Penrose MCP Server

Instructions

Implementation Reference

• src/index.ts:462-514 (handler)

  The handler function for the 'generate_diagram' tool. It validates the existence of the specified domain, substance, and style resources, generates a static SVG diagram depicting two objects 'A' and 'B' with a subset relationship arrow, and returns the SVG as a base64-encoded data URI.

      case "generate_diagram": {
        const { domain: domainName, substance: substanceName, style: styleName } = request.params.arguments as {
          domain: string;
          substance: string;
          style: string;
        };
  
        // Validate all components exist
        const domain = domains.get(domainName);
        if (!domain) throw new Error(`Domain ${domainName} not found`);
  
        const substance = substances.get(substanceName);
        if (!substance) throw new Error(`Substance ${substanceName} not found`);
  
        const style = styles.get(styleName);
        if (!style) throw new Error(`Style ${styleName} not found`);
  
        // Generate SVG diagram with proper XML declaration and formatting
        const svg = `<?xml version="1.0" encoding="UTF-8"?>
  <!DOCTYPE svg PUBLIC "-//W3C//DTD SVG 1.1//EN" "http://www.w3.org/Graphics/SVG/1.1/DTD/svg11.dtd">
  <svg width="${style.canvas.width}" height="${style.canvas.height}" xmlns="http://www.w3.org/2000/svg" version="1.1">
    <rect width="100%" height="100%" fill="white"/>
    <text x="10" y="20" font-family="Arial">Domain: ${domain.name}</text>
    <text x="10" y="40" font-family="Arial">Substance: ${substanceName}</text>
    <text x="10" y="60" font-family="Arial">Style: ${styleName}</text>
    
    <!-- Set visualization -->
    <circle cx="150" cy="150" r="50" fill="#e0e0e0" stroke="black"/>
    <text x="150" y="150" text-anchor="middle" font-family="Arial">A</text>
    
    <circle cx="250" cy="150" r="50" fill="#e0e0e0" stroke="black"/>
    <text x="250" y="150" text-anchor="middle" font-family="Arial">B</text>
    
    <!-- Subset relationship -->
    <defs>
      <marker id="arrowhead" markerWidth="10" markerHeight="7" 
      refX="9" refY="3.5" orient="auto">
        <polygon points="0 0, 10 3.5, 0 7" fill="black"/>
      </marker>
    </defs>
    <path d="M 190 150 L 210 150" stroke="black" marker-end="url(#arrowhead)"/>
  </svg>`;
  
        // Convert SVG to base64 with proper data URI format
        const svgBase64 = `data:image/svg+xml;base64,${Buffer.from(svg).toString('base64')}`;
  
        return {
          content: [{
            type: "text",
            text: svgBase64
          }]
        };
      }

• src/index.ts:288-301 (registration)

  Registration of the 'generate_diagram' tool in the list of available tools, including its description and input schema definition.

  {
    name: "generate_diagram",
    description: "Generate diagram from domain/substance/style",
    inputSchema: {
      type: "object",
      properties: {
        domain: { type: "string" },
        substance: { type: "string" },
        style: { type: "string" },
        variation: { type: "string" }
      },
      required: ["domain", "substance", "style"]
    }
  }