Agent Memory — promotion is earned, not asserted

Portability: stdlib only. No database, no embeddings, no network, no LLM calls.

The problem

A project's CLAUDE.md is a memory system with one tier and no eviction: every durable fact and every passing preference land in the same always-loaded file, until the important lines are diluted by the incidental ones. Facts learned mid-session vanish at teardown unless someone writes them down.

The fix is not more storage — it is a promotion ladder. A claim earns its way toward always-loaded context by recurring; a human confirms the last step.

The four tiers

Tiers are distinguished by injection policy, not storage format.

The gates

Nothing moves up because it sounded important. It moves up because it recurred.

• L0 → L1 — an explicit marker fires (a directive, a correction, a stated preference, a named lesson, a reproducible failure). Rule-based, high precision, deliberately low recall.
• L1 → L2 — ≥ 3 distinct sessions spanning ≥ 2 distinct calendar days. A claim stated outright needs 2 sessions; the distinct-day rule still applies. A verified claim promotes on one observation and is the only day-exempt path.
• L2 → L3 — held in ≥ 2 distinct projects, aged ≥ 30 days, uncontested.

Two gates refuse rather than guess. A claim whose text was altered by redaction never promotes on evidence alone — the flag firing is evidence the source was sensitive, and a lexical filter finding one secret is not proof it found all of them. A claim with an open contradiction is frozen at L1 until a human resolves it; the incumbent is never silently overwritten.

Use it

# what is remembered, and what is blocking the next promotion
python3 scripts/memory_inspect.py --tier L1

# where did this line come from — sessions, days, transcript, quoted source
python3 scripts/memory_inspect.py --why "PR base branch is dev"

# every claim with an open contradiction, both directions of the join
python3 scripts/memory_inspect.py --contested

# dry-run the promotion pass; writes nothing
python3 scripts/memory_promote.py

Three hooks run the loop unattended: SessionStart injects L2 + L3, UserPromptSubmit recalls relevant L1 atoms, SessionEnd captures and stages. Each is disabled independently with AGENT_MEMORY_SESSIONSTART=0, AGENT_MEMORY_USERPROMPTSUBMIT=0, AGENT_MEMORY_SESSIONEND=0. Every hook fails open: a broken memory system costs you memory, never a session.

Hard rules

1. Redact before writing. Every atom passes the filter before it reaches disk. Anything altered is quarantined from promotion.
2. Propose, never apply. Promotions land in .memory/staged/. Only an explicit /cs:memory adopt touches a CLAUDE.md, and it backs both up first.
3. Cite, don't invent. Every atom carries a back-pointer to the transcript line that produced it. --why resolving to ambiguous prints nothing rather than guess: a wrong citation is worse than a missing one.
4. Never surface a contested claim as fact. It is still injected — hiding the conflict is worse — but always tagged.
5. The committed tiers carry no paths. Promotion strips the back-pointer prefix, which embeds an OS username.

Forcing questions

Walk these one at a time before trusting the store.

1. Which line in your CLAUDE.md did you last actually read before acting?
2. Would you rather the agent forget a true thing, or remember a false one?
3. When two remembered rules disagree, who decides — and when?
4. What would make you delete .memory/ entirely?

Rationale, open decisions, field schema: ../../DESIGN.md.