diff --git a/lib/wx_pay/service.rb b/lib/wx_pay/service.rb
index 711a8d8..05f30a8 100644
--- a/lib/wx_pay/service.rb
+++ b/lib/wx_pay/service.rb
@@ -8,14 +8,14 @@ module WxPay
     INVOKE_UNIFIEDORDER_REQUIRED_FIELDS = %i(body out_trade_no total_fee spbill_create_ip notify_url trade_type)
     def self.invoke_unifiedorder(params, options = {})
       params = {
-        appid: options[:appid] || WxPay.appid,
-        mch_id: options[:mch_id] || WxPay.mch_id,
+        appid: options.delete(:appid) || WxPay.appid,
+        mch_id: options.delete(:mch_id) || WxPay.mch_id,
         nonce_str: SecureRandom.uuid.tr('-', '')
       }.merge(params)
 
       check_required_options(params, INVOKE_UNIFIEDORDER_REQUIRED_FIELDS)
 
-      r = invoke_remote("#{GATEWAY_URL}/pay/unifiedorder", make_payload(params))
+      r = invoke_remote("#{GATEWAY_URL}/pay/unifiedorder", make_payload(params), options)
 
       yield r if block_given?
 
@@ -25,8 +25,8 @@ module WxPay
     GENERATE_APP_PAY_REQ_REQUIRED_FIELDS = %i(prepayid noncestr)
     def self.generate_app_pay_req(params, options = {})
       params = {
-        appid: options[:appid] || WxPay.appid,
-        partnerid: options[:mch_id] || WxPay.mch_id,
+        appid: options.delete(:appid) || WxPay.appid,
+        partnerid: options.delete(:mch_id) || WxPay.mch_id,
         package: 'Sign=WXPay',
         timestamp: Time.now.to_i.to_s
       }.merge(params)
@@ -38,24 +38,25 @@ module WxPay
       params
     end
 
-    INVOKE_REFUND_REQUIRED_FIELDS = %i(out_refund_no total_fee refund_fee)
+    INVOKE_REFUND_REQUIRED_FIELDS = %i(out_refund_no total_fee refund_fee op_user_id)
     def self.invoke_refund(params, options = {})
       params = {
-        appid: options[:appid] || WxPay.appid,
-        mch_id: options[:mch_id] || WxPay.mch_id,
+        appid: options.delete(:appid) || WxPay.appid,
+        mch_id: options.delete(:mch_id) || WxPay.mch_id,
         nonce_str: SecureRandom.uuid.tr('-', ''),
-        op_user_id: options[:mch_id] || WxPay.mch_id
       }.merge(params)
 
+      params[:op_user_id] ||= params[:mch_id]
+
       check_required_options(params, INVOKE_REFUND_REQUIRED_FIELDS)
 
-      r = invoke_remote "#{GATEWAY_URL}/secapi/pay/refund",
-                        make_payload(params),
-                        {
-                          ssl_client_cert: options[:apiclient_cert] || WxPay.apiclient_cert,
-                          ssl_client_key: options[:apiclient_key] || WxPay.apiclient_key,
-                          verify_ssl: OpenSSL::SSL::VERIFY_NONE
-                        }
+      options = {
+        ssl_client_cert: options.delete(:apiclient_cert) || WxPay.apiclient_cert,
+        ssl_client_key: options.delete(:apiclient_key) || WxPay.apiclient_key,
+        verify_ssl: OpenSSL::SSL::VERIFY_NONE
+      }.merge(options)
+
+      r = invoke_remote("#{GATEWAY_URL}/secapi/pay/refund", make_payload(params), options)
 
       yield(r) if block_given?
 
@@ -65,20 +66,20 @@ module WxPay
     INVOKE_TRANSFER_REQUIRED_FIELDS = %i(partner_trade_no openid check_name amount desc spbill_create_ip)
     def self.invoke_transfer(params, options = {})
       params = {
-        mch_appid: options[:appid] || WxPay.appid,
-        mchid: options[:mch_id] || WxPay.mch_id,
+        mch_appid: options.delete(:appid) || WxPay.appid,
+        mchid: options.delete(:mch_id) || WxPay.mch_id,
         nonce_str: SecureRandom.uuid.tr('-', '')
       }.merge(params)
 
       check_required_options(params, INVOKE_TRANSFER_REQUIRED_FIELDS)
 
-      r = invoke_remote "#{GATEWAY_URL}/mmpaymkttransfers/promotion/transfers",
-                        make_payload(params),
-                        {
-                          ssl_client_cert: options[:apiclient_cert] || WxPay.apiclient_cert,
-                          ssl_client_key: options[:apiclient_key] || WxPay.apiclient_key,
-                          verify_ssl: OpenSSL::SSL::VERIFY_NONE
-                        }
+      options = {
+        ssl_client_cert: options.delete(:apiclient_cert) || WxPay.apiclient_cert,
+        ssl_client_key: options.delete(:apiclient_key) || WxPay.apiclient_key,
+        verify_ssl: OpenSSL::SSL::VERIFY_NONE
+      }.merge(options)
+
+      r = invoke_remote("#{GATEWAY_URL}/mmpaymkttransfers/promotion/transfers", make_payload(params), options)
 
       yield r if block_given?
 
@@ -88,30 +89,20 @@ module WxPay
     INVOKE_REVERSE_REQUIRED_FIELDS = %i(out_trade_no)
     def self.invoke_reverse(params, options = {})
       params = {
-        appid: options[:appid] || WxPay.appid,
-        mch_id: options[:mch_id] || WxPay.mch_id,
+        appid: options.delete(:appid) || WxPay.appid,
+        mch_id: options.delete(:mch_id) || WxPay.mch_id,
         nonce_str: SecureRandom.uuid.tr('-', '')
       }.merge(params)
 
       check_required_options(params, INVOKE_REVERSE_REQUIRED_FIELDS)
 
-      # 微信退款需要双向证书
-      # https://pay.weixin.qq.com/wiki/doc/api/jsapi.php?chapter=9_4
-      # https://pay.weixin.qq.com/wiki/doc/api/jsapi.php?chapter=4_3
-
-      WxPay.extra_rest_client_options = {
-        ssl_client_cert: WxPay.apiclient_cert.certificate,
-        ssl_client_key: WxPay.apiclient_cert.key,
+      options = {
+        ssl_client_cert: options.delete(:apiclient_cert) || WxPay.apiclient_cert,
+        ssl_client_key: options.delete(:apiclient_key) || WxPay.apiclient_key,
         verify_ssl: OpenSSL::SSL::VERIFY_NONE
-      }
+      }.merge(options)
 
-      r = invoke_remote "#{GATEWAY_URL}/secapi/pay/reverse",
-                        make_payload(params),
-                        {
-                          ssl_client_cert: options[:apiclient_cert] || WxPay.apiclient_cert,
-                          ssl_client_key: options[:apiclient_key] || WxPay.apiclient_key,
-                          verify_ssl: OpenSSL::SSL::VERIFY_NONE
-                        }
+      r = invoke_remote("#{GATEWAY_URL}/secapi/pay/reverse", make_payload(params), options)
 
       yield(r) if block_given?
 
@@ -121,20 +112,20 @@ module WxPay
     INVOKE_MICROPAY_REQUIRED_FIELDS = %i(body out_trade_no total_fee spbill_create_ip auth_code)
     def self.invoke_micropay(params, options = {})
       params = {
-        appid: options[:appid] || WxPay.appid,
-        mch_id: options[:mch_id] || WxPay.mch_id,
+        appid: options.delete(:appid) || WxPay.appid,
+        mch_id: options.delete(:mch_id) || WxPay.mch_id,
         nonce_str: SecureRandom.uuid.tr('-', '')
       }.merge(params)
 
       check_required_options(params, INVOKE_MICROPAY_REQUIRED_FIELDS)
 
-      r = invoke_remote "#{GATEWAY_URL}/pay/micropay",
-                        make_payload(params),
-                        {
-                          ssl_client_cert: options[:apiclient_cert] || WxPay.apiclient_cert,
-                          ssl_client_key: options[:apiclient_key] || WxPay.apiclient_key,
-                          verify_ssl: OpenSSL::SSL::VERIFY_NONE
-                        }
+      options = {
+        ssl_client_cert: options.delete(:apiclient_cert) || WxPay.apiclient_cert,
+        ssl_client_key: options.delete(:apiclient_key) || WxPay.apiclient_key,
+        verify_ssl: OpenSSL::SSL::VERIFY_NONE
+      }.merge(options)
+
+      r = invoke_remote("#{GATEWAY_URL}/pay/micropay", make_payload(params), options)
 
       yield(r) if block_given?
 
@@ -144,14 +135,14 @@ module WxPay
     ORDER_QUERY_REQUIRED_FIELDS = %i(out_trade_no)
     def self.order_query(params, options = {})
       params = {
-        appid: options[:appid] || WxPay.appid,
-        mch_id: options[:mch_id] || WxPay.mch_id,
+        appid: options.delete(:appid) || WxPay.appid,
+        mch_id: options.delete(:mch_id) || WxPay.mch_id,
         nonce_str: SecureRandom.uuid.tr('-', '')
       }.merge(params)
 
       check_required_options(params, ORDER_QUERY_REQUIRED_FIELDS)
 
-      r = invoke_remote "#{GATEWAY_URL}/pay/orderquery", make_payload(params)
+      r = invoke_remote("#{GATEWAY_URL}/pay/orderquery", make_payload(params), options)
 
       yield(r) if block_given?
 
--
libgit2 0.21.0