Browser Use IAB backend unavailable when project root is $HOME, but works in subdirectories #19667

Description

Browser Use fails to connect to the Codex in-app browser backend when the active project/workspace root is my macOS home directory (~). The same Codex app installation can use Browser Use successfully from a normal subdirectory project, such as ~/test.

This makes Browser Use appear project-root dependent: it works in non-home directories, but not when the workspace root is $HOME.

Environment

• Codex Desktop app: 26.422.30944 (CFBundleVersion 2080)
• Codex CLI: codex-cli 0.125.0
• macOS: 26.4.1 (25E253)
• Architecture: arm64
• Running in a macOS guest inside Parallels Desktop on a macOS host
• Auth method: ChatGPT login

Expected behavior

Browser Use should be able to connect to the in-app browser backend for any trusted local project root, including $HOME, or the app should clearly indicate that $HOME is unsupported as a project root for Browser Use.

Actual behavior

When the active workspace root is ~, Browser Use fails with:

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

In the chat UI this appears as:

I tried to open YouTube with the Browser Use plugin, but the in-app browser backend isn't available in this session: no Codex IAB backend was discovered.

Switching to another project directory, for example ~/test, allows Browser Use to operate the in-app browser successfully.

Reproduction steps

1. Open Codex Desktop on macOS.
2. Create or open a project whose workspace root is the user home directory (~).
3. Ask Codex to use Browser Use, for example: Browser Use open https://www.youtube.com/.
4. Observe that Browser Use cannot connect to the IAB backend.
5. Switch to a normal subdirectory project, for example ~/test.
6. Ask the same Browser Use request.
7. Observe that Browser Use works in that project.

Diagnostics checked

• browser-use@openai-bundled is enabled in ~/.codex/config.toml.
• Both ~ and ~/test are marked trusted in the Codex project config.
• The Browser Use skill and bundled plugin files exist locally.
• A direct Browser Use backend probe in the home-root thread fails with:

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

• This does not appear to be a target website issue, because the failure happens before navigation and also occurs with simple targets.
• This does not appear to be a general network issue, because Browser Use works from another local project directory in the same app installation.

Notes

This may be related to how Codex Desktop creates or scopes the in-app browser backend per thread/project. $HOME may be treated differently from normal project roots, or the IAB backend may not be registered for threads whose active workspace root is the home directory.