diff --git a/android/build.gradle b/android/build.gradle
index 0c3bf100a..0d478b418 100644
--- a/android/build.gradle
+++ b/android/build.gradle
@@ -52,5 +52,5 @@ android {
 dependencies {
     implementation "org.jetbrains.kotlin:kotlin-stdlib-jdk8:${safeExtGet('kotlin_version', '1.3.72')}"
     implementation "org.jetbrains.kotlin:kotlin-reflect:${safeExtGet('kotlin_version', '1.3.72')}"
-    implementation "io.agora.rtc:full-sdk:3.1.2"
+    implementation "io.agora.rtc:full-sdk:3.1.3"
 }
diff --git a/android/src/main/kotlin/io/agora/agora_rtc_engine/AgoraRtcEnginePlugin.kt b/android/src/main/kotlin/io/agora/agora_rtc_engine/AgoraRtcEnginePlugin.kt
index 47ba629dc..a71d4cae9 100644
--- a/android/src/main/kotlin/io/agora/agora_rtc_engine/AgoraRtcEnginePlugin.kt
+++ b/android/src/main/kotlin/io/agora/agora_rtc_engine/AgoraRtcEnginePlugin.kt
@@ -7,26 +7,28 @@ import androidx.annotation.NonNull
 import io.agora.rtc.RtcEngine
 import io.agora.rtc.base.RtcEngineManager
 import io.flutter.embedding.engine.plugins.FlutterPlugin
-import io.flutter.plugin.common.BinaryMessenger
-import io.flutter.plugin.common.EventChannel
-import io.flutter.plugin.common.MethodCall
-import io.flutter.plugin.common.MethodChannel
+import io.flutter.plugin.common.*
 import io.flutter.plugin.common.MethodChannel.MethodCallHandler
 import io.flutter.plugin.common.MethodChannel.Result
 import io.flutter.plugin.common.PluginRegistry.Registrar
 import io.flutter.plugin.platform.PlatformViewRegistry
+import java.io.FileNotFoundException
 import kotlin.reflect.full.declaredMemberFunctions
 import kotlin.reflect.jvm.javaMethod
 
 /** AgoraRtcEnginePlugin */
 class AgoraRtcEnginePlugin : FlutterPlugin, MethodCallHandler, EventChannel.StreamHandler {
+    private var registrar: Registrar? = null
+    private var binding: FlutterPlugin.FlutterPluginBinding? = null
+    private lateinit var applicationContext: Context
+
     /// The MethodChannel that will the communication between Flutter and native Android
     ///
     /// This local reference serves to register the plugin with the Flutter Engine and unregister it
     /// when the Flutter Engine is detached from the Activity
     private lateinit var methodChannel: MethodChannel
     private lateinit var eventChannel: EventChannel
-    private lateinit var applicationContext: Context
+
     private var eventSink: EventChannel.EventSink? = null
     private val manager = RtcEngineManager { methodName, data -> emit(methodName, data) }
     private val handler = Handler(Looper.getMainLooper())
@@ -45,8 +47,9 @@ class AgoraRtcEnginePlugin : FlutterPlugin, MethodCallHandler, EventChannel.Stre
         @JvmStatic
         fun registerWith(registrar: Registrar) {
             AgoraRtcEnginePlugin().apply {
-                initPlugin(registrar.context(), registrar.messenger(), registrar.platformViewRegistry())
+                this.registrar = registrar
                 rtcChannelPlugin.initPlugin(registrar.messenger())
+                initPlugin(registrar.context(), registrar.messenger(), registrar.platformViewRegistry())
             }
         }
     }
@@ -63,6 +66,7 @@ class AgoraRtcEnginePlugin : FlutterPlugin, MethodCallHandler, EventChannel.Stre
     }
 
     override fun onAttachedToEngine(@NonNull binding: FlutterPlugin.FlutterPluginBinding) {
+        this.binding = binding
         rtcChannelPlugin.onAttachedToEngine(binding)
         initPlugin(binding.applicationContext, binding.binaryMessenger, binding.platformViewRegistry)
     }
@@ -95,6 +99,10 @@ class AgoraRtcEnginePlugin : FlutterPlugin, MethodCallHandler, EventChannel.Stre
     }
 
     override fun onMethodCall(@NonNull call: MethodCall, @NonNull result: Result) {
+        if (call.method == "getAssetAbsolutePath") {
+            getAssetAbsolutePath(call, result)
+            return
+        }
         manager::class.declaredMemberFunctions.find { it.name == call.method }?.let { function ->
             function.javaMethod?.let { method ->
                 try {
@@ -114,4 +122,19 @@ class AgoraRtcEnginePlugin : FlutterPlugin, MethodCallHandler, EventChannel.Stre
         }
         result.notImplemented()
     }
+
+    private fun getAssetAbsolutePath(call: MethodCall, result: Result) {
+        call.arguments<String>()?.let {
+            val assetKey = registrar?.lookupKeyForAsset(it)
+                    ?: binding?.flutterAssets?.getAssetFilePathByName(it)
+            try {
+                applicationContext.assets.openFd(assetKey!!).close()
+                result.success("/assets/$assetKey")
+            } catch (e: Exception) {
+                result.error(e.javaClass.simpleName, e.message, e.cause)
+            }
+            return@getAssetAbsolutePath
+        }
+        result.error(IllegalArgumentException::class.simpleName, null, null)
+    }
 }
diff --git a/example/lib/config/agora.config.dart b/example/lib/config/agora.config.dart
index 12a4ebe61..945487a81 100644
--- a/example/lib/config/agora.config.dart
+++ b/example/lib/config/agora.config.dart
@@ -1,5 +1,9 @@
+/// Get your own App ID at https://dashboard.agora.io/
 const appId = YOUR_APP_ID;
+
+/// Please refer to https://docs.agora.io/en/Agora%20Platform/token
 const token = YOUR_TOEKN;
+
 const channelId = YOUR_CHANNEL_ID;
 const uid = YOUR_UID;
 const stringUid = YOUR_STRING_UID;
diff --git a/example/lib/examples/basic/join_channel_audio.dart b/example/lib/examples/basic/join_channel_audio.dart
index 392f967a8..3b18200fd 100644
--- a/example/lib/examples/basic/join_channel_audio.dart
+++ b/example/lib/examples/basic/join_channel_audio.dart
@@ -17,7 +17,10 @@ class JoinChannelAudio extends StatefulWidget {
 
 class _State extends State<JoinChannelAudio> {
   String channelId = config.channelId;
-  bool isJoined = false, openMicrophone = true, enableSpeakerphone = true;
+  bool isJoined = false,
+      openMicrophone = true,
+      enableSpeakerphone = true,
+      playEffect = false;
   TextEditingController _controller;
 
   @override
@@ -91,6 +94,36 @@ class _State extends State<JoinChannelAudio> {
     });
   }
 
+  _switchEffect() async {
+    if (playEffect) {
+      widget._engine?.stopEffect(1)?.then((value) {
+        setState(() {
+          playEffect = false;
+        });
+      })?.catchError((err) {
+        log('stopEffect $err');
+      });
+    } else {
+      widget._engine
+          ?.playEffect(
+              1,
+              await RtcEngineExtension.getAssetAbsolutePath(
+                  "assets/Sound_Horizon.mp3"),
+              -1,
+              1,
+              1,
+              100,
+              true)
+          ?.then((value) {
+        setState(() {
+          playEffect = true;
+        });
+      })?.catchError((err) {
+        log('playEffect $err');
+      });
+    }
+  }
+
   @override
   Widget build(BuildContext context) {
     return Stack(
@@ -133,6 +166,10 @@ class _State extends State<JoinChannelAudio> {
                 onPressed: this._switchSpeakerphone,
                 child: Text(enableSpeakerphone ? 'Speakerphone' : 'Earpiece'),
               ),
+              RaisedButton(
+                onPressed: this._switchEffect,
+                child: Text('${playEffect ? 'Stop' : 'Play'} effect'),
+              ),
             ],
           ),
         )
diff --git a/example/pubspec.yaml b/example/pubspec.yaml
index 9da0b40b4..3b69f97a8 100644
--- a/example/pubspec.yaml
+++ b/example/pubspec.yaml
@@ -48,6 +48,8 @@ flutter:
   # assets:
   #   - images/a_dot_burr.jpeg
   #   - images/a_dot_ham.jpeg
+  assets:
+    - assets/Sound_Horizon.mp3
 
   # An image asset can refer to one or more resolution-specific "variants", see
   # https://flutter.dev/assets-and-images/#resolution-aware.
diff --git a/ios/Classes/SwiftAgoraRtcEnginePlugin.swift b/ios/Classes/SwiftAgoraRtcEnginePlugin.swift
index f8ada518a..34df87aff 100644
--- a/ios/Classes/SwiftAgoraRtcEnginePlugin.swift
+++ b/ios/Classes/SwiftAgoraRtcEnginePlugin.swift
@@ -2,6 +2,7 @@ import Flutter
 import UIKit
 
 public class SwiftAgoraRtcEnginePlugin: NSObject, FlutterPlugin, FlutterStreamHandler {
+    private var registrar: FlutterPluginRegistrar?
     private var methodChannel: FlutterMethodChannel?
     private var eventChannel: FlutterEventChannel?
     private var eventSink: FlutterEventSink? = nil
@@ -16,6 +17,7 @@ public class SwiftAgoraRtcEnginePlugin: NSObject, FlutterPlugin, FlutterStreamHa
 
     public static func register(with registrar: FlutterPluginRegistrar) {
         let rtcEnginePlugin = SwiftAgoraRtcEnginePlugin()
+        rtcEnginePlugin.registrar = registrar
         rtcEnginePlugin.rtcChannelPlugin.initPlugin(registrar)
         rtcEnginePlugin.initPlugin(registrar)
     }
@@ -61,6 +63,10 @@ public class SwiftAgoraRtcEnginePlugin: NSObject, FlutterPlugin, FlutterStreamHa
     }
 
     public func handle(_ call: FlutterMethodCall, result: @escaping FlutterResult) {
+        if call.method == "getAssetAbsolutePath" {
+            getAssetAbsolutePath(call, result: result)
+            return
+        }
         if let params = call.arguments as? NSDictionary {
             let selector = NSSelectorFromString(call.method + "::")
             if manager.responds(to: selector) {
@@ -76,4 +82,18 @@ public class SwiftAgoraRtcEnginePlugin: NSObject, FlutterPlugin, FlutterStreamHa
         }
         result(FlutterMethodNotImplemented)
     }
+    
+    private func getAssetAbsolutePath(_ call: FlutterMethodCall, result: @escaping FlutterResult) {
+        if let assetPath = call.arguments as? String {
+            if let assetKey = registrar?.lookupKey(forAsset: assetPath) {
+                if let realPath = Bundle.main.path(forResource: assetKey, ofType: nil) {
+                    result(realPath)
+                    return
+                }
+            }
+            result(FlutterError.init(code: "FileNotFoundException", message: nil, details: nil))
+            return
+        }
+        result(FlutterError.init(code: "IllegalArgumentException", message: nil, details: nil))
+    }
 }
diff --git a/lib/rtc_engine.dart b/lib/rtc_engine.dart
index a1c503b7c..8919aefe4 100644
--- a/lib/rtc_engine.dart
+++ b/lib/rtc_engine.dart
@@ -2,3 +2,4 @@ export 'src/classes.dart';
 export 'src/enums.dart';
 export 'src/events.dart' show RtcEngineEventHandler;
 export 'src/rtc_engine.dart' show RtcEngine;
+export 'src/rtc_engine_extension.dart';
diff --git a/lib/src/rtc_channel.dart b/lib/src/rtc_channel.dart
index ae678abbb..862acae55 100644
--- a/lib/src/rtc_channel.dart
+++ b/lib/src/rtc_channel.dart
@@ -310,6 +310,7 @@ class RtcChannel with RtcChannelInterface {
   }
 }
 
+/// @nodoc
 mixin RtcChannelInterface
     implements
         RtcAudioInterface,
@@ -421,6 +422,7 @@ mixin RtcChannelInterface
   Future<String> getCallId();
 }
 
+/// @nodoc
 mixin RtcAudioInterface {
   /// Adjusts the playback volume of a specified remote user.
   ///
@@ -463,6 +465,7 @@ mixin RtcAudioInterface {
   Future<void> setDefaultMuteAllRemoteAudioStreams(bool muted);
 }
 
+/// @nodoc
 mixin RtcVideoInterface {
   /// Stops/Resumes receiving the video stream of the specified user.
   ///
@@ -488,6 +491,7 @@ mixin RtcVideoInterface {
   Future<void> setDefaultMuteAllRemoteVideoStreams(bool muted);
 }
 
+/// @nodoc
 mixin RtcVoicePositionInterface {
   /// Sets the sound position of a remote user.
   ///
@@ -508,6 +512,7 @@ mixin RtcVoicePositionInterface {
   Future<void> setRemoteVoicePosition(int uid, double pan, double gain);
 }
 
+/// @nodoc
 mixin RtcPublishStreamInterface {
   /// Sets the video layout and audio settings for CDN live.
   ///
@@ -552,6 +557,7 @@ mixin RtcPublishStreamInterface {
   Future<void> removePublishStreamUrl(String url);
 }
 
+/// @nodoc
 mixin RtcMediaRelayInterface {
   /// Starts to relay media streams across channels.
   ///
@@ -596,6 +602,7 @@ mixin RtcMediaRelayInterface {
   Future<void> stopChannelMediaRelay();
 }
 
+/// @nodoc
 mixin RtcDualStreamInterface {
   /// Sets the video stream type of the remote video stream when the remote user sends dual streams.
   ///
@@ -614,6 +621,7 @@ mixin RtcDualStreamInterface {
   Future<void> setRemoteDefaultVideoStreamType(VideoStreamType streamType);
 }
 
+/// @nodoc
 mixin RtcFallbackInterface {
   /// Sets the priority of a remote user's media stream.
   ///
@@ -628,6 +636,7 @@ mixin RtcFallbackInterface {
   Future<void> setRemoteUserPriority(int uid, UserPriority userPriority);
 }
 
+/// @nodoc
 mixin RtcMediaMetadataInterface {
   /// Registers the metadata observer.
   ///
@@ -654,6 +663,7 @@ mixin RtcMediaMetadataInterface {
   Future<void> sendMetadata(String metadata);
 }
 
+/// @nodoc
 mixin RtcEncryptionInterface {
   /// Enables built-in encryption with an encryption password before joining a channel.
   ///
@@ -708,6 +718,7 @@ mixin RtcEncryptionInterface {
   Future<void> enableEncryption(bool enabled, EncryptionConfig config);
 }
 
+/// @nodoc
 mixin RtcInjectStreamInterface {
   /// Injects an online media stream to a [ChannelProfile.LiveBroadcasting] channel.
   ///
@@ -739,6 +750,7 @@ mixin RtcInjectStreamInterface {
   Future<void> removeInjectStreamUrl(String url);
 }
 
+/// @nodoc
 mixin RtcStreamMessageInterface {
   /// Creates a data stream.
   ///
diff --git a/lib/src/rtc_engine.dart b/lib/src/rtc_engine.dart
index 7faa3d355..1e212ad73 100644
--- a/lib/src/rtc_engine.dart
+++ b/lib/src/rtc_engine.dart
@@ -15,6 +15,9 @@ class RtcEngine with RtcEngineInterface {
   static const EventChannel _eventChannel =
       EventChannel('agora_rtc_engine/events');
 
+  /// Exposing methodChannel to other files
+  static MethodChannel get methodChannel => _methodChannel;
+
   static RtcEngine _engine;
 
   RtcEngineEventHandler _handler;
@@ -867,6 +870,7 @@ class RtcEngine with RtcEngineInterface {
   }
 }
 
+/// @nodoc
 mixin RtcEngineInterface
     implements
         RtcUserInfoInterface,
@@ -1076,6 +1080,7 @@ mixin RtcEngineInterface
   Future<int> getNativeHandle();
 }
 
+/// @nodoc
 mixin RtcUserInfoInterface {
   /// Registers a user account.
   ///
@@ -1163,6 +1168,7 @@ mixin RtcUserInfoInterface {
   Future<UserInfo> getUserInfoByUid(int uid);
 }
 
+/// @nodoc
 mixin RtcAudioInterface {
   /// Enables the audio module.
   ///
@@ -1320,6 +1326,7 @@ mixin RtcAudioInterface {
       int interval, int smooth, bool report_vad);
 }
 
+/// @nodoc
 mixin RtcVideoInterface {
   /// Enables the video module.
   ///
@@ -1451,6 +1458,7 @@ mixin RtcVideoInterface {
   Future<void> setBeautyEffectOptions(bool enabled, BeautyOptions options);
 }
 
+/// @nodoc
 mixin RtcAudioMixingInterface {
   /// Starts playing and mixing the music file.
   ///
@@ -1578,6 +1586,7 @@ mixin RtcAudioMixingInterface {
   Future<void> setAudioMixingPitch(int pitch);
 }
 
+/// @nodoc
 mixin RtcAudioEffectInterface {
   /// Gets the volume of the audio effects.
   ///
@@ -1687,6 +1696,7 @@ mixin RtcAudioEffectInterface {
       AudioSessionOperationRestriction restriction);
 }
 
+/// @nodoc
 mixin RtcVoiceChangerInterface {
   /// Sets the local voice changer option.
   ///
@@ -1730,6 +1740,7 @@ mixin RtcVoiceChangerInterface {
   Future<void> setLocalVoiceReverb(AudioReverbType reverbKey, int value);
 }
 
+/// @nodoc
 mixin RtcVoicePositionInterface {
   /// Enables/Disables stereo panning for remote users.
   ///
@@ -1758,6 +1769,7 @@ mixin RtcVoicePositionInterface {
   Future<void> setRemoteVoicePosition(int uid, double pan, double gain);
 }
 
+/// @nodoc
 mixin RtcPublishStreamInterface {
   /// Sets the video layout and audio settings for CDN live.
   ///
@@ -1805,6 +1817,7 @@ mixin RtcPublishStreamInterface {
   Future<void> removePublishStreamUrl(String url);
 }
 
+/// @nodoc
 mixin RtcMediaRelayInterface {
   /// Starts to relay media streams across channels.
   ///
@@ -1848,6 +1861,7 @@ mixin RtcMediaRelayInterface {
   Future<void> stopChannelMediaRelay();
 }
 
+/// @nodoc
 mixin RtcAudioRouteInterface {
   /// Sets the default audio playback route.
   ///
@@ -1885,6 +1899,7 @@ mixin RtcAudioRouteInterface {
   Future<bool> isSpeakerphoneEnabled();
 }
 
+/// @nodoc
 mixin RtcEarMonitoringInterface {
   /// Enables in-ear monitoring.
   ///
@@ -1899,6 +1914,7 @@ mixin RtcEarMonitoringInterface {
   Future<void> setInEarMonitoringVolume(int volume);
 }
 
+/// @nodoc
 mixin RtcDualStreamInterface {
   /// Enables/Disables the dual video stream mode.
   ///
@@ -1930,6 +1946,7 @@ mixin RtcDualStreamInterface {
   Future<void> setRemoteDefaultVideoStreamType(VideoStreamType streamType);
 }
 
+/// @nodoc
 mixin RtcFallbackInterface {
   /// Sets the fallback option for the locally published video stream based on the network conditions.
   ///
@@ -1966,6 +1983,7 @@ mixin RtcFallbackInterface {
   Future<void> setRemoteUserPriority(int uid, UserPriority userPriority);
 }
 
+/// @nodoc
 mixin RtcTestInterface {
   /// Starts an audio call test.
   ///
@@ -2020,6 +2038,7 @@ mixin RtcTestInterface {
   Future<void> stopLastmileProbeTest();
 }
 
+/// @nodoc
 mixin RtcMediaMetadataInterface {
   /// Registers the metadata observer.
   ///
@@ -2047,6 +2066,7 @@ mixin RtcMediaMetadataInterface {
   Future<void> sendMetadata(String metadata);
 }
 
+/// @nodoc
 mixin RtcWatermarkInterface {
   /// Adds a watermark image to the local video.
   ///
@@ -2076,6 +2096,7 @@ mixin RtcWatermarkInterface {
   Future<void> clearVideoWatermarks();
 }
 
+/// @nodoc
 mixin RtcEncryptionInterface {
   /// Enables built-in encryption with an encryption password before joining a channel.
   ///
@@ -2130,6 +2151,7 @@ mixin RtcEncryptionInterface {
   Future<void> enableEncryption(bool enabled, EncryptionConfig config);
 }
 
+/// @nodoc
 mixin RtcAudioRecorderInterface {
   /// Starts an audio recording on the client.
   ///
@@ -2159,6 +2181,7 @@ mixin RtcAudioRecorderInterface {
   Future<void> stopAudioRecording();
 }
 
+/// @nodoc
 mixin RtcInjectStreamInterface {
   /// Injects an online media stream to a live broadcast.
   ///
@@ -2193,6 +2216,7 @@ mixin RtcInjectStreamInterface {
   Future<void> removeInjectStreamUrl(String url);
 }
 
+/// @nodoc
 mixin RtcCameraInterface {
   /// Switches between front and rear cameras.
   Future<void> switchCamera();
@@ -2281,6 +2305,7 @@ mixin RtcCameraInterface {
       CameraCapturerConfiguration config);
 }
 
+/// @nodoc
 mixin RtcStreamMessageInterface {
   /// Creates a data stream.
   ///