Make a Call

This guide covers how to make a call with the Vonage Client SDK. Before you begin, make sure you added the SDK to your app and (Android, iOS, JS).

NOTE: On iOS it is expected that you use CallKit for incoming and outgoing calls. Please follow the Outbound Calls Using iOS CallKit blog post.

Making a Call

The serverCall method allows you to initiate a voice call using the feature rich Voice API. When this method is called, the answer_url webhook that is configured for your Vonage Application will execute. That defines the logic and capabilities of the call.

// After creating a session
client.serverCall({to:phoneNumberOrUsername})
    .then(callId => {
        console.log("Id of created call: ", callId);
    })
    .catch(error => {
        console.error("Error making call: ", error);
    });

val client = VoiceClient(this.application.applicationContext)
client.serverCall(mapOf("to" to "PHONE_NUMBER")) {
    err, outboundCall ->
    when {
        err != null -> {
            // Handle call error. 
        }
        else -> {
            // Handle call success. 
        }
    }
}

let client = VGVoiceClient()
client.serverCall(["to": "PHONE_NUMBER"]) { error, callID in
    if error == nil {
        // Handle call success. 
    } else {
        // Handle call failure
    }
}

Custom Data

Including your own custom data allows you to pass context, in a key-value format, to your answer_url webhook server. If you supply a value with the to key, it will populate the top level to in the query you make to your webhook server. Other data will be under the custom_data object.

// After creating a session
client.serverCall({to:phoneNumberOrUsername, device_name: "Alice app"})
    .then(callId => {
        console.log("Id of created call: ", callId);
    })
    .catch(error => {
        console.error("Error making call: ", error);
    });

client.serverCall(mapOf("to" to "PHONE_NUMBER", "device_name" to "Alice app")) {
    err, outboundCall ->
    ...
}

client.serverCall(["to": "PHONE_NUMBER", "device_name": "Alice app"]) { error, callID in
    ...
}

The data will be available on the request's query made to your answer_url webhook server:

{
  "to": "447000000000",
  "from_user": "Alice",
  "conversation_uuid": "CON-8dd32088-66be-42ae-b0af-c9e12ca588ed",
  "uuid": "54c255ca-9c1c-4ecd-b175-a1d022dc7b07",
  "custom_data": {
      "to": "447000000000",
      "device_name": "Alice app"
    }
}

Listen For Call Events

To see updates on the state of a call, for example, to know if the other member answered or hung up the call, you should listen to leg status events.

To see updates on the status of the call:

// After creating a session
client.on("legStatusUpdate", (callId, legId, status) => {
    console.log({callId, legId, status});
});

client.on("callInvite", (callId, from, channelType) => {
    // Answer / Reject Call
    console.log({callId, from, channelType});
});

client.on("callHangup", (callId, callQuality, reason) => {
    console.log(`Call ${callId} has hung up, callQuality:${callQuality}, reason:${reason}`);
});

client.on("sessionError", (error) => {
    console.error({error});
});


client.setOnLegStatusUpdate { callId, legId, status -> 
    // Call leg updates
}

client.setCallInviteListener { callId, from, channelType ->
    // Handling incoming call invite            
}

client.setOnCallHangupListener { callId, callQuality, reason ->
    // Handle hangups
}

client.setSessionErrorListener { error ->
    // Handle session errors
}

Add the current ViewController, or similar, as a delegate for the voice client:

client.delegate = self

ViewController will now have to conform to VGVoiceClientDelegate, the didReceiveLegStatusUpdateForCall function will update you on changes to call legs for the active call:

extension ViewController: VGVoiceClientDelegate {
    func voiceClient(_ client: VGVoiceClient, didReceiveLegStatusUpdateForCall callId: String, withLegId legId: String, andStatus status: String) {
        // Call leg updates
    }
      
    func voiceClient(_ client: VGVoiceClient, didReceiveHangupForCall callId: String, withQuality callQuality: VGRTCQuality, reason: VGHangupReason) {
        // Handle hangups
    }
    
    func client(_ client: VGBaseClient, didReceiveSessionErrorWith reason: VGSessionErrorReason) {
        // Handle session errors
    }
}

Reference