Playwright-Lighthouse MCP Server

Instructions

Implementation Reference

• src/index.ts:452-503 (handler)

  The handler function that executes the take-screenshot tool. It navigates to the given URL, takes a JPEG screenshot (full page if specified), saves it to the screenshots directory, closes the browser, and returns text messages with the save path and the base64-encoded image.

  async ({ url, fullPage }) => {
    try {
      // Automatically launch browser and navigate to URL
      await navigateToUrl(url);
  
      const screenshot = await page!.screenshot({ fullPage, type: "jpeg", quality: 80 });
      
      // Create directory for screenshots if it doesn't exist
      const screenshotsDir = path.join(__dirname, "../screenshots");
      if (!existsSync(screenshotsDir)) {
        mkdirSync(screenshotsDir, { recursive: true });
      }
      
      // Save screenshot
      const screenshotPath = path.join(screenshotsDir, `screenshot-${Date.now()}.jpg`);
      writeFileSync(screenshotPath, screenshot);
  
      // Close browser after taking screenshot
      await closeBrowser();
      
      return {
        content: [
          {
            type: "text" as const,
            text: `Screenshot captured. ${fullPage ? "(Full page)" : ""}`,
          },
          {
            type: "text" as const,
            text: `Saved to: ${screenshotPath}`,
          },
          {
            type: "image" as const,
            data: screenshot.toString("base64"),
            mimeType: "image/jpeg",
          },
        ],
      };
    } catch (error) {
      // Close browser even when an error occurs
      await closeBrowser();
      
      return {
        content: [
          {
            type: "text" as const,
            text: `An error occurred while taking screenshot: ${error instanceof Error ? error.message : String(error)}`,
          },
        ],
        isError: true,
      };
    }
  }

• src/index.ts:448-451 (schema)

  Zod schema defining the input parameters for the take-screenshot tool: 'url' (required URL string) and 'fullPage' (optional boolean, defaults to false).

  {
    url: z.string().url().describe("URL of the website you want to capture"),
    fullPage: z.boolean().default(false).describe("If true, captures a screenshot of the entire page"),
  },

• src/index.ts:445-504 (registration)

  Registers the 'take-screenshot' tool with the MCP server using server.tool(), specifying the name, description, input schema, and handler function.

  server.tool(
    "take-screenshot",
    "Takes a screenshot of the currently open page",
    {
      url: z.string().url().describe("URL of the website you want to capture"),
      fullPage: z.boolean().default(false).describe("If true, captures a screenshot of the entire page"),
    },
    async ({ url, fullPage }) => {
      try {
        // Automatically launch browser and navigate to URL
        await navigateToUrl(url);
  
        const screenshot = await page!.screenshot({ fullPage, type: "jpeg", quality: 80 });
        
        // Create directory for screenshots if it doesn't exist
        const screenshotsDir = path.join(__dirname, "../screenshots");
        if (!existsSync(screenshotsDir)) {
          mkdirSync(screenshotsDir, { recursive: true });
        }
        
        // Save screenshot
        const screenshotPath = path.join(screenshotsDir, `screenshot-${Date.now()}.jpg`);
        writeFileSync(screenshotPath, screenshot);
  
        // Close browser after taking screenshot
        await closeBrowser();
        
        return {
          content: [
            {
              type: "text" as const,
              text: `Screenshot captured. ${fullPage ? "(Full page)" : ""}`,
            },
            {
              type: "text" as const,
              text: `Saved to: ${screenshotPath}`,
            },
            {
              type: "image" as const,
              data: screenshot.toString("base64"),
              mimeType: "image/jpeg",
            },
          ],
        };
      } catch (error) {
        // Close browser even when an error occurs
        await closeBrowser();
        
        return {
          content: [
            {
              type: "text" as const,
              text: `An error occurred while taking screenshot: ${error instanceof Error ? error.message : String(error)}`,
            },
          ],
          isError: true,
        };
      }
    }
  );