Skip to main content
Android
iOS
macOS
Web
Flutter
Linux C++
Unity

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.

Understand the tech

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:

Prerequisites

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

  • 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.

Project setup

Create a project

  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 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.**{*;}

Integrate the SDK

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

  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 scenarios, 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 above, and Video SDK version 4.3.0 or above at the same time, refer to handle integration issues.

Create a user interface

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"    android:background="#FFFFFF"    tools:context=".MainActivity">    <EditText        android:id="@+id/uid"        android:layout_width="150dp"        android:layout_height="40dp"        android:layout_marginStart="36dp"        android:layout_marginTop="48dp"        android:autofillHints=""        android:hint="@string/uid"        android:inputType="text"        android:lines="1"        android:padding="5dp"        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="11dp"        android:layout_marginTop="48dp"        android:layout_marginEnd="28dp"        android:onClick="onClickLogout"        android:text="@string/logout_button"        app:layout_constraintEnd_toEndOf="parent"        app:layout_constraintHorizontal_bias="0.0"        app:layout_constraintStart_toEndOf="@+id/login_button"        app:layout_constraintTop_toTopOf="parent" />    <Button        android:id="@+id/login_button"        android:layout_width="wrap_content"        android:layout_height="wrap_content"        android:layout_marginStart="4dp"        android:layout_marginTop="48dp"        android:layout_marginEnd="132dp"        android:onClick="onClickLogin"        android:text="@string/login_button"        app:layout_constraintEnd_toEndOf="parent"        app:layout_constraintHorizontal_bias="0.0"        app:layout_constraintStart_toEndOf="@+id/uid"        app:layout_constraintTop_toTopOf="parent" />    <EditText        android:id="@+id/channel_name"        android:layout_width="155dp"        android:layout_height="41dp"        android:layout_marginStart="36dp"        android:layout_marginTop="124dp"        android:layout_marginBottom="41dp"        android:autofillHints=""        android:ems="10"        android:hint="@string/channel_name"        android:inputType="text"        app:layout_constraintTop_toBottomOf="@+id/uid"        app:layout_constraintStart_toStartOf="parent"        app:layout_constraintTop_toTopOf="parent" />    <Button        android:id="@+id/subscribe_button"        android:layout_width="wrap_content"        android:layout_height="wrap_content"        android:layout_marginStart="4dp"        android:layout_marginTop="28dp"        android:layout_marginEnd="132dp"        android:onClick="onClickSubscribe"        android:text="@string/subscribe_button"        app:layout_constraintEnd_toEndOf="parent"        app:layout_constraintHorizontal_bias="0.0"        app:layout_constraintStart_toEndOf="@+id/channel_name"        app:layout_constraintTop_toBottomOf="@+id/login_button" />    <Button        android:id="@+id/unsubscribe_button"        android:layout_width="wrap_content"        android:layout_height="wrap_content"        android:layout_marginStart="11dp"        android:layout_marginTop="27dp"        android:layout_marginEnd="28dp"        android:onClick="onClickUnsubscribe"        android:text="@string/unsubscribe_button"        app:layout_constraintEnd_toEndOf="parent"        app:layout_constraintHorizontal_bias="0.0"        app:layout_constraintStart_toEndOf="@+id/subscribe_button"        app:layout_constraintTop_toBottomOf="@+id/logout_button" />    <EditText        android:id="@+id/msg_box"        android:layout_width="190dp"        android:layout_height="57dp"        android:layout_marginStart="37dp"        android:layout_marginTop="195dp"        android:layout_marginBottom="26dp"        android:autofillHints=""        android:ems="10"        android:hint="@string/msg"        android:inputType="textPersonName"        android:singleLine="false"        app:layout_constraintTop_toTopOf="parent"        app:layout_constraintStart_toStartOf="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="40dp"        android:layout_marginEnd="40dp"        android:onClick="onClickSendChannelMsg"        android:text="@string/send_channel_msg_button"        app:layout_constraintStart_toEndOf="@+id/msg_box"        app:layout_constraintHorizontal_bias="0.0"        app:layout_constraintEnd_toEndOf="parent"        app:layout_constraintTop_toBottomOf="@+id/unsubscribe_button" />    <TextView        android:id="@+id/message_history"        android:layout_width="412dp"        android:layout_height="339dp"        android:layout_marginTop="392dp"        android:background="#AEA8A8"        android:freezesText="false"        android:isScrollContainer="false"        android:scrollbars="vertical"        android:textColor="#2196F3"        app:layout_constraintBottom_toBottomOf="parent"        app:layout_constraintEnd_toEndOf="parent"        app:layout_constraintHorizontal_bias="0.491"        app:layout_constraintStart_toStartOf="parent"        app:layout_constraintTop_toTopOf="parent"        app:layout_constraintVertical_bias="0.352" /></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>

Implement Signaling

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.java file and replace <projectname> in package com.example.<projectname> with the name of your project.

Complete sample code for Signalling
package com.example.<projectname>;import android.content.pm.ActivityInfo;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.ErrorInfo;import io.agora.rtm.LockEvent;import io.agora.rtm.MessageEvent;import io.agora.rtm.PresenceEvent;import io.agora.rtm.PublishOptions;import io.agora.rtm.ResultCallback;import io.agora.rtm.RtmClient;import io.agora.rtm.RtmConfig;import io.agora.rtm.RtmConstants;import io.agora.rtm.RtmEventListener;import io.agora.rtm.RtmMessage;import io.agora.rtm.StorageEvent;import io.agora.rtm.SubscribeOptions;import io.agora.rtm.TopicEvent;public class MainActivity extends AppCompatActivity {    private EditText etUserId;    private EditText etChannelName;    private EditText etMessageContent;    // The user ID of the publisher    private String mUserId;    // The channel name of the message channel    private String mChannelName;    // The RTM client instance    private RtmClient mRtmClient;    // The TextView to show the messages that you send    private TextView mMessageHistory;    // Add the event listener    private RtmEventListener eventListener = new RtmEventListener() {        @Override        public void onMessageEvent(MessageEvent event) {            String text = "Message received from " + event.getPublisherId() + " Message: " + event.getMessage().getData() + "\n";            writeToMessageHistory(text);        }        @Override        public void onPresenceEvent(PresenceEvent event) {            String text = "receive presence event, user: " + event.getPublisherId() + " event: " + event.getEventType() + "\n";            writeToMessageHistory(text);        }        @Override        public void onConnectionStateChanged(String mChannelName, RtmConstants.RtmConnectionState state, RtmConstants.RtmConnectionChangeReason reason) {            String text = "Connection state changed to " + state + ", Reason: " + reason + "\n";            writeToMessageHistory(text);        }    };    @Override    protected void onCreate(Bundle savedInstanceState) {        super.onCreate(savedInstanceState);        setContentView(R.layout.activity_main);        setRequestedOrientation(ActivityInfo.SCREEN_ORIENTATION_PORTRAIT);    }    @Override    protected void onResume() {        super.onResume();    }    @Override    protected void onDestroy() {        super.onDestroy();    }    public void onClickLogin(View v)    {        try {            etUserId = (EditText) findViewById(R.id.uid);            mUserId = etUserId.getText().toString();            if (mUserId == null || mUserId.isEmpty()) {                showToast("invalid userId");                return;            }            RtmConfig config = new RtmConfig.Builder(getBaseContext().getString(R.string.app_id), mUserId)                .eventListener(eventListener)                .build();            mRtmClient = RtmClient.create(config);        } catch (Exception e) {            showToast("create rtm client is null");        }        if (mRtmClient == null) {            showToast("rtm client is null");            return;        }        // Log in the RTM server        String token =getBaseContext().getString(R.string.token);        mRtmClient.login(token, new ResultCallback<Void>() {            @Override            public void onSuccess(Void responseInfo) {                writeToMessageHistory("Successfully logged in to Signaling!\n");            }            @Override            public void onFailure(ErrorInfo errorInfo) {                CharSequence text = "User: " + mUserId + " Failed to log in to Signaling!" + errorInfo.toString();                int duration = Toast.LENGTH_SHORT;                runOnUiThread(new Runnable() {                    public void run() {                        Toast toast = Toast.makeText(getApplicationContext(), text, duration);                        toast.show();                    }                });            }        });    }    public void onClickSubscribe(View v)    {        if (mRtmClient == null) {            showToast("rtm client is null");            return;        }        // Subscribe to a channel        etChannelName = (EditText) findViewById(R.id.channel_name);        mChannelName = etChannelName.getText().toString();        SubscribeOptions options = new SubscribeOptions();        options.setWithMessage(true);        mRtmClient.subscribe(mChannelName, options, new ResultCallback<Void>() {            @Override            public void onSuccess(Void responseInfo) {                writeToMessageHistory("Successfully subscribe to the channel!\n");            }            @Override            public void onFailure(ErrorInfo errorInfo) {                writeToMessageHistory("Fail to subscribe to the channel!\n");            }        });    }    public void onClickLogout(View v)    {        if (mRtmClient == null) {            showToast("rtm client is null");        }        // Log out from the RTM server        mRtmClient.logout(new ResultCallback<Void>() {            @Override            public void onSuccess(Void responseInfo) {                writeToMessageHistory("Successfully log out from the channel!\n");            }            @Override            public void onFailure(ErrorInfo errorInfo) {                writeToMessageHistory("Fail to log out from the channel!\n");            }        });    }    public void onClickUnsubscribe(View v)    {        if (mRtmClient == null) {            showToast("rtm client is null");            return;        }        // Unsubscribe from a channel        etChannelName = (EditText) findViewById(R.id.channel_name);        mChannelName = etChannelName.getText().toString();        mRtmClient.unsubscribe(mChannelName, new ResultCallback<Void>() {            @Override            public void onSuccess(Void responseInfo) {                writeToMessageHistory("Successfully unsubscribe from the channel!\n");            }            @Override            public void onFailure(ErrorInfo errorInfo) {                writeToMessageHistory("Fail to unsubscribe from the channel!\n");            }        });    }    public void onClickSendChannelMsg(View v)    {        etMessageContent = findViewById(R.id.msg_box);        String message = etMessageContent.getText().toString();        // Publish a message        etChannelName = (EditText) findViewById(R.id.channel_name);        mChannelName = etChannelName.getText().toString();        PublishOptions options = new PublishOptions();        options.setCustomType("");        mRtmClient.publish(mChannelName, message, options, new ResultCallback<Void>() {            @Override            public void onSuccess(Void responseInfo) {                String text = "Message sent to channel " + mChannelName + " : " + message + "\n";                writeToMessageHistory(text);            }            @Override            public void onFailure(ErrorInfo errorInfo) {                String text = "Message fails to send to channel " + mChannelName + " Error: " + errorInfo + "\n";                writeToMessageHistory(text);            }        });    }    // Write message history to TextView    public void writeToMessageHistory(String record)    {        mMessageHistory = findViewById(R.id.message_history);        mMessageHistory.append(record);    }    private void showToast(String text) {        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.

Import Agora classes

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


_14
import io.agora.rtm.ErrorInfo;
_14
import io.agora.rtm.LockEvent;
_14
import io.agora.rtm.MessageEvent;
_14
import io.agora.rtm.PresenceEvent;
_14
import io.agora.rtm.PublishOptions;
_14
import io.agora.rtm.ResultCallback;
_14
import io.agora.rtm.RtmClient;
_14
import io.agora.rtm.RtmConfig;
_14
import io.agora.rtm.RtmConstants;
_14
import io.agora.rtm.RtmEventListener;
_14
import io.agora.rtm.RtmMessage;
_14
import io.agora.rtm.StorageEvent;
_14
import io.agora.rtm.SubscribeOptions;
_14
import io.agora.rtm.TopicEvent;

Initialize the Signaling engine

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


_7
String appId = getBaseContext().getString(R.string.app_id);
_7
// Create a configuration object
_7
RtmConfig config = new RtmConfig.Builder(appId, mUserId)
_7
.eventListener(eventListener)
_7
.build();
_7
// Use the configuration object to instantiate the engine
_7
mRtmClient = RtmClient.create(config);

Add an event listener

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:


_19
private RtmEventListener eventListener = new RtmEventListener() {
_19
@Override
_19
public void onMessageEvent(MessageEvent event) {
_19
String text = "Message received from " + event.getPublisherId() + " Message: " + event.getMessage().getData() + "\n";
_19
writeToMessageHistory(text);
_19
}
_19
_19
@Override
_19
public void onPresenceEvent(PresenceEvent event) {
_19
String text = "Received presence event, user: " + event.getPublisherId() + " event: " + event.getEventType() + "\n";
_19
writeToMessageHistory(text);
_19
}
_19
_19
@Override
_19
public void onConnectionStateChanged(String mChannelName, RtmConstants.RtmConnectionState state, RtmConstants.RtmConnectionChangeReason reason) {
_19
String text = "Connection state changed to " + state + ", Reason: " + reason + "\n";
_19
writeToMessageHistory(text);
_19
}
_19
};

Log in to Signaling

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.


_19
String token = getBaseContext().getString(R.string.token);
_19
mRtmClient.login(token, new ResultCallback<Void>() {
_19
@Override
_19
public void onSuccess(Void responseInfo) {
_19
writeToMessageHistory("Successfully logged in to Signaling!\n");
_19
}
_19
_19
@Override
_19
public void onFailure(ErrorInfo errorInfo) {
_19
CharSequence text = "User: " + mUserId + " failed to log in to Signaling!" + errorInfo.toString();
_19
int duration = Toast.LENGTH_SHORT;
_19
runOnUiThread(new Runnable() {
_19
public void run() {
_19
Toast toast = Toast.makeText(getApplicationContext(), text, duration);
_19
toast.show();
_19
}
_19
});
_19
}
_19
});

Use the login return value, or listen to the onConnectionStateChanged event notification to confirm that login is successful or obtain the error code and cause of 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 onConnectionStateChanged event 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.

Send a message

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


_20
// Send a message to a channel
_20
etMessageContent = findViewById(R.id.msg_box);
_20
String message = etMessageContent.getText().toString();
_20
etChannelName = (EditText) findViewById(R.id.channel_name);
_20
mChannelName = etChannelName.getText().toString();
_20
PublishOptions options = new PublishOptions();
_20
options.setCustomType("");
_20
mRtmClient.publish(mChannelName, message, options, new ResultCallback<Void>() {
_20
@Override
_20
public void onSuccess(Void responseInfo) {
_20
String text = "Message sent to channel " + mChannelName + " : " + message + "\n";
_20
writeToMessageHistory(text);
_20
}
_20
_20
@Override
_20
public void onFailure(ErrorInfo errorInfo) {
_20
String text = "Message fails to send to channel " + mChannelName + " Error: " + errorInfo + "\n";
_20
writeToMessageHistory(text);
_20
}
_20
});

info

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

Subscribe and unsubscribe

To receive messages sent to a channel, call subscribe to subscribe to channel messages:


_15
etChannelName = (EditText) findViewById(R.id.channel_name);
_15
mChannelName = etChannelName.getText().toString();
_15
SubscribeOptions options = new SubscribeOptions();
_15
options.setWithMessage(true);
_15
mRtmClient.subscribe(mChannelName, options, new ResultCallback<Void>() {
_15
@Override
_15
public void onSuccess(Void responseInfo) {
_15
writeToMessageHistory("Successfully subscribe to the channel!\n");
_15
}
_15
_15
@Override
_15
public void onFailure(ErrorInfo errorInfo) {
_15
writeToMessageHistory("Fail to subscribe to the channel!\n");
_15
}
_15
});

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


_14
etChannelName = (EditText) findViewById(R.id.channel_name);
_14
mChannelName = etChannelName.getText().toString();
_14
// Unsubscribe from a channel
_14
mRtmClient.unsubscribe(mChannelName, new ResultCallback<Void>() {
_14
@Override
_14
public void onSuccess(Void responseInfo) {
_14
writeToMessageHistory("Successfully unsubscribe from the channel!\n");
_14
}
_14
_14
@Override
_14
public void onFailure(ErrorInfo errorInfo) {
_14
writeToMessageHistory("Fail to unsubscribe from the channel!\n");
_14
}
_14
});

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

Log out of Signaling

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.


_15
// Logout of Signaling
_15
mRtmClient.logout(new ResultCallback<Void>() {
_15
@Override
_15
public void onSuccess(Void responseInfo) {
_15
writeToMessageHistory("Successfully log out from the channel!\n");
_15
}
_15
_15
@Override
_15
public void onFailure(ErrorInfo errorInfo) {
_15
writeToMessageHistory("Fail to log out from the channel!\n");
_15
}
_15
});
_15
_15
// Release resources
_15
mRtmClient.release();

Test Signaling

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.

Reference

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

Token authentication

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.

Signaling