Mermaid-Grammer-Inspector

#!/usr/bin/env node /** * Mermaid Grammar Inspector MCP Server * Provides Mermaid diagram syntax checking service */ import { program } from "commander"; import { FastMCP } from "fastmcp"; import { z } from "zod"; import pkg from "../package.json"; import { checkMermaid } from "./check"; import { ParseStatus } from "./parse"; /** * Start MCP server */ export const main = () => { program.name(pkg.name).description(pkg.description).version(pkg.version); program .option("--http", "Use HTTP transport mode") .option("-p, --port <number>", "HTTP server port", "3000") .parse(); const { http, port } = program.opts(); const [major, minor, patch] = pkg.version.split(".").map(Number); const server = new FastMCP({ name: pkg.mcpName, version: `${major}.${minor}.${patch}`, }); server.addTool({ name: "check", description: "Check if the text is a valid mermaid diagram. Returns an empty string if valid, otherwise returns the error message.", parameters: z.object({ text: z.string(), }), execute: async (args) => { try { const { status, message } = await checkMermaid(args.text); return status === ParseStatus.SUCCESS ? "" : message || "Unknown error"; } catch (error) { const errorMessage = error instanceof Error ? error.message : "Unexpected error occurred"; console.error("Error in check tool:", errorMessage); return `Internal error: ${errorMessage}`; } }, }); if (http) { const portNum = parseInt(port, 10) || 3000; server.start({ transportType: "httpStream", httpStream: { host: "0.0.0.0", port: portNum }, }); console.log(`🚀 MCP Server started (HTTP mode) - Port: ${portNum}`); } else { server.start({ transportType: "stdio" }); } }; main();