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  "description": "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. Here's how I fixed it.",
  "path": "/til/2026/02/04/a-hidden-character-can-hide-your-codex-sessions/",
  "publishedAt": "2026-02-04T19:06:54.000Z",
  "site": "https://danielraffel.me",
  "tags": [
    "Codex.app",
    "February 4, 2026",
    "@ajambrosino"
  ],
  "textContent": "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\nsessions vanished, which was alarming.\n\nThe 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.\n\n### What to ask Codex\n\n  * Search the Codex sessions folder1 for `U+2028`.\n  * Show the exact lines where it appears.\n  * Remove those characters from the affected session file(s).\n  * Verify the characters are gone.\n  * Quit and restart Codex.app to confirm sessions load again.\n\n\n\n### FWIW You'll probably never hit this issue\n\n> this is in the next release, you just helped speed up the testing 🙏\n>\n> — Andrew Ambrosino (@ajambrosino) February 4, 2026\n\n* * *\n\n1. 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.",
  "title": "A Hidden Character Can Hide Your Codex Sessions",
  "updatedAt": "2026-02-05T07:16:22.245Z"
}