Show Featured Image URL in API Result

Hi jeffreybetts

You can add the featured image url to the related posts with a filter.
Try it with this in your (child) theme’s functions.php file.

add_filter( 'related_posts_by_taxonomy', 'add_thumbnail_wp_rest_api_posts', 10, 4 );

function add_thumbnail_wp_rest_api_posts( $related, $post_id, $taxonomies, $args ) {
	if ( 'wp_rest_api' !== $args['type'] ) {
		return $related;
	}

	foreach ( $related as $key => $post ) {
		if ( is_object( $post ) ) {
			$related[ $key ]->post_thumbnail = get_the_post_thumbnail_url( $post );
		}
	}

	return $related;
}

btw:
consider creating a child theme instead of editing your theme directly – if you upgrade the theme all your modifications will be lost. Or create a plugin with the code above.