Sinch .NET SDK for Voice

The Sinch Voice .NET SDK allows you to quickly interact with the Voice API from inside your .NET applications. The fastest way to get started with the SDK is to check out our getting started guides. There you'll find all the instructions necessary to download, install, set up, and start using the SDK.

Syntax

When using the .NET SDK, the code representing requests and queries sent to and responses received from the Voice API are structured similarly to those that are sent and received using the Voice API itself.

The code sample on the side of this page is an example of how to use the .NET SDK to make a Text-to-speech phone call. The code is also displayed below, along with a Voice REST API call that accomplishes the same task, for reference:

using System;
using System.Net.Http;
using System.Threading.Tasks;
using System.Text;
using System.Text.Json;
using System.Net.Http.Headers;

class Program
{
    private const string _from = "<REPLACE_WITH_FROM_NUMBER>";
    private const string _to = "<REPLACE_WITH_TO_NUMBER>";
    private const string _key = "<REPLACE_WITH_APP_KEY>";
    private const string _secret = "<REPLACE_WITH_APP_SECRET>";

  public static async Task Main()
  {
    System.Net.Http.HttpClient client = new();

    string base64String = Convert.ToBase64String(Encoding.ASCII.GetBytes(_key + ":" + _secret));
    client.DefaultRequestHeaders.Authorization = new AuthenticationHeaderValue(@"Basic", base64String);

    string json = JsonSerializer.Serialize(new
    {
      method = "ttsCallout",
      ttsCallout = new {
        cli = "+14045001000",
        destination = new {
          type = "number",
          endpoint = _to
        },
        locale = "en-US",
        text = "Hello, this is a call from Sinch."
      }
    });

    using StringContent postData = new(json, Encoding.UTF8, "application/json");
    using HttpResponseMessage request = await client.PostAsync("https://calling.api.sinch.com/calling/v1/callouts", postData);
    string response = await request.Content.ReadAsStringAsync();

    Console.WriteLine(response);
  }
}

using System.Text.Json;
using Sinch;
using Sinch.Voice.Callouts.Callout;

var sinch = new SinchClient("YOUR_access_key", 
                            "YOUR_access_secret", 
                            "YOUR_project_id");

var voice = sinch.Voice("YOUR_application_key", "YOUR_application_secret");

CalloutResponse response = await voice.Callouts.Tts(new TextToSpeechCalloutRequest{
    Destination = new Destination{
        Type = DestinationType.Number,
        Endpoint = "YOUR_phone_number"
    },
    Text = "This is a Text to speech callout to test the Sinch dotnet Voice SDK."
});
    
Console.WriteLine(JsonSerializer.Serialize(response, new JsonSerializerOptions()
{
    WriteIndented = true
}));

This example highlights the following required to successfully make a Voice API call using the Sinch .NET SDK:

• Client initialization
• Voice domain access
• Endpoint usage
• Field population

Client

When using the Sinch .NET SDK, you initialize communication with the Sinch backend by initializing the .NET SDK's main client class. This client allows you to access the functionality of the Sinch .NET SDK.

Initialization

To start using the Voice API with the SDK, you need to initialize the main client class with your credentials from your Sinch dashboard and additionally create a Voice client object that uses your Voice app credentials.

using Sinch;

var sinch = new SinchClient("YOUR_access_key", 
                            "YOUR_access_secret", 
                            "YOUR_project_id");

var voice = sinch.Voice("YOUR_application_key", "YOUR_application_secret");

Or, if you only need to use Voice API:

using Sinch;

var sinch = new SinchClient(default, default, default);

var voice = sinch.Voice("YOUR_application_key", "YOUR_application_secret");

Voice domain

Endpoint categories

In the Sinch .NET SDK, Voice API endpoints are accessible through the client. The naming convention of the endpoint's representation in the SDK matches the API:

• Voice.Callouts
• Voice.Calls
• Voice.Conferences
• Voice.Applications

For example:

    using Sinch;
    using Sinch.Voice.Callouts.Callout;

    ...

    CalloutResponse response = await voice.Callouts.Tts(new TextToSpeechCalloutRequest{
    Destination = new Destination{
        Type = DestinationType.Number,
        Endpoint = "YOUR_phone_number"
    },
    Text = "This is a Text to speech callout to test the Sinch dotnet Voice SDK."
    });

Voice.Callouts endpoint category

Voice.Calls endpoint category

Voice.Conferences endpoint category

Voice.Applications endpoint category

Request and query parameters

Requests and queries made using the .NET SDK are similar to those made using the Voice API. Many of the fields are named and structured similarly. For example, consider a request to check on the status of a verification request by using the Identity of the request. One request is using the REST API, and the other is using our .NET SDK:

    var response = await voice.calls.Get(CallId);

    var request = await client.GetAsync("https://calling.api.sinch.com/calling/v1/calls/id/" + CallId);

Note that the path parameters that are used in the API are all passed as arguments to the corresponding .NET method.

Field name differences

When translating field names from the Voice API to the .NET SDK, remember that many of the API field names are in camelCase. In the .NET SDK, field names are in PascalCase. This pattern change manages almost all field name translations between the API and the SDK.

Responses

Response fields match the API responses. They are delivered as .NET objects. If there are any responses that differ significantly from the API responses, we note them in the endpoint category documentation.