Browser Use cannot navigate external sites because nodeRepl.fetch fails to start/find Codex app-server on Windows #21371

failed to start codex app-server: The system cannot find the path specified. (os error 3)
The failure happens when Browser Use performs the external-site safety/status check through nodeRepl.fetch.

Basic IAB commands work:

setupAtlasRuntime({ globals: globalThis, backend: "iab" }) succeeds.
agent.browser.nameSession(...) succeeds.
agent.browser.tabs.list() succeeds.
agent.browser.tabs.selected() succeeds.
But this fails:

await tab.goto("https://www.google.com");
The underlying fetch also fails directly:

await nodeRepl.fetch("https://chatgpt.com/backend-api/aura/site_status?site_url=https%3A%2F%2Fwww.google.com%2F&url_request_source=codex_browser_use", { method: "GET" });
I also observed that nodeRepl.homeDir was null, and process.env appeared empty inside the Node REPL kernel.

Codex logs showed the app-server existed and reported version 0.128.0-alpha.1.

### What steps can reproduce the bug?

1. Open Codex Desktop on Windows with the in-app browser open.
2. Use the Browser Use plugin.
3. Run:

```js
const { setupAtlasRuntime } = await import("C:/Users/<user>/.codex/plugins/cache/openai-bundled/browser-use/0.1.0-alpha1/scripts/browser-client.mjs");
await setupAtlasRuntime({ globals: globalThis, backend: "iab" });
await agent.browser.nameSession("Google test");
Confirm basic tab commands work:
await agent.browser.tabs.list();
globalThis.tab = await agent.browser.tabs.selected();
Try to navigate to an external site:
await tab.goto("https://www.google.com");
It fails with:
failed to start codex app-server: The system cannot find the path specified. (os error 3)

### What is the expected behavior?

Browser Use should open `https://www.google.com` in the in-app browser, or return a clear external-site/network/auth error if the safety check fails.

Restarting Codex Desktop did not fix the issue.

Resetting Node REPL state did not fix it.

The main app-server process appeared to exist. Logs included:

```text
Current reported app-server version: currentVersion=0.128.0-alpha.1
Logs also showed runtime paths were selected:

codexCliPath=C:\Users\<user>\AppData\Local\OpenAI\Codex\bin\codex.exe
nodePath=C:\Users\<user>\AppData\Local\OpenAI\Codex\bin\node.exe
nodeReplPath=C:\Users\<user>\AppData\Local\OpenAI\Codex\bin\node_repl.exe
nodeVersionValue=v24.14.0
platform=win32
A later Codex extension/runtime error surfaced from codex_analytics::client, where the client appeared to receive a Cloudflare challenge HTML page instead of the expected API response. Raw Cloudflare challenge tokens are omitted.

### Additional information

Restarting Codex Desktop did not fix the issue.

Resetting the Node REPL state did not fix it.

The main app-server process appeared to exist. Logs included:

```text
Current reported app-server version: currentVersion=0.128.0-alpha.1

Session/thread id from this run:
`019dfdeb-a356-7341-8e86-7137a288d467`

Logs also showed runtime paths were selected:


codexCliPath=C:\Users\HP\AppData\Local\OpenAI\Codex\bin\codex.exe
nodePath=C:\Users\HP\AppData\Local\OpenAI\Codex\bin\node.exe
nodeReplPath=C:\Users\HP\AppData\Local\OpenAI\Codex\bin\node_repl.exe
nodeVersionValue=v24.14.0
platform=win32
A later Codex extension/runtime error surfaced from codex_analytics::client, where the client appeared to receive a Cloudflare challenge HTML page instead of the expected API response. I am omitting the raw challenge tokens.