{
  "return_code":0,
  "return_message":"",
  "result":{
    "orders_count":5,
    "order":[
      {
        "id":"1",
        "customer":[
          {
            "id":"26",
            "email":"molestie.in@molestiesodales.co.uk",
            "first_name":"Adara",
            "last_name":"Cortez"
          }
        ],
        "status":[
          {
            "id":"3",
            "name":"Shipped",
            "history":[
              {
                "history":[
                  {
                    "id":"3",
                    "name":"Shipped",
                    "modified_time":"2014-03-25 15:29:00",
                    "notify":"True",
                    "comment":"Make Payable To: \nFrost\n\nSend To: \nAddress 1\n\nYour order will not ship until we receive payment.\n"
                  }
                ]
              }
            ],
            "refund_info": null
          }
        ]
      },
      {
        "id":"2",
        "customer":[
          {
            "id":"26",
            "email":"molestie.in@molestiesodales.co.uk",
            "first_name":"Adara",
            "last_name":"Cortez"
          }
        ],
        "status":[
          {
            "id":"1",
            "name":"Pending",
            "history":[
              {
                "history":[
                  {
                    "id":"1",
                    "name":"Pending",
                    "modified_time":"2014-03-25 15:30:58",
                    "notify":"True",
                    "comment":""
                  }
                ]
              }
            ],
            "refund_info": null
          }
        ]
      },
      {
        "id":"3",
        "customer":[
          {
            "id":"26",
            "email":"molestie.in@molestiesodales.co.uk",
            "first_name":"Adara",
            "last_name":"Cortez"
          }
        ],
        "status":[
          {
            "id":"1",
            "name":"Pending",
            "history":[
              {
                "history":[
                  {
                    "id":"1",
                    "name":"Pending",
                    "modified_time":"2014-03-25 15:31:57",
                    "notify":"True",
                    "comment":""
                  }
                ]
              }
            ],
            "refund_info": null
          }
        ]
      },
      {
        "id":"4",
        "customer":[
          {
            "id":"25",
            "email":"quis.lectus.Nullam@egetlacusMauris.co.uk",
            "first_name":"Adara",
            "last_name":"Huffman"
          }
        ],
        "status":[
          {
            "id":"3",
            "name":"Shipped",
            "history":[
              {
                "history":[
                  {
                    "id":"3",
                    "name":"Shipped",
                    "modified_time":"2014-03-25 15:34:52",
                    "notify":"True",
                    "comment":"Make Payable To: \nFrost\n\nSend To: \nAddress 1\n\nYour order will not ship until we receive payment.\n"
                  }
                ]
              }
            ],
            "refund_info": null
          }
        ]
      },
      {
        "id":"5",
        "customer":[
          {
            "id":"12",
            "email":"rutrum.justo.Praesent@risus.net",
            "first_name":"Darrel",
            "last_name":"Knapp"
          }
        ],
        "status":[
          {
            "id":"3",
            "name":"Shipped",
            "history":null,
            "refund_info":[
              {
                "shipping":0,
                "fee":0,
                "tax":0,
                "total_refunded":-38,
                "time":"2015-04-02 10:54:56",
                "comment":"Product Did Not Meet Customer’s Expectations",
                "refunded_items": [
                  {
                    "items": [
                      {
                        "product_id": "50",
                        "variant_id": "50",
                        "qty": 1,
                        "refund": -35
                      },
                      {
                        "product_id": "93",
                        "variant_id": "93",
                        "qty": 1,
                        "refund": -3
                      }
                    ]
                  }
                ]
              }
            ]
          }
        ]
      }
    ]
  }
}

index.php

<?php

include_once 'Connector.php';

$api = new Connector('PASTE_YOUR_API_KEY','PASTE_YOUR_STORE_KEY');

$params = array(
  'start'  => 0,
  'count'  => 5,
  'params' => 'id,customer,status'
);

try {

  /**
   * Return stdClass
   */
  $result = $api->request('order.list', $params);

  echo "Orders count: " . $result->orders_count . "\n" .
       "Orders list: \n";

  foreach($result->order[0] as $order) {

    $customer = $order->customer[0];
    $status   = $order->status[0];

    echo "Order ID: "       . $order->id       . "\n" .
         "Customer email: " . $customer->email . "\n" .
         "Order status: "   . $status->name    . "\n\n";

  }


} catch (Exception $e) {

  echo '#' . $e->getCode() . ' ' . $e->getMessage();

}

Connector.php

<?php

/**
 * Class Connector
 */
class Connector
{
  /**
   * URL to API API2Cart
   *
   * @var string A2C_URL
   */
  const A2C_URL = 'https://api.api2cart.com/v1.0/';

  /**
   * @var array $_params
   */
  private $_params = array();

  /**
   * @param string $apiKey
   * @param string $storeKey
   */
  public function __construct($apiKey, $storeKey = null)
  {
    $this->_params['api_key']   = $apiKey;

    if($storeKey !== null) {
      $this->_params['store_key'] = $storeKey;
    }
  }


  /**
   * Send request to API2Cart
   *
   * @param string $method Name method
   * @param array  $params List params for method
   *
   * @return stdClass
   *
   * @throws Exception
   */
  public function request($method, $params = array())
  {

    $params = array_merge($this->_params,$params);

    $ch = curl_init();

    $url = self::A2C_URL . $method . '.json?' . http_build_query($params);

    curl_setopt($ch, CURLOPT_URL, $url);
    curl_setopt($ch, CURLOPT_SSL_VERIFYPEER, true);
    curl_setopt($ch, CURLOPT_HEADER, false);
    curl_setopt($ch, CURLOPT_TIMEOUT, 300);
    curl_setopt($ch, CURLINFO_HEADER_OUT,true);
    curl_setopt($ch, CURLOPT_RETURNTRANSFER, 1);
    curl_setopt($ch, CURLOPT_USERAGENT, 
      "Mozilla/5.0 (Windows; U; Windows NT 5.1; en-US; " .
      "rv:1.8.1.1) Gecko/20061204 Firefox/2.0.0.1");
    curl_setopt($ch, CURLOPT_HTTPHEADER, array (
      "Accept: */*",
    ));

    try {

      $response = trim(curl_exec($ch));

      if(curl_errno($ch) != CURLE_OK) {
        throw new Exception(curl_error($ch));
      }

      curl_close($ch);

      return $this->validate($response);

    } catch (Exception $e) {

      throw $e;

    }
  }

  /**
   * Validate received response
   *
   * @param string $response Response
   *
   * @return stdClass
   *
   * @throws Exception
   */
  private function validate($response)
  {
    $result = json_decode($response);

    if($result === null) {
      throw new Exception('Response NULL');
    }

    if($result->return_code != 0) {
      throw new Exception($result->return_message, $result->return_code);
    }

    return $result->result;
  }
}