VS Code extension app-server exits in a fresh devcontainer because ~/.codex does not exist

Reproduce the failure with the Rust image and the extension entry in devcontainer.json, ensuring /home/vscode/.codex is absent. Start with the remote Codex.log path and trace the extension's app-server launch and CODEX_HOME handling; done means a fresh container reaches the Codex sign-in or setup screen instead of remaining on the loading view.

What version of the IDE extension are you using?

openai.chatgpt-26.707.91948-linux-arm64

What subscription do you have?

Business

Which IDE are you using?

Visual Studio Code 1.129.0 with Dev Containers 0.466.0

What platform is your computer?

Host: Darwin 25.5.0 arm64 arm; Remote environment: VS Code devcontainer Linux ARM64 mcr.microsoft.com/devcontainers/rust:2-1-trixie

What issue are you seeing?

On the first launch of the Codex extension inside a fresh devcontainer, the Codex panel remains stuck on the logo/loading view.

The extension itself installs successfully in the remote VS Code Server and begins activation. However, its bundled Codex app-server exits immediately because /home/vscode/.codex does not exist:

[info] Activating Codex extension
[info] [CodexMcpConnection] Spawning codex app-server
[error] [CodexMcpConnection] cli: message="WARNING: proceeding, even though we could not create PATH aliases: CODEX_HOME points to \"/home/vscode/.codex\", but that path does not exist
Error: CODEX_HOME points to \"/home/vscode/.codex\", but that path does not exist"
[error] [CodexMcpConnection] Codex process fatal error errorMessage="Codex process errored: Codex app-server process exited unexpectedly (code=1, signal=null)."
[error] [CodexWebviewProvider] Fatal error message="Codex process errored: Codex app-server process exited unexpectedly..."

Neither the repository, .devcontainer/.env, devcontainer.json, nor the container configuration explicitly sets CODEX_HOME.

A new devcontainer naturally does not have /home/vscode/.codex yet. The extension-launched app-server treats this first-run state as fatal, while the webview remains indefinitely on its loading screen.

What steps can reproduce the bug?

1. Create a devcontainer based on the Rust devcontainer image:

FROM mcr.microsoft.com/devcontainers/rust:2-1-trixie

2. Configure VS Code to install the Codex extension inside the container:

{
  "name": "Rust devcontainer",
  "service": "app",
  "workspaceFolder": "/workspaces/${localWorkspaceFolderBasename}",
  "customizations": {
    "vscode": {
      "extensions": [
        "openai.chatgpt"
      ]
    }
  }
}

3. Ensure this is a fresh container where /home/vscode/.codex does not already exist.
4. Open the repository in the devcontainer.
5. Open the Codex panel.
6. Observe that the panel remains on the logo/loading screen.
7. Inspect the remote log at:

/home/vscode/.vscode-server/data/logs/<timestamp>/exthost1/openai.chatgpt/Codex.log

8. Observe that the app-server exited because /home/vscode/.codex does not exist.

What is the expected behavior?

The extension should support first-run activation in a clean remote environment.

It should either:

1. create ~/.codex with appropriate ownership and permissions;
2. allow the Codex runtime to initialize its default state directory; or
3. display an actionable error instead of leaving the webview stuck indefinitely.

Installing the extension through devcontainer.json should be sufficient to reach the Codex sign-in or initial setup screen.

Additional information

The remote extension package was downloaded, signature-verified, and installed successfully. The failure occurs after activation when the extension spawns its app-server.

Creating /home/vscode/.codex during the image build appears to be a possible workaround:

RUN install -d -o vscode -g vscode /home/vscode/.codex

The remote extension-host log also contains the following warning:

PendingMigrationError: navigator is now a global in nodejs

That appears to be separately tracked by openai/codex#26509. The deterministic fatal error reported here is the app-server exit caused by the missing Codex home directory.