MCP Accessibility Bridge

Instructions

Implementation Reference

• src/tools/browserConnect.ts:17-38 (handler)

  The browserConnectHandler function that executes the browser_connect tool logic. It connects to a Chrome browser via the Chrome DevTools Protocol using the provided debug URL, retrieves the current page URL and title, and returns a success response with connection details.

  export async function browserConnectHandler(
    args: { debugUrl?: string }
  ): Promise<ReturnType<typeof toolSuccess | typeof toolError>> {
    try {
      const url = args.debugUrl ?? 'http://localhost:9222';
      await browserManager.connect(url);
  
      const { page } = browserManager.requireConnection();
      const currentUrl = page.url();
      const title = await page.title().catch(() => '');
  
      return toolSuccess({
        connected: true,
        debugUrl: url,
        currentUrl,
        pageTitle: title,
        message: `Connected to Chrome at ${url}. Active page: "${title || currentUrl}"`,
      });
    } catch (error) {
      return toolError(error);
    }
  }

• src/tools/browserConnect.ts:5-15 (schema)

  The browserConnectSchema defines the input validation for the browser_connect tool. It accepts an optional debugUrl parameter with a default value of 'http://localhost:9222', which must be a valid URL.

  export const browserConnectSchema = {
    debugUrl: z
      .string()
      .url()
      .optional()
      .default('http://localhost:9222')
      .describe(
        'Chrome remote debugging URL. Default: http://localhost:9222. ' +
        'Start Chrome with --remote-debugging-port=9222.'
      ),
  };

• src/index.ts:20-32 (registration)

  Registration of the browser_connect tool with the MCP server. It registers the tool name, title, description, input schema, and the handler function.

  server.registerTool(
    'browser_connect',
    {
      title: 'Connect to Chrome Browser',
      description:
        'Connect to a running Chrome browser via the Chrome DevTools Protocol (CDP). ' +
        'Chrome must be started with --remote-debugging-port=9222. ' +
        'Command: /Applications/Google\\ Chrome.app/Contents/MacOS/Google\\ Chrome ' +
        '--remote-debugging-port=9222 --user-data-dir=/tmp/chrome-debug-profile',
      inputSchema: browserConnectSchema,
    },
    browserConnectHandler
  );