diff --git a/Readme-en.md b/Readme-en.md
index 4b619a1..730a274 100644
--- a/Readme-en.md
+++ b/Readme-en.md
@@ -9,6 +9,9 @@ Use Android Device owner privilege to manage your device.
 [IzzyOnDroid F-Droid Repository](https://apt.izzysoft.de/fdroid/index/apk/com.bintianqi.owndroid)
 [Releases on GitHub](https://github.com/BinTianqi/OwnDroid/releases)
 
+> [!NOTE]
+> ColorOS users should download testkey version from releases on GitHub
+
 ## Features
 
 - System
@@ -104,21 +107,31 @@ Solution: Use OwnDroid testkey version
 
 ## API
 
-|    ID     | Description      | Extras                                | Minimum Android version |
-|:---------:|------------------|---------------------------------------|:-----------------------:|
-|   HIDE    | Hide an app      | `package`: package name of target app |                         |
-|  UNHIDE   | Unhide an app    | `package`: package name of target app |                         |
-|  SUSPEND  | Suspend an app   | `package`: package name of target app |            7            |
-| UNSUSPEND | Unsuspend an app | `package`: package name of target app |            7            |
-|   LOCK    | Lock screen      |                                       |                         |
+| ID                     | Extras        | Minimum Android version |
+|------------------------|---------------|:-----------------------:|
+| HIDE                   | `package`     |                         |
+| UNHIDE                 | `package`     |                         |
+| SUSPEND                | `package`     |            7            |
+| UNSUSPEND              | `package`     |            7            |
+| ADD_USER_RESTRICTION   | `restriction` |                         |
+| CLEAR_USER_RESTRICTION | `restriction` |                         |
+| LOCK                   |               |                         |
+
+[Available user restrictions](https://developer.android.com/reference/android/os/UserManager#constants_1)
 
-Use this API in adb shell
 ```shell
-am broadcast -a com.bintianqi.owndroid.action.<ID> -n com.bintianqi.owndroid/.ApiReceiver --es key <API_KEY>
-# Example
+# An example of hiding app in ADB shell
 am broadcast -a com.bintianqi.owndroid.action.HIDE -n com.bintianqi.owndroid/.ApiReceiver --es key abcdefg --es package com.example.app
 ```
-If the return value is 0, the operation is successful.
+
+```kotlin
+// An example of hiding app in Kotlin
+val intent = Intent("com.bintianqi.owndroid.action.HIDE")
+    .setComponent(ComponentName("com.bintianqi.owndroid", "com.bintianqi.owndroid.ApiReceiver"))
+    .putExtra("key", "abcdefg")
+    .putExtra("package", "com.example.app")
+context.sendBroadcast(intent)
+```
 
 ## Build
 
diff --git a/Readme.md b/Readme.md
index 2877b2f..4402f37 100644
--- a/Readme.md
+++ b/Readme.md
@@ -9,6 +9,9 @@
 [IzzyOnDroid F-Droid Repository](https://apt.izzysoft.de/fdroid/index/apk/com.bintianqi.owndroid)
 [Releases on GitHub](https://github.com/BinTianqi/OwnDroid/releases)
 
+> [!NOTE]
+> ColorOS用户应在GitHub上的releases下载testkey版本
+
 ## 功能
 
 - 系统
@@ -104,21 +107,31 @@ java.lang.IllegalStateException: Unexpected @ProvisioningPreCondition
 
 ## API
 
-|    ID     | 描述       | Extras             | 最小安卓版本 |
-|:---------:|----------|--------------------|:------:|
-|   HIDE    | 隐藏一个应用   | `package`: 目标应用的包名 |        |
-|  UNHIDE   | 取消隐藏一个应用 | `package`: 目标应用的包名 |        |
-|  SUSPEND  | 挂起一个应用   | `package`: 目标应用的包名 |   7    |
-| UNSUSPEND | 取消挂起一个应用 | `package`: 目标应用的包名 |   7    |
-|   LOCK    | 锁屏       |                    |        |
+| ID                     | Extra         | 最小安卓版本 |
+|------------------------|---------------|:------:|
+| HIDE                   | `package`     |        |
+| UNHIDE                 | `package`     |        |
+| SUSPEND                | `package`     |   7    |
+| UNSUSPEND              | `package`     |   7    |
+| ADD_USER_RESTRICTION   | `restriction` |        |
+| CLEAR_USER_RESTRICTION | `restriction` |        |
+| LOCK                   |               |        |
+
+[可用的用户限制](https://developer.android.google.cn/reference/android/os/UserManager#constants_1)
 
-在adb shell中使用API
 ```shell
-am broadcast -a com.bintianqi.owndroid.action.<ID> -n com.bintianqi.owndroid/.ApiReceiver --es key <API_KEY>
-# 示例
+# 一个在ADB shell中隐藏app的示例
 am broadcast -a com.bintianqi.owndroid.action.HIDE -n com.bintianqi.owndroid/.ApiReceiver --es key abcdefg --es package com.example.app
 ```
-如果返回值为0，操作成功
+
+```kotlin
+// 一个在Kotlin中隐藏app的示例
+val intent = Intent("com.bintianqi.owndroid.action.HIDE")
+    .setComponent(ComponentName("com.bintianqi.owndroid", "com.bintianqi.owndroid.ApiReceiver"))
+    .putExtra("key", "abcdefg")
+    .putExtra("package", "com.example.app")
+context.sendBroadcast(intent)
+```
 
 ## 构建
 
diff --git a/app/src/main/java/com/bintianqi/owndroid/ApiReceiver.kt b/app/src/main/java/com/bintianqi/owndroid/ApiReceiver.kt
index a45f3af..d1df5a5 100644
--- a/app/src/main/java/com/bintianqi/owndroid/ApiReceiver.kt
+++ b/app/src/main/java/com/bintianqi/owndroid/ApiReceiver.kt
@@ -9,7 +9,7 @@ import com.bintianqi.owndroid.dpm.getReceiver
 
 class ApiReceiver: BroadcastReceiver() {
     override fun onReceive(context: Context, intent: Intent) {
-        val requestKey = intent.getStringExtra("key") ?: ""
+        val requestKey = intent.getStringExtra("key")
         var log = "OwnDroid API request received. action: ${intent.action}\nkey: $requestKey"
         val sp = SharedPrefs(context)
         if(!sp.isApiEnabled) return
@@ -18,6 +18,7 @@ class ApiReceiver: BroadcastReceiver() {
             val dpm = context.getDPM()
             val receiver = context.getReceiver()
             val app = intent.getStringExtra("package")
+            val restriction = intent.getStringExtra("restriction")
             if(!app.isNullOrEmpty()) log += "\npackage: $app"
             try {
                 @SuppressWarnings("NewApi")
@@ -26,7 +27,9 @@ class ApiReceiver: BroadcastReceiver() {
                     "com.bintianqi.owndroid.action.UNHIDE" -> dpm.setApplicationHidden(receiver, app, false)
                     "com.bintianqi.owndroid.action.SUSPEND" -> dpm.setPackagesSuspended(receiver, arrayOf(app), true).isEmpty()
                     "com.bintianqi.owndroid.action.UNSUSPEND" -> dpm.setPackagesSuspended(receiver, arrayOf(app), false).isEmpty()
-                    "com.bintianqi.owndroid.action.LOCK" -> { dpm.lockNow(); null }
+                    "com.bintianqi.owndroid.action.ADD_USER_RESTRICTION" -> { dpm.addUserRestriction(receiver, restriction); true }
+                    "com.bintianqi.owndroid.action.CLEAR_USER_RESTRICTION" -> { dpm.clearUserRestriction(receiver, restriction); true }
+                    "com.bintianqi.owndroid.action.LOCK" -> { dpm.lockNow(); true }
                     else -> {
                         log += "\nInvalid action"
                         false