
        	register_rest_route( 'routename/v1','optionspage', array(
        	  'methods' => WP_REST_Server::ALLMETHODS,
        	  'callback' => [$this, 'custom_api_page_cb'],
        	) );
        }
        public function custom_api_page_cb() {
    
         return $_SERVER['REQUEST_METHOD']
        }
        ```
    
 6.  [Log in to add feedback](https://login.wordpress.org/?redirect_to=https%3A%2F%2Fdeveloper.wordpress.org%2Freference%2Fclasses%2Fwp_rest_server%2F%3Freplytocom%3D5890%23feedback-editor-5890)

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