Create Tasks from Phone Calls using TwiML: Receive an Incoming Call

We've seen how to create Tasks using the TaskRouter REST API and how to accept a Task Reservation using both the REST API and Assignment Callback instructions. TaskRouter also introduces new TwiML instructions that you can use to create a Task from a Twilio phone call.

Receive an Incoming Call

To receive an incoming phone call, we first need a Twilio phone number. In this example we'll use a US toll-free number, but you can use a Voice capable number from any country.

Before purchasing or setting up the phone number, we need to add on to our Program.cs to handle incoming calls:

Program.cs

1using System;
2using System.Net;
3using SimpleWebServer;
4using Twilio;
5using Twilio.Rest.Taskrouter.V1.Workspace;
6using Twilio.Rest.Taskrouter.V1.Workspace.Task;
7using Twilio.TwiML;
8
9namespace taskroutercsharp
10{
11    class MainClass
12    {
13        // Find your Account Sid and Auth Token at twilio.com/user/account
14        const string AccountSid = "{{ account_sid }}";
15        const string AuthToken = "{{ auth_token }}";
16        const string WorkspaceSid = "{{ workspace_sid }}";
17        const string WorkflowSid = "{{ workflow_sid }}";
18
19        public static void Main(string[] args)
20        {
21            // Initialize the Twilio client
22            TwilioClient.Init(AccountSid, AuthToken);
23
24            WebServer ws = new WebServer(SendResponse, "http://localhost:8080/");
25            ws.Run();
26            Console.WriteLine("A simple webserver. Press a key to quit.");
27            Console.ReadKey();
28            ws.Stop();
29        }
30
31        public static HttpListenerResponse SendResponse(HttpListenerContext ctx)
32        {
33            HttpListenerRequest request = ctx.Request;
34            HttpListenerResponse response = ctx.Response;
35
36            String endpoint = request.RawUrl;
37
38            if (endpoint.EndsWith("assignment_callback"))
39            {
40                response.StatusCode = (int)HttpStatusCode.OK;
41                response.ContentType = "application/json";
42                response.StatusDescription = "{\"instruction\":\"accept\"}";
43                return response;
44            }
45            else if (endpoint.EndsWith("create_task"))
46            {
47                response.StatusCode = (int)HttpStatusCode.OK;
48                response.ContentType = "application/json";
49                TaskResource task = TaskResource.Create(
50                    WorkspaceSid,
51                    attributes: "{\"selected_language\":\"es\"}",
52                    workflowSid: WorkflowSid);
53
54                response.StatusDescription = task.Attributes;
55                return response;
56            }
57            else if (endpoint.EndsWith("accept_reservation"))
58            {
59                response.StatusCode = (int)HttpStatusCode.OK;
60                response.ContentType = "application/json";
61                var taskSid = request.QueryString["TaskSid"];
62                var reservationSid = request.QueryString["ReservationSid"];
63                ReservationResource reservation = ReservationResource.Update(
64                    WorkspaceSid,
65                    taskSid,
66                    reservationSid,
67                    ReservationResource.StatusEnum.Accepted);
68
69                response.StatusDescription = "{\"reservation_status\":\"" + reservation.ReservationStatus + "\"}";
70                return response;
71            }
72            else if (endpoint.EndsWith("incoming_call"))
73            {
74                response.StatusCode = (int)HttpStatusCode.OK;
75                response.ContentType = "application/xml";
76                var twiml = new VoiceResponse();
77                twiml.Gather(new Gather(numDigits: 1, action: "enqueue_call")
78                    .Say("Para Espanol oprima el uno.", language: "es" )
79                    .Say("For English, please hold or press two.", language: "en"));
80
81                response.StatusDescription = twiml.ToString();
82                return response;
83            }
84            response.StatusCode = (int)HttpStatusCode.OK;
85            return response;
86        }
87    }
88}

You can use the Buy Numbers section of the Twilio Voice and Messaging web portal to purchase a new phone number, or use an existing Twilio phone number. Open the phone number details page and point the Voice Request URL at your new endpoint:

TaskRouter Quickstart showing phone number properties and request URLs for voice and messaging.

Using any phone, call the Twilio number. You will be prompted to press one for Spanish or two for English. However, when you press a digit, you'll hear an error message. That's because our <Gather> verb is pointing to another endpoint, enqueue_call, which we haven't implemented yet. In the next step we'll add the required endpoint and use it to create a new Task based on the language selected by the caller.

Next: Create a Task using Enqueue »