This snippet removes the “extensions” from the GraphQL response:

add_filter( 'graphql_request_results', function( $response ) {
	// If it's an ExecutionResult object, we need to handle it differently
	if ( $response instanceof \GraphQL\Executor\ExecutionResult ) {
		// Convert to array and remove extensions if they exist
		$array = $response->toArray();
		if ( isset( $array['extensions'] ) ) {
			unset( $array['extensions'] );
		}
		return $array;
	}

	// Handle array responses
	if ( is_array( $response ) && isset( $response['extensions'] ) ) {
		unset( $response['extensions'] );
	}

	// Handle object responses
	if ( is_object( $response ) && isset( $response->extensions ) ) {
		unset( $response->extensions );
	}

	return $response;
}, 99, 1 );

Before

After

Remove Extensions from GraphQL Response