Connect24.Sdk 0.6.0

Connect24 .NET SDK

One API for email, SMS and WhatsApp.

dotnet add package Connect24.Sdk

Quick start

Get your account id and an API key from the Connect24 dashboard (Settings → API keys).

using Connect24;

var client = new Connect24Client(
    accountId: "acc_3f9c1a7b4e2d",
    apiKey: Environment.GetEnvironmentVariable("CONNECT24_API_KEY")!);

await client.Messages.SendSmsAsync(
    to: "+27821234567",
    text: "Your payment is due tomorrow.");

Every channel, one shape

// SMS
await client.Messages.SendSmsAsync("+27821234567", "Your delivery is on its way.");

// WhatsApp — free-form inside the 24-hour window, a template outside it
await client.Messages.SendWhatsAppAsync("+27821234567", "Your order has shipped.");
await client.Messages.SendWhatsAppAsync("+27821234567", templateName: "payment_reminder");

// Email
await client.Messages.SendEmailAsync(
    to: "customer@example.com",
    subject: "Payment reminder",
    html: "<p>Your account is overdue.</p>",
    from: new MessageSender("collections@acme.co.za", "Acme Collections"));

Attachments

await client.Messages.SendEmailAsync(
    to: "customer@example.com",
    subject: "Your invoice",
    html: "<p>Invoice attached.</p>",
    attachments: [new Attachment(
        name: "invoice.pdf",
        contentType: "application/pdf",
        content: Convert.ToBase64String(File.ReadAllBytes("invoice.pdf")))]);

For an inline image, give the attachment a contentId and reference it as <img src="cid:logo">. Total attachment size is capped at roughly 7 MB per message.

Templates

Store the copy once, send it with values:

await client.Templates.CreateAsync(new TemplateRequest(
    name: "payment_reminder",
    subject: "Payment due, {{name}}",
    html: "<p>Hi {{name}}, {{amount}} is due on {{date}}.</p>"));

await client.Messages.SendTemplateAsync(
    MessageChannel.Email, "customer@example.com", "payment_reminder",
    new Dictionary<string, string> { ["name"] = "Thabo", ["amount"] = "R450", ["date"] = "25 Aug" });

Editing a template bumps its version, so a send stays traceable to the body that produced it.

Not sending twice

Pass an idempotency key when a network failure leaves you unsure whether a send arrived. A repeat with the same key returns the original message instead of sending again:

await client.Messages.SendAsync(request, idempotencyKey: $"invoice-{invoiceId}");

Suppressions

Hard bounces, spam complaints and unsubscribes are suppressed automatically, and sending to a suppressed address returns 403 rather than silently dropping the message — so your code can tell "sent" from "refused".

var blocked = await client.Suppressions.ListAsync();
await client.Suppressions.AddAsync("someone@example.com", reason: "unsubscribe");
await client.Suppressions.RemoveAsync("someone@example.com");

Every email automatically carries the one-click List-Unsubscribe headers mailbox providers expect, pointing at a hosted unsubscribe page — you do not need to build one.

Checking what happened

var accepted = await client.Messages.SendSmsAsync("+27821234567", "Hello");

var message = await client.Messages.GetAsync(accepted.Id);
Console.WriteLine(message.Status);   // queued → sent → delivered

var recent = await client.Messages.ListAsync(channel: MessageChannel.Email, limit: 20);

Dependency injection

builder.Services.AddSingleton(_ => new Connect24Client(
    builder.Configuration["Connect24:AccountId"]!,
    builder.Configuration["Connect24:ApiKey"]!));

Or supply your own HttpClient (from IHttpClientFactory, with your own retry policy):

var client = new Connect24Client(new Connect24ClientOptions
{
    AccountId = "acc_3f9c1a7b4e2d",
    ApiKey = apiKey,
    HttpClient = httpClientFactory.CreateClient("connect24"),
});

Errors

Failed calls throw Connect24ApiException with the HTTP status:

try
{
    await client.Messages.SendSmsAsync("+27821234567", "Hello");
}
catch (Connect24ApiException ex) when (ex.StatusCode == 401)
{
    // Key is wrong or revoked.
}
catch (Connect24ApiException ex) when (ex.StatusCode == 400)
{
    // ex.Message names the field that was rejected.
}

Sender identity — read this

Until your sending domain is verified, the From line is your account's configured sender, and the from: you pass becomes the Reply-To:

from:     Connect24 <donotreply@<your-account>.azurecomm.net>
reply-to: Acme Collections <collections@acme.co.za>     <- what you passed

Replies still reach you, so nothing is lost — but recipients see the platform address, not yours. Verify a domain in the dashboard to send as collections@acme.co.za with your own display name.

Keeping your key safe

The account id (acc_…) is safe to commit. The API key (ck_live_…) is a secret: load it from configuration, an environment variable or a secret store. Revoke a leaked key in the dashboard — revocation takes effect immediately.

Use a ck_test_… key in development: test keys are accepted and recorded, but nothing is ever sent, delivered or billed. The recipient chooses the simulated outcome, so you can exercise your failure paths:

Supported platforms

.NET 8 and later, plus .NET Framework 4.6.1+ / .NET Standard 2.0.