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Codex Issues / #19463

Browser Use cannot discover Codex In-App Browser backend

Open 💬 6 comments Opened Apr 24, 2026 by moksha-z

Title:
Browser Use cannot discover Codex In-App Browser backend

Environment:

  • Codex desktop app
  • macOS
  • Browser Use plugin: openai-bundled/browser-use/0.1.0-alpha1
  • Backend requested: iab
  • Date: 2026-04-25

Issue:
When using the Browser Use skill to open any URL in the Codex in-app browser, the runtime fails before navigation.

Tried URLs:

Expected:
Browser Use should connect to the current Codex in-app browser tab and navigate to the requested URL.

Actual:
The Node REPL call:

setupAtlasRuntime({ globals: globalThis, backend: "iab" })

fails with:

Failed to connect to browser-use backend "iab". No Codex IAB backends were discovered.

Notes:

  • The Browser Use plugin is enabled.
  • The in-app browser can be opened manually with Cmd + Shift + B.
  • The failure happens before any page navigation.
  • This appears to be an IAB backend discovery/registration problem, not a website-specific problem.

View original on GitHub ↗

6 Comments

neusse · 2 months ago

I think I have identified the issue and have a work around until it is fixed.

https://github.com/openai/codex/issues/19423#issuecomment-4317666215

Liudon · 2 months ago

I've encountered this problem as well.

marcelsafin · 2 months ago

same

zach-jaggars · 2 months ago

Same issue, here is the feedback id: 019dd488-81d1-7ce1-affe-9aed15ace538

aston314 · 2 months ago

I can reproduce this as well, with the following environment:

  • Codex desktop: 26.429.30905
  • macOS: 26.3 (25D125)
  • Browser Use plugin: openai-bundled/browser-use/0.1.0-alpha1
  • backend: iab
  • Chrome: 147.0.7727.138

Repro steps:

  1. Open Codex desktop.
  2. Use the bundled browser-use skill to call setupAtlasRuntime({ globals: globalThis, backend: "iab" }).
  3. The failure happens before any page navigation.

Actual result:
Failed to connect to browser-use backend "iab". No Codex IAB backends were discovered.

Expected result:
Browser Use should connect to the current Codex in-app browser and start navigating.

Additional notes:

  • Chrome itself is working normally.
  • I also confirmed locally that the app can open a window, but iab backend discovery still fails.
  • This looks more like an IAB backend discovery / registration issue than a website-specific problem.
mbrq-cs · 2 months ago

Same issue. I consistently can replicate the issue in any chat after compact. Feedback id: 019e0081-d220-7173-a272-9daf9e0783cf