OneSend2U SDK — Overview

OneSend2U is a CPaaS (Communications Platform as a Service) platform for sending multi-channel notifications — SMS, Email, and WhatsApp — through multiple providers (Twilio, Infobip, SMTP) from a single unified API.

The OneSend2U .NET SDK (OneSend2U.Sdk) is a lightweight NuGet package that gives any .NET application typed access to the full OneSend2U API surface. It requires only .NET 10 and the SDK package — no additional frameworks or dependencies.

What the SDK provides

The SDK wraps 42 API endpoints across 8 sub-clients, all accessible from a single OneSend2UClient entry point:

Sub-client	Endpoints	Purpose
`client.Notifications`	4	Send and query notifications
`client.Templates`	9	Template configurations and content
`client.Messages`	3	Track individual message delivery
`client.Webhooks`	7	Manage webhook subscriptions
`client.ApiLogs`	2	Query API request/response logs
`client.Contacts`	5	Manage contact records
`client.ContactsGroups`	6	Manage contact groups
`client.Consents`	6	Manage recipient consents

Key features

Multi-channel: SMS, Email, and WhatsApp from one API call
Multi-provider: Twilio, Infobip, SMTP — the platform routes automatically
Webhooks: Real-time delivery status callbacks with HMAC-SHA256 signature verification
Consent management: Built-in support for regulatory compliance
Template system: Dynamic variable substitution with preview and validation
Minimal dependencies: Works in any .NET 10 application with no extra frameworks required

Authentication

The SDK authenticates using API Keys. Every request sends two HTTP headers:

Header	Description
`X-API-Key`	Your API key (obtain from the admin panel under API Keys)
`X-Tenant-Id`	Your tenant identifier

Sending notifications works with any valid API Key. Reading templates, messages, webhooks, contacts, consents, and API logs requires the tenant admin to have assigned the corresponding permissions to the user linked to your API Key.

Quick start

using OneSend2U.Sdk.Models.Enums;

// 1. Install
// dotnet add package OneSend2U.Sdk

// 2. Register
services.AddOneSend2U(options =>
{
    options.BaseUrl = "https://api.onesend2u.com";
    options.ApiKey  = "your-api-key";
    options.TenantId = "your-tenant-id";
});

// 3. Send
var result = await client.Notifications.SendAsync(new SendNotificationRequest
{
    TransactionId       = Guid.NewGuid().ToString(),
    Application         = "myapp",
    Region              = "us",
    Language            = "en",
    NotificationType    = "trans",
    NotificationSubtype = "invoice",
    Recipients          = [new NotificationRecipient { Channel = Channel.Sms, Recipient = "+15550001234" }],
    TemplateVariables   = [new Dictionary<string, string> { ["customer_name"] = "Jane Doe" }]
});

Documentation sections