Filters and example code for Yoast SEO sitemaps

yoast_seo_sitemap_add_custom_type.php

<?php
/********* DO NOT COPY THE PARTS ABOVE THIS LINE *********/

/* Create a Yoast SEO sitemap for a custom post type
 * Credit: Team Yoast
 * Last Tested: Unknown
 * Documentation: https://developer.yoast.com/features/xml-sitemaps/api/#add-a-custom-post-type
 * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * 
 * HOW TO USE
 * Replace TYPE with your custom type
 */

add_action('init', 'enable_custom_sitemap');

function enable_custom_sitemap()
{
  global $wpseo_sitemaps;
  if (isset($wpseo_sitemaps) && !empty($wpseo_sitemaps)) {
    $wpseo_sitemaps->register_sitemap('TYPE', 'create_TYPE_sitemap');
  }
}

yoast_seo_sitemap_add_external.php

<?php
/********* DO NOT COPY THE PARTS ABOVE THIS LINE *********/

/* Add External Sitemap to Yoast Sitemap Index
* Credit: Paul https://wordpress.org/support/users/paulmighty/
* Modified by: Team Yoast
* Last Tested: Aug 25 2017 using Yoast SEO 5.3.2 on WordPress 4.8.1
* Documentation:
* https://developer.yoast.com/features/xml-sitemaps/api/#add-additionalexternal-xml-sitemaps-to-the-xml-sitemap-index
* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * 
* This code adds two external sitemaps and must be modified before using.
* Replace http://www.example.com/external-sitemap-#.xml with your external sitemap URL.
* Replace 2017-05-22T23:12:27+00:00 with the time and date your external sitemap was last updated.
* Format: yyyy-MM-dd'T'HH:mm:ssZ
* If you have more/less sitemaps, add/remove the additional section.
* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * 
* Please note that changes will be applied upon next sitemap update.
* To manually refresh the sitemap, please disable and enable the sitemaps.
*/

add_filter('wpseo_sitemap_index', 'add_sitemap_custom_items');

function add_sitemap_custom_items($sitemap_custom_items)
{
  $sitemap_custom_items .= '
<sitemap>
<loc>http://www.example.com/external-sitemap-1.xml</loc>
<lastmod>2017-05-22T23:12:27+00:00</lastmod>
</sitemap>';

  /* Add Additional Sitemap
   * This section can be removed or reused as needed
   */
  $sitemap_custom_items .= '
<sitemap>
<loc>http://www.example.com/external-sitemap-2.xml</loc>
<lastmod>2017-05-22T23:12:27+00:00</lastmod>
</sitemap>';

  /* DO NOT REMOVE ANYTHING BELOW THIS LINE
   * Send the information to Yoast SEO
   */
  return $sitemap_custom_items;
}

yoast_seo_sitemap_change_entries_per_page.php

<?php
/********* DO NOT COPY THE PARTS ABOVE THIS LINE *********/

/* Change the number of entries per sitemap
 * Credit: Yoast Team
 * Last Tested: Oct 17 2018 using Yoast SEO 8.4 on WordPress 4.9.8
 * Limit should be either lower than 100 or a multiple of 100 to avoid problems with the sitemap pagination
 * Documentation: https://developer.yoast.com/features/xml-sitemaps/api/#alter-the-number-of-sitemap-entries
 * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * 
 */

add_filter('wpseo_sitemap_entries_per_page', 'max_entries_per_sitemap');

function max_entries_per_sitemap() {
  return 10;
}

yoast_seo_sitemap_remove_homepage.php

<?php
/********* DO NOT COPY THE PARTS ABOVE THIS LINE *********/

/* Remove homepage from the page sitemap
 * Credit: Yoast team
 * Last Tested:  Jun 20 2024 using Yoast SEO 22.9 on WordPress 6.5.4
 */

add_filter( 'wpseo_sitemap_url', function ( $output, $url ) {
	if ( $url['loc']  === home_url( '/' ) ) {
		return '';
	}

	return $output;
}, 10, 2 );

The first example, file-yoast_seo_sitemap_add_custom_type-php, is not complete. Function is not properly closed. Also, we don't know what create_TYPE_sitemap callable is and does, how to create our own implementation.

@djboris88 The plugin automatically detects most custom post types (CPT), so you'd only need this in some instances. You can check under Admin > Yoast SEO > Settings > Content types to see if your CPT was detected automatically.

The code requires that you replace TYPE with your CPT. For example, if your CPT is called recipe, the register sitemap line would change as shown here.

$wpseo_sitemaps->register_sitemap( 'recipe', 'create_recipe_sitemap' );