CWP – ConvertKit RSS email ID

/**

 * RSS feed, add ConvertKit email query string (Part 1)

 */

function cwp_rss_convertkit_email( $url ) {

	return add_query_arg( 'adt_ei', 'subscriber.email_address', $url );

}

add_filter( 'the_permalink_rss', 'cwp_rss_convertkit_email' );

/**

 * Modify ConvertKit email string (Part 2)

 * esc_url will remove "{" and "}" so this adds them back on this specfiic URL

 */

function cwp_rss_convertkit_email_expand( $url ) {

	return str_replace( 'subscriber.email_address', '{{ subscriber.email_address }}', $url );

}

add_filter( 'clean_url', 'cwp_rss_convertkit_email_expand' );