Quickstart: .NET (C# / VB.NET)

This quickstart takes about ten minutes. You activate a license from .NET, persist it to disk, confirm it validates with no network connection, and release the seat again. C# and VB.NET consume the same assembly - SWS.dll, imported as SWS.Licensing - and every example on this page is shown in both languages.

Before you start

From Getting started you should have your vendor id (console → Settings), a license key (issued by an order, Orders → Create, and emailed to the customer), and the NuGet package:

dotnet add package SoftActivate.Sdk

The whole program

This is a complete, runnable integration: the same loop your application runs on every start.

using System;
using System.IO;
using System.Threading.Tasks;
using SWS.Licensing;

internal static class Program
{
    private static async Task<int> Main()
    {
        using var client = new LicensingClient("https://lm.sws.softactivate.com")
        {
            // your tenant coordinates - vendor id from the console (Settings),
            // license key from your order's delivery email
            VendorId = "YOUR-VENDOR-ID",
            LicenseKey = "XXXXX-XXXXX-XXXXX-XXXXX-XXXXX",
            TrustedDomain = "sws.softactivate.com"
        };

        // your product's Reference Id (console -> Products): a key for a
        // different product is refused - see the product binding guide
        client.SetProductId("YOUR_PRODUCT_ID");

        // after the first (online) activation, every later start validates the
        // stored license file with no network access at all
        License? existing = File.Exists("license.dat")
            ? License.Parse(File.ReadAllText("license.dat"))
            : null;

        // with no stored license this activates the device (online, once); with one
        // it verifies the chain, the device fingerprint and the dates locally -
        // and renews online only when needed
        LicenseValidationResult result = await client.ValidateLicenseAsync(existing);

        if (!result.IsValid)
        {
            // the precise status says WHY - expired, revoked, bound to another
            // machine, subscription lapsed... each deserves different UX; see the
            // statuses reference: /licensing/docs/status-codes/
            Console.Error.WriteLine($"License is not valid: {result.Status}");
            return 1;
        }

        // persist the new or renewed certificate whenever one is issued
        if (result.UpdatedLicense != null)
            File.WriteAllText("license.dat", result.UpdatedLicense.Serialize());

        License current = result.UpdatedLicense ?? existing!;
        Console.WriteLine($"License is valid until {current.ExpirationDate:u}.");
        return 0;
    }
}

Imports System
Imports System.IO
Imports System.Threading.Tasks
Imports SWS.Licensing

Module Program
    Function Main() As Integer
        Return MainAsync().GetAwaiter().GetResult()
    End Function

    Private Async Function MainAsync() As Task(Of Integer)
        ' your tenant coordinates - vendor id from the console (Settings),
        ' license key from your order's delivery email
        Using client As New LicensingClient("https://lm.sws.softactivate.com") With {
            .VendorId = "YOUR-VENDOR-ID",
            .LicenseKey = "XXXXX-XXXXX-XXXXX-XXXXX-XXXXX",
            .TrustedDomain = "sws.softactivate.com"
        }
            ' your product's Reference Id (console -> Products): a key for a
            ' different product is refused - see the product binding guide
            client.SetProductId("YOUR_PRODUCT_ID")

            ' after the first (online) activation, every later start validates the
            ' stored license file with no network access at all
            Dim existing As License = Nothing
            If File.Exists("license.dat") Then
                existing = License.Parse(File.ReadAllText("license.dat"))
            End If

            ' with no stored license this activates the device (online, once); with
            ' one it verifies the chain, the device fingerprint and the dates
            ' locally - and renews online only when needed
            Dim result As LicenseValidationResult = Await client.ValidateLicenseAsync(existing)

            If Not result.IsValid Then
                ' the precise status says WHY - expired, revoked, bound to another
                ' machine, subscription lapsed... each deserves different UX; see
                ' the statuses reference: /licensing/docs/status-codes/
                Console.Error.WriteLine($"License is not valid: {result.Status}")
                Return 1
            End If

            ' persist the new or renewed certificate whenever one is issued
            If result.UpdatedLicense IsNot Nothing Then
                File.WriteAllText("license.dat", result.UpdatedLicense.Serialize())
            End If

            Dim current As License = If(result.UpdatedLicense, existing)
            Console.WriteLine($"License is valid until {current.ExpirationDate:u}.")
            Return 0
        End Using
    End Function
End Module

Replace the vendor id and license key with yours, put deployment-root.crt next to the binary (in your real product, embed it as a resource or install it with your application), and run it.

Run it three times

First run (online): no license.dat exists, so ValidateLicenseAsync activates the device with the service. The SDK receives the license and the program saves it to license.dat.
Second run (disconnect the network if you like): the stored license is verified entirely on the machine, and no network access happens. This is the everyday path your customers' machines take on every start.
Moving on: when you are done with this machine, release its seat so the key can activate elsewhere:

await client.DeactivateLicenseAsync();
File.Delete("license.dat"); // the local file is now meaningless

Await client.DeactivateLicenseAsync()
File.Delete("license.dat") ' the local file is now meaningless

When validation says no

A false result.IsValid can mean several different things. result.Status tells you whether the license is expired, revoked, bound to a different device (BadContext), or waiting on a lapsed subscription (PaymentRequired, with the subscription state in result.StatusMessage), and each case deserves different UX. The statuses and errors reference maps every status to a recommended action.

Next: the C++ quickstart, or the statuses and errors reference.