Memento

Memento

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

Commands

/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.

2. 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 is a baton pass, not a recap — it briefs the next session on the work that remains, not the work that's done. The record of what happened is the notebook's job, and Phase 1 just put it there.

The selection test for every line: would deleting it change what the next session does? If not, it doesn't go in.

The block should be:

• Short — 10-20 lines. The next chat has a full context window; don't waste it on briefing.
• Forward-facing — done work gets one positioning clause in the opening line, then appears only where it's a dependency or constraint on the remaining work.
• Actionable — end with the goal and the next step.
• Honest — if something is uncertain or incomplete, say so.

Format — bracketed sections that are empty are omitted, never padded:

---

We're working on [what] in [location], currently at [position in the work].

[Working tree dirty? Say what the diff is FOR and its state — half-finished,
done-but-unverified, or discard-worthy. The next session sees the file list in
`git status`; the intent behind it is the part only you can hand over.]

[Dead ends: approaches tried and abandoned this session that a fresh agent would
plausibly retry. One line each: "Don't retry X — fails because Y (note NNNN)."]

[Decisions waiting on the user. If the session ended blocked on one, lead with it.]

Next: [the goal, then the immediate step toward it — enough intent that the next
session can re-derive the plan if the literal step turns out moot.]

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. The orientation is a baton pass, not a recap. The notebook holds what happened; the orientation holds only what changes what the next session does. Don't duplicate notebook content — the next session can /notebook recover.
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. For uncommitted work, hand over the intent, not the inventory. git status already shows the files. What it can't show is what the diff is trying to do and whether it can be trusted — that's the part the handoff carries.