A Hidden Character Can Hide Your Codex Sessions

Today I learned that a single weird Unicode line separator (U+2028) can make Codex.app skip loading session history. I quit and restarted the app and all my sessions vanished, which was alarming.

The fix was simple: remove the offending U+2028 characters from the sessions JSONL file. After that, I quit and restarted again and everything came back. Clearly that one character was the culprit.

What to ask Codex

• Search the Codex sessions folder1 for U+2028.
• Show the exact lines where it appears.
• Remove those characters from the affected session file(s).
• Verify the characters are gone.
• Quit and restart Codex.app to confirm sessions load again.

FWIW You'll probably never hit this issue

this is in the next release, you just helped speed up the testing 🙏

— Andrew Ambrosino (@ajambrosino) February 4, 2026

1. You’ll want to search the Codex sessions folder in your home directory. On macOS, the path is ~/.codex/sessions. Ask Codex to scan that folder for hidden Unicode line separators and clean them up.