Send a fax with ASP.NET

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You can quickly see how the Fax API works by sending yourself a fax using the Fax API.

What you need to know before you start

Before you can get started, you need the following already set up:

• Set all Fax API configuration settings.
• ASP.NET 6.0 or later SDK and ASP.NET Runtime and a familiarity with how to create an app.

Set up your ASP.NET application

Create a new project folder and open a command prompt. Execute the following command to create a new ASP.NET console application:

dotnet new console

This creates a new console application and project.

Modify your application

1. Open the Program.cs file in your project folder. Replace everything in the file with the following code:

Fax fax = new Fax("to_number", "YOUR_content_url", "YOUR_callback_url"});
sms.sendFax(fax, "YOUR_project_id", "YOUR_access_key", "YOUR_access_secret");
Console.ReadLine();

2. Next, create a new file in the project folder named Fax.cs. Populate that file with the "Fax.cs" code found on this page.

using System.Text;
using Newtonsoft.Json;

public class Fax
{
    public string to { get; set; } 
    public string url { get; set; }
    public string callbackUrl { get; set; }
    
    public Fax(string to, string url, string callbackUrl)
    {
        this.to = to;
        this.url = url;
        this.callbackUrl = callbackUrl;
    }

    public async void sendFax(Fax fax, string projectId, string accessKey, string accessSecret)
    {
        using (var client = new HttpClient())
        {
            var base64String = Convert.ToBase64String(Encoding.ASCII.GetBytes(accessKey + ":" + accessSecret));
            client.DefaultRequestHeaders.Add("Authorization", "Basic "+ base64String);
            string json = JsonConvert.SerializeObject(fax);
            var postData = new StringContent(json, Encoding.UTF8, "application/json");
            var request = await client.PostAsync("https://fax.api.sinch.com/v3/projects/" + projectId + "/faxes", postData);
            var response = await request.Content.ReadAsStringAsync();

            Console.WriteLine(response);
        }
 
    }

}

This code sends a fax to a specified number using the Sinch Fax API.

To

In this example you want to fax a phone number. Change the value of the to_number parameter to the phone number you verified in your dashboard in E.164 format.

Content URL

The Fax API can send either files directly or the URL of a web page or other online resource. For the purposes of this tutorial, use a web page because it's the easiest way to get started. Change the value of YOUR_content_url to the URL of the web page.

Callback URL

If you provide a callback URL on your Fax service, the Fax API can send notification events to your server about your outgoing fax, such as when or if the fax was delivered. You can set that callback URL in your request body. Change the value of YOUR_callback_url to the URL of your server that's listening to incoming requests.

Fill in your parameters

Before you can run the code, you need to update some more values in the Program.cs file so you can connect to your Sinch account. Update the following parameters with your own values:

Save the file.

Build your project

Before executing your code, you must first compile your application. Execute the following command:

dotnet build

Send your first fax

Now you can execute the code and send your fax. Run the following command:

dotnet run

You should receive a fax to the number you specified with the web page that you configured.

Additional resources

• API specification