Web Inspector MCP

#!/usr/bin/env node import { Server } from "@modelcontextprotocol/sdk/server/index.js"; import { StdioServerTransport } from "@modelcontextprotocol/sdk/server/stdio.js"; import { createToolDefinitions } from "./tools/common/registry.js"; import type { ToolMetadata } from "./tools/common/types.js"; import { setupRequestHandlers } from "./requestHandler.js"; import { parseArgs } from "node:util"; import { setSessionConfig } from "./toolHandler.js"; import { readFileSync } from "node:fs"; import { fileURLToPath } from "node:url"; import { dirname, join } from "node:path"; // Get package.json version const __dirname = dirname(fileURLToPath(import.meta.url)); const PACKAGE_ROOT = join(__dirname, ".."); // Expose package root for tools that need to spawn child processes (e.g., npx playwright) // Tests and non-CLI environments can override or ignore this. if (!process.env.MCP_WEB_INSPECTOR_PACKAGE_ROOT) { process.env.MCP_WEB_INSPECTOR_PACKAGE_ROOT = PACKAGE_ROOT; } const packageJson = JSON.parse( readFileSync(join(__dirname, "../package.json"), "utf-8") ); const VERSION = packageJson.version; // Parse command line arguments const { values } = parseArgs({ options: { 'no-save-session': { type: 'boolean', default: false, }, 'expose-sensitive-network-data': { type: 'boolean', default: false, }, 'user-data-dir': { type: 'string', default: './.mcp-web-inspector', }, 'headless': { type: 'boolean', default: false, }, 'print-tools-json': { type: 'boolean', default: false, }, 'print-tools-md': { type: 'boolean', default: false, }, }, strict: false, }); // Configure session settings (session saving is enabled by default) const baseDir = String(values['user-data-dir'] || './.mcp-web-inspector'); const sessionConfig = { saveSession: !Boolean(values['no-save-session']), userDataDir: `${baseDir}/user-data`, screenshotsDir: `${baseDir}/screenshots`, headlessDefault: Boolean(values['headless']), exposeSensitiveNetworkData: Boolean(values['expose-sensitive-network-data']), }; setSessionConfig(sessionConfig); async function runServer() { // Create tool definitions with session config const TOOLS = createToolDefinitions(sessionConfig); // CLI utilities: print tools metadata (JSON/Markdown) and exit if (values['print-tools-json']) { process.stdout.write(JSON.stringify(TOOLS, null, 2)); return; } if (values['print-tools-md']) { const md = formatToolsMarkdown(TOOLS); process.stdout.write(md + "\n"); return; } console.error(`Starting mcp-web-inspector v${VERSION}`); const server = new Server( { name: "mcp-web-inspector", version: VERSION, }, { capabilities: { resources: {}, tools: {}, }, } ); // Setup request handlers setupRequestHandlers(server, TOOLS); // Graceful shutdown logic function shutdown() { console.error('Shutdown signal received'); process.exit(0); } process.on('SIGINT', shutdown); process.on('SIGTERM', shutdown); process.on('exit', shutdown); process.on('uncaughtException', (err) => { console.error('Uncaught Exception:', err); }); // Create transport and connect const transport = new StdioServerTransport(); await server.connect(transport); } runServer().catch((error) => { console.error("Fatal error in main():", error); process.exit(1); }); // Render a simple Markdown for tools (flat list) function formatToolsMarkdown(tools: ToolMetadata[]): string { const lines: string[] = []; for (const t of tools) { lines.push(`#### \`${t.name}\``); if (t.description) lines.push(String(t.description)); // Parameters const schema: any = (t as any).inputSchema; if (schema && schema.properties) { lines.push(''); lines.push('- Parameters:'); const req = new Set(Array.isArray(schema.required) ? schema.required : []); for (const key of Object.keys(schema.properties)) { const p = schema.properties[key] || {}; const type = p.type || 'any'; const desc = p.description || ''; const required = req.has(key) ? 'required' : 'optional'; lines.push(` - ${key} (${type}, ${required}): ${desc}`); } } // Output bullets const outputs = (t as any).outputs as string | string[] | undefined; if (outputs) { const list = Array.isArray(outputs) ? outputs : [outputs]; lines.push(''); lines.push('- Output:'); for (const item of list) { const s = String(item); lines.push(/^\s*[-*]/.test(s) ? ` ${s}` : ` - ${s}`); } } // Examples const examples = (t as any).examples as string[] | undefined; if (examples && examples.length) { lines.push(''); lines.push('- Examples:'); for (const ex of examples) lines.push(`- ${ex}`); } // Example outputs const exampleOutputs = (t as any).exampleOutputs as { call: string; output: string }[] | undefined; if (exampleOutputs && exampleOutputs.length) { for (const eo of exampleOutputs) { lines.push(''); lines.push(`- Example Output (${eo.call}):`); lines.push('```'); lines.push(eo.output); lines.push('```'); } } lines.push(''); } return lines.join('\n'); }