TransferCallOut.md

Transfer call to an agent

There could be various occasions when a bot would like to transfer call to a human agent. Like any other channel, Telephony channel allows you to transfer call to an agent over a phone number. Read an overview of Human Handoff approaches in the Bot Framework here.

Initiate transfer

You can send an event created using EventFactory.CreateHandoffInitiation method to initiate call transfer.

protected override async Task OnMessageActivityAsync(ITurnContext<IMessageActivity> turnContext, CancellationToken cancellationToken)
{
    string requestMessage = turnContext.Activity.Text.Trim().ToLower();
    string responseMessage = null;

    if (string.Equals("0", requestMessage) ||
        string.Equals("Talk to agent", requestMessage, System.StringComparison.OrdinalIgnoreCase))
    {
		var context = new { TargetPhoneNumber = "+14251231234" };
		var transcript = new List<Activity> { };
		var handoffInitiateEvent = EventFactory.CreateHandoffInitiation(turnContext, context, new Transcript(transcript));
		await turnContext.SendActivityAsync(handoffInitiateEvent);
    }
    else if (string.Equals("1", requestMessage) ||
        string.Equals("one", requestMessage, System.StringComparison.OrdinalIgnoreCase))
    {
        var responseText = @"Hello and thank you for calling billing department.  
          If you are a current customer, press 1.  
          If you are a new customer, press 2.";
          
        responseMessage = SimpleConvertToSSML(responseText, "en-US", "en-US-JessaNeural");
    }
    else
    {
        responseMessage = SimpleConvertToSSML("What I heard was \"" + requestMessage + "\"", "en-US", "en-US-GuyNeural");
    }

    if (!string.IsNullOrWhiteSpace(responseMessage))
    {
        await turnContext.SendActivityAsync(
            GetActivity(responseMessage, responseMessage),
            cancellationToken);
    }
}

Track transfer status

You can handle handoff.status event to know if transfer was successful.

protected override async Task OnEventActivityAsync(ITurnContext<IEventActivity> turnContext, CancellationToken cancellationToken)
{
	string eventName = turnContext.Activity.Name;

	if (string.Equals(eventName, "handoff.status"))
	{
		dynamic handoffStatus = turnContext.Activity.Value;
		string state = handoffStatus["state"];
		if (string.Equals(state, "accepted"))
		{
			// Hand off has been accepted by the target successfully
			// Bot is no more in the loop.
		} else if (string.Equals(state, "failed"))
		{
			// Hand off has failed.
			// Bot is still connected to end user.
			string errorMessage = handoffStatus["message"];
		}
	}

	await base.OnEventActivityAsync(turnContext, cancellationToken);
}

Notes

• Phone number should be in international format without dashes ex: +14251231234
• If target doesn't pick up the call, Telephony Channel would keep calling target again and again.
• Need transfer with context? Have a gander at NumberPoolingTransfer