WpfVisualTreeMcp

MCP server for inspecting WPF application Visual Trees - enables AI agents to debug and analyze WPF UI hierarchies in real-time

📢 Latest Updates: See RELEASE_NOTES.md for recent improvements including screenshot capture, DLL auto-injection, AdornerLayer/Popup traversal, and IPC deadlock fixes.

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.

Quick Start

Prerequisites

• Windows 10/11
• .NET 8.0 SDK or later
• A WPF application to inspect

Installation

Option 1: Download Release (Recommended)

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 at server\WpfVisualTreeMcp.Server.exe

Option 2: Build from Source

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

Option 3: .NET Tool (Coming Soon)

dotnet tool install -g WpfVisualTreeMcp

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

Tool	Description
wpf_list_processes	List all running WPF applications
wpf_attach	Attach to a WPF application (supports auto_inject for DLL injection)
wpf_get_visual_tree	Get the visual tree hierarchy (default depth: 25, max: 100)
wpf_get_element_properties	Get all dependency properties of an element
wpf_find_elements	Search for elements by type or name (partial matching)
wpf_find_elements_deep	Deep search across all windows including adorners/popups
wpf_capture_screenshot	Capture a screenshot of the window or element (returns image)
wpf_get_bindings	Get data bindings for an element (includes MultiBinding, converter, StringFormat)
wpf_get_binding_errors	List all captured binding errors
wpf_clear_binding_errors	Clear the captured binding errors list
wpf_get_data_context	Get DataContext type, properties, INPC status, and inheritance chain
wpf_get_resources	Enumerate resource dictionaries
wpf_get_styles	Get applied styles and templates
wpf_watch_property	Monitor a property for changes
wpf_highlight_element	Visually highlight an element
wpf_click_element	Click a control — UI Automation invoke (Invoke/Toggle/Select/ExpandCollapse) by default, physical=true for a real OS mouse click. State-changing.
wpf_set_text	Set text/value of a TextBox/ComboBox/PasswordBox — UI Automation IValueProvider.SetValue by default, physical=true to type via OS keyboard input. State-changing.
wpf_send_keys	Send a keyboard shortcut (Ctrl+S, Alt+F4, F5, Enter, ...) to an element or the focused window. State-changing.
wpf_get_layout_info	Get layout information
wpf_export_tree	Export visual tree to XAML or JSON

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

Future Considerations

• Symmetric x64 helper for x86-server-to-x64-target injection
• Visual tree diff/comparison
• Performance diagnostics
• Visual tree modification capabilities

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: 20 tools auto-discovered via [McpServerTool] attributes (17 read-only inspection + 3 state-changing: wpf_click_element, wpf_set_text, wpf_send_keys)
• 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.