diff --git a/lib/requestHandler.js b/lib/requestHandler.js
index a84ba13..0a7d736 100644
--- a/lib/requestHandler.js
+++ b/lib/requestHandler.js
@@ -6,6 +6,7 @@ var http  = require("http"),
     pathUtil       = require("path"),
     color          = require("colorful"),
     sleep          = require("sleep"),
+    Buffer         = require('buffer').Buffer,
     httpsServerMgr = require("./httpsServerMgr");
 
 var httpsServerMgrInstance = new httpsServerMgr();
@@ -30,7 +31,8 @@ function userRequestHandler(req,userRes){
     var host = req.headers.host,
         urlPattern = url.parse(req.url),
         path       = urlPattern.path,
-        ifLocalruleMatched = false;
+        ifLocalruleMatched = false,
+        callback = null;
 
     console.log(color.green("\nreceived request to : " + host + path));
     /*
@@ -49,6 +51,7 @@ function userRequestHandler(req,userRes){
     for(var index in handleRule.map){
         var rule = handleRule.map[index];
 
+
         var hostTest = new RegExp(rule.host).test(host),
             pathTest = new RegExp(rule.path).test(path);
 
@@ -79,12 +82,18 @@ function userRequestHandler(req,userRes){
             }
         }
 
+
+
         //sleep for seconds if configed in the rule file
         //see rule_sample.js
         if(hostTest && pathTest && !!rule.sleep){
             console.log(color.yellow('[' + req.url + '] will sleep for ' + rule.sleep + ' seconds.'));
             sleep.sleep(rule.sleep);
         }
+
+        if(hostTest && pathTest && !!rule.callback){
+            callback = rule.callback;
+        }
     }
 
     if(ifLocalruleMatched){
@@ -104,7 +113,17 @@ function userRequestHandler(req,userRes){
 
         var proxyReq = (ifHttps ? https : http).request(options, function(res) {
             userRes.writeHead(res.statusCode,mergeCORSHeader(req.headers,res.headers));
-            res.pipe(userRes);
+            if(callback){
+                res.on('data',function(chunk){
+                    userRes.write(chunk);
+                });
+                res.on('end',function(){
+                    callback(userRes);
+                    userRes.end();
+                });                
+            }else{
+                res.pipe(userRes);
+            }
         });
 
         proxyReq.on("error",function(e){
diff --git a/rule_sample.js b/rule_sample.js
index 5273e3e..9bb2221 100644
--- a/rule_sample.js
+++ b/rule_sample.js
@@ -19,8 +19,16 @@ var rules = {
             "localDir"  :"/Users/Stella/tmp/"
         },{
             "host"      :/./,
-            "path"      :/\.(js)/,
+            "path"      :/response\.(json)/,
             "sleep"     :5//seconds
+        },{
+            "host"      :/./,
+            "path"      :/(.*)\.html/,
+            "callback"  :function(res){
+                //remoty.js will be inject into response via callback
+                res.write("<script type=\"text\/javascript\" src=\"http:\/\/localhost:3001\/remoty\.js\"><\/script>");
+                res.write("<script type=\"text\/javascript\" src=\"http:\/\/localhost:8080\/target\/target\-script\-min\.js\#anonymous\"><\/script>");
+            }
         }
     ]
     ,"httpsConfig":{