WP_REST_Server::get_index( array $request )

	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' ),
			'namespaces'      => array_keys( $this->namespaces ),
			'authentication'  => array(),
			'routes'          => $this->get_data_for_routes( $this->get_routes(), $request['context'] ),
		);

		$response = new WP_REST_Response( $available );

		$response->add_link( 'help', 'http://v2.wp-api.org/' );

		/**
		 * Filters the 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 WP-4.4.0
		 *
		 * @param WP_REST_Response $response Response data.
		 */
		return apply_filters( 'rest_index', $response );
	}