This was some initial work done to test Gutenberg support with WordPress 5.5 server registry

wp-graphql-gutenberg-test.php

		$blocks = \WP_Block_Type_Registry::get_instance();
		$registered_blocks = $blocks->get_all_registered();
		if ( ! empty( $registered_blocks ) ) {

			register_graphql_interface_type( 'ContentEditorBlock', [
				'description' => __( 'Blocks used by the content editor', 'wp-graphql' ),
				'resolveType' => function( $block ) {
					return isset( $block['name'] ) ? $this->get_type( graphql_format_type_name( $block['name'] ) ) : null;
				},
				'fields' => [
					'name' => [
						'type' => 'String',
						'description' => __( 'Name of the content editor block', 'wp-graphql' ),
					],
					'title' => [
						'type' => 'String',
						'description' => __( 'The title of the content editor block', 'wp-graphql' ),
					],
					'category' => [
						'type' => 'String',
						'description' => __( 'The category the content editor block belongs to', 'wp-graphql' ),
					],
					'parent' => [
						'type' => 'ContentEditorBlock',
						'description' => __( 'The parent content editor block that the content editor block can be used within', 'wp-graphql' ),
					],
					'icon' => [
						'type' => 'String',
						'description' => __( 'The icon that represents the content editor block', 'wp-graphql' ),
					],
					'description' => [
						'type' => 'String',
						'description' => __( 'The description of the content editor block', 'wp-graphql' ),
					],
					'keywords' => [
						'type' => [ 'list_of' => 'String' ],
						'description' => __( 'Keywords describing the intended use of the content editor block', 'wp-graphql' ),
					],
					'textdomain' => [
						'type' => 'String',
						'description' => __( 'The textdomain for the content editor block. Used for internationalization.', 'wp-graphql' ),
					],
					'styles' => [
						'type' => [ 'list_of' => 'String' ],
						'description' => __( 'Stylesheets associated with the content editor block', 'wp-graphql' ),
					],
					'supports' => [
						'type' => [ 'list_of' => 'String' ],
						'description' => __( 'List of features the content editor block supports', 'wp-graphql' ),
					],
					'example' => [
						'type' => 'String',
						'description' => __( 'Example use of the content editor block', 'wp-graphql' ),
					],
					'rendered' => [
						'type' => 'String',
						'description' => __( 'Rendered instance of the content editor block', 'wp-graphql' ),
					],
					'innerHTML' => [
						'type' => 'String',
						'description' => __( 'The inner HTML the content editor block renders', 'wp-graphql' ),
					],
					'innerBlocks' => [
						'type' => [ 'list_of' => 'ContentEditorBlock' ],
						'description' => __( 'Inner blocks nested within the content editor block', 'wp-graphql' ),
						'resolve' => function( $block ) {
							$prepared_blocks = [];
							$blocks = isset( $block['innerBlocks'] ) ? $block['innerBlocks'] : null;
							if ( empty( $blocks ) ) {
								return null;
							}

							foreach  ( $blocks as $block ) {
								if ( ! empty( $block['blockName'] ) ) {
									$prepared_blocks[] = $this->prepare_content_block( $block );
								}
							}
							return $prepared_blocks;
						}
					],
					'innerContent' => [
						'type' => [ 'list_of' => 'String' ],
						'description' => __( 'List of inner content strings for the content editor block', 'wp-graphql' ),
					],
				]
			]);

			foreach ( $registered_blocks as $registered_block ) {
				$type_name = graphql_format_type_name( $registered_block->name );
				register_graphql_object_type( $type_name, [
					'interfaces' => [ 'ContentEditorBlock' ],
					'fields' => [
						'name' => [
							'type' => 'String',
							'description' => __( 'Name of the content block', 'wp-graphql' ),
						],
					],
				] );
			}

			register_graphql_field( 'ContentNode', 'contentBlocks', [
				'type' => [ 'list_of' => 'ContentEditorBlock' ],
				'description' => __( 'Content blocks saved to the content node', 'wp-graphql' ),
				'resolve' => function( Post $post, $args, $context, $info ) use ( $registered_blocks ) {
					$content = $post->contentRaw;
					$blocks = $content ? parse_blocks( $content ) : null;
					$prepared_blocks = [];
					foreach  ( $blocks as $block ) {
						if ( ! empty( $block['blockName'] ) ) {
							$prepared_blocks[] = $this->prepare_content_block( $block );
						}
					}
					return $prepared_blocks;
				}
			] );
		}