# wordpress-seo/28.3/src/functions.php

Yoast SEO – Advanced SEO with real-time guidance and built-in AI, version 28.3. 39 lines.

- Page: https://pluginprobe.com/plugins/wordpress-seo/28.3/code/src/functions.php
- Raw: https://pluginprobe.com/plugins/wordpress-seo/28.3/raw/src/functions.php
- Modified: 2023-09-19T09:07:18+00:00

Line numbers below start at 1. Link to a line or a range by appending a fragment to the
page URL, for example `https://pluginprobe.com/plugins/wordpress-seo/28.3/code/src/functions.php#L10-L20`.

```php
<?php
/**
 * WPSEO plugin file.
 *
 * @package WPSEO\Internals
 */

if ( ! defined( 'WPSEO_VERSION' ) ) {
	header( 'Status: 403 Forbidden' );
	header( 'HTTP/1.1 403 Forbidden' );
	exit();
}

use Yoast\WP\SEO\Main;

if ( is_dir( WPSEO_PATH . YOAST_VENDOR_PREFIX_DIRECTORY ) ) {
	require_once WPSEO_PATH . YOAST_VENDOR_PREFIX_DIRECTORY . '/guzzlehttp/guzzle/src/functions.php';
}

/**
 * Retrieves the main instance.
 *
 * @phpcs:disable WordPress.NamingConventions -- Should probably be renamed, but leave for now.
 *
 * @return Main The main instance.
 */
function YoastSEO() {
	// phpcs:enable

	static $main;

	if ( $main === null ) {
		$main = new Main();
		$main->load();
	}

	return $main;
}

```