Codex fails on shared Linux systems due to global /tmp/codex-ipc permissions

What version of the IDE extension are you using?

Visual Studio Code (Remote SSH)

What subscription do you have?

ChatGPT Plus

Which IDE are you using?

VS Code

What platform is your computer?

macOS (client) + Linux HPC cluster (remote)

What issue are you seeing?

Summary

The Codex VS Code extension appears to create and use a global IPC directory:

/tmp/codex-ipc

On shared Linux systems (e.g. HPC clusters), the directory becomes owned by whichever user launches Codex first.

Subsequent users cannot create their own IPC sockets and the extension fails to start.

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Environment

• VS Code Remote SSH
• Linux (multi-user HPC cluster)
• OpenAI ChatGPT / Codex VS Code Extension
• Release version: 26.602.30954
• Previously reproduced on pre-release version as well

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Error

The extension repeatedly logs:

listen EACCES: permission denied /tmp/codex-ipc/ipc-4208563.sock

Codex never initializes.

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Reproduction

Login node A:

drwxr-xr-x 2 xz4366 xz4366 /tmp/codex-ipc

Login node B:

drwxr-xr-x 2 wz3008 wz3008 /tmp/codex-ipc

The directory owner changes depending on who first starts Codex on that node.

Any subsequent user receives:

EACCES: permission denied

when attempting to create:

/tmp/codex-ipc/ipc-<uid>.sock

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Additional Information

I verified that:

• Home directory quota is not the cause.
• Inode quota issues were resolved.
• CODEX_HOME was moved to a user-owned scratch directory.
• TMPDIR/TMP/TEMP were redirected to a user-owned scratch directory.
• The extension still attempts to use /tmp/codex-ipc.
• The issue reproduces on multiple login nodes.

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Expected Behavior

The extension should use a user-scoped runtime location, such as:

$XDG_RUNTIME_DIR

or

/tmp/codex-ipc-$UID

or

/tmp/codex-ipc-$USER

instead of a single global directory shared across all users.

What steps can reproduce the bug?

1. Install the OpenAI Codex VS Code extension on a shared Linux system (e.g. HPC cluster or multi-user server).

1. User A opens Codex through VS Code Remote SSH.

1. Observe that the extension creates:

/tmp/codex-ipc

owned by User A with permissions similar to:

drwxr-xr-x

1. Disconnect User A.

1. Login as User B on the same machine.

1. Open Codex through VS Code Remote SSH.

1. Observe repeated errors:

listen EACCES: permission denied /tmp/codex-ipc/ipc-<uid>.sock

1. Codex never initializes and remains unavailable.

Additional observation:

The same behavior reproduces across multiple login nodes. The owner of /tmp/codex-ipc changes depending on which user first launches Codex on that node.

What is the expected behavior?

_No response_

Additional information

_No response_