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:

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 »