launch_browser

Instructions

Implementation Reference

• src/index.ts:14-21 (schema)

  Zod schema defining the input parameters for launch_browser: browser type (chromium/firefox/webkit), headless mode, and optional viewport dimensions.

  const LaunchBrowserSchema = z.object({
    browser: z.enum(['chromium', 'firefox', 'webkit']).default('chromium'),
    headless: z.boolean().default(true),
    viewport: z.object({
      width: z.number().default(1280),
      height: z.number().default(1024)
    }).optional()
  });

• src/index.ts:131-157 (registration)

  Registration of the 'launch_browser' tool in the ListToolsRequestSchema handler, exposing its name, description, and JSON Schema input definition to MCP clients.

  {
    name: 'launch_browser',
    description: 'Launch a new browser instance (chromium, firefox, or webkit)',
    inputSchema: {
      type: 'object',
      properties: {
        browser: {
          type: 'string',
          enum: ['chromium', 'firefox', 'webkit'],
          default: 'chromium',
          description: 'Browser engine to use'
        },
        headless: {
          type: 'boolean',
          default: true,
          description: 'Run browser in headless mode'
        },
        viewport: {
          type: 'object',
          properties: {
            width: { type: 'number', default: 1280 },
            height: { type: 'number', default: 720 }
          }
        }
      }
    }
  },

• src/index.ts:411-456 (handler)

  Handler function that executes the launch_browser tool logic: validates params via Zod schema, closes any existing browser, launches a new Playwright browser (chromium/firefox/webkit), creates a browser context with optional viewport, opens a new page, sets up console log listeners, and returns a success message.

  case 'launch_browser': {
    const params = LaunchBrowserSchema.parse(args);
    
    // Close existing browser if any
    if (currentBrowser) {
      await currentBrowser.close();
    }
  
    // Clear console logs
    consoleLogs = [];
  
    // Launch new browser
    const browserType = params.browser === 'firefox' ? firefox : 
                      params.browser === 'webkit' ? webkit : chromium;
    
    currentBrowser = await browserType.launch({ 
      headless: params.headless 
    });
    
    currentContext = await currentBrowser.newContext({
      viewport: params.viewport ? {
        width: params.viewport.width,
        height: params.viewport.height
      } : undefined
    });
    
    currentPage = await currentContext.newPage();
  
    // Set up console event listener
    currentPage.on('console', (msg) => {
      consoleLogs.push({
        level: msg.type(),
        message: msg.text(),
        timestamp: new Date()
      });
    });
  
    return {
      content: [
        {
          type: 'text',
          text: `Browser ${params.browser} launched successfully ${params.headless ? '(headless)' : '(headed)'}`
        }
      ]
    };
  }