Windows app: Computer Use initialization fails for a WSL workspace with “sandboxCwd is not a local file URI”

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

26.901.5003.0

What subscription do you have?

ChatGPT Pro 20x

What platform is your computer?

Microsoft Windows NT 10.0.26200.0 x64 Using the Windows Codex desktop app with a project workspace in WSL. Workspace path: /home//projects/ (anonymized)

What issue are you seeing?

Computer Use fails to initialize when using the Windows Codex app with a project workspace in WSL. This repeatedly blocks visual verification after UI changes.

Terminal commands and project file access work in the same workspace, but the node_repl call used to initialize Computer Use fails before any browser interaction occurs.

Steps to reproduce

1. Open a project located in the WSL filesystem in the Windows Codex app.
2. Start a task in that workspace.
3. Ask Codex to use Computer Use for UI visual verification.
4. The agent attempts to initialize Computer Use through node_repl:

if (!globalThis.sky) {
  const { sky } = await import("@oai/sky");
  globalThis.sky = sky;
}
nodeRepl.write("Computer Use initialized");

Actual behavior

The tool call fails with the following error. The workspace path below has been anonymized:

tool call error: tool call failed for `node_repl/js`

Caused by:
    Mcp error: -32602: js: codex/sandbox-state-meta:
    sandboxCwd is not a local file URI:
    file:///home/<user>/projects/<project>

The failure occurs during runtime initialization, before navigating to or interacting with a webpage.

Expected behavior

Computer Use should initialize successfully for a WSL-backed workspace.

If this environment combination is currently unsupported, the app should clearly explain the limitation and provide a supported workflow for visual verification.

Troubleshooting already attempted

• Updated the Codex app.
• Fully quit and restarted the app.
• Retested initialization; the same error persists.
• Confirmed that terminal commands and project file access work in the workspace.

Impact

This repeatedly prevents the agent from completing visual verification after frontend changes, even though code editing and terminal operations work.

Could you confirm whether this is a bug or a current limitation of Computer Use with WSL workspaces?

What steps can reproduce the bug?

1. Open the Windows Codex desktop app (version 26.901.5003.0).
2. Use a project workspace located in WSL, such as /home//projects/.
3. Ask the agent to use Computer Use to visually verify a local web page.
4. The agent calls node_repl/js with the following initialization code:

if (!globalThis.sky) {
  const { sky } = await import("@oai/sky");
  globalThis.sky = sky;
}
nodeRepl.write("Computer Use initialized");

5. The call fails before any browser interaction with:

Mcp error: -32602: js: codex/sandbox-state-meta:
sandboxCwd is not a local file URI:
file:///home/<user>/projects/<project>

The workspace path above is anonymized. Terminal commands and project file access work in the same task. Updating and fully restarting the app did not resolve the issue.

What is the expected behavior?

Computer Use should initialize successfully when the Windows Codex app is working with a WSL project, allowing the agent to complete browser-based visual verification.

If Computer Use with WSL workspaces is currently unsupported, the app should clearly explain this limitation and provide a supported alternative, rather than failing during initialization with a low-level workspace URI error.

Additional information

No response

Start by reproducing the Windows Codex desktop app flow with a WSL-backed workspace and the node_repl/js initialization using @oai/sky. Trace how the sandboxCwd value is handled when it is file:///home//projects/. Done means Computer Use initializes successfully, or the app clearly reports that this workspace combination is unsupported and identifies a supported workflow.