CookieDarb · Oct 19, 2026 · Oct 19, 2026
diff --git a/includes/class-create-block-theme-api.php b/includes/class-create-block-theme-api.php
@@ -153,7 +153,7 @@ public function register_rest_routes() {
 	}
 
 	/**
-	 * Add README data and theme.json data to the current theme REST API response.
+	 * Add README data, theme.json data, and normalized theme tags to the current theme REST API response.
 	 *
 	 * @param WP_REST_Response $response The response object.
 	 * @param WP_Theme          $theme    The theme object.
@@ -171,10 +171,12 @@ public function add_additional_data_to_theme_response( $response, $theme ) {
 
 		$data = $response->get_data();
 
-		// Add README data and theme.json data.
+		// Add README data, theme.json data, and normalized theme tags.
 		try {
 			$data['readme']     = CBT_Theme_Readme::get_sections();
 			$data['theme_json'] = CBT_Theme_JSON_Resolver::get_theme_file_contents();
+			$active_tags        = $current_theme->get( 'Tags' );
+			$data['theme_tags'] = CBT_Theme_Tags::normalize_tags( is_array( $active_tags ) ? $active_tags : array() );
 		} catch ( Exception $error ) {
 			return new WP_Error(
 				'theme_data_retrieval_failed',

diff --git a/includes/create-theme/theme-tags.php b/includes/create-theme/theme-tags.php
@@ -19,12 +19,80 @@ public static function theme_tags_list( $theme ) {
 			$theme['tags-layout'] ?? array(),
 			$theme['tags-features'] ?? array(),
 		);
-		$custom_tags          = array_map( 'trim', explode( ',', $theme['tags_custom'] ?? '' ) );
-		$tags                 = array_unique( array_merge( $checkbox_tags_merged, $custom_tags ) );
+		$custom_tags          = explode( ',', $theme['tags_custom'] ?? '' );
+		$tags                 = self::normalize_tags( array_merge( $checkbox_tags_merged, $custom_tags ) );
 
 		return implode( ', ', $tags );
 	}
 
+	/**
+	 * Get mapping of lowercase feature labels and slugs to canonical slugs.
+	 *
+	 * @return array<string, string> Map of lowercase labels and slugs to canonical slugs.
+	 */
+	protected static function get_label_to_slug_map() {
+		static $map = null;
+		if ( null !== $map ) {
+			return $map;
+		}
+
+		$map = array();
+		if ( ! function_exists( 'get_theme_feature_list' ) ) {
+			return $map;
+		}
+
+		$feature_list = get_theme_feature_list( false );
+		if ( ! is_array( $feature_list ) ) {
+			return $map;
+		}
+
+		foreach ( $feature_list as $group ) {
+			if ( ! is_array( $group ) ) {
+				continue;
+			}
+			foreach ( $group as $slug => $label ) {
+				$map[ strtolower( $label ) ] = $slug;
+			}
+		}
+
+		return $map;
+	}
+
+	/**
+	 * Normalize an array or comma-separated list of tags to valid, lowercase WordPress theme slugs.
+	 *
+	 * @param array|string $tags Tags to normalize.
+	 * @return array Normalized list of tag slugs.
+	 */
+	public static function normalize_tags( $tags ) {
+		if ( is_string( $tags ) ) {
+			$tags = explode( ',', $tags );
+		}
+
+		if ( ! is_array( $tags ) ) {
+			return array();
+		}
+
+		$label_to_slug = self::get_label_to_slug_map();
+		$normalized    = array();
+
+		foreach ( $tags as $tag ) {
+			if ( ! is_string( $tag ) ) {
+				continue;
+			}
+
+			$tag = trim( $tag );
+			if ( '' === $tag ) {
+				continue;
+			}
+
+			$lower_tag    = strtolower( $tag );
+			$normalized[] = $label_to_slug[ $lower_tag ] ?? sanitize_title( $lower_tag );
+		}
+
+		return array_values( array_unique( array_filter( $normalized ) ) );
+	}
+
 	/**
 	 * Render theme tags form section.
 	 *
@@ -136,6 +204,7 @@ protected static function is_active_theme_tag( $tag ) {
 
 		$tag               = strtolower( $tag );
 		$active_theme_tags = wp_get_theme()->get( 'Tags' );
+		$active_theme_tags = is_array( $active_theme_tags ) ? self::normalize_tags( $active_theme_tags ) : array();
 		$default_tags      = self::list_default_tags();
 		$merged_tags       = array_unique( array_merge( $default_tags, $active_theme_tags ) );
 

diff --git a/src/editor-sidebar/metadata-editor-modal.js b/src/editor-sidebar/metadata-editor-modal.js
@@ -43,6 +43,19 @@ const ALLOWED_SCREENSHOT_MEDIA_TYPES = [
 
 const WP_MINIMUM_VERSIONS = generateWpVersions( WP_VERSION ); // eslint-disable-line no-undef
 
+const getInitialThemeTags = ( themeData ) => {
+	if ( Array.isArray( themeData?.theme_tags ) ) {
+		return themeData.theme_tags.join( ', ' );
+	}
+	if ( Array.isArray( themeData?.tags?.raw ) ) {
+		return themeData.tags.raw.join( ', ' );
+	}
+	if ( typeof themeData?.tags?.rendered === 'string' ) {
+		return themeData.tags.rendered;
+	}
+	return '';
+};
+
 export const ThemeMetadataEditorModal = ( { onRequestClose } ) => {
 	const [ theme, setTheme ] = useState( {
 		name: '',
@@ -78,7 +91,7 @@ export const ThemeMetadataEditorModal = ( { onRequestClose } ) => {
 			requires_wp: themeData.requires_wp,
 			author: themeData.author.raw,
 			author_uri: themeData.author_uri.raw,
-			tags_custom: themeData.tags.rendered,
+			tags_custom: getInitialThemeTags( themeData ),
 			screenshot: themeData.screenshot,
 			recommended_plugins: themeData.readme?.recommended_plugins || '',
 			font_credits: themeData.readme?.fonts || '',

diff --git a/tests/test-theme-tags.php b/tests/test-theme-tags.php
@@ -0,0 +1,68 @@
+<?php
+/**
+ * @package Create_Block_Theme
+ */
+class Test_Create_Block_Theme_Tags extends WP_UnitTestCase {
+
+	/**
+	 * Tests that normalize_tags converts display labels to slugs, lowercases custom tags,
+	 * handles comma-separated strings as well as arrays, trims whitespace, and deduplicates.
+	 */
+	public function test_normalize_tags() {
+		$tags = array(
+			'Blog',
+			'blog',
+			'  Block Editor Styles  ',
+			'Site Editor',
+			'RTL-Language-Support',
+			'translation-ready',
+			'Food & Drink',
+			'',
+			'   ',
+		);
+
+		$normalized = CBT_Theme_Tags::normalize_tags( $tags );
+
+		$this->assertSame(
+			array(
+				'blog',
+				'block-styles',
+				'full-site-editing',
+				'rtl-language-support',
+				'translation-ready',
+				'food-and-drink',
+			),
+			$normalized
+		);
+
+		// Also verify comma-separated string input.
+		$string_input = 'Blog, Block Editor Styles, custom-tag';
+		$this->assertSame(
+			array(
+				'blog',
+				'block-styles',
+				'custom-tag',
+			),
+			CBT_Theme_Tags::normalize_tags( $string_input )
+		);
+	}
+
+	/**
+	 * Tests that theme_tags_list merges checkbox tags and custom tags, normalizes them,
+	 * removes duplicates, and formats the output as a comma-separated string.
+	 */
+	public function test_theme_tags_list() {
+		$theme = array(
+			'tags-subject'  => array( 'Blog' ),
+			'tags-features' => array( 'Block Editor Styles' ),
+			'tags_custom'   => 'blog, RTL-Language-Support, translation-ready, Site Editor',
+		);
+
+		$tags_list = CBT_Theme_Tags::theme_tags_list( $theme );
+
+		$this->assertSame(
+			'blog, block-styles, rtl-language-support, translation-ready, full-site-editing',
+			$tags_list
+		);
+	}
+}