2026-04-25 STRC Vault Split Metrics Drop

Brain note count dropped 1611 → 1210 (-401) overnight on 2026-04-24 → 2026-04-25. Not data loss. The drop is the planned STRC vault separation completing on disk.

What brain-stats.jsonl shows

Folder2026-04-242026-04-25Δ
research/1161-115
notes/853568-285
sources/261241-20
_templates/2126+5
sites/3491+57
Total16111210-401

research/ collapse is the entire ~/Brain/research/strc/ workbench moving to ~/STRC/research/. Most of the notes/ drop is STRC-tagged hypothesis notes, paper distillations, and cross-vault wikilinks rewritten or migrated. sources/ drop is STRC-only papers moving to the dedicated vault’s sources/.

Why this looks like an incident but is not

  • Cron observation 7228 flagged “Brain Vault Lost 401 Notes Overnight” — the diff is real, the alarm is wrong.
  • The split was planned and announced: see STRC bridge stub and the AGENTS.md ~/STRC/ callout.
  • Public site wiki.strc.egor.lol sources directly from the new vault — proof the migration is intentional, not corruption.
  • Daily backup to Forgejo runs at the end of brain-sync.sh, so a true loss would be recoverable from the previous push.

Lesson for monitors

A single “total notes” gauge is too coarse once vaults split. Going forward:

  • Treat large negative deltas as suspicious only when they cross a vault boundary that wasn’t supposed to move.
  • The metrics cron should track ~/Brain/ and ~/STRC/ separately (or report both deltas in the same run) so a planned migration nets to zero.
  • When in doubt, compare against git log --since=... in the vault — real loss leaves a footprint there too.

Connections