diff --git a/lib/compat/wordpress-6.0/class-wp-theme-json-gutenberg.php b/lib/compat/wordpress-6.0/class-wp-theme-json-gutenberg.php
index a78e89e397604a..d811d9666964ca 100644
--- a/lib/compat/wordpress-6.0/class-wp-theme-json-gutenberg.php
+++ b/lib/compat/wordpress-6.0/class-wp-theme-json-gutenberg.php
@@ -16,6 +16,47 @@
  */
 class WP_Theme_JSON_Gutenberg extends WP_Theme_JSON_5_9 {
 
+	/**
+	 * Metadata for style properties.
+	 *
+	 * Each element is a direct mapping from the CSS property name to the
+	 * path to the value in theme.json & block attributes.
+	 */
+	const PROPERTIES_METADATA = array(
+		'background'                 => array( 'color', 'gradient' ),
+		'background-color'           => array( 'color', 'background' ),
+		'border-radius'              => array( 'border', 'radius' ),
+		'border-top-left-radius'     => array( 'border', 'radius', 'topLeft' ),
+		'border-top-right-radius'    => array( 'border', 'radius', 'topRight' ),
+		'border-bottom-left-radius'  => array( 'border', 'radius', 'bottomLeft' ),
+		'border-bottom-right-radius' => array( 'border', 'radius', 'bottomRight' ),
+		'border-color'               => array( 'border', 'color' ),
+		'border-width'               => array( 'border', 'width' ),
+		'border-style'               => array( 'border', 'style' ),
+		'color'                      => array( 'color', 'text' ),
+		'font-family'                => array( 'typography', 'fontFamily' ),
+		'font-size'                  => array( 'typography', 'fontSize' ),
+		'font-style'                 => array( 'typography', 'fontStyle' ),
+		'font-weight'                => array( 'typography', 'fontWeight' ),
+		'letter-spacing'             => array( 'typography', 'letterSpacing' ),
+		'line-height'                => array( 'typography', 'lineHeight' ),
+		'margin'                     => array( 'spacing', 'margin' ),
+		'margin-top'                 => array( 'spacing', 'margin', 'top' ),
+		'margin-right'               => array( 'spacing', 'margin', 'right' ),
+		'margin-bottom'              => array( 'spacing', 'margin', 'bottom' ),
+		'margin-left'                => array( 'spacing', 'margin', 'left' ),
+		'padding'                    => array( 'spacing', 'padding' ),
+		'padding-top'                => array( 'spacing', 'padding', 'top' ),
+		'padding-right'              => array( 'spacing', 'padding', 'right' ),
+		'padding-bottom'             => array( 'spacing', 'padding', 'bottom' ),
+		'padding-left'               => array( 'spacing', 'padding', 'left' ),
+		'--wp--style--block-gap'     => array( 'spacing', 'blockGap' ),
+		'text-decoration'            => array( 'typography', 'textDecoration' ),
+		'text-transform'             => array( 'typography', 'textTransform' ),
+		'filter'                     => array( 'filter', 'duotone' ),
+		'writing-mode'               => array( 'typography', 'writingMode' ),
+	);
+
 	/**
 	 * The top-level keys a theme.json can have.
 	 *
@@ -30,6 +71,96 @@ class WP_Theme_JSON_Gutenberg extends WP_Theme_JSON_5_9 {
 		'version',
 	);
 
+	/**
+	 * The valid properties under the settings key.
+	 *
+	 * @var array
+	 */
+	const VALID_SETTINGS = array(
+		'appearanceTools' => null,
+		'border'          => array(
+			'color'  => null,
+			'radius' => null,
+			'style'  => null,
+			'width'  => null,
+		),
+		'color'           => array(
+			'background'       => null,
+			'custom'           => null,
+			'customDuotone'    => null,
+			'customGradient'   => null,
+			'defaultGradients' => null,
+			'defaultPalette'   => null,
+			'duotone'          => null,
+			'gradients'        => null,
+			'link'             => null,
+			'palette'          => null,
+			'text'             => null,
+		),
+		'custom'          => null,
+		'layout'          => array(
+			'contentSize' => null,
+			'wideSize'    => null,
+		),
+		'spacing'         => array(
+			'blockGap' => null,
+			'margin'   => null,
+			'padding'  => null,
+			'units'    => null,
+		),
+		'typography'      => array(
+			'customFontSize' => null,
+			'dropCap'        => null,
+			'fontFamilies'   => null,
+			'fontSizes'      => null,
+			'fontStyle'      => null,
+			'fontWeight'     => null,
+			'letterSpacing'  => null,
+			'lineHeight'     => null,
+			'textDecoration' => null,
+			'textTransform'  => null,
+			'writingMode'    => null,
+		),
+	);
+
+	/**
+	 * The valid properties under the styles key.
+	 *
+	 * @var array
+	 */
+	const VALID_STYLES = array(
+		'border'     => array(
+			'color'  => null,
+			'radius' => null,
+			'style'  => null,
+			'width'  => null,
+		),
+		'color'      => array(
+			'background' => null,
+			'gradient'   => null,
+			'text'       => null,
+		),
+		'filter'     => array(
+			'duotone' => null,
+		),
+		'spacing'    => array(
+			'margin'   => null,
+			'padding'  => null,
+			'blockGap' => 'top',
+		),
+		'typography' => array(
+			'fontFamily'     => null,
+			'fontSize'       => null,
+			'fontStyle'      => null,
+			'fontWeight'     => null,
+			'letterSpacing'  => null,
+			'lineHeight'     => null,
+			'textDecoration' => null,
+			'textTransform'  => null,
+			'writingMode'    => null,
+		),
+	);
+
 	/**
 	 * Returns the current theme's wanted patterns(slugs) to be
 	 * registered from Pattern Directory.