Penrose MCP server for AI agents

The Penrose MCP Server allows you to create beautiful mathematical diagrams through natural language using the Model Context Protocol (MCP). This server integrates with the Penrose system to provide tools for working with its domain-specific languages for mathematical visualization.

Installation

To get started with the Penrose MCP Server, follow these steps:

Clone the repository:

git clone https://github.com/penrose/mcp-server.git
cd mcp-server

Install dependencies:
```
npm install
```

Usage

The Penrose MCP Server works with three domain-specific languages that combine to create mathematical diagrams:

Working with Penrose Languages

Domain (DSL) - Define mathematical types and relationships
Substance - Describe mathematical objects and their relationships
Style - Specify visual representation rules

Starting the Server

Run the server using:

npm start

By default, the server will run on port 3000. You can configure a different port with:

PORT=8080 npm start

Making Requests to the Server

You can interact with the server by sending HTTP requests:

curl -X POST http://localhost:3000/diagram \
  -H "Content-Type: application/json" \
  -d '{
    "domain": "your DSL content here",
    "substance": "your substance content here",
    "style": "your style content here"
  }'

Configuration Options

The server can be configured by creating a config.json file in the root directory:

{
  "port": 3000,
  "logLevel": "info",
  "cacheDiagrams": true,
  "maxCacheSize": 100
}

Examples

Basic Triangle Example

Here's a simple example that creates a triangle diagram:

# Domain (DSL)
type Point
type Triangle = (Point, Point, Point)

# Substance
Point A
Point B
Point C
Triangle t = (A, B, C)

# Style
Triangle {
  shape: triangle(this.0, this.1, this.2)
  color: blue
}

Submit these three components to the server to generate your diagram.

Troubleshooting

If you encounter issues with the server:

Check that all dependencies are properly installed
Verify your request format matches the expected JSON structure
Examine the server logs for specific error messages
Ensure your mathematical definitions are valid in the Penrose system

How to install this MCP server

For Claude Code

To add this MCP server to Claude Code, run this command in your terminal:

claude mcp add-json "penrose" '{"command":"npx","args":["-y","penrose-mcp"]}'

See the official Claude Code MCP documentation for more details.

For Cursor

There are two ways to add an MCP server to Cursor. The most common way is to add the server globally in the ~/.cursor/mcp.json file so that it is available in all of your projects.

If you only need the server in a single project, you can add it to the project instead by creating or adding it to the .cursor/mcp.json file.

Adding an MCP server to Cursor globally

To add a global MCP server go to Cursor Settings > Tools & Integrations and click "New MCP Server".

When you click that button the ~/.cursor/mcp.json file will be opened and you can add your server like this:

{
    "mcpServers": {
        "penrose": {
            "command": "npx",
            "args": [
                "-y",
                "penrose-mcp"
            ]
        }
    }
}

Adding an MCP server to a project

To add an MCP server to a project you can create a new .cursor/mcp.json file or add it to the existing one. This will look exactly the same as the global MCP server example above.

How to use the MCP server

Once the server is installed, you might need to head back to Settings > MCP and click the refresh button.

The Cursor agent will then be able to see the available tools the added MCP server has available and will call them when it needs to.

You can also explicitly ask the agent to use the tool by mentioning the tool name and describing what the function does.

For Claude Desktop

To add this MCP server to Claude Desktop:

1. Find your configuration file:

macOS: ~/Library/Application Support/Claude/claude_desktop_config.json
Windows: %APPDATA%\Claude\claude_desktop_config.json
Linux: ~/.config/Claude/claude_desktop_config.json

2. Add this to your configuration file:

{
    "mcpServers": {
        "penrose": {
            "command": "npx",
            "args": [
                "-y",
                "penrose-mcp"
            ]
        }
    }
}

3. Restart Claude Desktop for the changes to take effect