diff --git a/app.js b/app.js
index 20cd91e..2bde6c8 100644
--- a/app.js
+++ b/app.js
@@ -7,25 +7,20 @@
 import 'es.shim'
 import { $, bind } from 'wkit'
 
-async function test1() {
+function test1() {
   try {
-    var result = window.webkit.messageHandlers.app.postMessage({
-      value: 'Test 1'
+    window.webkit.messageHandlers.app.postMessage({
+      data: { foo: 'Test 1' }
     })
-    $('#output').innerHTML = 'output: ' + result
+    $('#output').innerHTML = '这是没有回调的 '
   } catch (err) {
     alert(err)
   }
 }
-async function test2() {
-  let key = 'cb_' + Math.random().toString().slice(2)
 
-  native.$on(key, function (v) {
-    $('#output').innerHTML = v
-  })
-  await window.webkit.messageHandlers.app.postMessage({
-    value: new Date(),
-    key
+function test2() {
+  native.handler('blabla', { foo: 'bar' }).then(r => {
+    $('#output').innerHTML = JSON.stringify(r)
   })
 }
 
diff --git a/inject.js b/inject.js
index 1b09817..0840957 100644
--- a/inject.js
+++ b/inject.js
@@ -4,6 +4,31 @@
  * @date 2023/07/21 17:38:11
  */
 
+function defer() {
+  let obj = {}
+  obj.promise = new Promise((resolve, reject) => {
+    obj.resolve = resolve
+    obj.reject = reject
+  })
+  return obj
+}
+
+function rand(prefix = 'cb_') {
+  return prefix + Math.random().toString().slice(2)
+}
+
+function handler(event, data = {}, once = true) {
+  let _ = defer()
+  let callback = rand()
+  native[once ? '$once' : '$on'](callback, _.resolve)
+  window.webkit.messageHandlers.app.postMessage({
+    event,
+    data,
+    callback
+  })
+  return _.promise
+}
+
 class EventEmitter {
   //
   __events__ = Object.create(null)
@@ -52,3 +77,10 @@ class EventEmitter {
 }
 
 window.native = new EventEmitter()
+
+Object.assign(native, {
+  fs: {
+    read(filepath) {}
+  },
+  handler
+})
diff --git a/main.py b/main.py
index a0e9701..dd51dda 100755
--- a/main.py
+++ b/main.py
@@ -79,12 +79,20 @@ class WebKitWindow(Gtk.Window):
     data = message.get_js_value()
     data = json.loads(data.to_json(0))
     print('这是py收到的值: ',data)
-    key = data.get('key')
+    event = data.get('event')
+    callback = data.get('callback')
+    res = {"foo": 123, "bar": (11,22,33)}
 
-    if key :
-      scripts = 'native.$emit("' + key + '", "这是py返回的值 ' + data.get('value') + '")'
-      self.webview.evaluate_javascript(scripts, -1)
-  
+    match event:
+      case 'fs':
+        pass
+
+      case _:
+        if callback :
+          scripts = 'native.$emit("' + callback + '",' + json.dumps(res) + ')'
+          print(scripts)
+          self.webview.evaluate_javascript(scripts, -1)
+      
 
 
   def on_decide_policy(self, webview, decision, decision_type):