C# / .NET SDK

CastBrick.SDK is the official .NET SDK. It targets net8.0 and netstandard2.0 — works in ASP.NET Core, console apps, Azure Functions, and any .NET Standard project.

Installation

dotnet add package CastBrick.SDK

Initialization

using CastBrick.SDK;

var cb = new CastBrickClient(new CastBrickOptions
{
    ApiKey = Environment.GetEnvironmentVariable("CASTBRICK_API_KEY")!
});

With IHttpClientFactory (ASP.NET Core)

// Program.cs
builder.Services.AddHttpClient<CastBrickClient>();
builder.Services.AddSingleton(new CastBrickOptions
{
    ApiKey = builder.Configuration["CastBrick:ApiKey"]!
});

SMS

Send

using CastBrick.SDK.Models.Sms;

var result = await cb.Sms.SendAsync(new SendSmsRequest
{
    Recipients = ["+244923000000", "+244912000000"],
    Content = "Your verification code is 1234",
    SenderId = "MyApp", // optional
});

Console.WriteLine($"{result.MessageId} — {result.Status}");

Schedule for later

await cb.Sms.SendAsync(new SendSmsRequest
{
    Recipients = ["+244923000000"],
    Content = "Scheduled message",
    ScheduledAt = DateTime.UtcNow.AddHours(2),
});

List / Get / Cancel

var page = await cb.Sms.ListAsync(page: 1, pageSize: 20);
var msg   = await cb.Sms.GetAsync(messageId);
await cb.Sms.CancelScheduledAsync(messageId);

Contacts

using CastBrick.SDK.Models.Contacts;

// List
var page = await cb.Contacts.ListAsync(search: "João");

// Get
var contact = await cb.Contacts.GetAsync(contactId);

// Create (comma-separated phone numbers)
await cb.Contacts.CreateAsync(new CreateContactRequest
{
    PhoneNumbers = "+244923000000,+244912000000",
});

// Delete
await cb.Contacts.DeleteAsync(contactId);

// Contact lists
var list = await cb.Contacts.CreateListAsync("VIP Customers");
await cb.Contacts.AddToListAsync(list.Id, contact.Id);
await cb.Contacts.RemoveFromListAsync(list.Id, contact.Id);

Broadcasts

using CastBrick.SDK.Models.Broadcasts;

// Create
var id = await cb.Broadcasts.CreateAsync(new CreateBroadcastRequest
{
    Name    = "Black Friday",
    Message = "50% off everything today!",
    ContactListId = listId,  // optional
    SenderId = "MyApp",      // optional
});

// Send immediately
await cb.Broadcasts.SendAsync(id);

// Update with schedule
await cb.Broadcasts.UpdateAsync(id, new UpdateBroadcastRequest
{
    Name    = "Black Friday",
    Message = "50% off everything today!",
    ScheduleAt = new DateTime(2026, 11, 28, 9, 0, 0, DateTimeKind.Utc),
});

// Other operations
await cb.Broadcasts.CancelAsync(id);
var newId = await cb.Broadcasts.DuplicateAsync(id);
await cb.Broadcasts.DeleteAsync(id);

Error Handling

try
{
    await cb.Sms.SendAsync(...);
}
catch (CastBrickApiException ex)
{
    Console.WriteLine($"{ex.StatusCode}: {ex.ResponseBody}");
    // 401 → invalid or revoked API key
    // 402 → insufficient credits
    // 422 → validation error
}

C# / .NET SDK

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