Puppeteer MCP Server

Instructions

Implementation Reference

• index.ts:333-382 (handler)

  Handler for puppeteer_evaluate tool: executes the provided JavaScript script in the browser page context, overrides console methods to capture logs, returns execution result and console output.
  case "puppeteer_evaluate": try { await page.evaluate(() => { window.mcpHelper = { logs: [], originalConsole: { ...console }, }; ["log", "info", "warn", "error"].forEach((method) => { (console as any)[method] = (...args: any[]) => { window.mcpHelper.logs.push(`[${method}] ${args.join(" ")}`); (window.mcpHelper.originalConsole as any)[method](...args); }; }); }); const result = await page.evaluate(args.script); const logs = await page.evaluate(() => { Object.assign(console, window.mcpHelper.originalConsole); const logs = window.mcpHelper.logs; delete (window as any).mcpHelper; return logs; }); return { content: [ { type: "text", text: `Execution result:\n${JSON.stringify( result, null, 2 )}\n\nConsole output:\n${logs.join("\n")}`, }, ], isError: false, }; } catch (error) { return { content: [ { type: "text", text: `Script execution failed: ${(error as Error).message}`, }, ], isError: true, }; }
• index.ts:111-121 (schema)

  Schema definition for puppeteer_evaluate tool, specifying input as a JavaScript script string.
  { name: "puppeteer_evaluate", description: "Execute JavaScript in the browser console", inputSchema: { type: "object", properties: { script: { type: "string", description: "JavaScript code to execute" }, }, required: ["script"], }, },
• index.ts:18-122 (registration)

  Registration of puppeteer_evaluate in the TOOLS array used for listing available tools.
  const TOOLS: Tool[] = [ { name: "puppeteer_navigate", description: "Navigate to a URL", inputSchema: { type: "object", properties: { url: { type: "string" }, }, required: ["url"], }, }, { name: "puppeteer_screenshot", description: "Take a screenshot of the current page or a specific element", inputSchema: { type: "object", properties: { name: { type: "string", description: "Name for the screenshot" }, selector: { type: "string", description: "CSS selector for element to screenshot", }, width: { type: "number", description: "Width in pixels (default: 800)", }, height: { type: "number", description: "Height in pixels (default: 600)", }, }, required: ["name"], }, }, { name: "puppeteer_click", description: "Click an element on the page", inputSchema: { type: "object", properties: { selector: { type: "string", description: "CSS selector for element to click", }, }, required: ["selector"], }, }, { name: "puppeteer_fill", description: "Fill out an input field", inputSchema: { type: "object", properties: { selector: { type: "string", description: "CSS selector for input field", }, value: { type: "string", description: "Value to fill" }, }, required: ["selector", "value"], }, }, { name: "puppeteer_select", description: "Select an element on the page with Select tag", inputSchema: { type: "object", properties: { selector: { type: "string", description: "CSS selector for element to select", }, value: { type: "string", description: "Value to select" }, }, required: ["selector", "value"], }, }, { name: "puppeteer_hover", description: "Hover an element on the page", inputSchema: { type: "object", properties: { selector: { type: "string", description: "CSS selector for element to hover", }, }, required: ["selector"], }, }, { name: "puppeteer_evaluate", description: "Execute JavaScript in the browser console", inputSchema: { type: "object", properties: { script: { type: "string", description: "JavaScript code to execute" }, }, required: ["script"], }, }, ];
• index.ts:463-465 (registration)

  Registration of the call tool handler which dispatches to puppeteer_evaluate case based on name.
  server.setRequestHandler(CallToolRequestSchema, async (request) => handleToolCall(request.params.name, request.params.arguments ?? {}) );
• index.ts:459-461 (registration)

  Registration of list tools handler which includes puppeteer_evaluate from TOOLS.
  server.setRequestHandler(ListToolsRequestSchema, async () => ({ tools: TOOLS, }));