Codex Desktop browser-use iab backend is discovered but session/tab commands hang

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

26.506.31421

What subscription do you have?

ChatGPT Pro

What platform is your computer?

Darwin arm64

What issue are you seeing?

The Browser / browser-use plugin is visible and the in-app browser backend is discovered, but real browser commands hang indefinitely.

The plugin file exists and imports successfully:
~/.codex/plugins/cache/openai-bundled/browser-use/0.1.0-alpha2/scripts/browser-client.mjs

Sometimes setupAtlasRuntime({ globals: globalThis }) succeeds and agent.browsers.list() returns:

• Chrome, type extension
• Codex In-app Browser, type iab

However, browser commands hang and eventually reset the JS/Node REPL session:

• await agent.browsers.get("iab") sometimes hangs
• await browser.nameSession("...") hangs
• await browser.tabs.list() hangs
• await browser.tabs.new() hangs

Chrome backend is also listed, but agent.browsers.get("chrome") returned:
Browser is not available: chrome.

What steps can reproduce the bug?

1. Start Codex Desktop App.
2. Enable/use the Browser / browser-use plugin.
3. In a Codex thread, run browser-use setup through the Node REPL:

const { setupAtlasRuntime } = await import("/Users/rim/.codex/plugins/cache/openai-bundled/browser-use/0.1.0-alpha2/scripts/browser-client.mjs");
await setupAtlasRuntime({ globals: globalThis });
globalThis.browser = await agent.browsers.get("iab");
await browser.nameSession("Browser smoke");
await browser.tabs.list();


### What is the expected behavior?

browser-use should connect to the Codex in-app browser and allow basic browser automation commands.

Expected:
- `agent.browsers.get("iab")` returns the in-app browser backend.
- `browser.nameSession(...)` completes.
- `browser.tabs.list()` returns tabs.
- `browser.tabs.new()` creates a new browser tab.


### Additional information

Environment:
- macOS on Apple Silicon arm64
- Codex Desktop App: 26.506.31421
- Also tested: 26.506.31004
- browser-use plugin: 0.1.0-alpha2

Troubleshooting already tried:
- Restarted Codex.
- Force-killed Codex helper and node_repl processes.
- Removed `$TMPDIR/codex-ipc`.
- Removed temporary `.com.openai.codex.*` files.
- Reset `~/Library/Application Support/Codex/Partitions/codex-browser-app`.
- Rebooted macOS.
- Reinstalled Codex Desktop App without deleting user data.
- Downgraded from 26.506.31421 to 26.506.31004.
- Disabled and re-enabled the browser-use plugin.
- Deleted plugin cache; Codex recreated it from bundled marketplace.

Confirmed plugin paths:
- Source: `~/.codex/.tmp/bundled-marketplaces/openai-bundled/plugins/browser-use`
- Cache: `~/.codex/plugins/cache/openai-bundled/browser-use`

This looks like a browser command transport issue below the skill/instruction layer: plugin files exist and backend discovery sometimes works, but session/tab operations never respond.