Browser Use IAB backend can see selected tab but cannot control it on Windows

Summary

The Browser Use plugin's in-app browser backend can discover the selected IAB tab, but control operations fail on Windows with failed to start codex app-server: 系统找不到指定的路径。 (os error 3).

This blocks navigation and DOM inspection through Browser Use, even when the in-app browser is already open and loaded.

Environment

• OS: Windows
• Codex desktop app
• Browser Use plugin: 0.1.0-alpha1
• In-app browser tab tested with: https://www.baidu.com/

What works

Using Browser Use's Node runtime setup with backend: "iab" succeeds, and the selected tab is visible:

const { setupAtlasRuntime } = await import('.../browser-client.mjs');
await setupAtlasRuntime({ globals: globalThis, backend: 'iab' });
await agent.browser.tabs.selected();

Observed selected tab shape:

{
  "selected": true,
  "title": "百度一下，你就知道",
  "url": "https://www.baidu.com/"
}

What fails

These operations fail:

await agent.browser.tabs.new();
await tab.goto('https://www.baidu.com/');
await tab.playwright.domSnapshot();

Error:

failed to start codex app-server: 系统找不到指定的路径。 (os error 3)

The stack points into the generated Browser Use Node kernel around kernel.js:1675.

Additional observations

• Named pipe check showed only a codex-browser-use\\<uuid> pipe.
• No codex-browser-use-iab pipe was present.
• Retrying after restarting Codex produced a new codex-browser-use\\<uuid> pipe but still no codex-browser-use-iab pipe.
• backend: "chrome" separately failed with expected native-host connection error, so this report is specifically about the IAB backend/app-server path.
• The Chrome DevTools MCP fallback worked against the same in-app browser/page, so the browser page itself was reachable by another tool.

Expected behavior

After setupAtlasRuntime({ backend: 'iab' }) succeeds and the selected IAB tab is visible, Browser Use should be able to navigate, inspect DOM snapshots, and control the tab.

Actual behavior

Read-only tab discovery works, but control operations fail while starting codex app-server due to a missing path on Windows.