Memento

Memento

Save what matters, then produce a handoff for the next chat.

Commands

| Command | Action | |---------|--------| | /memento | Notebook triage + generate handoff | | /memento auto | Show whether auto-compaction safety net is on or off | | /memento auto on | Enable auto mode (preserves context across compaction) | | /memento auto off | Disable auto mode |

/memento auto

The auto-compaction safety net is controlled by a flag file at ~/.claude/.memento-auto.

• /memento auto — check if ~/.claude/.memento-auto exists. Report: Memento auto: on or Memento auto: off. One line, nothing else.
• /memento auto on — create ~/.claude/.memento-auto (touch). Report: Memento auto: on. If hooks aren't configured yet, show the setup block from the Auto-Compaction section below.
• /memento auto off — remove ~/.claude/.memento-auto. Report: Memento auto: off.

What this does

Two things, in order:

1. Persist — scan the conversation for unsaved decisions, learnings, constraints, or failures. Save each one via /notebook save. This is the durable part — it survives regardless of whether the user pastes anything.

1. Orient — produce a short text block that gives a blank chat enough context to pick up where this one left off. This is the ephemeral part — it captures working state that's too in-the-moment for a notebook note.

Execution

Phase 1: Notebook Triage

Before generating the handoff, assess whether this session has unsaved knowledge.

Check signals:

• Have any /notebook save calls happened this session? How recently?
• Have decisions been made, constraints discovered, bugs hit, or approaches changed since the last save (or since session start if no saves)?
• Is there a _notebook/ at all? If not, the entire session is unsaved.

Decision:

• Session is well-persisted (recent notebook saves cover the important stuff) → skip to Phase 2. Say: Notebook is current — skipping to handoff.
• Session has unsaved knowledge → save each unsaved decision, constraint, learning, or failure via /notebook save (delegate fully — follow notebook's save protocol for type inference, note format, index and lessons updates). If no notebook exists yet, initialize it first.
• Session was trivial (no meaningful decisions or learnings, just exploration or small edits) → skip saves. Don't manufacture notes.

Report what you saved:

Saved 3 notes before handoff:
- 0008 decision: switched from REST to WebSocket for live updates
- 0009 constraint: Supabase RLS doesn't support cross-schema joins
- 0010 learning: canvas XOR needs globalAlpha:1 on offscreen canvas

Phase 2: Generate Orientation

Read available context to ground the orientation:

• _notebook/_index.md (if exists)
• PROJECT_STATE.md (if exists)
• Recent git log (git log --oneline -5)
• git diff --stat and git status for uncommitted work
• Your own knowledge of what's happening in this conversation

Then produce a short orientation block. This should be:

• Short — 10-20 lines. The next chat has a full context window; don't waste it on briefing.
• Present-tense — describe what IS, not what happened.
• Actionable — end with what to do next.
• Honest — if something is uncertain or incomplete, say so.

Format:

---

We're working on [what] in [location].

[2-4 sentences: current state — what's built, what works, what's in progress.
Include the current approach/strategy if it's non-obvious.]

[1-2 sentences: any uncommitted work or in-flight changes the next session should know about.]

Next: [the literal next step]

For full context: read `_notebook/_index.md` and `_notebook/lessons.md`, or run `/notebook recover`.

---

That's it. Don't add headers, tiers, or ceremony. Just a clean block of text.

Output

Print the orientation block directly. Then one line — dry, brief, Memento-flavored. Examples:

• Don't trust your memory. Paste this.
• You won't remember any of this. Copy it.
• The next you starts from zero. This is what you left yourself.

Pick one or riff on the tone. No explanation, no instructions beyond the line.

Auto-Compaction Safety Net

Memento includes hook scripts that automatically preserve context when auto-compaction fires — no manual /memento needed.

How it works:

1. PreCompact → scripts/pre-compact.sh reads the transcript, extracts last 5 user messages + last assistant response, writes to .memento-handoff
2. Compaction runs (most context lost)
3. SessionStart(compact) → scripts/post-compact.sh reads .memento-handoff, injects it into the post-compaction context with a recovery directive

Setup — add to ~/.claude/settings.json:

{
  "hooks": {
    "PreCompact": [
      {
        "matcher": "auto",
        "hooks": [
          {
            "type": "command",
            "command": "~/.claude/skills/memento/scripts/pre-compact.sh"
          }
        ]
      }
    ],
    "SessionStart": [
      {
        "matcher": "compact",
        "hooks": [
          {
            "type": "command",
            "command": "~/.claude/skills/memento/scripts/post-compact.sh"
          }
        ]
      }
    ]
  }
}

Toggle with /memento auto on and /memento auto off. The hooks stay in settings permanently — the flag file controls whether they do anything.

Add .memento-handoff to your global gitignore (~/.gitignore_global) — it's a temp file that gets cleaned up after injection.

Rules

1. Notebook save is the real work. The orientation block is a nice-to-have. Even if the user never pastes it, the notebook saves ensure nothing is lost.
2. Don't duplicate notebook content in the orientation. The next session can /notebook recover. The orientation just bridges the gap between "blank chat" and "recovered context" — it's the 30-second version.
3. Don't repeat CLAUDE.md. Project conventions load automatically. Don't waste orientation space on them.
4. Be concrete. File paths, function names, error messages > vague descriptions.
5. If there's uncommitted work, say so. The next session needs to know what's in the working tree.

Source & license

This open-source skill is cataloged on AgentStack and links to its original source — we do not rehost the code.

• Author: catcatcatstudio
• Source: catcatcatstudio/cat-skills
• License: MIT
• Homepage: https://catcatcat.ai

Install and usage instructions live in the source repository linked above.