.NET SDK Reference

The official Stendly .NET SDK provides a type-safe, async-first interface for interacting with the Stendly API. It uses HttpClient with connection pooling, automatic retry, and full nullable annotations.

Installation

dotnet add package Stendly

Requirements

• .NET 8.0+ (.NET 10.0 recommended)

Quick Start

using Stendly;

var client = new StendlyClient(new HttpClient(), "st_live_your_key_here");

var intent = await client.Intents.CreateIntentAsync(4999, "order_001");
Console.WriteLine($"Pay to: {intent.ReferenceAddress}");

Client Initialization

Constructor requires HttpClient first:

public StendlyClient(HttpClient httpClient, string apiKey, string environment = "mainnet", int maxRetries = 2)

Namespaces

Intents (IIntentsClient)

// CreateIntentAsync(amountCents, orderId, terminalId?, idempotencyKey?, cancellationToken?)
var intent = await client.Intents.CreateIntentAsync(4999, "order_001");

// RetrieveIntentAsync(intentId, cancellationToken?)
var retrieved = await client.Intents.RetrieveIntentAsync(intentId);

Terminals (ITerminalsClient)

// CreateTerminalAsync(name, cancellationToken?)
var terminal = await client.Terminals.CreateTerminalAsync("Main Counter");

// ListTerminalsAsync(cancellationToken?)
var terminals = await client.Terminals.ListTerminalsAsync();

Webhooks (IWebhooksClient)

// UpdateWebhookUrlAsync(url, cancellationToken?)
await client.Webhooks.UpdateWebhookUrlAsync("https://myshop.com/webhooks/stendly");

// ConstructEventAsync(byte[] payload, string signatureHeader, string webhookSecret, ...)
// NOTE: payload is byte[], method is ASYNC
var webhookEvent = await client.Webhooks.ConstructEventAsync(
    rawBodyBytes, signature, webhookSecret
);
// webhookEvent.Event contains the event type (e.g., "payment_intent.succeeded")

Merchant (IMerchantClient)

var profile = await client.Merchant.GetProfileAsync();  // GET /api/b2b/merchants/me
var stats = await client.Merchant.GetStatsAsync();       // GET /api/b2b/merchants/stats

Error Handling

All exceptions inherit from StendlyException:

StendlyException
├── StendlyAuthenticationException (401/403)
├── StendlyValidationException (400)
├── StendlyRateLimitException (429)
├── StendlyApiConnectionException (network)
└── StendlySignatureVerificationException (webhook)

API Endpoints

Operation	Method	Path
Create Intent	POST	/api/merchants/intents
Retrieve Intent	GET	/api/merchants/intents/{id}
Create Terminal	POST	/api/b2b/merchants/terminals
List Terminals	GET	/api/b2b/merchants/terminals
Update Webhook	PATCH	/api/b2b/merchants/webhook
Get Profile	GET	/api/b2b/merchants/me
Get Stats	GET	/api/b2b/merchants/stats