Human-In-the-Loop MCP Server

A powerful Model Context Protocol (MCP) Server that enables AI assistants to interact with humans through intuitive GUI dialogs. This server bridges the gap between automated AI processes and human decision-making by providing tools for real-time user input, choices, confirmations, and feedback.

🚀 Features

💬 Interactive Dialog Tools

• Text Input: Get text, numbers, or other data from users
• Multiple Choice: Present options for single or multiple selections
• Multi-line Input: Collect longer text content, code, or detailed descriptions
• Confirmation Dialogs: Ask for yes/no decisions before proceeding
• Information Messages: Display notifications and status updates
• LLM Guidance: Built-in prompting guidance for when to use human-in-the-loop tools

🖥️ Cross-Platform Support

• Windows: Modern Windows 11-style GUI with beautiful styling, hover effects, and enhanced visual design
• macOS: Native macOS experience with SF Pro Display fonts and proper window management
• Linux: Ubuntu-compatible GUI with modern styling and system fonts

⚡ Advanced Features

• Non-blocking Operation: All dialogs run in separate threads
• Timeout Protection: Configurable timeouts prevent hanging
• Platform Detection: Automatic optimization for each operating system
• Modern UI Design: Beautiful Windows 11-style interface with smooth animations and hover effects
• Error Handling: Comprehensive error reporting and recovery
• Health Monitoring: Built-in health check and status reporting
• Keyboard Shortcuts: Full keyboard navigation support

🎨 Modern Visual Design

The Human-In-the-Loop MCP Server features a beautiful, modern interface designed for the current era:

Windows 11-Style Interface

• Clean, modern color scheme with Windows 11-inspired design language
• Smooth hover effects on buttons and interactive elements
• Enhanced typography using Segoe UI and Consolas fonts
• Consistent spacing and improved visual hierarchy
• Professional appearance suitable for business and development environments

Cross-Platform Consistency

• Platform-specific fonts and styling (SF Pro on macOS, Segoe UI on Windows, Ubuntu on Linux)
• Adaptive sizing and positioning based on screen characteristics
• Native-feeling interfaces that respect platform conventions

Enhanced User Experience

• Keyboard shortcuts for all dialogs (Enter to confirm, Escape to cancel)
• Improved focus management with logical tab order
• Better accessibility with high contrast colors and clear visual feedback
• Responsive design that works on different screen sizes

📦 Installation

Prerequisites

• Python 3.8 or higher
• tkinter (usually included with Python)
• pip package manager

Quick Start

1. Clone the repository:

   git clone https://github.com/GongRzhe/Human-In-the-Loop-MCP-Server.git
   cd Human-In-the-Loop-MCP-Server
   

2. Create a virtual environment (recommended):

   python -m venv .venv
   
   # Windows
   .venv\Scripts\activate
   
   # macOS/Linux
   source .venv/bin/activate
   

3. Install dependencies:

   pip install fastmcp pydantic
   

4. Run the server:

   python human_loop_server.py
   

Platform-Specific Setup

macOS

• Grant Python accessibility permissions in System Preferences > Security & Privacy > Accessibility
• This allows proper window focus and app activation

Windows

• No additional setup required
• Windows Defender may prompt for network access permission

Linux

• Ensure tkinter is installed: sudo apt-get install python3-tk (Ubuntu/Debian)
• Some distributions may require additional GUI libraries

🛠️ Usage

Basic Integration

The server provides several MCP tools that can be used by AI assistants:

Get User Input

# Request text input from user
result = await get_user_input(
    title="User Information",
    prompt="Please enter your name:",
    default_value="",
    input_type="text"
)

Get User Choice

# Present multiple options
result = await get_user_choice(
    title="Select Option",
    prompt="Choose your preferred programming language:",
    choices=["Python", "JavaScript", "Java", "C++"],
    allow_multiple=False
)

Multi-line Input

# Collect longer text content
result = await get_multiline_input(
    title="Code Review",
    prompt="Please provide your code review comments:",
    default_value=""
)

Confirmation Dialog

# Ask for confirmation
result = await show_confirmation_dialog(
    title="Confirm Action",
    message="Are you sure you want to delete this file?"
)

Information Message

# Display information
result = await show_info_message(
    title="Process Complete",
    message="Your file has been successfully processed!"
)

Get LLM Guidance

# Get comprehensive guidance on when to use human-in-the-loop tools
guidance = await get_human_loop_prompt()
# Returns structured guidance with examples and best practices

Response Format

All tools return structured responses:

{
    "success": true,
    "user_input": "User's response",
    "cancelled": false,
    "platform": "darwin",
    "input_type": "text"
}

Health Check

Monitor server status:

status = await health_check()
# Returns detailed platform and status information

🧠 LLM Integration Guidance

The server includes built-in prompting guidance to help AI assistants understand when and how to use human-in-the-loop tools effectively:

guidance = await get_human_loop_prompt()

This tool returns comprehensive guidance including:

• When to use each tool type
• Best practices for user interaction
• Decision framework for human-in-the-loop integration
• Example scenarios and usage patterns
• Workflow integration tips

Smart Decision Making

The guidance helps LLMs make intelligent decisions about when to pause for human input:

• Ambiguous requirements → Ask for clarification
• Creative decisions → Get user preferences
• Destructive actions → Require confirmation
• Missing information → Request specific details
• Long processes → Provide status updates

This ensures human interaction is meaningful and well-timed, enhancing rather than interrupting the user experience.

🔧 Configuration

Environment Variables

Variable	Description	Default
HILMCP_TIMEOUT	Dialog timeout in seconds	300
HILMCP_FONT_SIZE	UI font size	Platform-specific

Customization

You can modify the server by:

1. Changing Fonts: Edit get_system_font() function
2. Window Sizes: Modify geometry settings in dialog classes
3. Timeouts: Adjust timeout values in tool functions
4. Platform Behavior: Customize platform-specific configurations

📋 API Reference

Tools

Tool	Description
get_user_input	Single-line text/number input
get_user_choice	Multiple choice selection
get_multiline_input	Multi-line text input
show_confirmation_dialog	Yes/No confirmation
show_info_message	Information display
get_human_loop_prompt	Get guidance on when to use human-in-the-loop tools
health_check	Server status check

Parameters

get_user_input

• title (str): Dialog window title
• prompt (str): Question/prompt text
• default_value (str): Pre-filled value
• input_type (str): "text", "integer", or "float"

get_user_choice

• title (str): Dialog window title
• prompt (str): Question/prompt text
• choices (List[str]): Available options
• allow_multiple (bool): Allow multiple selections

get_multiline_input

• title (str): Dialog window title
• prompt (str): Question/prompt text
• default_value (str): Pre-filled text

show_confirmation_dialog

• title (str): Dialog window title
• message (str): Confirmation message

show_info_message

• title (str): Dialog window title
• message (str): Information message

get_human_loop_prompt

• No parameters required
• Returns comprehensive guidance for LLMs on when and how to use human-in-the-loop tools

🔍 Troubleshooting

Common Issues

GUI Not Appearing

• Check if GUI environment is available
• Verify tkinter installation
• Run health check to diagnose issues

Permission Errors (macOS)

• Grant accessibility permissions in System Preferences
• Restart terminal after granting permissions

Import Errors

• Ensure virtual environment is activated
• Install dependencies: pip install fastmcp pydantic

Dialog Timeout

• Increase timeout value in environment variables
• Check if user interaction is required

Visual Issues on Windows

• Ensure you're running on Windows 10/11 for best visual experience
• Some styling features may be limited on older Windows versions
• Update your graphics drivers if experiencing display issues

Debug Mode

Enable debug logging:

python human_loop_server.py --debug

🏗️ Development

Project Structure

Human-In-the-Loop-MCP-Server/
├── human_loop_server.py    # Main server implementation
├── .gitignore             # Git ignore file
├── .venv/                 # Virtual environment
└── README.md              # This file

Contributing

1. Fork the repository
2. Create a feature branch: git checkout -b feature-name
3. Make your changes
4. Add tests if applicable
5. Commit your changes: git commit -am 'Add feature'
6. Push to the branch: git push origin feature-name
7. Submit a pull request

Code Style

• Follow PEP 8 guidelines
• Use type hints
• Add docstrings for functions and classes
• Include error handling

📄 License

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

🤝 Acknowledgments

• Built with FastMCP framework
• Uses Pydantic for data validation
• Cross-platform GUI powered by tkinter

🔗 Links

• Repository: https://github.com/GongRzhe/Human-In-the-Loop-MCP-Server
• Issues: Report bugs or request features
• MCP Protocol: Learn about Model Context Protocol

📊 Usage Examples

Example 1: Collecting User Preferences

# Get user's preferred settings
preferences = await get_user_choice(
    title="Setup Preferences",
    prompt="Select your preferred theme:",
    choices=["Dark", "Light", "Auto"],
    allow_multiple=False
)

# Configure based on user choice
if preferences["selected_choice"] == "Dark":
    apply_dark_theme()

Example 2: Code Review Workflow

# Get code for review
code = await get_multiline_input(
    title="Code Review",
    prompt="Paste the code you want reviewed:",
    default_value=""
)

# Process the code
analysis = analyze_code(code["user_input"])

# Show results
await show_info_message(
    title="Review Complete",
    message=f"Analysis complete. Found {len(analysis.issues)} issues."
)

Example 3: Confirmation Before Action

# Confirm before destructive action
confirmation = await show_confirmation_dialog(
    title="Delete Confirmation",
    message="This will permanently delete all selected files. Continue?"
)

if confirmation["confirmed"]:
    delete_files()
    await show_info_message("Success", "Files deleted successfully!")
else:
    await show_info_message("Cancelled", "Operation cancelled by user.")

Example 4: LLM Using Built-in Guidance

# LLM gets guidance on when to use human-in-the-loop tools
guidance = await get_human_loop_prompt()

# LLM analyzes the situation using the decision framework
user_request = "Create a backup of my important files"

# Following guidance: "ambiguous requirements" → ask for clarification
file_location = await get_user_input(
    title="Backup Configuration",
    prompt="Which directory contains your important files?",
    default_value="~/Documents"
)

backup_format = await get_user_choice(
    title="Backup Options", 
    prompt="Choose backup format:",
    choices=["Full Backup", "Compressed Archive", "Sync Copy"]
)

# Following guidance: "destructive actions" → require confirmation
if backup_format["selected_choice"] == "Full Backup":
    confirmed = await show_confirmation_dialog(
        title="Confirm Backup",
        message=f"Create full backup of {file_location['user_input']}? This may take several minutes."
    )
    
    if confirmed["confirmed"]:
        # Perform backup with status updates
        await show_info_message("Backup Started", "Creating backup... Please wait.")
        # ... backup process ...
        await show_info_message("Success", "Backup completed successfully!")

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