WpfVisualTreeMcp

Let AI agents see, debug and drive running WPF apps. Snoop + Playwright for AI, exposed over the Model Context Protocol — visual tree, data bindings, screenshots, clicks, text input and keyboard, against any running WPF process, no source changes needed.

An AI agent queries controls by visible text, fills the form, selects a list item, clicks Submit — then explains why the Status box stayed empty by pulling the app's binding errors. Every step is one MCP tool call (or CLI command).

Quickstart (60 seconds)

1. Download and extract the latest release zip (requires the .NET 8 Desktop Runtime).

2. Register it in your MCP client — for Claude Code, add to .mcp.json:

   {
     "mcpServers": {
       "wpf-visual-tree": {
         "command": "C:/path/to/WpfVisualTreeMcp.Server.exe",
         "args": []
       }
     }
   }

3. Ask your agent: "Look at my running WPF app and tell me why the Save button is disabled."

Prefer the terminal? The same exe is a full CLI: WpfVisualTreeMcp.Server.exe help.

Related MCP server: mcp-test-utils

Overview

WpfVisualTreeMcp is a Model Context Protocol (MCP) server that allows AI coding agents (Claude Code, Cursor, GitHub Copilot) to inspect and interact with running WPF applications. Think of it as giving your AI assistant the same capabilities as tools like Snoop WPF or Visual Studio's Live Visual Tree.

Why This Matters

Debugging WPF UI issues traditionally requires manual inspection with specialized tools. This project bridges that gap by exposing WPF inspection capabilities through MCP, enabling AI agents to:

• Understand UI structure during code reviews

• Diagnose binding errors automatically

• Suggest fixes for layout issues

• Assist with UI refactoring tasks

• Analyze visual tree hierarchies in real-time

Features

Core Inspection

• Process Discovery - List all running WPF applications available for inspection

• Visual Tree Navigation - Traverse the complete visual tree hierarchy

• Logical Tree Access - Navigate the logical tree structure

• Property Inspection - Read all dependency properties of any UI element

Binding & Resources

• Binding Analysis - Inspect bindings with converter, StringFormat, FallbackValue, MultiBinding support

• DataContext Inspection - View DataContext type, properties, INPC status, and inheritance chain

• Binding Error Detection - Automatically capture and report binding errors with classification

• Resource Enumeration - Browse resource dictionaries at any scope

• Style Inspection - View applied styles and templates

Search & Monitoring

• Element Search - Find elements by type, name, or property values

• Deep Search - Search entire tree including AdornerLayer and Popup elements

• Property Watching - Monitor property changes in real-time

Interaction & Export

• Screenshot Capture - Capture window/element screenshots visible to AI agents

• Element Highlighting - Visually highlight elements in the running app

• Control Click (v0.4.0) - Click elements via UI Automation (Invoke/Toggle/Select/ExpandCollapse) or a real OS mouse click

• Set Text (new in v0.5.0) - Fill a TextBox/ComboBox/PasswordBox via UI Automation IValueProvider.SetValue, with a TextBox.Text / PasswordBox.Password / reflected-Text fallback, or physical=true to type via OS keyboard input (full Unicode BMP)

• Send Keys (new in v0.5.0) - Send keyboard shortcuts (Ctrl+S, Alt+F4, F5, Enter, Ctrl+Shift+F, ...) to an element or the focused window via OS keyboard input

• Layout Information - Get detailed layout metrics

• Tree Export - Export visual tree to XAML or JSON format

• Auto-Injection - Inject Inspector into running WPF processes (no source changes needed); multi-architecture since v0.6.0 — a 64-bit server can inject into 32-bit WPF apps via a bundled WpfInjectorHelper.exe

Dual-Mode CLI (new in v0.4.0)

The same WpfVisualTreeMcp.Server.exe runs as either an MCP stdio server (no arguments, default) or as a one-shot CLI (any recognised subcommand). Useful when the MCP server isn't connected, for scripting, and for verifying the pipeline manually. Run WpfVisualTreeMcp.Server.exe help for the full command list. Output is JSON on stdout; diagnostics go to stderr.

How it compares

vs. the general tool categories:

vs. other WPF MCP servers. Most WPF MCP servers are built on UI Automation (FlaUI): they read the accessibility tree, and can only reach WPF internals — bindings, DataContext, ViewModel state — if you install their in-process probe into the app you want to inspect. This server takes the Snoop route instead: it injects at runtime, so it reads the real visual tree and diagnoses binding errors and DataContext with zero changes to the target app — nothing to add to your build, nothing to ship into production.

In short: UIA-based tools see what accessibility exposes, and computer-use agents see pixels. This project gives the agent the same insider view a WPF developer has in Snoop — with no probe to install in the target app — plus the widest set of hands to act on it, over a protocol every AI coding tool speaks.

Installation

Prerequisites

• Windows 10/11

• .NET 8.0 SDK or later

• A WPF application to inspect

Installation

Option 1: .NET tool / NuGet (Recommended)

dotnet tool install -g WpfVisualTreeMcp     # installs the `wpfinspect` command

The package is also published as an MCP server package (PackageType: McpServer), so MCP clients that support NuGet-hosted servers can launch it directly:

dnx WpfVisualTreeMcp                        # runs the MCP stdio server

Option 2: Download Release

Download the latest release from GitHub Releases:

1. Download WpfVisualTreeMcp-vX.X.X-win-x64.zip

2. Extract to a folder (e.g., C:\Tools\WpfVisualTreeMcp)

3. The MCP server executable is WpfVisualTreeMcp.Server.exe

Option 3: Build from Source

git clone https://github.com/faze79/WpfVisualTreeMcp.git
cd WpfVisualTreeMcp
dotnet build -c Release

Configuration

The server uses the official Microsoft/Anthropic MCP SDK for .NET, providing guaranteed compatibility with Claude Code and other MCP clients.

Claude Code

Option 1: Command Line (Recommended)

Use the claude mcp add command to add the server directly:

# Add to current project only
claude mcp add wpf-visual-tree -- C:/path/to/WpfVisualTreeMcp/publish/WpfVisualTreeMcp.Server.exe

# Add globally (available in all projects)
claude mcp add --scope user wpf-visual-tree -- C:/path/to/WpfVisualTreeMcp/publish/WpfVisualTreeMcp.Server.exe

You can verify the server was added:

claude mcp list

Option 2: Project-level JSON Configuration

Create or edit .mcp.json in your project root:

{
  "mcpServers": {
    "wpf-visual-tree": {
      "command": "C:/path/to/WpfVisualTreeMcp/publish/WpfVisualTreeMcp.Server.exe",
      "args": []
    }
  }
}

Option 3: Global JSON Configuration

Add to ~/.claude/settings.json:

{
  "mcpServers": {
    "wpf-visual-tree": {
      "command": "C:/path/to/WpfVisualTreeMcp/publish/WpfVisualTreeMcp.Server.exe",
      "args": []
    }
  }
}

Important Notes:

• Use absolute paths to the built .exe file

• Use forward slashes (/) in paths on Windows

• Build in Release mode for production: dotnet build -c Release

• Restart Claude Code after configuration changes

Cursor

Add to your Cursor settings (.cursor/mcp.json):

{
  "mcpServers": {
    "wpf-visual-tree": {
      "command": "C:/path/to/WpfVisualTreeMcp/publish/WpfVisualTreeMcp.Server.exe",
      "args": []
    }
  }
}

Self-Hosted Mode (Recommended)

For your WPF application to be inspectable, add a reference to the Inspector DLL and initialize it on startup:

1. Add a project reference to WpfVisualTreeMcp.Inspector

2. In your App.xaml.cs:

using System.Diagnostics;
using System.Windows;
using WpfVisualTreeMcp.Inspector;

public partial class App : Application
{
    protected override void OnStartup(StartupEventArgs e)
    {
        base.OnStartup(e);

        // Initialize the WPF Visual Tree Inspector
        InspectorService.Initialize(Process.GetCurrentProcess().Id);
    }

    protected override void OnExit(ExitEventArgs e)
    {
        InspectorService.Instance?.Dispose();
        base.OnExit(e);
    }
}

This enables the MCP server to connect to your application via named pipes for real-time inspection.

Usage Examples

List Running WPF Applications

Use the wpf_list_processes tool to show all running WPF applications.

Attach and Inspect Visual Tree

Attach to the MyApp.exe WPF application and show me the visual tree of the main window.

Find Binding Errors

Check the attached WPF application for any binding errors and explain what's causing them.

Search for Elements

Find all Button elements in the visual tree that have IsEnabled set to false.

Export Visual Tree

Export the visual tree of the current window to JSON format so I can analyze the structure.

Architecture

┌─────────────────────────────────────────────────────────────┐
│                    AI Agent (Claude Code)                    │
└─────────────────────────┬───────────────────────────────────┘
                          │ MCP Protocol (stdio)
                          ▼
┌─────────────────────────────────────────────────────────────┐
│                 WpfVisualTreeMcp Server                      │
│  ┌─────────────────┐  ┌─────────────────┐  ┌─────────────┐  │
│  │   MCP Handler   │  │  Tree Navigator │  │   Injector  │  │
│  │  (Tools/Res.)   │  │   & Inspector   │  │   Manager   │  │
│  └────────┬────────┘  └────────┬────────┘  └──────┬──────┘  │
└───────────┼────────────────────┼───────────────────┼────────┘
            │                    │                   │
            └────────────────────┼───────────────────┘
                                 │ Named Pipes / IPC
                                 ▼
┌─────────────────────────────────────────────────────────────┐
│                   Target WPF Application                     │
│  ┌─────────────────────────────────────────────────────────┐│
│  │              Injected Inspector DLL                      ││
│  │  • VisualTreeHelper access                              ││
│  │  • LogicalTreeHelper access                             ││
│  │  • Property/Binding inspection                          ││
│  │  • Resource dictionary enumeration                      ││
│  └─────────────────────────────────────────────────────────┘│
└─────────────────────────────────────────────────────────────┘

For detailed architecture documentation, see docs/ARCHITECTURE.md.

Available Tools

For complete tool documentation, see docs/TOOLS_REFERENCE.md.

Roadmap

Phase 1: Core Inspection ✅

• Project structure and architecture

• Process discovery and enumeration

• Basic process attachment

• Visual tree navigation

• Property inspection

• Element search

Phase 2: Advanced Features ✅

• IPC communication via named pipes

• Binding analysis and error detection

• Resource dictionary enumeration

• Style and template inspection

• Property change monitoring (with notifications)

Phase 3: Interaction & Diagnostics ✅

• Element highlighting overlay

• XAML/JSON export

• Screenshot capture (returns MCP ImageContentBlock)

• DLL auto-injection into running WPF processes (x64/x86)

• AdornerLayer and Popup visual tree traversal

Phase 4: CLI + Driving the App ✅ (v0.4.0 / v0.5.0)

• Dual-mode executable (MCP stdio + one-shot CLI) (v0.4.0)

• Control click via UI Automation patterns (v0.4.0)

• Physical OS mouse click as opt-in fallback (v0.4.0)

• User-level Claude Code skill bundling the CLI (v0.4.0)

• Set text/value via UI Automation IValueProvider + fallbacks (v0.5.0)

• Physical keyboard typing with Unicode BMP support (v0.5.0)

• Keyboard shortcuts (Ctrl+S, Alt+F4, F5, ...) via OS input (v0.5.0)

Phase 5: Multi-architecture ✅ (v0.6.0)

• Cross-bitness auto-injection (64-bit server → 32-bit target)

• Architecture-matching WpfInjectorHelper.exe (32-bit .NET 8)

• Removes v0.5.0 known limitation; both x86 and x64 WPF apps drivable

Phase 6: Query engine & full driving ✅ (v0.7.0)

• Query elements by visible text, property values, visibility

• Enriched results: text, automation id, enabled/visible state, screen bounds

• wpf_select_item — select in ComboBox/ListBox/TabControl by text or index

• Double / right click; scroll-into-view before physical input

• Screen-mode screenshots (popups, dropdowns, context menus visible)

• Set-text read-back verification; weak element-handle cache

• Critical IPC serialization fix (request parameters were silently dropped)

Phase 7: Distribution & agent ergonomics ✅ (v0.7.1 / v0.8.0)

• NuGet package, installable via dnx / dotnet tool install (MCP server package type)

• Published to nuget.org (trusted publishing / OIDC) and the official MCP registry

• Binding-error capture fixed (was never wired up), IPC parameter-drop fix

• wpf_wait_for — wait for an element/condition, no sleep-and-retry loops

• Concurrent IPC connections (a long wait no longer blocks other commands)

Next up

Live property editing shipped in v0.9.0 (wpf_set_property + wpf_revert_property). Next: wpf_diff to measure the before/after effect automatically.

• wpf_set_property / wpf_revert_property — live-edit a dependency property, then undo (v0.9.0)

• wpf_diff — before/after snapshot to verify a change's effect

• wpf_record → wpf_export_test — record a driven workflow, export an xUnit + driver test

• Inspector-only NuGet package for self-hosted mode (reference instead of injection)

• Streaming binding-error / property-change notifications to the MCP client

• WinUI 3 support

See docs/ROADMAP.md for the full prioritized plan (rationale, design notes, effort, and suggested sequencing).

Contributing

Contributions are welcome! Please feel free to submit a Pull Request.

Development Setup

1. Clone the repository:

   git clone https://github.com/faze79/WpfVisualTreeMcp.git
   cd WpfVisualTreeMcp

2. Open in Visual Studio 2022 or VS Code:

   code .
   # or
   start WpfVisualTreeMcp.sln

3. Build and run tests:

   dotnet build
   dotnet test

4. Run the sample WPF app for testing:

   dotnet run --project samples/SampleWpfApp

Project Structure

WpfVisualTreeMcp/
├── src/
│   ├── WpfVisualTreeMcp.Server/        # MCP Server (.NET 8) - Uses official MCP SDK
│   │   ├── Program.cs                  # Server initialization with MCP SDK
│   │   ├── WpfTools.cs                 # 20 WPF tools (17 inspection + click/set-text/send-keys)
│   │   ├── Cli/CliRunner.cs            # One-shot CLI front-end (v0.4.0)
│   │   └── Services/                   # Process & IPC management
│   ├── WpfVisualTreeMcp.Inspector/     # Injected DLL (.NET Framework 4.8)
│   ├── WpfVisualTreeMcp.Injector/      # Managed injection logic (CreateRemoteThread; net48 + net8.0)
│   ├── WpfVisualTreeMcp.InjectorHelper/# x86 .NET 8 helper exe for cross-arch injection (v0.6.0)
│   ├── WpfVisualTreeMcp.Bootstrapper/  # Native C++ DLL for CLR hosting
│   └── WpfVisualTreeMcp.Shared/        # Shared models & IPC contracts
├── samples/
│   └── SampleWpfApp/                   # Test application
├── tests/
│   └── WpfVisualTreeMcp.Tests/         # Unit tests (48 tests)
├── publish/                            # Published server + native DLLs
│   └── native/{x64,x86}/              # Architecture-specific bootstrapper
└── docs/                               # Documentation

Technical Details

• MCP SDK: Built with the official C# MCP SDK from Microsoft/Anthropic

• Protocol: JSON-RPC 2.0 over stdio transport

• Target Framework: .NET 8.0 (Server) / .NET Framework 4.8 + .NET 8.0-windows (Inspector, dual-target)

• IPC: Named Pipes for server-to-application communication

• Tools: 24 tools auto-discovered via [McpServerTool] attributes (18 read-only inspection incl. wpf_wait_for + 6 state-changing: wpf_click_element, wpf_select_item, wpf_set_text, wpf_send_keys, wpf_set_property, wpf_revert_property)

• CLI: same executable runs as one-shot CLI when given a subcommand (Program.cs routes via CliRunner.IsCliCommand)

Acknowledgments

• Inspired by Snoop WPF - the original WPF spy utility

• Built on the Model Context Protocol by Anthropic

• Thanks to the .NET and WPF community

License

This project is licensed under the MIT License - see the LICENSE file for details.