有点明白了。可以使用自定义属性扩展现有模式，这些属性将有自己的回调解析程序。中对自定义类型的引用documentation.

Place this class to your functions.php

class GQLRegister 
{
  var $itemName = null;
  var $itemProps = null;
  var $responseName = null;
  var $responseParams = null;
  var $responseParamsFunction = null;

  function __construct(
    $itemName, 
    $itemProps, 
    $responseName, 
    $responseParams, 
    $responseParamsFunction) {    
    $this->itemName = $itemName;
    $this->itemProps = $itemProps;
    $this->responseName = $responseName;
    $this->responseParams = $responseParams;
    $this->responseParamsFunction = $responseParamsFunction;
    add_action(\'graphql_register_types\', [ $this, \'setItemType\' ]);
    add_action(\'graphql_register_types\', [ $this, \'setResponseType\' ]);
    add_action(\'graphql_register_types\', [ $this, \'setResponseParamsType\' ]);
  }

  function setItemType() {
    register_graphql_object_type($this->itemName, [ \'fields\' => $this->itemProps ]);
  }

  function setResponseType() {
    register_graphql_object_type($this->responseName, [
      \'fields\' => [
        \'count\' => [ \'type\' => \'Integer\' ],
        \'items\' => [ \'type\' => [ \'list_of\' => $this->itemName ]],
        \'errors\' => [ \'type\' => [ \'list_of\' => \'String\' ]]
      ]
    ]);
  }

  function setResponseParamsType() {
    register_graphql_field(\'RootQuery\', $this->responseName, [
      \'type\' => $this->responseName,
      \'args\' => $this->responseParams,
      \'resolve\' => $this->responseParamsFunction
    ]);
  }
}

new GQLRegister(
  \'CustomUser\',                               // define fields of a single object
  [
    \'id\' => [ \'type\' => \'Integer\' ],
    \'name\' => [ \'type\' => \'String\' ]
  ], 
  \'CustomUserResponse\',
  [                                           // define input parameters for new property
    \'page\' => [ \'type\' => \'Integer\' ],
    \'count\' => [ \'type\' => \'Integer\' ]
  ],
  function($root, $args, $context, $info) {   // extract data from DB in this method
    // $users = get_users($args);

    return [                                
      \'count\' => 1,                           // count($users) 
      \'items\' => [[ \'name\' => \'Demo User\' ]]  // $users
    ];
  }
);

{
  "data": {
    "customUserResponse": {
      "count": 1,
      "items": [
        {
          "name": "Demo User"
        }
      ]
    }
  }
}