XamlMcp MCP server

XamlMcp

<!-- mcp-name: io.github.trrahul/xamlmcp -->

XamlMcp is an open-source XAML MCP server and AI inspection toolkit for Avalonia, WPF, WinUI 3, and .NET MAUI. It lets Claude Code, Codex, GitHub Copilot, and other MCP clients inspect and drive a running application: walk the visual or logical tree, read and write properties, inspect styles and resources, capture screenshots, send input, invoke commands and automation patterns, and observe changes over an authenticated local transport.

See the XamlMcp installation and configuration guide for a focused setup path across supported frameworks and AI clients.

The current release is 1.0.0-preview.3. It supports Avalonia, modern .NET WPF, self-contained unpackaged WinUI 3, and .NET MAUI on Windows and Android. Protocol version 2 is stable. Native MAUI nodes, iOS, and Mac Catalyst are unsupported.

See the changelog for user-facing release history and the framework feature and tool matrix for per-tool support and capability limits. The preview release guide explains the package roles, installation options, and verification commands.

Packages

Install

Prerequisite: the app you inspect can target .NET 8 or later, but the xamlmcp tool (and building this repo or the sample from source) needs the .NET 10 SDK/runtime.

Add the agent package for your UI framework:

dotnet add package XamlMcp.Avalonia --version 1.0.0-preview.3
dotnet add package XamlMcp.Wpf --version 1.0.0-preview.3
dotnet add package XamlMcp.WinUI --version 1.0.0-preview.3
dotnet add package XamlMcp.Maui --version 1.0.0-preview.3

The agent's floor is Avalonia 11.3.18. If your project pins older references (the current avalonia.app template pins 11.3.0) restore fails with a NU1605 package-downgrade error — bump your Avalonia.* package references to at least 11.3.18.

Install the MCP server tool:

dotnet tool install --global XamlMcp.Server --version 1.0.0-preview.3

You can also run the server without a global installation:

dnx XamlMcp.Server@1.0.0-preview.3

Attach the Avalonia agent

Two entry points provide explicit diagnostic opt-in. Nothing listens unless you enable the agent per build (option B) or per launch (option A):

using XamlMcp.Avalonia;

// Option A - fluent, in BuildAvaloniaApp. Compiled in, but INERT unless the
// XAML_MCP=1 environment variable is set when the app launches.
public static AppBuilder BuildAvaloniaApp()
    => AppBuilder.Configure<App>()
        .UsePlatformDetect()
        .AttachXamlMcp();

// Option B - on the Application instance (e.g. in OnFrameworkInitializationCompleted).
// Marked [Conditional("DEBUG")]: the CALL SITE disappears from YOUR Release builds.
public override void OnFrameworkInitializationCompleted()
{
    this.AttachXamlMcp();
    base.OnFrameworkInitializationCompleted();
}

Shortened. The full README is on GitHub.