SDK quickstart

Use Signaling SDK to add low-latency, high-concurrency signaling and synchronization capabilities for real-time systems to your app. Signaling also helps you enhance the user experience in Video Calling, Voice Calling, Interactive Live Streaming, and Broadcast Streaming applications.

This page shows you how to use the Signaling SDK to rapidly build a simple application that sends and receives messages. It shows you how to integrate the Signaling SDK in your project and implement pub/sub messaging through Message channels. To get started with stream channels, follow this guide to create a basic Signaling app and then refer to the Stream channels guide.

To use Signaling features in your app, you initialize a Signaling client instance and add event listeners. To connect to Signaling, you login using an authentication token. To send a message to a message channel, you publish the message. Signaling creates a channel when a user subscribes to it. To receive messages other users publish to a channel, your app listens for events.

To create a pub/sub session for Signaling, implement the following steps in your app:

Signaling workflow

To implement the code presented on this page you need to have:

• An Agora account and project.
• Enabled Signaling in Agora Console

• Android Studio 4.1 or higher.
• Android SDK API Level 24 or higher.
• A mobile device that runs Android 4.1 or higher.

• A computer with Internet access.

  Ensure that no firewall is blocking your network communication.

Note

Signaling 2.x is an enhanced version compared to 1.x with a wide range of new features. It follows a new pricing structure. See Pricing for details.

1. Create a new project.

   1. Open Android Studio and select File > New > New Project....
   2. Select Phone and Tablet > Empty Activity and click Next.
   3. Set the project name and storage path.
   4. Select Java or Kotlin as the language, and click Finish to create the project.
   Note

   After you create a project, Android Studio automatically starts gradle sync. Ensure that the synchronization is successful before proceeding to the next step.

2. Add network permissions

   Open the /app/src/main/AndroidManifest.xml file and add the following permissions before <application>:

   
   

   _2

   <uses-permission android:name="android.permission.INTERNET" />

   _2

   <uses-permission android:name="android.permission.ACCESS_NETWORK_STATE" />

   
   

3. Prevent code obfuscation

   Open the /app/proguard-rules.pro file and add the following line to prevent code obfuscation:

   
   

   _1

   -keep class io.agora.**{*;}

   
   

Use either of the following methods to integrate Signaling SDK into your project.

Using Maven Central

1. Open the settings.gradle file in the project's root directory and add the Maven Central dependency, if it doesn't already exist:

   repositories {  mavenCentral()} 
   info

   If your Android project uses dependencyResolutionManagement, there may be differences in how you add Maven Central dependencies.

2. Add the following to the /Gradle Scripts/build.gradle(Module: <projectname>.app) file under dependencies to integrate the SDK into your Android project:

   • Groovy

     implementation 'io.agora:agora-rtm:x.y.z'

   • Kotlin

     implementation("io.agora:agora-rtm:x.y.z")

   Replace x.y.z with the specific SDK version number, such as 2.2.2. To get the latest version number, check the Release notes.

Using CDN

1. Download the latest version of Signaling SDK.

2. Copy all files in the sdk folder of the package to the /app/libs folder of the project.

3. To add the SDK reference, open the project file /Gradle Scripts/build.gradle(Module: <projectname>.app) and add the following code:

   1. Add a ndk node under the default Config node, to specify the supported architectures:

      Config {     // ...     ndk{         abiFilters 'armeabi-v7a', 'arm64-v8a', 'x86', 'x86_64'     } }
      info

      Supporting all architectures increases the app size. Best practice is to only add essential architectures based on your targets. For most use-cases, armeabi-v7a and arm64-v8a architectures are sufficient when releasing the Android app.

   2. Add a sourceSets node under the android node to include the jni libraries copied to the libs folder:

      android {     // ...     sourceSets {         main {             jniLibs.srcDirs = ['libs']         }     } }

   3. To include all jar files in the libs folder as dependencies, add the following under the dependencies node:

      dependencies {     implementation fileTree(dir: 'libs', include: ['*.jar'])     // ... }

info

To integrate Signaling SDK version 2.2.0 or later alongside Video SDK version 4.3.0 or later, refer to handle integration issues.

This section helps you create a simple user interface to explore the basic features of Signaling. Modify it according to your specific needs.

The demo interface consists of the following UI elements:

• Input boxes for user ID, channel name, and message
• Buttons to log in and log out of Signaling
• Buttons to subscribe and unsubscribe from a channel
• A button to publish a message

Sample code to create the user interface

Open the /app/res/layout/activity_main.xml file, and replace the contents with the following:

<?xml version="1.0" encoding="utf-8"?><androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"    xmlns:app="http://schemas.android.com/apk/res-auto"    xmlns:tools="http://schemas.android.com/tools"    android:layout_width="match_parent"    android:layout_height="match_parent"    tools:context=".MainActivity">    <EditText        android:id="@+id/uid"        android:layout_width="130dp"        android:layout_height="wrap_content"        android:layout_marginStart="20dp"        android:layout_marginTop="40dp"        android:hint="@string/uid"        android:inputType="text"        app:layout_constraintStart_toStartOf="parent"        app:layout_constraintTop_toTopOf="parent" />    <Button        android:id="@+id/logout_button"        android:layout_width="wrap_content"        android:layout_height="wrap_content"        android:layout_marginStart="5dp"        android:onClick="onClickLogout"        android:text="@string/logout_button"        app:layout_constraintStart_toEndOf="@+id/login_button"        app:layout_constraintBottom_toBottomOf="@id/uid" />    <Button        android:id="@+id/login_button"        android:layout_width="wrap_content"        android:layout_height="wrap_content"        android:layout_marginStart="5dp"        android:onClick="onClickLogin"        android:text="@string/login_button"        app:layout_constraintStart_toEndOf="@+id/uid"        app:layout_constraintBottom_toBottomOf="@id/uid" />    <EditText        android:id="@+id/channel_name"        android:layout_width="130dp"        android:layout_height="wrap_content"        android:layout_marginStart="20dp"        android:layout_marginTop="20dp"        android:hint="@string/channel_name"        android:inputType="text"        app:layout_constraintTop_toBottomOf="@+id/uid"        app:layout_constraintStart_toStartOf="parent" />    <Button        android:id="@+id/subscribe_button"        android:layout_width="wrap_content"        android:layout_height="wrap_content"        android:layout_marginStart="5dp"        android:onClick="onClickSubscribe"        android:text="@string/subscribe_button"        app:layout_constraintStart_toEndOf="@+id/channel_name"        app:layout_constraintBottom_toBottomOf="@+id/channel_name" />    <Button        android:id="@+id/unsubscribe_button"        android:layout_width="wrap_content"        android:layout_height="wrap_content"        android:layout_marginStart="5dp"        android:onClick="onClickUnsubscribe"        android:text="@string/unsubscribe_button"        app:layout_constraintStart_toEndOf="@+id/subscribe_button"        app:layout_constraintBottom_toBottomOf="@+id/subscribe_button" />    <EditText        android:id="@+id/msg_box"        android:layout_width="0dp"        android:layout_height="wrap_content"        android:layout_marginTop="20dp"        android:layout_marginStart="20dp"        android:layout_marginEnd="20dp"        android:hint="@string/msg"        android:inputType="text"        android:singleLine="false"        app:layout_constraintStart_toStartOf="parent"        app:layout_constraintEnd_toEndOf="parent"        app:layout_constraintTop_toBottomOf="@+id/channel_name" />    <Button        android:id="@+id/send_channel_msg_button"        android:layout_width="wrap_content"        android:layout_height="wrap_content"        android:layout_marginTop="2dp"        android:onClick="onClickSendChannelMsg"        android:text="@string/send_channel_msg_button"        app:layout_constraintTop_toBottomOf="@+id/msg_box"        app:layout_constraintEnd_toEndOf="@id/msg_box" />    <TextView        android:id="@+id/message_history"        android:layout_width="0dp"        android:layout_height="0dp"        android:layout_marginTop="20dp"        android:background="#eee"        android:paddingStart="10dp"        android:paddingEnd="10dp"        app:layout_constraintBottom_toBottomOf="parent"        app:layout_constraintEnd_toEndOf="parent"        app:layout_constraintStart_toStartOf="parent"        app:layout_constraintTop_toBottomOf="@id/send_channel_msg_button" /></androidx.constraintlayout.widget.ConstraintLayout>

Open the app/res/values/strings.xml file and add following string resources:

<resources>    <string name="app_name">Signaling Quickstart</string>    <string name="login_button">Login</string>    <string name="logout_button">Logout</string>    <string name="subscribe_button">Subscribe</string>    <string name="unsubscribe_button">Unsubscribe</string>    <string name="send_channel_msg_button">Publish message</string>    <string name="uid">User ID</string>    <string name="msg">Message content</string>    <string name="channel_name">Channel name</string>    <string name="app_id">your_appid</string>    <string name="token">your_token</string></resources>

A complete code sample that implements the basic features of Signaling is presented here for your reference. To use the sample code, copy the following lines into the /app/src/main/java/com/example/<projectname>/MainActivity file and replace <projectname> in package com.example.<projectname> with the name of your project.

Complete sample code for Signalling

Java

package com.example.<projectname>;import android.os.Bundle;import android.view.View;import android.widget.EditText;import android.widget.TextView;import android.widget.Toast;import androidx.appcompat.app.AppCompatActivity;import io.agora.rtm.*;public class JavaActivity extends AppCompatActivity {    private EditText etUserId;    private EditText etChannelName;    private EditText etMessageContent;    private TextView mMessageHistory;    private RtmClient mRtmClient;    private final RtmEventListener eventListener = new RtmEventListener() {        @Override        public void onMessageEvent(MessageEvent event) {            String text = "Message received from " + event.getPublisherId()                     + ", Message: " + event.getMessage().getData();            writeToMessageHistory(text);        }        @Override        public void onPresenceEvent(PresenceEvent event) {            String text = "Received presence event, user: " + event.getPublisherId()                     + ", Event: " + event.getEventType();            writeToMessageHistory(text);        }        @Override        public void onLinkStateEvent(LinkStateEvent event) {            String text = "Connection state changed to " + event.getCurrentState()                     + ", Reason: " + event.getReason();            writeToMessageHistory(text);        }    };    @Override    protected void onCreate(Bundle savedInstanceState) {        super.onCreate(savedInstanceState);        setContentView(R.layout.activity_main);    }    public void onClickLogin(View v) {        etUserId = findViewById(R.id.uid);        String userId = etUserId.getText().toString();        String token = getString(R.string.token);        if (createClient(userId)) {            login(token);        }    }    public void onClickLogout(View v) {        logout();    }    public void onClickSubscribe(View v) {        etChannelName = findViewById(R.id.channel_name);        String channelName = etChannelName.getText().toString();        subscribe(channelName);    }    public void onClickUnsubscribe(View v) {        etChannelName = findViewById(R.id.channel_name);        String channelName = etChannelName.getText().toString();        unsubscribe(channelName);    }    public void onClickSendChannelMsg(View v) {        etChannelName = findViewById(R.id.channel_name);        String channelName = etChannelName.getText().toString();        etMessageContent = findViewById(R.id.msg_box);        String message = etMessageContent.getText().toString();        publishMessage(channelName, message);    }    private boolean createClient(String userId) {        if (userId.isEmpty()) {            showToast("Invalid userId");            return false;        }        try {            RtmConfig config = new RtmConfig.Builder(getString(R.string.app_id), userId)                    .eventListener(eventListener)                    .build();            mRtmClient = RtmClient.create(config);            return true;        } catch (Exception e) {            showToast("Error creating RTM client.");            return false;        }    }    private void login(String token) {        if (mRtmClient == null) {            showToast("RTM client is null");            return;        }        mRtmClient.login(token, new ResultCallback<>() {            @Override            public void onSuccess(Void responseInfo) {                writeToMessageHistory("Successfully logged in to Signaling!");            }            @Override            public void onFailure(ErrorInfo errorInfo) {                writeToMessageHistory("Failed to log in to Signaling: " + errorInfo);            }        });    }    private void logout() {        if (mRtmClient == null) {            showToast("RTM client is null");            return;        }        mRtmClient.logout(new ResultCallback<>() {            @Override            public void onSuccess(Void responseInfo) {                writeToMessageHistory("Successfully logged out.");            }            @Override            public void onFailure(ErrorInfo errorInfo) {                writeToMessageHistory("Failed to log out: " + errorInfo);            }        });    }    private void subscribe(String channelName) {        if (mRtmClient == null) {            showToast("RTM client is null");            return;        }        SubscribeOptions options = new SubscribeOptions();        options.setWithMessage(true);        mRtmClient.subscribe(channelName, options, new ResultCallback<>() {            @Override            public void onSuccess(Void responseInfo) {                writeToMessageHistory("Successfully subscribed to the channel!");            }            @Override            public void onFailure(ErrorInfo errorInfo) {                writeToMessageHistory("Failed to subscribe to the channel: " + errorInfo);            }        });    }    private void unsubscribe(String channelName) {        if (mRtmClient == null) {            showToast("RTM client is null");            return;        }        mRtmClient.unsubscribe(channelName, new ResultCallback<>() {            @Override            public void onSuccess(Void responseInfo) {                writeToMessageHistory("Successfully unsubscribed from the channel!");            }            @Override            public void onFailure(ErrorInfo errorInfo) {                writeToMessageHistory("Failed to unsubscribe from the channel: " + errorInfo);            }        });    }    private void publishMessage(String channelName, String message) {        if (mRtmClient == null) {            showToast("RTM client is null");            return;        }        PublishOptions options = new PublishOptions();        options.setCustomType("");        mRtmClient.publish(channelName, message, options, new ResultCallback<>() {            @Override            public void onSuccess(Void responseInfo) {                writeToMessageHistory("Message sent to channel " + channelName + ": " + message);            }            @Override            public void onFailure(ErrorInfo errorInfo) {                writeToMessageHistory("Failed to send message to channel " + channelName + ": " + errorInfo);            }        });    }    private void writeToMessageHistory(String record) {        if (mMessageHistory == null) {            mMessageHistory = findViewById(R.id.message_history);        }        mMessageHistory.append("- " + record + "\n");    }    private void showToast(String text) {        Toast.makeText(this, text, Toast.LENGTH_SHORT).show();    }}

Kotlin

package com.example.<projectname>import android.content.pm.ActivityInfoimport android.os.Bundleimport android.view.Viewimport android.widget.EditTextimport android.widget.TextViewimport android.widget.Toastimport androidx.appcompat.app.AppCompatActivityimport io.agora.rtm.*class MainActivity : AppCompatActivity() {    private lateinit var etUserId: EditText    private lateinit var etChannelName: EditText    private lateinit var etMessageContent: EditText    private var mRtmClient: RtmClient? = null    private lateinit var mMessageHistory: TextView    private val eventListener = object : RtmEventListener {        override fun onMessageEvent(event: MessageEvent) {            val text = "Message received from ${event.publisherId}, Message: ${event.message.data}"            writeToMessageHistory(text)        }        override fun onPresenceEvent(event: PresenceEvent) {            val text = "Received presence event, user: ${event.publisherId}, Event: ${event.eventType}"            writeToMessageHistory(text)        }        override fun onLinkStateEvent(event: LinkStateEvent) {            val text = "Connection state changed to ${event.currentState}, Reason: ${event.reason}"            writeToMessageHistory(text)        }    }    override fun onCreate(savedInstanceState: Bundle?) {        super.onCreate(savedInstanceState)        setContentView(R.layout.activity_main)        setRequestedOrientation(ActivityInfo.SCREEN_ORIENTATION_PORTRAIT)    }    fun onClickLogin(v: View) {        etUserId = findViewById(R.id.uid)        val userId = etUserId.text.toString()        val token = getString(R.string.token)        if (createClient(userId)) {            login(token)        }    }    fun onClickLogout(v: View) {        logout()    }    fun onClickSubscribe(v: View) {        etChannelName = findViewById(R.id.channel_name)        val channelName = etChannelName.text.toString()        subscribe(channelName)    }    fun onClickUnsubscribe(v: View) {        etChannelName = findViewById(R.id.channel_name)        val channelName = etChannelName.text.toString()        unsubscribe(channelName)    }    fun onClickSendChannelMsg(v: View) {        etChannelName = findViewById(R.id.channel_name)        val channelName = etChannelName.text.toString()        etMessageContent = findViewById(R.id.msg_box)        val message = etMessageContent.text.toString()        publishMessage(channelName, message)    }    private fun createClient(userId: String): Boolean {        if (userId.isEmpty()) {            showToast("Invalid userId")            return false        }        return try {            val config = RtmConfig.Builder(getString(R.string.app_id), userId)                .eventListener(eventListener)                .build()            mRtmClient = RtmClient.create(config)            true        } catch (e: Exception) {            showToast("Error creating RTM client.")            false        }    }    private fun login(token: String) {        mRtmClient?.login(token, object : ResultCallback<Void?> {            override fun onSuccess(responseInfo: Void?) {                writeToMessageHistory("Successfully logged in to Signaling!")            }            override fun onFailure(errorInfo: ErrorInfo) {                writeToMessageHistory("Failed to log in to Signaling: $errorInfo")            }        }) ?: showToast("RTM client is null")    }    private fun logout() {        mRtmClient?.logout(object : ResultCallback<Void?> {            override fun onSuccess(responseInfo: Void?) {                writeToMessageHistory("Successfully logged out.")            }            override fun onFailure(errorInfo: ErrorInfo) {                writeToMessageHistory("Failed to log out: $errorInfo")            }        }) ?: showToast("RTM client is null")    }    private fun subscribe(channelName: String) {        mRtmClient ?: run {            showToast("RTM client is null")            return        }        val options = SubscribeOptions().apply {            withMessage = true        }        mRtmClient!!.subscribe(channelName, options, object : ResultCallback<Void?> {            override fun onSuccess(responseInfo: Void?) {                writeToMessageHistory("Successfully subscribed to the channel!")            }            override fun onFailure(errorInfo: ErrorInfo) {                writeToMessageHistory("Failed to subscribe to the channel: $errorInfo")            }        })    }    private fun unsubscribe(channelName: String) {        mRtmClient ?: run {            showToast("RTM client is null")            return        }        mRtmClient!!.unsubscribe(channelName, object : ResultCallback<Void?> {            override fun onSuccess(responseInfo: Void?) {                writeToMessageHistory("Successfully unsubscribed from the channel!")            }            override fun onFailure(errorInfo: ErrorInfo) {                writeToMessageHistory("Failed to unsubscribe from the channel: $errorInfo")            }        })    }    private fun publishMessage(channelName: String, message: String) {        mRtmClient ?: run {            showToast("RTM client is null")            return        }        val options = PublishOptions().apply {            customType = ""        }        mRtmClient!!.publish(channelName, message, options, object : ResultCallback<Void?> {            override fun onSuccess(responseInfo: Void?) {                writeToMessageHistory("Message sent to channel $channelName: $message")            }            override fun onFailure(errorInfo: ErrorInfo) {                writeToMessageHistory("Failed to send message to channel $channelName: $errorInfo")            }        })    }    private fun writeToMessageHistory(record: String) {        mMessageHistory = findViewById(R.id.message_history)        mMessageHistory.append("- $record\n")    }    private fun showToast(text: String) {        Toast.makeText(this, text, Toast.LENGTH_SHORT).show()    }}

Follow the implementation steps to understand the core API calls in the sample code or use the snippets in your own code.

To use Signaling APIs in your project, import the relevant Agora classes and interfaces:

Java

import io.agora.rtm.*;

Kotlin

import io.agora.rtm.*

Before calling any other Signaling SDK API, initialize an RtmClient object instance.

Java

private boolean createClient(String userId) {    if (userId.isEmpty()) {        showToast("Invalid userId");        return false;    }    try {        RtmConfig config = new RtmConfig.Builder(getString(R.string.app_id), userId)                .eventListener(eventListener)                .build();        mRtmClient = RtmClient.create(config);        return true;    } catch (Exception e) {        showToast("Error creating RTM client.");        return false;    }}

Kotlin

private fun createClient(userId: String): Boolean {    if (userId.isEmpty()) {        showToast("Invalid userId")        return false    }    return try {        // Create a configuration object        val config = RtmConfig.Builder(getString(R.string.app_id), userId)            .eventListener(eventListener)            .build()        // Use the configuration object to instantiate the engine        mRtmClient = RtmClient.create(config)        true    } catch (e: Exception) {        showToast("Error creating RTM client.")        false    }}

The event listener enables you to implement the processing logic in response to Signaling events. Use the following code to handle event notifications or display received messages:

Java

private RtmEventListener eventListener = new RtmEventListener() {    @Override    public void onMessageEvent(MessageEvent event) {        String text = "Message received from " + event.getPublisherId()                 + " Message: " + event.getMessage().getData();        writeToMessageHistory(text);    }    @Override    public void onPresenceEvent(PresenceEvent event) {        String text = "Received presence event, user: " + event.getPublisherId()                 + " Event: " + event.getEventType();        writeToMessageHistory(text);   }    @Override    public void onLinkStateEvent(LinkStateEvent event) {        String text = "Connection state changed to " + event.getCurrentState()                 + ", Reason: " + event.getReason();        writeToMessageHistory(text);    }};

Kotlin

private val eventListener = object : RtmEventListener {    override fun onMessageEvent(event: MessageEvent) {        val text = "Message received from ${event.publisherId} Message: ${event.message.data}"        writeToMessageHistory(text)    }    override fun onPresenceEvent(event: PresenceEvent) {        val text = "Received presence event, user: ${event.publisherId} event: ${event.eventType}"        writeToMessageHistory(text)    }    override fun onLinkStateEvent(event: LinkStateEvent) {        val text = "Connection state changed to ${event.currentState}, Reason: ${event.reason}"        writeToMessageHistory(text)    }}

To connect to Signaling and access Signaling network resources, such as sending messages, and subscribing to channels, call login.

During a login operation, the client attempts to establish a connection with Signaling. Once the connection is established, the client transmits heartbeat information to the Signaling server at fixed intervals to keep the client active until the client actively logs out or is disconnected. The connection is interrupted when timeout occurs. During this period, users may freely access the Signaling network resources subject to their own permissions and usage restrictions.

Java

private void login(String token) {    if (mRtmClient == null) {        showToast("RTM client is null");        return;    }    mRtmClient.login(token, new ResultCallback<>() {        @Override        public void onSuccess(Void responseInfo) {            writeToMessageHistory("Successfully logged in to Signaling!");        }        @Override        public void onFailure(ErrorInfo errorInfo) {            writeToMessageHistory("Failed to log in to Signaling: " + errorInfo);        }    });}

Kotlin

private fun login(token: String) {    mRtmClient?.login(token, object : ResultCallback<Void?> {        override fun onSuccess(responseInfo: Void?) {            writeToMessageHistory("Successfully logged in to Signaling!")        }        override fun onFailure(errorInfo: ErrorInfo) {            writeToMessageHistory("Failed to log in to Signaling: $errorInfo")        }    }) ?: showToast("RTM client is null")}

To confirm that login is successful, use the login return value, or listen to the onLinkStateEvent event notification which provides the error code and reason for the login failure. When performing a login operation, the client's network connection state is CONNECTING. After a successful login, the state is updated to CONNECTED.

Best practice

To continuously monitor the network connection state of the client, best practice is to continue to listen for onLinkStateEvent notifications throughout the life cycle of the application. For further details, see Event Listeners.

caution

After a user successfully logs into Signaling, the application's PCU increases, which affects your billing data.

To distribute a message to all subscribers of a message channel, call publish. The following code sends a string type message.

Java

private void publishMessage(String channelName, String message) {    if (mRtmClient == null) {        showToast("RTM client is null");        return;    }    PublishOptions options = new PublishOptions();    options.setCustomType("");    mRtmClient.publish(channelName, message, options, new ResultCallback<>() {        @Override        public void onSuccess(Void responseInfo) {            writeToMessageHistory("Message sent to channel " + channelName + ": " + message);        }        @Override        public void onFailure(ErrorInfo errorInfo) {            writeToMessageHistory("Failed to send message to channel " + channelName + ": " + errorInfo);        }    });}

Kotlin

private fun publishMessage(channelName: String, message: String) {    mRtmClient ?: run {        showToast("RTM client is null")        return    }    val options = PublishOptions().apply {        customType = ""    }    mRtmClient!!.publish(channelName, message, options, object : ResultCallback<Void?> {        override fun onSuccess(responseInfo: Void?) {            writeToMessageHistory("Message sent to channel $channelName: $message")        }        override fun onFailure(errorInfo: ErrorInfo) {            writeToMessageHistory("Failed to send message to channel $channelName: $errorInfo")        }    })}

info

Before calling publish to send a message, serialize the message payload as a string.

To subscribe to a channel, call subscribe. When you subscribe to a channel, you receive all messages published to the channel.

Java

private void subscribe(String channelName) {    if (mRtmClient == null) {        showToast("RTM client is null");        return;    }    SubscribeOptions options = new SubscribeOptions();    options.setWithMessage(true);    mRtmClient.subscribe(channelName, options, new ResultCallback<>() {        @Override        public void onSuccess(Void responseInfo) {            writeToMessageHistory("Successfully subscribed to the channel!");        }        @Override        public void onFailure(ErrorInfo errorInfo) {            writeToMessageHistory("Failed to subscribe to the channel: " + errorInfo);        }    });}

Kotlin

private fun subscribe(channelName: String) {    mRtmClient ?: run {        showToast("RTM client is null")        return    }    val options = SubscribeOptions().apply {        withMessage = true    }    mRtmClient!!.subscribe(channelName, options, object : ResultCallback<Void?> {        override fun onSuccess(responseInfo: Void?) {            writeToMessageHistory("Successfully subscribed to the channel!")        }        override fun onFailure(errorInfo: ErrorInfo) {            writeToMessageHistory("Failed to subscribe to the channel: $errorInfo")        }    })}

When you no longer need to receive messages from a channel, call unsubscribe to unsubscribe from the channel:

Java

private void unsubscribe(String channelName) {    if (mRtmClient == null) {        showToast("RTM client is null");        return;    }    mRtmClient.unsubscribe(channelName, new ResultCallback<>() {        @Override        public void onSuccess(Void responseInfo) {            writeToMessageHistory("Successfully unsubscribed from the channel!");        }        @Override        public void onFailure(ErrorInfo errorInfo) {            writeToMessageHistory("Failed to unsubscribe from the channel: " + errorInfo);        }    });}

Kotlin

private fun unsubscribe(channelName: String) {    mRtmClient ?: run {        showToast("RTM client is null")        return    }    mRtmClient!!.unsubscribe(channelName, object : ResultCallback<Void?> {        override fun onSuccess(responseInfo: Void?) {            writeToMessageHistory("Successfully unsubscribed from the channel!")        }        override fun onFailure(errorInfo: ErrorInfo) {            writeToMessageHistory("Failed to unsubscribe from the channel: $errorInfo")        }    })}

For more information about subscribing and sending messages, see Message channels and Stream channels.

When a user no longer needs to use Signaling, call logout. Logging out means closing the connection between the client and Signaling. The user is automatically logged out or unsubscribed from all message and stream channels. Other users in the channel receive an onPresenceEvent notification of the user leaving the channel.

Java

private void logout() {    if (mRtmClient == null) {        showToast("RTM client is null");        return;    }    mRtmClient.logout(new ResultCallback<>() {        @Override        public void onSuccess(Void responseInfo) {            writeToMessageHistory("Successfully logged out.");        }        @Override        public void onFailure(ErrorInfo errorInfo) {            writeToMessageHistory("Failed to log out: " + errorInfo);        }    });    // Release resources    mRtmClient.release();}

Kotlin

private fun logout() {    mRtmClient?.logout(object : ResultCallback<Void?> {        override fun onSuccess(responseInfo: Void?) {            writeToMessageHistory("Successfully logged out.")        }        override fun onFailure(errorInfo: ErrorInfo) {            writeToMessageHistory("Failed to log out: $errorInfo")        }    }) ?: showToast("RTM client is null")    // Release resources    mRtmClient.release()}

Take the following steps to test the sample code:

1. Use the Token Builder to generate a Signaling token:

   1. Select Signaling from the Agora products dropdown.
   2. Fill in your app ID and app certificate from Agora Console. Leave the remaining fields blank.
   3. Click Generate Token.

2. In strings.xml, replace the values for app_id and token with your app ID and generated token.

3. Enable developer options on your Android test device. Turn on USB debugging, connect the Android device to your development machine through a USB cable, and check that your device appears in the Android device options.

4. In Android Studio, click Sync Project with Gradle Files to resolve project dependencies and update the configuration.

5. After synchronization is successful, click ▶️. Android Studio starts compilation. After a few moments, the app is installed and launched on your Android device.

6. Use the device as the receiving end and perform the following operations:

   1. Enter your User ID and click Login.
   2. Enter the Channel name and click Subscribe .

7. On a second Android device, repeat the previous steps to install and launch the app. Use this device as the sending end.

   1. Enter a different User ID and click Login.
   2. Enter the same Channel name.
   3. Type a message and click Publish message.

8. Swap the sending and receiving device roles and repeat the previous steps.

   Congratulations! You have successfully integrated Signaling into your project.

This section contains content that completes the information on this page, or points you to documentation that explains other aspects to this product.

In this guide you retrieve a temporary token from a Token Builder. To understand how to create an authentication server for development purposes, see Secure authentication with tokens.

Agora provides the following open source sample projects on GitHub for your reference.

Java

• Quickstart
• Tutorial

Kotlin

• Quickstart
• Tutorial

Download the projects or view the source code for more detailed examples.

• RtmConfig
• RtmClient.create
• login
• logout
• publish
• subscribe
• unsubscribe
• release
• Event Listeners