close-session

You close the session in four steps. Don't just dump — audit. Everything you write, you announce briefly; anything promoted to rules/concepts needs the user's verbal "yes" first.

Step 1 — Capture what's new

Scan this session for observations worth keeping. Append each to .claude/memory/MEMORY.md as a ONE-LINE [YYYY-MM-DD]-prefixed entry. Short, scannable, no essays (long rationale belongs in a concept article, step 2).

Step 2 — Audit & promote (the valuable part)

Read the date-tagged entries in MEMORY.md. Look for repetition: did this pattern appear on 3+ different dates? Surface 2-4 candidates, be specific: "noticed [date], [date], [date] you said X — codify as a rule or a concept article?"

• User says yes → write knowledge/concepts/<topic>.md (facts + rationale; frontmatter per knowledge/index.md spec) or .claude/rules/<name>.md (mechanical always/never constraint; only for patterns stable 6+ months). Update knowledge/index.md (one line per concept).
• Promoted or long-absorbed entries get PRUNED from MEMORY.md — that's how it stays under its caps (180 lines / 32 KB / 3000 chars per line).

Step 3 — Refresh the MEMORY.md header

The header (everything above the first ---) is «current state of work», 2-3 sentences, REPLACED every close — never a chronicle of past sessions. Per-session detail lives in the handoff, not stacked in the header.

Step 4 — Write the handoff

Copy context/handoffs/HANDOFF-TEMPLATE.md → context/handoffs/<topic>-<YYYY-MM-DD>.md and fill its five sections (what was done · where things stand · memory updates · next steps · opening note). The SessionStart hook injects the newest handoff next time — this file IS the "remember where we left off" mechanism.

Also check (30 seconds)

• Experiment hygiene: any experiments/*-YYYYMMDD/ older than 30 days → ask: still active or close (distill → delete)?
• Backlogs: projects/*/BACKLOG.md task statuses reflect today's reality.
• Caps: if MEMORY.md is near any cap, do a deeper prune now, not "next time".

What NOT to do

• Don't promote without the user's yes. Repetition makes a CANDIDATE, not a rule.
• Don't stack "Prior session" paragraphs in the MEMORY header — replace it.
• Don't write a handoff longer than ~1 screen. It's a note, not a transcript.