diff --git a/src/BaseAbstractGateway.php b/src/BaseAbstractGateway.php
index 96a0be3..ab5addc 100644
--- a/src/BaseAbstractGateway.php
+++ b/src/BaseAbstractGateway.php
@@ -6,6 +6,23 @@
 
 abstract class BaseAbstractGateway extends AbstractGateway
 {
+    public function getDefaultParameters()
+    {
+        return array(
+           'environment' => 'production'
+        );
+    }
+
+    public function getEnvironment()
+    {
+        return $this->getParameter('environment');
+    }
+
+    public function setEnvironment($environment)
+    {
+        $this->setParameter('environment', $environment);
+    }
+
     public function setTradeType($tradeType)
     {
         $this->setParameter('trade_type', $tradeType);
diff --git a/src/Message/BaseAbstractRequest.php b/src/Message/BaseAbstractRequest.php
index 30959db..eec29c1 100644
--- a/src/Message/BaseAbstractRequest.php
+++ b/src/Message/BaseAbstractRequest.php
@@ -10,6 +10,15 @@
  */
 abstract class BaseAbstractRequest extends AbstractRequest
 {
+    public function getEnvironment()
+    {
+        return $this->getParameter('environment');
+    }
+
+    public function setEnvironment($envinronment)
+    {
+        return $this->setParameter('environment', $envinronment);
+    }
 
     /**
      * @return mixed
diff --git a/src/Message/BaseAbstractResponse.php b/src/Message/BaseAbstractResponse.php
index 4b25f45..2df897e 100644
--- a/src/Message/BaseAbstractResponse.php
+++ b/src/Message/BaseAbstractResponse.php
@@ -6,11 +6,11 @@
 
 /**
  * Class BaseAbstractResponse
+ *
  * @package Omnipay\WechatPay\Message
  */
 abstract class BaseAbstractResponse extends AbstractResponse
 {
-
     /**
      * Is the response successful?
      *
@@ -20,6 +20,26 @@ public function isSuccessful()
     {
         $data = $this->getData();
 
-        return isset($data['result_code']) && $data['result_code'] == 'SUCCESS';
+        return isset($data['result_code']) && $data['result_code'] === 'SUCCESS';
+    }
+
+    /**
+     * Gateway Reference
+     *
+     * @return null|string A reference provided by the gateway to represent this transaction
+     */
+    public function getTransactionReference()
+    {
+        return $this->getData()['transaction_id'] ?? null;
+    }
+
+    /**
+     * Get the transaction ID as generated by the merchant website.
+     *
+     * @return string
+     */
+    public function getTransactionId()
+    {
+        return $this->getData()['out_trade_no'] ?? null;
     }
 }
diff --git a/src/Message/CloseOrderRequest.php b/src/Message/CloseOrderRequest.php
index 3a6f46f..8c5795c 100644
--- a/src/Message/CloseOrderRequest.php
+++ b/src/Message/CloseOrderRequest.php
@@ -17,6 +17,19 @@ class CloseOrderRequest extends BaseAbstractRequest
 {
     protected $endpoint = 'https://api.mch.weixin.qq.com/pay/closeorder';
 
+    protected $sandboxEndpoint = 'https://api.mch.weixin.qq.com/sandboxnew/pay/closeorder';
+
+    /**
+     * @return string
+     */
+    public function getEndpoint()
+    {
+        if ($this->getEnvironment() == 'production') {
+            return $this->endpoint;
+        }
+
+        return $this->sandboxEndpoint;
+    }
 
     /**
      * Get the raw data array for this message. The format of this varies from gateway to
@@ -73,7 +86,7 @@ public function setOutTradeNo($outTradeNo)
     public function sendData($data)
     {
         $body     = Helper::array2xml($data);
-        $response = $this->httpClient->request('POST', $this->endpoint, [], $body)->getBody();
+        $response = $this->httpClient->request('POST', $this->getEndpoint(), [], $body)->getBody();
         $payload  = Helper::xml2array($response);
 
         return $this->response = new CloseOrderResponse($this, $payload);
diff --git a/src/Message/CreateMicroOrderRequest.php b/src/Message/CreateMicroOrderRequest.php
index 752a563..301367b 100644
--- a/src/Message/CreateMicroOrderRequest.php
+++ b/src/Message/CreateMicroOrderRequest.php
@@ -14,8 +14,9 @@
  */
 class CreateMicroOrderRequest extends CreateOrderRequest
 {
-    protected $endpoint = 'https://api.mch.weixin.qq.com/pay/micropay';
+    protected $endpoint        = 'https://api.mch.weixin.qq.com/pay/micropay';
 
+    protected $sandboxEndpoint = 'https://api.mch.weixin.qq.com/sandboxnew/pay/micropay';
 
     /**
      * Get the raw data array for this message. The format of this varies from gateway to
@@ -77,7 +78,7 @@ public function setAuthCode($authCode)
      */
     public function sendData($data)
     {
-        $request      = $this->httpClient->request('POST', $this->endpoint, [], Helper::array2xml($data));
+        $request      = $this->httpClient->request('POST', $this->getEndpoint(), [], Helper::array2xml($data));
         $response     = $request->getBody();
         $responseData = Helper::xml2array($response);
 
diff --git a/src/Message/CreateOrderRequest.php b/src/Message/CreateOrderRequest.php
index c9e79af..c1282d1 100644
--- a/src/Message/CreateOrderRequest.php
+++ b/src/Message/CreateOrderRequest.php
@@ -14,8 +14,21 @@
  */
 class CreateOrderRequest extends BaseAbstractRequest
 {
-    protected $endpoint = 'https://api.mch.weixin.qq.com/pay/unifiedorder';
+    protected $endpoint        = 'https://api.mch.weixin.qq.com/pay/unifiedorder';
 
+    protected $sandboxEndpoint = 'https://api.mch.weixin.qq.com/sandboxnew/pay/unifiedorder';
+
+    /**
+     * @return string
+     */
+    public function getEndpoint()
+    {
+        if ($this->getEnvironment() == 'production') {
+            return $this->endpoint;
+        }
+
+        return $this->sandboxEndpoint;
+    }
 
     /**
      * Get the raw data array for this message. The format of this varies from gateway to
@@ -42,7 +55,7 @@ public function getData()
             $this->validate('open_id');
         }
 
-        $data = array(
+        $data = [
             'appid'            => $this->getAppId(),//*
             'mch_id'           => $this->getMchId(),
             'sub_appid'        => $this->getSubAppId(),
@@ -63,7 +76,7 @@ public function getData()
             'limit_pay'        => $this->getLimitPay(),
             'openid'           => $this->getOpenId(),//*(trade_type=JSAPI)
             'nonce_str'        => md5(uniqid()),//*
-        );
+        ];
 
         $data = array_filter($data);
 
@@ -72,7 +85,6 @@ public function getData()
         return $data;
     }
 
-
     /**
      * @return mixed
      */
@@ -81,7 +93,6 @@ public function getTradeType()
         return $this->getParameter('trade_type');
     }
 
-
     /**
      * @return mixed
      */
@@ -90,7 +101,6 @@ public function getDeviceInfo()
         return $this->getParameter('device_Info');
     }
 
-
     /**
      * @return mixed
      */
@@ -99,7 +109,6 @@ public function getBody()
         return $this->getParameter('body');
     }
 
-
     /**
      * @return mixed
      */
@@ -108,7 +117,6 @@ public function getDetail()
         return $this->getParameter('detail');
     }
 
-
     /**
      * @return mixed
      */
@@ -117,7 +125,6 @@ public function getAttach()
         return $this->getParameter('attach');
     }
 
-
     /**
      * @return mixed
      */
@@ -126,7 +133,6 @@ public function getOutTradeNo()
         return $this->getParameter('out_trade_no');
     }
 
-
     /**
      * @return mixed
      */
@@ -135,7 +141,6 @@ public function getFeeType()
         return $this->getParameter('fee_type');
     }
 
-
     /**
      * @return mixed
      */
@@ -144,7 +149,6 @@ public function getTotalFee()
         return $this->getParameter('total_fee');
     }
 
-
     /**
      * @return mixed
      */
@@ -153,7 +157,6 @@ public function getSpbillCreateIp()
         return $this->getParameter('spbill_create_ip');
     }
 
-
     /**
      * @return mixed
      */
@@ -162,7 +165,6 @@ public function getTimeStart()
         return $this->getParameter('time_start');
     }
 
-
     /**
      * @return mixed
      */
@@ -171,7 +173,6 @@ public function getTimeExpire()
         return $this->getParameter('time_expire');
     }
 
-
     /**
      * @return mixed
      */
@@ -180,7 +181,6 @@ public function getGoodsTag()
         return $this->getParameter('goods_tag');
     }
 
-
     /**
      * @return mixed
      */
@@ -189,7 +189,6 @@ public function getNotifyUrl()
         return $this->getParameter('notify_url');
     }
 
-
     /**
      * @return mixed
      */
@@ -198,7 +197,6 @@ public function getLimitPay()
         return $this->getParameter('limit_pay');
     }
 
-
     /**
      * @return mixed
      */
@@ -207,7 +205,6 @@ public function getOpenId()
         return $this->getParameter('open_id');
     }
 
-
     /**
      * @param mixed $deviceInfo
      */
@@ -216,7 +213,6 @@ public function setDeviceInfo($deviceInfo)
         $this->setParameter('device_Info', $deviceInfo);
     }
 
-
     /**
      * @param mixed $body
      */
@@ -225,7 +221,6 @@ public function setBody($body)
         $this->setParameter('body', $body);
     }
 
-
     /**
      * @param mixed $detail
      */
@@ -234,7 +229,6 @@ public function setDetail($detail)
         $this->setParameter('detail', $detail);
     }
 
-
     /**
      * @param mixed $attach
      */
@@ -243,7 +237,6 @@ public function setAttach($attach)
         $this->setParameter('attach', $attach);
     }
 
-
     /**
      * @param mixed $outTradeNo
      */
@@ -252,7 +245,6 @@ public function setOutTradeNo($outTradeNo)
         $this->setParameter('out_trade_no', $outTradeNo);
     }
 
-
     /**
      * @param mixed $feeType
      */
@@ -261,7 +253,6 @@ public function setFeeType($feeType)
         $this->setParameter('fee_type', $feeType);
     }
 
-
     /**
      * @param mixed $totalFee
      */
@@ -270,7 +261,6 @@ public function setTotalFee($totalFee)
         $this->setParameter('total_fee', $totalFee);
     }
 
-
     /**
      * @param mixed $spbillCreateIp
      */
@@ -279,7 +269,6 @@ public function setSpbillCreateIp($spbillCreateIp)
         $this->setParameter('spbill_create_ip', $spbillCreateIp);
     }
 
-
     /**
      * @param mixed $timeStart
      */
@@ -288,7 +277,6 @@ public function setTimeStart($timeStart)
         $this->setParameter('time_start', $timeStart);
     }
 
-
     /**
      * @param mixed $timeExpire
      */
@@ -297,7 +285,6 @@ public function setTimeExpire($timeExpire)
         $this->setParameter('time_expire', $timeExpire);
     }
 
-
     /**
      * @param mixed $goodsTag
      */
@@ -306,13 +293,11 @@ public function setGoodsTag($goodsTag)
         $this->setParameter('goods_tag', $goodsTag);
     }
 
-
     public function setNotifyUrl($notifyUrl)
     {
         $this->setParameter('notify_url', $notifyUrl);
     }
 
-
     /**
      * @param mixed $tradeType
      */
@@ -321,7 +306,6 @@ public function setTradeType($tradeType)
         $this->setParameter('trade_type', $tradeType);
     }
 
-
     /**
      * @param mixed $limitPay
      */
@@ -330,7 +314,6 @@ public function setLimitPay($limitPay)
         $this->setParameter('limit_pay', $limitPay);
     }
 
-
     /**
      * @param mixed $openId
      */
@@ -343,7 +326,7 @@ public function setOpenId($openId)
     /**
      * Send the request with specified data
      *
-     * @param  mixed $data The data to send
+     * @param mixed $data The data to send
      *
      * @return ResponseInterface
      * @throws \Psr\Http\Client\Exception\NetworkException
@@ -352,7 +335,7 @@ public function setOpenId($openId)
     public function sendData($data)
     {
         $body     = Helper::array2xml($data);
-        $response = $this->httpClient->request('POST', $this->endpoint, [], $body)->getBody();
+        $response = $this->httpClient->request('POST', $this->getEndpoint(), [], $body)->getBody();
         $payload  = Helper::xml2array($response);
 
         return $this->response = new CreateOrderResponse($this, $payload);
diff --git a/src/Message/QueryOrderRequest.php b/src/Message/QueryOrderRequest.php
index c8ccabb..5dbeeb4 100644
--- a/src/Message/QueryOrderRequest.php
+++ b/src/Message/QueryOrderRequest.php
@@ -17,6 +17,20 @@ class QueryOrderRequest extends BaseAbstractRequest
 {
     protected $endpoint = 'https://api.mch.weixin.qq.com/pay/orderquery';
 
+    protected $sandboxEndpoint = 'https://api.mch.weixin.qq.com/sandboxnew/pay/orderquery';
+
+
+    /**
+     * @return string
+     */
+    public function getEndpoint()
+    {
+        if ($this->getEnvironment() == 'production') {
+            return $this->endpoint;
+        }
+
+        return $this->sandboxEndpoint;
+    }
 
     /**
      * Get the raw data array for this message. The format of this varies from gateway to
@@ -95,7 +109,7 @@ public function setTransactionId($transactionId)
     public function sendData($data)
     {
         $body     = Helper::array2xml($data);
-        $response = $this->httpClient->request('POST', $this->endpoint, [], $body)->getBody();
+        $response = $this->httpClient->request('POST', $this->getEndpoint(), [], $body)->getBody();
         $payload  = Helper::xml2array($response);
 
         return $this->response = new QueryOrderResponse($this, $payload);
diff --git a/src/Message/QueryRefundRequest.php b/src/Message/QueryRefundRequest.php
index 0935f46..767a6c0 100644
--- a/src/Message/QueryRefundRequest.php
+++ b/src/Message/QueryRefundRequest.php
@@ -17,6 +17,19 @@ class QueryRefundRequest extends BaseAbstractRequest
 {
     protected $endpoint = 'https://api.mch.weixin.qq.com/pay/refundquery';
 
+    protected $sandboxEndpoint = 'https://api.mch.weixin.qq.com/sandboxnew/pay/refundquery';
+
+    /**
+     * @return string
+     */
+    public function getEndpoint()
+    {
+        if ($this->getEnvironment() == 'production') {
+            return $this->endpoint;
+        }
+
+        return $this->sandboxEndpoint;
+    }
 
     /**
      * Get the raw data array for this message. The format of this varies from gateway to
@@ -153,7 +166,7 @@ public function setRefundId($refundId)
      */
     public function sendData($data)
     {
-        $request      = $this->httpClient->request('POST', $this->endpoint, [], Helper::array2xml($data));
+        $request      = $this->httpClient->request('POST', $this->getEndpoint(), [], Helper::array2xml($data));
         $response     = $request->getBody();
         $responseData = Helper::xml2array($response);
 
diff --git a/src/Message/RefundOrderRequest.php b/src/Message/RefundOrderRequest.php
index 651ef2b..93fbc28 100644
--- a/src/Message/RefundOrderRequest.php
+++ b/src/Message/RefundOrderRequest.php
@@ -18,6 +18,21 @@ class RefundOrderRequest extends BaseAbstractRequest
 {
     protected $endpoint = 'https://api.mch.weixin.qq.com/secapi/pay/refund';
 
+    protected $sandboxEndpoint = 'https://api.mch.weixin.qq.com/sandboxnew/pay/refund';
+
+
+    /**
+     * @return string
+     */
+    public function getEndpoint()
+    {
+        if ($this->getEnvironment() == 'production') {
+            return $this->endpoint;
+        }
+
+        return $this->sandboxEndpoint;
+    }
+
 
     /**
      * Get the raw data array for this message. The format of this varies from gateway to
@@ -268,7 +283,7 @@ public function sendData($data)
             'ssl_key' => $this->getKeyPath(),
         ];
 
-        $result = $client->request('POST', $this->endpoint, $options)->getBody()->getContents();
+        $result = $client->request('POST', $this->getEndpoint(), $options)->getBody()->getContents();
 
         $responseData = Helper::xml2array($result);
 
diff --git a/src/Message/SandboxGetSignKeyRequest.php b/src/Message/SandboxGetSignKeyRequest.php
new file mode 100644
index 0000000..1de48e5
--- /dev/null
+++ b/src/Message/SandboxGetSignKeyRequest.php
@@ -0,0 +1,63 @@
+<?php
+
+namespace Omnipay\WechatPay\Message;
+
+use Omnipay\Common\Exception\InvalidRequestException;
+use Omnipay\Common\Http\Exception\NetworkException;
+use Omnipay\Common\Http\Exception\RequestException;
+use Omnipay\Common\Message\ResponseInterface;
+use Omnipay\WechatPay\Helper;
+
+/**
+ * Class GetSignKey
+ *
+ * @package Omnipay\WechatPay\Message
+ * @author  Ionut Cioflan <ionut.cioflan@dcsplus.net>
+ */
+class SandboxGetSignKeyRequest extends BaseAbstractRequest
+{
+    protected $sandboxEndpoint = 'https://api.mch.weixin.qq.com/sandboxnew/pay/getsignkey';
+
+    /**
+     * Get the raw data array for this message. The format of this varies from gateway to
+     * gateway, but will usually be either an associative array, or a SimpleXMLElement.
+     *
+     * @return mixed
+     * @throws InvalidRequestException
+     */
+    public function getData()
+    {
+        $this->validate(
+            'mch_id'
+        );
+
+        $data = array(
+            'mch_id'           => $this->getMchId(),
+            'nonce_str'        => md5(uniqid('', true)),//*
+        );
+
+        $data = array_filter($data);
+
+        $data['sign'] = Helper::sign($data, $this->getApiKey());
+
+        return $data;
+    }
+
+    /**
+     * Send the request with specified data
+     *
+     * @param mixed $data The data to send
+     *
+     * @return ResponseInterface
+     * @throws NetworkException
+     * @throws RequestException
+     */
+    public function sendData($data)
+    {
+        $request      = $this->httpClient->request('POST', $this->sandboxEndpoint, [], Helper::array2xml($data));
+        $response     = $request->getBody();
+        $responseData = Helper::xml2array($response);
+
+        return $this->response = new SandboxGetSignKeyResponse($this, $responseData);
+    }
+}
diff --git a/src/Message/SandboxGetSignKeyResponse.php b/src/Message/SandboxGetSignKeyResponse.php
new file mode 100644
index 0000000..f29dc20
--- /dev/null
+++ b/src/Message/SandboxGetSignKeyResponse.php
@@ -0,0 +1,46 @@
+<?php
+
+namespace Omnipay\WechatPay\Message;
+
+/**
+ * Class GetSignKeyResponse
+ *
+ * @package Omnipay\WechatPay\Message
+ * @author  Ionut Cioflan <ionut.cioflan@dcsplus.net>
+ */
+class SandboxGetSignKeyResponse extends BaseAbstractResponse
+{
+    /**
+     * @var SandboxGetSignKeyRequest
+     */
+    protected $request;
+
+    /**
+     * Is the response successful?
+     *
+     * @return boolean
+     */
+    public function isSuccessful()
+    {
+        return isset($this->getData()['return_code']) && $this->getData()['return_code'] === 'SUCCESS';
+    }
+
+    public function getSandboxKey()
+    {
+        return isset($this->getData()['sandbox_signkey']) ? $this->getData()['sandbox_signkey'] : null;
+    }
+
+    public function getReturnMessage()
+    {
+        if (isset($this->getData()['return_msg'])) {
+            return $this->getData()['return_msg'];
+        }
+
+
+        if (isset($this->getData()['retmsg'])) {
+            return $this->getData()['retmsg'];
+        }
+
+        return null;
+    }
+}
diff --git a/src/NativeGateway.php b/src/NativeGateway.php
index d834492..523b3f2 100644
--- a/src/NativeGateway.php
+++ b/src/NativeGateway.php
@@ -29,4 +29,14 @@ public function shortenUrl($parameters = array())
     {
         return $this->createRequest('\Omnipay\WechatPay\Message\ShortenUrlRequest', $parameters);
     }
+
+    /**
+     * @param array $parameters
+     *
+     * @return \Omnipay\WechatPay\Message\SandboxGetSignKeyRequest
+     */
+    public function getSandboxSignKey($parameters = array())
+    {
+        return $this->createRequest(\Omnipay\WechatPay\Message\SandboxGetSignKeyRequest::class, $parameters);
+    }
 }