How to verify if a valid license exists for a given Microsoft Store app on a given device.

README.md

This code sample shows one can verify if a license exists for a given Microsoft Store app.

public static async Task<ReadOnlyDictionary<string, bool>> VerifyAsync(params string[] productIds)
{
    using StringContent content = new($"{{\"IdType\":\"ProductId\",\"ProductIds\":[{string.Join(",", productIds.Select(_ => $"\"{_}\""))}]}}", Encoding.UTF8, "application/json");
    productIds = (await Client.ParseAsync(RequestUris.Item1, content).ConfigureAwait(false)).Descendants("ProductId").Select(_ => _.Value).ToArray();

    using var stream = await Client.GetStreamAsync(string.Format(RequestUris.Item2, string.Join(",", productIds))).ConfigureAwait(false); var source = stream.Parse();
    var result = await LicenseManager.GetSatisfactionInfosAsync(source.Ids("ContentIds"), source.Ids("KeyIds")).AsTask().ConfigureAwait(false);

    if (result.ExtendedError is not null) throw result.ExtendedError;
    return new(productIds.Zip(result.LicenseSatisfactionInfos.Select(_ => _.Value.IsSatisfied), (Key, Value) => new { Key, Value }).ToDictionary(_ => _.Key, _ => _.Value));
}

• First resolve & validate specified product IDs.

• Get content & key IDs for given product IDs.

• Check if given licenses exist on the system & return the result.

Store.cs

using System;
using System.IO;
using System.Xml;
using System.Linq;
using System.Text;
using System.Net.Http;
using System.Xml.Linq;
using Windows.Globalization;
using System.Threading.Tasks;
using System.Collections.Generic;
using System.Collections.ObjectModel;
using System.Runtime.Serialization.Json;
using Windows.ApplicationModel.Store.LicenseManagement;

public static class Store
{
    static readonly HttpClient Client = new();

    static readonly (string, string) RequestUris;

    static Store()
    {
        var market = new GeographicRegion().CodeTwoLetter;
        RequestUris = new(
            $"https://storeedgefd.dsx.mp.microsoft.com/v9.0/products?market={market}&locale=iv&deviceFamily=Windows.Desktop",
            $"https://storesdk.dsx.mp.microsoft.com/v8.0/Sdk/products/contentId?market={market}&locale=iv&deviceFamily=Windows.Desktop&productIds={{0}}"
        );
    }

    public static async Task<ReadOnlyDictionary<string, bool>> VerifyAsync(params string[] productIds)
    {
        using StringContent content = new($"{{\"IdType\":\"ProductId\",\"ProductIds\":[{string.Join(",", productIds.Select(_ => $"\"{_}\""))}]}}", Encoding.UTF8, "application/json");
        productIds = (await Client.ParseAsync(RequestUris.Item1, content).ConfigureAwait(false)).Descendants("ProductId").Select(_ => _.Value).ToArray();

        using var stream = await Client.GetStreamAsync(string.Format(RequestUris.Item2, string.Join(",", productIds))).ConfigureAwait(false); var source = stream.Parse();
        var result = await LicenseManager.GetSatisfactionInfosAsync(source.Ids("ContentIds"), source.Ids("KeyIds")).AsTask().ConfigureAwait(false);

        if (result.ExtendedError is not null) throw result.ExtendedError;
        return new(productIds.Zip(result.LicenseSatisfactionInfos.Select(_ => _.Value.IsSatisfied), (Key, Value) => new { Key, Value }).ToDictionary(_ => _.Key, _ => _.Value));
    }

    static IEnumerable<string> Ids(this XElement source, string name) => source.Descendants(name).SelectMany(_ => _.Elements().Select(_ => _.Value));

    static async Task<XElement> ParseAsync(this HttpClient source, string requestUri, HttpContent content)
    {
        using var message = await source.PostAsync(requestUri, content).ConfigureAwait(false); message.EnsureSuccessStatusCode();
        using var stream = await message.Content.ReadAsStreamAsync().ConfigureAwait(false);
        return stream.Parse();
    }

    static XElement Parse(this Stream source)
    {
        using var reader = JsonReaderWriterFactory.CreateJsonReader(source, XmlDictionaryReaderQuotas.Max);
        return XElement.Load(reader);
    }
}