REST Simple Extention

Extends public WordPress REST API post type responses with:

• A grouped taxonomies field containing terms for registered taxonomies
• featured_img metadata with image URLs by size

Requirements

• WordPress 6.0+
• PHP 7.4+

Installation

1. Copy the plugin folder to: wp-content/plugins/rest-simple-extention
2. Activate REST Simple Extention in Plugins.

What it adds to REST responses

For all public post types (except attachment), the plugin adds:

• A taxonomies field containing taxonomy term names grouped by taxonomy slug.
• A featured_img object with:
  • alt
  • full
  • large
  • medium
  • thumbnail

Example request:

GET /wp-json/wp/v2/posts

Example response fragment:

{
    "id": 123,
    "taxonomies": {
        "category": ["News", "Updates"],
        "post_tag": ["Release", "API"]
    },
    "featured_img": {
        "alt": "Hero image",
        "full": "https://example.com/uploads/2026/02/hero.jpg",
        "large": "https://example.com/uploads/2026/02/hero-1024x576.jpg",
        "medium": "https://example.com/uploads/2026/02/hero-300x169.jpg",
        "thumbnail": "https://example.com/uploads/2026/02/hero-150x150.jpg"
    }
}

Filters

Use these filters to customize behavior:

rest_extended_default_post_types

Change the list of public post types that receive extra REST fields.

add_filter( 'rest_extended_default_post_types', function( $post_types ) {
        return array( 'post', 'page' );
} );

rest_extended_default_taxonomies

Change which registered taxonomies are included in the taxonomies REST field.

The second argument ($post_types) lets you conditionally return taxonomies by post type. In this plugin, it is passed as an array containing the current post type during response preparation.

add_filter( 'rest_extended_default_taxonomies', function( $taxonomies, $post_types ) {
        $current_post_type = is_array( $post_types ) && ! empty( $post_types[0] ) ? $post_types[0] : '';

        if ( 'post' === $current_post_type ) {
                return array( 'category', 'post_tag' );
        }

        if ( 'product' === $current_post_type ) {
                return array( 'product_cat', 'product_tag' );
        }

        return array(); // Or return $taxonomies to keep defaults.
}, 10, 2 );

Notes

• Fields are read-only (update_callback is null).
• If no taxonomy terms/image are present, empty arrays/empty strings are returned where applicable.

Changelog

1.0.0

• Initial production-ready release.
• Added REST field registration for taxonomy terms and featured image metadata.
• Added safer handling for missing image sizes and invalid taxonomy/post data.