Codex Desktop IAB cannot inspect external pages because app-server fails to start on Windows

Potential duplicates detected. Please review them and close your issue if it is a duplicate.

• #19314
• #19298
• #19187

Powered by Codex Action

I’m seeing what appears to be the same Windows app-server failure, with a bit more isolation around Browser Use.

Environment:

• Codex Desktop: OpenAI.Codex_26.422.3464.0_x64__2p2nqsd0c76g0
• Codex CLI: codex-cli 0.125.0
• Windows
• System Node was upgraded from v22.17.1 to v22.22.2

What I checked:

• Browser Use skill/plugin files are present:
• .codex/plugins/cache/openai-bundled/browser-use/0.1.0-alpha1/skills/browser/SKILL.md
• .codex/plugins/cache/openai-bundled/browser-use/0.1.0-alpha1/scripts/browser-client.mjs
• setupAtlasRuntime({ backend: "iab" }) can initialize.
• agent.browser.tabs.list() works.
• Local navigation reaches the browser. For example, navigating to http://localhost:3000 returns the expected browser error net::ERR_CONNECTION_REFUSED.
• Programmatic navigation to an external URL, e.g. https://www.fox.com, fails with:

failed to start codex app-server: The system cannot find the path specified. (os error 3)

Additional behavior:

• If I manually enter https://www.fox.com/home in the in-app browser, the page loads.
• After that, Browser Use can see selected tab metadata such as URL/title.
• But DOM inspection, screenshot capture, or interaction on that manually loaded external tab still fails with the same failed to start codex app-server error.

This makes it look less like a missing Browser Use skill/plugin-cache problem and more like the Desktop app-server bridge used by nodeRepl.fetch / external-site permission or status checks is missing or resolving to the wrong path.

Follow-up with a local workaround that appears to confirm the root cause.

After reboot, Codex Desktop was still launching node_repl.exe from:

C:\Users\georg\AppData\Local\OpenAI\Codex\bin\node_repl.exe

But that path did not exist on disk. The installed packaged copy exists at:

C:\Program Files\WindowsApps\OpenAI.Codex_26.422.3464.0_x64__2p2nqsd0c76g0\app\resources\node_repl.exe

I manually recreated the missing local directory and copied node_repl.exe from the packaged app resources into the stale AppData path. That changed the failure from:

failed to start codex app-server: The system cannot find the path specified. (os error 3)

to:

failed to start codex app-server: The system cannot find the file specified. (os error 2)

Searching strings in node_repl.exe showed it starts:

codex app-server --listen stdio://

So I also copied the packaged codex.exe into the same AppData bin directory:

C:\Users\georg\AppData\Local\OpenAI\Codex\bin\codex.exe

After that, the authenticated fetch bridge started working. This call succeeded:

nodeRepl.fetch("https://chatgpt.com/backend-api/aura/site_status?site_url=https%3A%2F%2Fwww.fox.com")

Response:

{
  "feature_status": {
    "user_site_settings_toggle": false,
    "agent": false,
    "side_chat": false,
    "cursor_chat": false,
    "page_view": false,
    "page_content": false,
    "analytics": false
  },
  "debug_reason": null,
  "enabled": true
}

Browser Use then no longer failed with the app-server error. Programmatic navigation to https://www.fox.com/home reached the page, and DOM access worked afterward.

This seems to confirm that the bug is Codex Desktop launching node_repl.exe from a stale/missing user-local binary path, and that node_repl.exe expects a companion codex.exe beside it for codex app-server. The fix likely needs to ensure the AppData bin cache is created/refreshed correctly, or that Desktop launches the packaged resource binaries directly.

same here Browser Use on Windows is broken

Confirming @neusse method workaround fixed the same issue for me on Windows.

My %LOCALAPPDATA%\OpenAI\Codex\bin directory was missing. After copying node_repl.exe and codex.exe from the installed Codex Desktop package resources into that bin directory, nodeRepl.fetch(...) and Browser Use external navigation started working again.

confirming also it fixed the issue on y side with Windows 11

I believe the root cause is related to a corrupted upgrade state.

After deleting all existing Codex files and performing a clean install from the Microsoft Store, Codex installs and runs correctly. However, during the upgrade process, it appears that parts of the previous version were not fully removed while the new version was also installed.

This leaves the system in a mixed-version state, which can cause the wrong binaries to load and then fail when expected files are missing.

I believe the root cause is related to a corrupted upgrade state. After deleting all existing Codex files and performing a clean install from the Microsoft Store, Codex installs and runs correctly. However, during the upgrade process, it appears that parts of the previous version were not fully removed while the new version was also installed. This leaves the system in a mixed-version state, which can cause the wrong binaries to load and then fail when expected files are missing.

I tried it, removed .codex in the user folder and openai/codex folders in appdata. Still no luck on Windows 11. I have to reapply the "files copy" fix

I can reproduce the same root failure on Windows, but with one important difference from the "missing helper bin path" theory.

Environment:

• Codex Desktop package: OpenAI.Codex_26.422.3464.0_x64__2p2nqsd0c76g0
• app version observed locally: 0.125.0-alpha.3
• Browser Use plugin: openai-bundled/browser-use/0.1.0-alpha1
• Platform: Windows x64

What I verified locally:

1. Browser Use bootstrap works:

• setupAtlasRuntime({ globals: globalThis, backend: "iab" }) succeeds
• agent.browser.tabs.new() succeeds
• created tab is about:blank

1. Plain nodeRepl.fetch policy behavior looks normal:

• nodeRepl.fetch("https://example.com")
• result: nodeRepl.fetch URL is not allowlisted

1. The failure is specific to the authenticated ChatGPT fetch path used by Browser Use:

• nodeRepl.fetch("https://chatgpt.com/backend-api/aura/site_status?site_url=https%3A%2F%2Fwww.google.com")
• result:

failed to start codex app-server: The system cannot find the path specified. (os error 3)

1. tab.goto("https://www.google.com/") fails with the same error:

• failed to start codex app-server: The system cannot find the path specified. (os error 3)

Important extra detail:

• %LOCALAPPDATA%\OpenAI\Codex\bin exists on this machine
• %LOCALAPPDATA%\Packages\OpenAI.Codex_2p2nqsd0c76g0\LocalCache\Local\OpenAI\Codex\bin also exists
• both contain:
• codex.exe
• node_repl.exe
• node.exe
• rg.exe
• codex-command-runner.exe
• codex-windows-sandbox-setup.exe

I also tested after disabling Settings > Configuration > Codex dependencies and fully restarting Codex. The behavior did not change.

So this still looks like the same Browser Use / authenticated fetch / app-server startup bug, but on this machine it does not appear to be explained solely by a missing %LOCALAPPDATA%\OpenAI\Codex\bin directory.

I can confirm this issue on another Windows machine, and I’ve already tried a much broader set of local fixes without resolving it.

Environment:

• Codex Desktop package: OpenAI.Codex 26.422.3464.0
• Package family: OpenAI.Codex_2p2nqsd0c76g0
• Codex Desktop runtime observed in logs: app.version=0.125.0-alpha.3
• OS: Windows x64
• Browser Use plugin cache path:

C:\Users\<user>\.codex\plugins\cache\openai-bundled\browser-use\0.1.0-alpha1

Observed behavior:

• Manual navigation in the in-app browser works
• The in-app browser can render external pages if I paste the URL myself
• But Browser Use / IAB automation still fails with:

failed to start codex app-server: The system cannot find the path specified. (os error 3)

This means the browser surface itself is alive, but the automation/control bridge is broken.

I can also reproduce that:

• agent.browser.tabs.list() works
• agent.browser.tabs.new() works
• but operations such as:
• tab.goto("https://...")
• tab.playwright.domSnapshot()
• attaching to a manually opened external page

all fail with the same app-server error.

Additional remediation steps I tried beyond restart / repair / reinstall:

1. Rebuilt Browser Use plugin cache
2. Rebuilt bundled marketplace cache
3. Removed stale workspace/project path references from Codex config
4. Performed a deeper reset of Codex Desktop local user-state/cache directories
5. Removed an older globally installed npm @openai/codex shim from PATH to avoid version conflicts
6. Re-tested after full reboot / restart

None of the above fixed the problem.

One notable detail:

• manual URL entry in the in-app browser succeeds
• only automated inspection/navigation through IAB fails

So this appears specifically related to the Codex Desktop Windows app-server/helper path used by Browser Use automation, not to general network access or page rendering.

I can still reproduce this on Windows 11 today, after the local helper bin directories have been populated.

Environment observed locally:

• OS: Windows 11
• Codex CLI on PATH: codex-cli 0.118.0
• Local Codex helper codex.exe file version: 0.126.0-alpha.8
• Browser Use plugin: openai-bundled/browser-use/0.1.0-alpha1
• Browser Use plugin entry exists:

%USERPROFILE%\.codex\plugins\cache\openai-bundled\browser-use\0.1.0-alpha1\scripts\browser-client.mjs

Local helper bin state:

• %LOCALAPPDATA%\OpenAI\Codex\bin exists
• %LOCALAPPDATA%\Packages\OpenAI.Codex_2p2nqsd0c76g0\LocalCache\Local\OpenAI\Codex\bin exists
• both directories contain:
• codex.exe
• node_repl.exe
• node.exe
• rg.exe
• codex-command-runner.exe
• codex-windows-sandbox-setup.exe

Repro attempted from Codex Desktop Browser Use:

const { setupAtlasRuntime } = await import("%USERPROFILE%/.codex/plugins/cache/openai-bundled/browser-use/0.1.0-alpha1/scripts/browser-client.mjs");
const backend = "iab";
await setupAtlasRuntime({ globals: globalThis, backend });
await agent.browser.nameSession("test google");
globalThis.tab = await agent.browser.tabs.new();
await tab.goto("https://www.google.com");

Actual result:

failed to start codex app-server: The system cannot find the path specified. (os error 3)

So this still looks like the same Browser Use / IAB / authenticated app-server startup failure, but in this repro the expected local helper bin directories are already present. That suggests the bug is not only the missing %LOCALAPPDATA%\OpenAI\Codex\bin case; there may also be a path resolution or process launch issue after the helper files exist.

same failed to execute Node: Access is denied. (os error 5)

Confirming this same issue on Windows. Browser Use on Windows is broken because it was installed from Microsoft Store and it was at protected folder under C:\Program Files\WindowsApps\OpenAI.Codex_26.422.8496.0_x64__2p2nqsd0c76g0\ whereas browser use expects the node_repl at C:\Users\{UserName}\AppData\Local\OpenAI\Codex\bin. Plugin needs to be fixed for Windows.

Since the Windows Store is the only official way of getting Codex on Windows... does this means no one at Open AI has tested this on Windows... and not even their CI has tried it on Windows?

It seems to be working now on version 26.506.31421
With this update they have probably put a workaround browser use bundle (alpha2) in the right path now.

<img width="873" height="515" alt="Image" src="https://github.com/user-attachments/assets/4d0f9e57-8e84-4de5-9bb5-c2ebe4ea6bfa" />