Recall

The failure this prevents is not missing knowledge. It is knowledge that was written down, indexed, and then not opened.

That failure has a shape: the answer existed in the project's own files, the assistant answered from general habit instead, and nobody noticed until the user said "isn't that already written down somewhere?" — because it was. Delivery hooks do not close this. A hook fires on keywords in the message; it cannot know that a settled note three folders away decides the question.

When it runs

Two moments, no exceptions:

• The first substantive reply of a session. Not the greeting — the first answer that carries work.
• A subject shift. The thread moves to something it was not about: a different deliverable, a different field, a different kind of question. If you are unsure whether the subject shifted, it shifted.

Inside one continuing subject, later replies do not repeat the sweep. It has already run.

What to sweep — five places, all of them

1. memory/00-INDEX.md — the map of what exists at all. Read this first; it names the layers the rest of the sweep will visit.
2. memory/knowledge/ — findings that passed the gate.
3. DECISIONS.md — what was settled, and what superseded what.
4. The rule catalog (.claude/ballast.rules.json, plus the user-level one) — standing corrections that apply whether or not a keyword matched this message.
5. skills/ and memory/goal/ — procedures already forged, and the skeleton of any goal in flight.

Scan at the index level — titles, headings, entry names. Then open what looks relevant and actually read it before answering.

Do not stop at the first hit

A sweep that ends when something turns up is the same failure wearing a better hat.

• Finding one does not end the sweep. Visit all five places even after an answer appears in the second.
• The layers hold different things. A rule is not a verified fact; a verified fact is not a settled decision; a settled decision is not a forged procedure. One layer answering the question does not mean the others have nothing to add — often they qualify or contradict it.
• Open widely, not carefully. Read the candidates together rather than one at a time, and delegate a broad pass when the surface is large. Opening fewer files is not economy; it is the omission this skill exists to prevent.

Leave the sweep visible

Say in one line what you swept and what you opened — including when nothing matched. A sweep nobody can see is indistinguishable from a sweep that never ran, and the next session will redo the same reading.

Swept index, knowledge/, DECISIONS, rules, skills — opened knowledge/pricing-copy.md and decision D-014; nothing in skills or goal touches this.

How this differs from the other lookups

• goal's mobilize phase splits a stated goal top-down and asks what each branch needs. It starts from the task and reasons down.
• knowledge-base's lookup runs before researching a topic.
• recall runs before answering at all, and it reasons the other way: from what is held, upward. Top-down mobilization only summons what the task is already known to need — it cannot summon what you did not know was there. That gap is where this skill lives, and it is why a project can have both and still be caught by "that was already written down."

Part of ballast — foundations first, every solved path kept, done means checks pass.