UML-MCP-Server

English | 中文

UML-MCP Server is a UML diagram generation tool based on MCP (Model Context Protocol), which can help users generate various types of UML diagrams through natural language description or directly writing PlantUML code.

Functional Features

• Supports multiple UML diagram types: class diagram, sequence diagram, activity diagram, use case diagram, state diagram, component diagram, deployment diagram, object diagram
• UML diagrams can be generated through natural language description
• You can directly use PlantUML code to generate UML diagrams
• Return PlantUML code and accessible URL links for easy sharing and viewing
• Simultaneously save the generated UML diagram locally and provide the local file path
• Support custom save path and specify the output directory for UML images
• As an MCP server, it can integrate with clients that support MCP, such as Claude
• A comprehensive logging system that records server operating status and operation logs

Installation

Installing via Smithery

To install UML Diagram Generation Tool for Claude Desktop automatically via Smithery:

npx -y @smithery/cli install @Swayingleaves/uml-mcp-server --client claude

Manual Installation

1. Clone repository:

git clone https://github.com/yourusername/UML-MCP-Server.git
cd UML-MCP-Server

2. Create and activate a virtual environment:

python -m venv uml-mcp-venv
source uml-mcp-venv/bin/activate  # Linux/Mac
# Or
uml-mcp-venv\Scripts\activate  # Windows

3. Install dependencies:

pip install -r requirements.txt

Usage Method

Used as a Python Library

from fix_plantuml import generate_uml

# Create UML code
uml_code = """
@startuml
Title: Simple Class Diagram

class User {
-String name
-String email
+login()
+logout()
}

class Order {
-int id
-Date date
+process()
}

User "1" -- "many" Order: places
@enduml
"""

# Generate URLs, code, and local paths for UML diagrams
result = generate_uml(uml_code)

# Output result
print("PlantUML code: ")
print(result["code"])
print("\nPlantUML URL:")
print(result["url"])
print("\nLocal file path: ")
print(result["local_path"])

Configure MCP in Cursor

The Cursor supports MCP (Model Context Protocol) servers, allowing you to directly generate UML diagrams using UML-MCP Server in the Cursor. The configuration steps are as follows:

1. Ensure that the latest version of Cursor IDE (which supports MCP functionality) is installed.

2. Open the configuration file of Cursor:

• On macOS: ~/Library/Application Support/Cursor/config.json
• On Windows: %APPDATA%\Cursor\config.json
• On Linux: ~/.config/Cursor/config.json

3. Add or modify the 'mcpServer' section in the configuration file:

{
    "mcpServers": {
        "UML-MCP-Server": {
            "command": "uv",
            "args": [
                "--directory",
                "/Users/yourpath/UML-MCP-Server",
                "run",
                "uml_mcp_server.py"
            ],
            "output_dir": "/Users/yourpath/uml-output"
        }
    }
}

Configuration Description:

• UML-MCP-Server: The name of the MCP server can be modified as needed
• Command: Use UV as the running command
• args:
  • directory: Specify the absolute path of the project directory
  • run: Run the command
  • uml_mcp_server.py: Main program file
• output_dir: Specify the output directory for UML images

Please modify the following path according to your actual situation:

• Replace '/Users/Yourpath/UML-MCP Server' with the actual path of your UML-MCP Server project
• Replace '/Users/Yourpath/uml-output' with the directory path where you want to save the UML image

4. Save the configuration file and restart the Cursor.

5. Use UML-MCP Server in Cursor:

• Open a new chat window
• In the toolbar at the bottom of the chat interface, you will see the "UML-MCP Server" tool icon
• Clicking on this icon will bring up the options menu for UML tools
• Select the UML diagram type you need (such as "Generate Class Diagram", "Generate Sequence Diagram", etc.)

Using UML Tools in Cursor

In the Cursor, you can input:

For example:

1. Understand the certification process of the project
2. Generate UML code for the authentication process and generate a flowchart through UML-MCP Server
3. Attention: "output_dir": "/Users/my-project/uml-output"

The Results Returned by UML Tools

Regardless of how UML tools are used, Cursor will call UML-MCP-Server and return the following:

1. PlantUML Code - You can copy this code to use in other PlantUML tools
2. PlantUML URL - You can open this URL in a browser to view the generated UML diagram
3. Local file path - The generated UML image is saved in this local path

For example:

Class diagram generated:

PlantUML code:
@startuml
Title: User and Order System
class User {
-String name
-String email
+login()
+logout()
}
class Order {
-int id
-Date date
+process()
}
User "1" -- "many" Order: places
@enduml

PlantUML URL：
http://www.plantuml.com/plantuml/png/~1UDgCqB5Bn0G1k1zYWM_EfPYQYY0Qd9oQc9oQaPcKYYcKc9gMYaiKc9gK...

Local file path:
/Users/username/projects/UML-MCP-Server/output/class_diagram_12345.png

You can view the generated UML diagram in the following ways:

• Click on the returned URL link to view in the browser
• Open the local file path in the file browser to view the saved image
• In Cursor, you can use Markdown syntax to directly display images in the chat window

Troubleshooting

If you encounter problems while using UML-MCP Server, you can try the following steps:

1. Check log files: View the log files in the 'logs' directory for error details
2. Verify Dependency Installation: Ensure that all dependencies are installed correctly
3. Check network connection: Ensure that PlantUML server (www.plantuml.com) can be accessed
4. Check output directory permissions: Ensure that the program has permission to write to the 'output' directory

Common problems and solutions:

• Unable to generate UML diagram: Check for error messages in the log, which may be due to network issues or temporary unavailability of PlantUML server
• Image not saved locally: Check if the 'output' directory exists and has write permission
• MCP server cannot start: Check the log file to ensure there are no port conflicts or other program errors

Contribution

Welcome to contribute code, report issues, or provide improvement suggestions! Please participate in project development through GitHub Issues or Pull Requests.

License

This project adopts the MIT license. Please refer to the LICENSE document for details.