XamlMcp: an MCP server for XAML apps

XamlMcp lets Claude Code, Codex, GitHub Copilot, and other AI coding assistants inspect and drive live Avalonia, WPF, WinUI 3, and .NET MAUI applications. Use the Model Context Protocol to read the UI tree, properties, styles, and resources; capture screenshots; send input; and run automation actions.

Supported XAML frameworks

The same protocol covers four UI frameworks. Some operations depend on platform or runtime capabilities; check the full feature matrix for exact limits.

Install the XAML MCP server

The application references one framework agent. Your development environment also needs the xamlmcp MCP server tool.

dotnet add package XamlMcp.Avalonia --version VERSION
dotnet add package XamlMcp.Wpf --version VERSION
dotnet add package XamlMcp.WinUI --version VERSION
dotnet add package XamlMcp.Maui --version VERSION

dotnet tool install --global XamlMcp.Server --version VERSION

using XamlMcp.Avalonia;

AppBuilder.Configure<App>()
    .UsePlatformDetect()
    .AttachXamlMcp();

using XamlMcp.Wpf;

protected override void OnStartup(StartupEventArgs e)
{
    this.AttachXamlMcp();
    base.OnStartup(e);
}

private WinUiXamlMcpSession? _xamlMcp;
private IDisposable? _windowRegistration;

#if DEBUG
var session = WinUiXamlMcp.Attach();
_xamlMcp = session;
_windowRegistration = session.RegisterWindow(window);
window.Closed += async (_, _) =>
{
    _windowRegistration?.Dispose();
    await session.DisposeAsync();
};
#endif

using XamlMcp.Maui;

#if DEBUG
builder.UseXamlMcp();
#endif

Configure Claude, Codex, and GitHub Copilot

XamlMcp runs as a local stdio MCP server. Your client starts it when needed; you do not run a persistent server process. The commands below pin the published preview and require the .NET 10 SDK.

claude mcp add --scope user xamlmcp -- dnx XamlMcp.Server@VERSION

codex mcp add xamlmcp -- dnx XamlMcp.Server@VERSION

{
  "servers": {
    "xamlmcp": {
      "command": "dnx",
      "args": ["XamlMcp.Server@VERSION"]
    }
  }
}

{
  "mcpServers": {
    "xamlmcp": {
      "command": "dnx",
      "args": ["XamlMcp.Server@VERSION"]
    }
  }
}

Verify the XamlMcp connection

Launch the instrumented application first. For Avalonia's fluent attachment form, launch it with XAML_MCP=1. Then open Claude Code or Codex with the XamlMcp server enabled and ask:

Use XamlMcp to list the running applications, attach to my app, and show its UI tree.

The client performs this tool sequence:

If the client returns the application's UI tree, the framework package, discovery transport, MCP server, authentication, and client configuration are working together. These are MCP tool calls made by the AI client, not terminal commands.

Native dialogs and windows

A native file picker or message box is a separate Win32 window. It does not belong to the application's XAML tree, so it will not appear in tree and ordinary XamlMcp input cannot address it.

The optional Windows Driver runs inside XamlMcp.Server to cover that boundary. It is disabled by default. Enable it in the command registered with your MCP client:

claude mcp add --scope user xamlmcp -- dnx XamlMcp.Server@VERSION --enable-driver
codex mcp add xamlmcp -- dnx XamlMcp.Server@VERSION --enable-driver

dialog-wait and dialog-act handle app-opened native dialogs. window-list and window-act inspect and manage the application's top-level windows.

XAML inspection and automation tools

XamlMcp exposes a consistent tool surface across frameworks. The capability map returned by attach is authoritative for the current process.