codex - 💡(How to fix) Fix Windows sandbox blocks bundled Chrome plugin/node_repl startup with os error 740

What version of the Codex App are you using?

Codex Desktop package path observed in logs:

OpenAI.Codex_26.519.11010.0_x64__2p2nqsd0c76g0

Bundled Chrome plugin path observed locally:

chrome@openai-bundled / 26.519.81530

What subscription do you have?

PRO

What platform is your computer?

Native Windows. Exact Windows version was not collected in this session.

What issue are you seeing?

The bundled Chrome plugin cannot start its official node_repl runtime on Windows. This blocks @chrome tasks before Codex can list or claim browser tabs.

This is not a Chrome website, tab, cookie, or extension-page issue. The failure happens before the browser client is imported and before any Chrome tab interaction.

Impact:

• @chrome tasks fail immediately.
• The official Chrome plugin workflow cannot reach browser.user.openTabs().
• Because this is a Chrome plugin task, Codex must not fall back to CDP, generic Playwright, OS window control, screenshots, or PowerShell-based browser automation.

Session name / task

Browser session name attempted by Codex:

🔎 크몽 자동응답

The user asked Codex to use @chrome to work in an already-open authenticated browser tab. The specific site is not important to the failure because the runtime dies before any browser access.

Steps to reproduce

1. Start Codex Desktop on Windows.

2. Enable bundled Chrome plugin:

   • [plugins."chrome@openai-bundled"] enabled = true
   • [plugins."browser@openai-bundled"] enabled = true

3. Configure Windows sandbox as elevated:

   [windows]
   sandbox = "elevated"

4. Restart Codex Desktop completely.

5. In a Codex thread, ask for an @chrome task.

6. The Chrome skill attempts to start the official runtime via node_repl.

7. Even a minimal node_repl command fails:

   nodeRepl.write('ok');

Expected behavior

node_repl should start successfully and return ok for the minimal command. Then the bundled Chrome plugin should be able to import scripts/browser-client.mjs, initialize agent.browsers.get("extension"), and list/claim open Chrome tabs.

Actual behavior

node_repl exits immediately:

node_repl kernel exited unexpectedly
node_repl diagnostics: {"kernel_pid":...,"kernel_status":"running","kernel_stderr_tail":"windows sandbox failed: spawn setup refresh","reason":"stdout_eof","stream_error":null}

sandbox.log shows the current failure is not just stale state. A fresh retry after js_reset produced a new log entry:

[2026-05-27 23:20:15.532 codex.exe] START: C:\Users\Administrator\AppData\Local\OpenAI\Codex\bin\5b9024f90663758b\node.exe --experimental-vm-modules C:\Users\ADMINI~1\AppData\Local\Temp\.tmpeAR3Px\kernel.js --session-id 2a869807028c420784cf779
[2026-05-27 23:20:15.632 codex.exe] setup refresh: spawning C:\Users\Administrator\AppData\Local\OpenAI\Codex\bin\958d608b5e0546a5\codex-windows-sandbox-setup.exe (cwd=C:\Users\Administrator\Documents\Codex, payload_len=4868)
[2026-05-27 23:20:15.638 codex.exe] setup refresh: failed to spawn C:\Users\Administrator\AppData\Local\OpenAI\Codex\bin\958d608b5e0546a5\codex-windows-sandbox-setup.exe: 요청한 작업을 수행하려면 권한 상승이 필요합니다. (os error 740)

Important distinction

General shell_command calls in the same Codex session can succeed. Those logs show sandbox setup using the WindowsApps packaged helper path and completing with errors=[]:

setup refresh: spawning C:\Program Files\WindowsApps\OpenAI.Codex_26.519.11010.0_x64__2p2nqsd0c76g0\app\resources\codex-windows-sandbox-setup.exe (cwd=C:\WINDOWS\system32, payload_len=4888)
setup refresh: processed 3 write roots (read roots delegated); errors=[]
setup binary completed

The failing path is specific to node_repl startup, which tries to spawn the AppData helper:

C:\Users\Administrator\AppData\Local\OpenAI\Codex\bin\958d608b5e0546a5\codex-windows-sandbox-setup.exe

That helper fails with os error 740 while the WindowsApps helper path succeeds for normal shell commands.

Configuration observed

Relevant config:

sandbox_mode = "danger-full-access"

[windows]
sandbox = "elevated"

[mcp_servers.node_repl]
command = "C:\\Users\\Administrator\\AppData\\Local\\OpenAI\\Codex\\bin\\3c238e29bbc930ff\\node_repl.exe"
startup_timeout_sec = 120

[mcp_servers.node_repl.env]
NODE_REPL_NODE_PATH = "C:\\Users\\Administrator\\AppData\\Local\\OpenAI\\Codex\\bin\\5b9024f90663758b\\node.exe"
CODEX_HOME = "C:\\Users\\Administrator\\.codex"
CODEX_CLI_PATH = "C:\\Program Files\\WindowsApps\\OpenAI.Codex_26.519.11010.0_x64__2p2nqsd0c76g0\\app\\resources\\codex.exe"
BROWSER_USE_AVAILABLE_BACKENDS = "chrome,iab"
BROWSER_USE_MARKETPLACE_NAME = "openai-bundled"

Things already tried

• Used only the official bundled Chrome plugin workflow.
• Loaded the bundled Chrome skill from:
  • C:\Users\Administrator\.codex\plugins\cache\openai-bundled\chrome\26.519.81530\skills\chrome\SKILL.md
• Verified scripts/browser-client.mjs exists.
• Verified official diagnostic scripts exist:
  • check-extension-installed.js
  • check-native-host-manifest.js
  • chrome-is-running.js
  • installed-browsers.js
  • open-chrome-window.js
• Tried the Chrome connection twice; both failed before tab listing.
• Tried minimal node_repl execution, independent of Chrome code:
  • nodeRepl.write('ok')
• Restarted Codex Desktop completely.
• Set [windows] sandbox = "elevated" and restarted Codex.
• Confirmed normal shell commands can still succeed through the WindowsApps helper path.
• Confirmed setup_error.json was stale and not the sole evidence.
• Retried after js_reset; the failure reproduced and wrote a fresh sandbox.log entry.
• Tried a new @chrome attempt; it still failed with the same windows sandbox failed: spawn setup refresh message.

Related issues

This appears related to the broader Windows sandbox refresh issue family, but with a narrower failure mode where normal shell commands succeed and the bundled Chrome plugin/node_repl startup fails through an AppData helper path:

• #14409
• #15809

Suggested investigation area

Please check why node_repl sandbox setup refresh uses or triggers this AppData helper path:

C:\Users\Administrator\AppData\Local\OpenAI\Codex\bin\958d608b5e0546a5\codex-windows-sandbox-setup.exe

instead of the WindowsApps packaged helper path that succeeds for regular shell commands:

C:\Program Files\WindowsApps\OpenAI.Codex_26.519.11010.0_x64__2p2nqsd0c76g0\app\resources\codex-windows-sandbox-setup.exe

The AppData helper path appears to require elevation but is being spawned in a way that fails with Windows os error 740.