diff --git a/installer/ElfisaPharmacy.iss b/installer/ElfisaPharmacy.iss
index 6bdad70..ba49fbd 100644
--- a/installer/ElfisaPharmacy.iss
+++ b/installer/ElfisaPharmacy.iss
@@ -3,7 +3,7 @@
 
 #define MyAppName "Электронная Фармация"
 #define MyAppBrand "ЭльФиСА"
-#define MyAppVersion "2.0.3"
+#define MyAppVersion "2.0.4"
 #define MyAppPublisher "PharmData"
 #define MyAppURL "https://cdn.24pharmdata.ru"
 #define MyAppSupportURL "https://24pharmdata.ru"
diff --git a/src/Elfisa.Avalonia/Elfisa.Avalonia.csproj b/src/Elfisa.Avalonia/Elfisa.Avalonia.csproj
index bb8e0fe..c55b8ac 100644
--- a/src/Elfisa.Avalonia/Elfisa.Avalonia.csproj
+++ b/src/Elfisa.Avalonia/Elfisa.Avalonia.csproj
@@ -5,9 +5,9 @@
     <Nullable>enable</Nullable>
     <ApplicationManifest>app.manifest</ApplicationManifest>
     <AvaloniaUseCompiledBindingsByDefault>true</AvaloniaUseCompiledBindingsByDefault>
-    <Version>2.0.3</Version>
-    <AssemblyVersion>2.0.3.0</AssemblyVersion>
-    <FileVersion>2.0.3.0</FileVersion>
+    <Version>2.0.4</Version>
+    <AssemblyVersion>2.0.4.0</AssemblyVersion>
+    <FileVersion>2.0.4.0</FileVersion>
     <Product>ЭльФиСА — Электронная Фармация</Product>
     <Company>PharmData</Company>
     <!-- Кросс-платформенная публикация задаётся флагами CLI (RID + self-contained). -->
diff --git a/src/Elfisa.Avalonia/ViewModels/UpdateViewModel.cs b/src/Elfisa.Avalonia/ViewModels/UpdateViewModel.cs
new file mode 100644
index 0000000..bc18047
--- /dev/null
+++ b/src/Elfisa.Avalonia/ViewModels/UpdateViewModel.cs
@@ -0,0 +1,95 @@
+using System;
+using System.Diagnostics;
+using System.Threading.Tasks;
+using Avalonia.Controls.ApplicationLifetimes;
+using CommunityToolkit.Mvvm.ComponentModel;
+using CommunityToolkit.Mvvm.Input;
+using Elfisa.Core;
+
+namespace Elfisa.Avalonia.ViewModels;
+
+/// <summary>Окно «Доступно обновление»: скачивает установщик и запускает его.</summary>
+public partial class UpdateViewModel : ViewModelBase
+{
+    private readonly UpdateInfo _info;
+    private readonly Action _close;
+
+    public UpdateViewModel(UpdateInfo info, Action close)
+    {
+        _info = info;
+        _close = close;
+    }
+
+    public string Message =>
+        $"Установлена версия {_info.CurrentVersion}.\nДоступна новая версия {_info.LatestVersion}.";
+
+    [ObservableProperty] private bool _busy;
+    [ObservableProperty] private double _progress;
+    [ObservableProperty] private string _status = "";
+
+    [RelayCommand]
+    private void Later() => _close();
+
+    [RelayCommand]
+    private async Task UpdateAsync()
+    {
+        // Не-Windows: установщика нет — открываем страницу релиза в браузере.
+        if (!OperatingSystem.IsWindows())
+        {
+            OpenUrl(string.IsNullOrWhiteSpace(_info.ReleaseUrl) ? "https://cdn.24pharmdata.ru" : _info.ReleaseUrl);
+            _close();
+            return;
+        }
+
+        try
+        {
+            Busy = true;
+            Status = "Скачивание обновления…";
+            var progress = new Progress<double>(p =>
+            {
+                Progress = p;
+                Status = $"Скачивание обновления… {p:0}%";
+            });
+            var setupPath = await UpdateService.DownloadSetupAsync(progress);
+
+            Status = "Запуск установки…";
+            LaunchInstallerAndExit(setupPath);
+        }
+        catch (Exception ex)
+        {
+            Busy = false;
+            Status = "Не удалось обновить: " + ex.Message;
+        }
+    }
+
+    /// <summary>Тихая установка поверх + перезапуск приложения, затем закрываем себя.</summary>
+    private void LaunchInstallerAndExit(string setupPath)
+    {
+        var exe = Process.GetCurrentProcess().MainModule?.FileName;
+        var inner = $"\"{setupPath}\" /VERYSILENT /SUPPRESSMSGBOXES /NORESTART";
+        if (!string.IsNullOrEmpty(exe))
+            inner += $" && start \"\" \"{exe}\"";
+
+        Process.Start(new ProcessStartInfo("cmd.exe")
+        {
+            Arguments = "/c \"" + inner + "\"",
+            UseShellExecute = false,
+            CreateNoWindow = true,
+        });
+
+        // Закрываем приложение, чтобы установщик заменил файлы (CloseApplications=yes).
+        if (global::Avalonia.Application.Current?.ApplicationLifetime is IClassicDesktopStyleApplicationLifetime d)
+            d.Shutdown();
+        else
+            Environment.Exit(0);
+    }
+
+    private static void OpenUrl(string url)
+    {
+        try
+        {
+            Process.Start(new ProcessStartInfo(url) { UseShellExecute = true });
+        }
+        catch { /* игнорируем */ }
+    }
+}
diff --git a/src/Elfisa.Avalonia/Views/ShellView.axaml.cs b/src/Elfisa.Avalonia/Views/ShellView.axaml.cs
index 5aa2e3f..cd91df6 100644
--- a/src/Elfisa.Avalonia/Views/ShellView.axaml.cs
+++ b/src/Elfisa.Avalonia/Views/ShellView.axaml.cs
@@ -1,15 +1,25 @@
+using System;
+using System.Reflection;
 using Avalonia;
 using Avalonia.Controls;
 using Avalonia.Controls.ApplicationLifetimes;
 using Avalonia.Interactivity;
 using Avalonia.Markup.Xaml;
+using Avalonia.Threading;
 using Elfisa.Avalonia.ViewModels;
+using Elfisa.Core;
 
 namespace Elfisa.Avalonia.Views;
 
 public partial class ShellView : UserControl
 {
-    public ShellView() => AvaloniaXamlLoader.Load(this);
+    private static bool _updateChecked; // один раз за запуск
+
+    public ShellView()
+    {
+        AvaloniaXamlLoader.Load(this);
+        Loaded += OnLoaded;
+    }
 
     private async void OnSettingsClick(object? sender, RoutedEventArgs e)
     {
@@ -18,4 +28,28 @@ public partial class ShellView : UserControl
         if (owner is not null) await win.ShowDialog(owner);
         else win.Show();
     }
+
+    // Проверка обновлений при первом появлении шелла. Тихо игнорируем офлайн/ошибки.
+    private async void OnLoaded(object? sender, RoutedEventArgs e)
+    {
+        if (_updateChecked) return;
+        _updateChecked = true;
+
+        try
+        {
+            var current = Assembly.GetEntryAssembly()?.GetName().Version ?? new Version(0, 0, 0, 0);
+            var info = await UpdateService.CheckAsync(current);
+            if (info is not { Available: true }) return;
+
+            await Dispatcher.UIThread.InvokeAsync(async () =>
+            {
+                var win = new UpdateWindow();
+                win.DataContext = new UpdateViewModel(info, win.Close);
+                var owner = (Application.Current?.ApplicationLifetime as IClassicDesktopStyleApplicationLifetime)?.MainWindow;
+                if (owner is not null) await win.ShowDialog(owner);
+                else win.Show();
+            });
+        }
+        catch { /* обновление не должно мешать работе */ }
+    }
 }
diff --git a/src/Elfisa.Avalonia/Views/UpdateWindow.axaml b/src/Elfisa.Avalonia/Views/UpdateWindow.axaml
new file mode 100644
index 0000000..787c72f
--- /dev/null
+++ b/src/Elfisa.Avalonia/Views/UpdateWindow.axaml
@@ -0,0 +1,28 @@
+<Window xmlns="https://github.com/avaloniaui"
+        xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
+        xmlns:vm="using:Elfisa.Avalonia.ViewModels"
+        x:Class="Elfisa.Avalonia.Views.UpdateWindow"
+        x:DataType="vm:UpdateViewModel"
+        Width="440" Height="240" CanResize="False"
+        WindowStartupLocation="CenterOwner"
+        Background="{DynamicResource Bg}"
+        Title="Обновление">
+
+    <StackPanel Margin="24" Spacing="16">
+        <TextBlock Text="Доступно обновление" Classes="h1"/>
+
+        <TextBlock Text="{Binding Message}" TextWrapping="Wrap"/>
+
+        <StackPanel Spacing="6" IsVisible="{Binding Busy}">
+            <ProgressBar Minimum="0" Maximum="100" Value="{Binding Progress}" Height="8"/>
+        </StackPanel>
+
+        <TextBlock Text="{Binding Status}" Foreground="{DynamicResource Muted}"
+                   TextWrapping="Wrap" IsVisible="{Binding Status, Converter={x:Static StringConverters.IsNotNullOrEmpty}}"/>
+
+        <StackPanel Orientation="Horizontal" HorizontalAlignment="Right" Spacing="10" Margin="0,4,0,0">
+            <Button Content="Позже" Command="{Binding LaterCommand}" IsEnabled="{Binding !Busy}" Padding="18,9"/>
+            <Button Classes="primary" Content="Обновить" Command="{Binding UpdateCommand}" IsEnabled="{Binding !Busy}"/>
+        </StackPanel>
+    </StackPanel>
+</Window>
diff --git a/src/Elfisa.Avalonia/Views/UpdateWindow.axaml.cs b/src/Elfisa.Avalonia/Views/UpdateWindow.axaml.cs
new file mode 100644
index 0000000..2978091
--- /dev/null
+++ b/src/Elfisa.Avalonia/Views/UpdateWindow.axaml.cs
@@ -0,0 +1,9 @@
+using Avalonia.Controls;
+using Avalonia.Markup.Xaml;
+
+namespace Elfisa.Avalonia.Views;
+
+public partial class UpdateWindow : Window
+{
+    public UpdateWindow() => AvaloniaXamlLoader.Load(this);
+}
diff --git a/src/Elfisa.Core/UpdateService.cs b/src/Elfisa.Core/UpdateService.cs
new file mode 100644
index 0000000..1d963de
--- /dev/null
+++ b/src/Elfisa.Core/UpdateService.cs
@@ -0,0 +1,96 @@
+using System.Net.Http;
+using System.Text.Json;
+
+namespace Elfisa.Core;
+
+/// <summary>Результат проверки обновления.</summary>
+public sealed class UpdateInfo
+{
+    public bool Available { get; init; }
+    public string CurrentVersion { get; init; } = "";
+    public string LatestVersion { get; init; } = "";
+    public string ReleaseUrl { get; init; } = "";
+    public string SetupUrl { get; init; } = "";
+}
+
+/// <summary>
+/// Проверка и скачивание обновлений Avalonia-клиента.
+/// Смотрит в Gitea Releases (тот же репозиторий, что и старый WinForms-апдейтер),
+/// установщик тянет с CDN. Никаких токенов — репозиторий и CDN публичны.
+/// </summary>
+public static class UpdateService
+{
+    private const string ReleasesLatest =
+        "https://git.24pharmdata.ru/api/v1/repos/pharmdata/elfisa-pharmacy/releases/latest";
+
+    /// <summary>Стабильный URL установщика на CDN (всегда последняя версия).</summary>
+    public const string SetupUrl = "https://cdn.24pharmdata.ru/ElfisaPharmacy-Setup.exe";
+
+    /// <summary>Проверяет наличие новой версии. Возвращает null при офлайне/ошибке (не мешаем работе).</summary>
+    public static async Task<UpdateInfo?> CheckAsync(Version current)
+    {
+        try
+        {
+            using var http = new HttpClient { Timeout = TimeSpan.FromSeconds(8) };
+            http.DefaultRequestHeaders.Add("Accept", "application/json");
+            var json = await http.GetStringAsync(ReleasesLatest).ConfigureAwait(false);
+            using var doc = JsonDocument.Parse(json);
+            var root = doc.RootElement;
+            var tag = root.TryGetProperty("tag_name", out var t) ? t.GetString() : null;
+            var latest = ParseVersion(tag);
+            if (latest is null) return null;
+            var htmlUrl = root.TryGetProperty("html_url", out var h) ? h.GetString() : null;
+            return new UpdateInfo
+            {
+                Available = latest > current,
+                CurrentVersion = current.ToString(),
+                LatestVersion = latest.ToString(),
+                ReleaseUrl = htmlUrl ?? "",
+                SetupUrl = SetupUrl,
+            };
+        }
+        catch
+        {
+            return null;
+        }
+    }
+
+    /// <summary>Скачивает установщик с CDN во временный файл. Возвращает путь.</summary>
+    public static async Task<string> DownloadSetupAsync(IProgress<double>? progress, CancellationToken ct = default)
+    {
+        var path = Path.Combine(Path.GetTempPath(), "ElfisaPharmacy-Setup.exe");
+        using var http = new HttpClient { Timeout = TimeSpan.FromMinutes(10) };
+        using var resp = await http.GetAsync(SetupUrl, HttpCompletionOption.ResponseHeadersRead, ct).ConfigureAwait(false);
+        resp.EnsureSuccessStatusCode();
+        var total = resp.Content.Headers.ContentLength ?? -1;
+        await using var src = await resp.Content.ReadAsStreamAsync(ct).ConfigureAwait(false);
+        await using var dst = new FileStream(path, FileMode.Create, FileAccess.Write, FileShare.None);
+        var buffer = new byte[81920];
+        long readTotal = 0;
+        int n;
+        while ((n = await src.ReadAsync(buffer, ct).ConfigureAwait(false)) > 0)
+        {
+            await dst.WriteAsync(buffer.AsMemory(0, n), ct).ConfigureAwait(false);
+            readTotal += n;
+            if (total > 0) progress?.Report(readTotal * 100.0 / total);
+        }
+        return path;
+    }
+
+    /// <summary>Разбирает тег вида v2.0.4 / 2.0.4 / 2.0.4-beta в Version.</summary>
+    private static Version? ParseVersion(string? tag)
+    {
+        if (string.IsNullOrWhiteSpace(tag)) return null;
+        tag = tag.Trim();
+        if (tag.StartsWith("v", StringComparison.OrdinalIgnoreCase)) tag = tag[1..];
+        var dash = tag.IndexOf('-');
+        if (dash > 0) tag = tag[..dash];
+        switch (tag.Split('.').Length)
+        {
+            case 1: tag += ".0.0.0"; break;
+            case 2: tag += ".0.0"; break;
+            case 3: tag += ".0"; break;
+        }
+        return Version.TryParse(tag, out var v) ? v : null;
+    }
+}