.NET SDK

dotnet add package OrsunPay --version 0.1.0 --source ./packages

using OrsunPay;

static string Required(string name) =>
    Environment.GetEnvironmentVariable(name) ?? throw new InvalidOperationException(name);

using var client = new OrsunPayClient(
    Required("ORSUNPAY_API_KEY"),
    Required("ORSUNPAY_MERCHANT_ID"),
    new Uri(Required("ORSUNPAY_API_BASE_URL")));

static async Task<string?> GetOrderStatusAsync(
    OrsunPayClient client, string orderId, CancellationToken cancellationToken)
{
    var result = await client.GetPaymentByOrderAsync(orderId, cancellationToken);
    return result.Data["transaction"]?["status"]?.GetValue<string>();
}

var status = await GetOrderStatusAsync(client, "example-order-42", CancellationToken.None);