Agent Attic — AI skill for Claude Code

attic

Keep a copy of every file before an AI coding agent overwrites it.

Agents edit files fast, in bulk, and without asking. Most of the time that is the point. The rest of the time you want the previous version back, and `git` only helps if the file was committed, tracked, and clean when it happened.

Attic is about 200 lines of `bash` with no dependencies beyond `jq` for the hooks. It stores one copy per distinct version, deduplicated by content hash. Everything fails closed and fails loudly: if a previous version cannot be preserved, the destructive step is refused and the reason says why, because silent unprotection is the one failure mode a safety net must never have.

$ attic-snap notes.md
attic: /work/notes.md -> /work/.attic/notes.md/2026-08-20T144428Z.c88cbd31.md

$ attic-snap --list notes.md
2026-08-20T151203Z.2410d456.md
2026-08-20T144428Z.c88cbd31.md

$ attic-snap --restore .attic/notes.md/2026-08-20T144428Z.c88cbd31.md notes.md
attic: /work/notes.md -> /work/.attic/notes.md/2026-08-20T152014Z.9f1abc02.md
attic: restored .attic/notes.md/2026-08-20T144428Z.c88cbd31.md -> notes.md

Restoring snapshots the current file first, so recovering an old version can never destroy the newer one. If that safety snapshot cannot be stored, the restore is refused instead; see [If something is refused](#if-something-is-refused).

Documentation

• docs/scope.md — what this covers and, more importantly, what it does not. Read this before relying on it.
• docs/pattern.md — the method-here-instance-there split that keeps the tool this small, and how to apply it to your own agent rules.

What it does not do

Read [docs/scope.md](docs/scope.md) before relying on this. It protects against **overwrites**, not against unsaved in-editor work, and not against losing the directory. Those are different problems with different owners, and treating one mechanism as if it covered all three is how people end up confidently unprot