codex - 💡(How to fix) Fix Windows Codex App: Browser Use unavailable because Node REPL tool is not exposed [4 comments, 4 participants]

What version of the Codex App are you using (From “About Codex” dialog)?

Codex Desktop Windows: 26.422.2437.0

Additional local runtime info:

codex-cli 0.124.0-alpha.2
Browser Use plugin: openai-bundled/browser-use/0.1.0-alpha1

What subscription do you have?

Plus

What platform is your computer?

Microsoft Windows NT 10.0.26200.0 x64
WSL workspace enabled

What issue are you seeing?

Browser Use is installed and enabled, but it cannot be used because the required Node REPL JavaScript tool is not exposed to Codex sessions.

Observed state:

browser_use      true
in_app_browser   true
js_repl          true

The Browser Use plugin exists locally and browser-client.mjs is present:

/mnt/c/Users/kutay/.codex/plugins/cache/openai-bundled/browser-use/0.1.0-alpha1/scripts/browser-client.mjs

However, tool discovery does not expose any of the required Node REPL execution tools:

mcp__node_repl__js
node_repl js
js
js_reset

Only unrelated MCP tools are available, such as Supabase and Cloudflare. Because of this, the Browser Use skill cannot bootstrap:

const { setupAtlasRuntime } = await import(".../scripts/browser-client.mjs");
const backend = "iab";
await setupAtlasRuntime({ globals: globalThis, backend });

No Browser Use IAB bridge/socket appears in WSL:

/tmp/codex-browser-use*

and ss -xlpn | rg 'codex-browser-use|browser-use|codex' does not show a Browser Use socket.

The app-server process starts, but only normal MCP servers are visible. No Node REPL or Browser Use bridge process appears.

What steps can reproduce the bug?

Feedback / uploaded thread id:

019dbf64-6f3b-78e1-98c6-b269727ee9e2

Steps:

1. Use Codex Desktop on Windows with a WSL workspace.
2. Ensure Browser Use is installed/enabled.
3. Enable js_repl:

/mnt/c/Users/kutay/.codex/bin/wsl/codex features enable js_repl

1. Fully quit Codex Desktop and restart it.
2. Open a new thread and request Browser Use on the in-app browser, for example:

Use Browser Use to inspect the current in-app browser tab at http://localhost:5173/

1. The Browser Use skill cannot start because the required Node REPL js tool is not available in the model/tool environment.

Diagnostics after restart:

/mnt/c/Users/kutay/.codex/bin/wsl/codex features list | rg 'browser_use|in_app_browser|js_repl'

returns:

browser_use                         stable             true
in_app_browser                      stable             true
js_repl                             experimental       true
js_repl_tools_only                  under development  false

But tool discovery still does not expose mcp__node_repl__js / node_repl js.

What is the expected behavior?

When browser_use, in_app_browser, and js_repl are enabled and the Browser Use plugin is installed, Codex sessions should expose the required Node REPL JavaScript execution tool, typically mcp__node_repl__js, so the Browser Use skill can bootstrap browser-client.mjs with backend: "iab" and control/inspect the in-app browser.

Additional information

This appears related to, but distinct from, the existing Windows Browser Use issues where Node REPL is available but IAB control/navigation fails:

• #19187
• #19298

In this case, the Node REPL tool is not exposed at all, so Browser Use cannot even reach the bootstrap phase.

A Playwright CLI fallback can test the same local app successfully, so the local web app itself is not the blocker.