- Engine autosave module: Preferences (autoSave.enabled/intervalMinutes=5/maxVersions=20/
saveCurrentProject/recoveryJournal/recoveryIntervalSeconds), persisted in the per-user data
dir; prefs.get/set/reset commands.
- Background worker (filmcraft-autosave thread): the UI thread only hands over the Arc<Project>
snapshot; JSON encoding and atomic writes happen on the worker. Premiere-style auto-saves to
<project dir>/Auto-Save/<name>-YYYY-MM-DD_HH-MM-SS.fcproj (local time), only when changed,
rotated to Maximum Project Versions, optionally also saving the project.
- Recovery journal: debounced snapshot of unsaved changes in <data>/Recovery/<session>/ guarded
by an OS file lock; on launch, sessions whose lock is free and that left a snapshot are offered.
Clean quit removes the journal (or keeps it, marked cleanExit, if changes were unsaved).
- Commands: file.recover, file.discardRecovery, file.recoveryList, file.autoSaveNow,
file.autoSaveStatus, file.listAutoSaves.
- UI: Preferences ▸ Auto Save page (Edit ▸ Preferences, Cmd+,; FilmCraft ▸ Settings… on macOS),
"Recover Unsaved Changes" dialog at startup, Revert confirmation; all with automation ids.
- Desktop: --recover / --no-recover / --data-dir; local-time offset via chrono (clock).
- Verified in the app: edits, kill -9, relaunch, dialog, Recover restores the edits (unsaved, original path).
- docs/project-files.md: auto-save, recovery and measured costs (2,000 clips: 2.5 ms encode,
1.4 MB, ~30 ms atomic write+fsync, all off the UI thread). ROADMAP M11 updated.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Brandon Thomas