When using GraphiQL or any other client for testing GraphQL queries, you might need to debug the request processing. You can use Xdebug for debugging the PHP execution of a GraphQL query just as you would for other HTTP requests. To start debugging, add the ?XDEBUG_SESSION_START=PHPSTORM parameter to the endpoint URL. The following example shows how to establish a connection between Xdebug and PHPStorm IDE.
Architect Magento | Tech Blogger | Magento Trainer