Windows Codex app: Browser plugin unavailable; node_repl elevated sandbox failed with spawn setup refresh

Summary

On Windows Codex app, Browser plugin / in-app browser control is not available as an installable plugin in the plugin installer candidates, even though the Codex manual says Browser use requires installing and enabling the Browser plugin. Separately, node_repl initially failed under the Windows elevated sandbox with windows sandbox failed: spawn setup refresh.

Environment

• OS version: Windows 10.0.26200.0
• PowerShell version: 5.1.26100.8457
• System Node: v24.11.1
• Codex app version from node_repl config env: 26.602.40724
• Workspace path redacted: C:\tmp\codex-browser-test
• Plugin config observed: only chrome@openai-bundled installed; no Browser plugin entry

What happened

1. In-app browser was manually opened in Codex app.
2. Asked Codex to call/control the in-app browser and navigate to Facebook.
3. Tool discovery showed no dedicated Browser / in-app browser control tool.
4. node_repl failed repeatedly with:

windows sandbox failed: spawn setup refresh

1. Local shell Node worked normally:

node -v -> v24.11.1
node child_process.spawnSync('cmd.exe', ...) -> spawn-ok
workspace write test -> ok

1. Codex config initially had:

[windows]
sandbox = "elevated"

1. After changing it to the documented fallback:

[windows]
sandbox = "unelevated"

nodeRepl.write('ok') succeeded.

1. However, Browser plugin still cannot be installed: list_available_plugins_to_install returned plugins such as canva, computer-use, figma, github, google-drive, etc., but no Browser plugin. Tool search still exposes only node_repl, not a Browser tool.

Expected behavior

• If the Codex app manual says Browser use requires the Browser plugin, the Browser plugin should be available to install/enable, or the app should explain why it is unavailable for this account/workspace/platform.
• If the Windows elevated sandbox setup fails, the app should surface an actionable diagnostic or fallback suggestion to use unelevated.

Actual behavior

• Browser plugin is not available in install candidates.
• In-app browser can be manually opened but Codex cannot control it.
• node_repl initially failed under elevated sandbox until config was manually changed to unelevated.

Workaround

Changing ~/.codex/config.toml from sandbox = "elevated" to sandbox = "unelevated" restored node_repl, but did not make Browser plugin/tools available.

Notes

No secrets, cookies, browser cache, or auth files were read during diagnosis.