mcp-mermiad

#!/usr/bin/env node /** * Mermaid MCP Server * Model Context Protocol server for Mermaid diagram generation */ import { Server } from '@modelcontextprotocol/sdk/server/index.js'; import { StdioServerTransport } from '@modelcontextprotocol/sdk/server/stdio.js'; import { CallToolRequestSchema, ErrorCode, ListToolsRequestSchema, McpError, } from '@modelcontextprotocol/sdk/types.js'; // Import tools import { generateDiagram, validateDiagramSyntax, getDiagramInformation, listSupportedDiagramTypes, convertDiagram } from './tools/core.js'; import { listDiagramTemplates, getTemplate, createCustomTemplate, searchTemplates } from './tools/templates.js'; // Import utilities import { initializeMermaid, cleanup } from './utils/mermaid.js'; import fs from 'fs'; import path from 'path'; import { fileURLToPath } from 'url'; // CLI preflight: support --version and --help without starting the server { const args = process.argv.slice(2); if (args.includes('--version') || args.includes('-v')) { try { const __filename = fileURLToPath(import.meta.url); const __dirname = path.dirname(__filename); const pkgPath = path.resolve(__dirname, '..', 'package.json'); let pkg: any = undefined; try { pkg = JSON.parse(fs.readFileSync(pkgPath, 'utf8')); } catch (e) { try { const alt = path.resolve(process.cwd(), 'package.json'); pkg = JSON.parse(fs.readFileSync(alt, 'utf8')); } catch (e2) { console.log('mermaid-mcp (version unknown)'); process.exit(0); } } console.log(`mermaid-mcp ${pkg.version || 'unknown'}`); process.exit(0); } catch (err) { console.log('mermaid-mcp (version unknown)'); process.exit(0); } } if (args.includes('--help') || args.includes('-h')) { console.log('mermaid-mcp - Mermaid MCP Server'); console.log('Usage: mermaid-mcp [options]'); console.log(' --version, -v Print version'); console.log(' --help, -h Show this help'); process.exit(0); } } /** * MCP Tool definitions with enhanced descriptions */ const TOOLS = [ // Core Diagram Tools { name: 'generateDiagram', description: 'Generate and render a Mermaid diagram to SVG file. Supports all 22+ diagram types with advanced layout options.', inputSchema: { type: 'object', properties: { code: { type: 'string', description: 'Mermaid diagram code (e.g., "flowchart TD\\nA --> B")' }, options: { type: 'object', description: 'Rendering options (theme, layout, format)', properties: { config: { type: 'object', description: 'Mermaid configuration', properties: { theme: { type: 'string', enum: ['default', 'dark', 'forest', 'neutral', 'base'] }, securityLevel: { type: 'string', enum: ['strict', 'loose', 'antiscript', 'sandbox'] }, fontSize: { type: 'number' }, fontFamily: { type: 'string' } } }, layout: { type: 'object', description: 'Advanced layout configuration', properties: { engine: { type: 'string', enum: ['elk', 'dagre', 'tidy-tree'] }, direction: { type: 'string', enum: ['TB', 'TD', 'BT', 'RL', 'LR'] }, spacing: { type: 'number' } } } } }, filename: { type: 'string', description: 'Output filename (optional, auto-generated if not provided)' }, outputPath: { type: 'string', description: 'Output directory path (optional, defaults to current directory)' } }, required: ['code'] } }, { name: 'validateDiagram', description: 'Validate Mermaid diagram syntax and provide detailed error messages and suggestions.', inputSchema: { type: 'object', properties: { code: { type: 'string', description: 'Mermaid diagram code to validate' } }, required: ['code'] } }, { name: 'getDiagramInfo', description: 'Analyze diagram code and return metadata (type, complexity, node/edge count, estimated render time).', inputSchema: { type: 'object', properties: { code: { type: 'string', description: 'Mermaid diagram code to analyze' } }, required: ['code'] } }, { name: 'listSupportedTypes', description: 'List all supported Mermaid diagram types (22+ types including flowchart, sequence, class, etc.).', inputSchema: { type: 'object', properties: {}, required: [] } }, { name: 'convertDiagram', description: 'Convert diagram to different formats. Currently supports SVG (PNG/PDF coming soon).', inputSchema: { type: 'object', properties: { code: { type: 'string', description: 'Mermaid diagram code' }, format: { type: 'string', description: 'Output format', enum: ['svg', 'png', 'pdf'] }, options: { type: 'object', description: 'Conversion options' }, filename: { type: 'string', description: 'Output filename' }, outputPath: { type: 'string', description: 'Output directory path' } }, required: ['code'] } }, // Template Tools { name: 'listTemplates', description: 'List available pre-built diagram templates (50+ templates) by category or type.', inputSchema: { type: 'object', properties: { category: { type: 'string', description: 'Filter by category (flowchart, sequence, class, etc.)' }, type: { type: 'string', description: 'Filter by diagram type' } }, required: [] } }, { name: 'getTemplate', description: 'Get a specific diagram template by ID with complete code and metadata.', inputSchema: { type: 'object', properties: { templateId: { type: 'string', description: 'Template ID (e.g., "flowchart-basic", "sequence-api")' } }, required: ['templateId'] } }, { name: 'searchTemplates', description: 'Search templates by keyword (name, description, type, tags, or code content).', inputSchema: { type: 'object', properties: { query: { type: 'string', description: 'Search query (e.g., "authentication", "database", "workflow")' } }, required: ['query'] } }, { name: 'createCustomTemplate', description: 'Create a custom template from diagram code for reuse in current session.', inputSchema: { type: 'object', properties: { name: { type: 'string', description: 'Template name' }, description: { type: 'string', description: 'Template description' }, code: { type: 'string', description: 'Mermaid diagram code' }, category: { type: 'string', description: 'Template category (optional)' }, tags: { type: 'array', items: { type: 'string' }, description: 'Template tags (optional)' } }, required: ['name', 'description', 'code'] } } ]; /** * Map tool names to handler functions */ const TOOL_HANDLERS = { generateDiagram, validateDiagram: validateDiagramSyntax, getDiagramInfo: getDiagramInformation, listSupportedTypes: listSupportedDiagramTypes, convertDiagram, listTemplates: listDiagramTemplates, getTemplate, searchTemplates, createCustomTemplate }; /** * Main server class */ class MermaidMCPServer { private server: Server; private transport: StdioServerTransport; constructor() { this.server = new Server( { name: 'mermaid-mcp-server', version: '1.0.0', }, { capabilities: { resources: {}, tools: {}, }, } ); this.transport = new StdioServerTransport(); this.setupHandlers(); } private setupHandlers() { // List available tools this.server.setRequestHandler(ListToolsRequestSchema, async () => { return { tools: TOOLS.map(tool => ({ name: tool.name, description: tool.description, inputSchema: tool.inputSchema })) }; }); // Handle tool calls this.server.setRequestHandler(CallToolRequestSchema, async (request) => { const { name, arguments: args } = request.params; try { const handler = TOOL_HANDLERS[name as keyof typeof TOOL_HANDLERS]; if (!handler) { throw new McpError( ErrorCode.MethodNotFound, `Unknown tool: ${name}` ); } const result = await handler({ name, arguments: args || {} }); return { content: result.content, isError: result.isError || false }; } catch (error: any) { console.error(`Error in tool ${name}:`, error); if (error instanceof McpError) { throw error; } throw new McpError( ErrorCode.InternalError, `Tool execution failed: ${error.message}` ); } }); // Handle server lifecycle this.server.onerror = (error) => { console.error('[MCP Error]', error); }; process.on('SIGINT', async () => { await this.shutdown(); process.exit(0); }); process.on('SIGTERM', async () => { await this.shutdown(); process.exit(0); }); } async start() { try { console.error('🎨 Initializing Mermaid MCP Server...'); // Initialize Mermaid await initializeMermaid({ theme: 'default', startOnLoad: false, securityLevel: 'antiscript', // Use antiscript to bypass DOMPurify logLevel: 'error' }); console.error('✅ Mermaid initialized successfully'); console.error('🚀 Starting MCP server...'); await this.server.connect(this.transport); console.error('✅ Mermaid MCP Server is running'); console.error('📋 Available tools:', TOOLS.length); console.error('🎯 Ready for GitHub Copilot integration!'); } catch (error) { console.error('❌ Failed to start server:', error); process.exit(1); } } async shutdown() { try { console.error('🛑 Shutting down Mermaid MCP Server...'); cleanup(); await this.server.close(); console.error('✅ Server shutdown complete'); } catch (error) { console.error('❌ Error during shutdown:', error); } } } // Start the server async function main() { const server = new MermaidMCPServer(); await server.start(); } // Handle unhandled errors process.on('unhandledRejection', (reason, promise) => { console.error('Unhandled Rejection at:', promise, 'reason:', reason); process.exit(1); }); process.on('uncaughtException', (error) => { console.error('Uncaught Exception:', error); process.exit(1); }); if (import.meta.url === `file://${process.argv[1]}`) { main().catch((error) => { console.error('Failed to start:', error); process.exit(1); }); }