Cowork/local agent mode: session outputs shown as project files vanish from view after re-choosing the project folder — indistinguishable from data loss
What happened
A Cowork (local agent mode) session generated five agent config files. In the app they appeared to be in my project folder (Documents/Claude Code/Fixing Stuff). I renamed the folder in Finder, re-chose it in Claude to continue in forked sessions, and the folder then showed as empty. Undoing the rename restored the name but the files never reappeared. It looked exactly like Claude had deleted my files.
What was actually happening
The files were never written to the chosen folder. They lived in the session sandbox at ~/Library/Application Support/Claude/local-agent-mode-sessions/<id>/<id>/agent/local_ditto_<id>/outputs/. Re-choosing the folder re-bound the session to the real (empty) directory, silently dropping the outputs from view. It took extensive filesystem forensics (transcript archaeology, inode/crtime comparison) to establish that nothing was deleted and to locate the files.
Why this is a bug
- The UI presents sandbox outputs as if they are in the user's chosen folder, but the folder on disk stays empty — a Finder check contradicts the app.
- Renaming the project folder + re-choosing it orphans the outputs view with no warning, error, or pointer to where the files physically are.
- There is no user-visible path from "my files disappeared" back to the
local_dittooutputs directory. For a user, this is indistinguishable from data loss and caused a serious panic.
Suggested fixes
Warn when a chosen project folder's identity changes; surface the physical output location in the UI; or sync outputs into the chosen folder.
Environment
Claude Desktop (macOS, Darwin 24.6.0), Claude Code 2.1.237–2.1.241 sessions involved.
🤖 Filed with Claude Code on the user's behalf