Browser Use iab backend can read tabs but tab.goto fails with nodeRepl.fetch request failed

What happened?

The Browser Use iab backend can connect to the in-app browser and read tab state, but navigation fails.

Environment

• macOS
• Codex desktop app
• Browser Use plugin: openai-bundled/browser-use/0.1.0-alpha1
• In-app browser open, current URL: about:blank

Steps to reproduce

1. Initialize Browser Use with backend iab:

const { setupAtlasRuntime } = await import('/Users/cy/.codex/plugins/cache/openai-bundled/browser-use/0.1.0-alpha1/scripts/browser-client.mjs');
await setupAtlasRuntime({ globals: globalThis, backend: 'iab' });

1. Run:

await agent.browser.tabs.list();
const tab = await agent.browser.tabs.selected();
await tab.title();
await tab.url();
await tab.goto('https://example.com/');

Expected behavior

The in-app browser navigates to https://example.com/.

Actual behavior

The read operations work:

• tabs.list() returns one tab with url: about:blank, title: about:blank
• tabs.selected() returns the selected tab
• tab.title() returns about:blank
• tab.url() returns about:blank

But navigation fails:

Error: nodeRepl.fetch request failed

A stepwise diagnostic showed the same result:

[
  {"name":"tabs.list","ok":true,"value":[{"id":"1","url":"about:blank","title":"about:blank"}]},
  {"name":"tabs.selected","ok":true,"value":{"hasTab":true,"id":"1"}},
  {"name":"title","ok":true,"value":"about:blank"},
  {"name":"url","ok":true,"value":"about:blank"},
  {"name":"tab.goto","ok":false,"message":"nodeRepl.fetch request failed","string":"Error: nodeRepl.fetch request failed"}
]

Additional notes

• Restarting Codex did not fix the issue.
• Reinstalling Codex did not fix the issue.
• External Chrome controlled through Computer Use can open https://www.bilibili.com/, so the machine network and target website are not the problem.
• Sending Cmd+L, writing clipboard text, Cmd+V, and Enter via tab.cua returned success, but the in-app browser remained on about:blank.