.NET SDK

The official C# / .NET SDK for Sendexa. One package, one client, every API — SMS, OTP, WhatsApp, Email, Voice, and Webhook verification.

Zero Dependencies

Uses only System.Net.Http and System.Text.Json — both built into .NET 6+.

DI-Friendly

Accepts an optional HttpClient for IHttpClientFactory integration in ASP.NET Core.

Fully Async

Every API method is async with CancellationToken support throughout.

Immutable Records

Request and response types use C# records with init-only properties and nullable annotations.

Installation

Bash

dotnet add package Sendexa.SDK

Requirements

.NET 6 or later. Zero external dependencies — uses only System.Net.Http.HttpClient and System.Text.Json, both built into the .NET runtime.

Initialise the Client

Register as a singleton in your DI container and inject it where needed — the client is thread-safe and manages its own connection pool.

// Program.cs
builder.Services.AddSingleton(new SendexaClient(new SendexaConfig
{
    ApiKey    = builder.Configuration["Sendexa:ApiKey"],
    ApiSecret = builder.Configuration["Sendexa:ApiSecret"],
}));

// Or with IHttpClientFactory
builder.Services.AddHttpClient();
builder.Services.AddSingleton<SendexaClient>(sp =>
{
    var http = sp.GetRequiredService<IHttpClientFactory>().CreateClient("sendexa");
    return new SendexaClient(new SendexaConfig
    {
        ApiKey    = builder.Configuration["Sendexa:ApiKey"],
        ApiSecret = builder.Configuration["Sendexa:ApiSecret"],
    }, http);
});

API Examples

Send single and bulk SMS messages with delivery tracking.

using Sendexa.Resources;

// Send a single SMS
var resp = await client.Sms.SendAsync(new SendSmsRequest
{
    To      = "0244123456",
    From    = "MyBrand",
    Message = "Your order #1234 has been confirmed!",
});
Console.WriteLine($"{resp.Data?.MessageId} {resp.Data?.Status}");

// Send bulk SMS
await client.Sms.SendBulkAsync(new SendBulkSmsRequest
{
    From    = "MyBrand",
    Message = "Hello from MyBrand!",   // shared fallback
    Messages =
    [
        new BulkSmsMessage { To = "0244123456", Message = "Hi Alice!" },
        new BulkSmsMessage { To = "0555987654" },   // uses shared message
    ],
});

// Check delivery status
var status = await client.Sms.GetStatusAsync(resp.Data!.MessageId!);
Console.WriteLine(status.Data?.Status); // "delivered"

// Resend a failed message
await client.Sms.ResendAsync(resp.Data.MessageId!);

Error Handling

All API errors throw a SendexaException with structured properties for easy branching.

using Sendexa;
using Sendexa.Resources;

try
{
    await client.Sms.SendAsync(new SendSmsRequest
    {
        To = "0244123456", From = "MyBrand", Message = "Hi!",
    });
}
catch (SendexaException ex)
{
    Console.WriteLine(ex.Status);     // HTTP status  e.g. 403
    Console.WriteLine(ex.Code);       // API code     e.g. "SENDER_ID_NOT_APPROVED"
    Console.WriteLine(ex.Message);    // Human text   e.g. "Sender ID not approved"
    Console.WriteLine(ex.RequestId);  // Trace ID for Sendexa support
}

Property	Type	Description
Status	int	HTTP status code (400, 401, 403, 429…)
Code	string	Machine-readable error code from the API
Message	string	Human-readable description of the error
RequestId	string?	Sendexa trace ID — include when contacting support
Raw	object?	Full raw error payload from the API

Best Practices

Register SendexaClient as a singleton in your DI container — do not instantiate per request
Pass an HttpClient from IHttpClientFactory to benefit from connection pooling and resiliency policies
Store credentials in environment variables or appsettings.json / Azure Key Vault, never in source code
Always await client.Webhooks.Verify() before processing any webhook event
Pass CancellationToken from your controller/handler to every async call for graceful cancellation