Iteration close

iteration-close — distill, shed, prove takeover, rehearse bootstrap, seed next

A product that iterates forever accumulates two silent debts, and this skill pays both down at every iteration boundary — safely (nothing is lost) but ruthlessly (nothing dead is kept):

• Dead files linger and rot into two-truths — a deprecated tree sits around for weeks; a runbook keeps claiming a component is "not built" long after it shipped.
• Knowledge that lives only in a chat window dies with it — a whole working pipeline once died in a scratchpad; hard-won decisions nearly died in chat. Keep the lesson, not the artifact.

It is generic: it works on any repo by reading that repo's own conventions, and where a convention is absent it creates the minimum rather than assuming or erroring. "A fresh window or new machine can continue" is a HOPE until it is TESTED; being current (pull) is always safe, but publishing (push) is a deliberate choice.

Step 0 — orient to THIS repo (discover, else plan to create)

Read whichever entry doc exists — CLAUDE.md / AGENTS.md / README / a docs/ index — and discover five things. Use what you find; where something is absent, note it as a gap this close will fill (each phase below says how), never invent a path that isn't there.

1. Lesson/decision record — where does this repo bank decisions? (CHANGELOG, docs/adr/, DECISIONS.md, or a repo-specific register.) If none, Phase 1 creates a single DECISIONS.md.
2. Confirmed-upload command — a deliberate push step (bin/sync, make deploy, a documented git push discipline)? If yes, that IS the upload channel; never bypass it. If none, Phase 3a uses plain git push after a diffstat + confirm.
3. Bootstrap command — how does a fresh clone come alive? (bin/bootstrap, bin/sync-setup, install.sh, make setup, a package-manager install.) If none, Phase 4 creates one.
4. Test command — from CI config, package.json scripts, a Makefile, or the language default (pytest / go test / cargo test / npm test). If none is discoverable, the repo has no runnable suite yet: treat that as an explicit state below — never read it as "green", never REFUSE on a repo that legitimately has none.
5. Grounding / gate skill — a product-grounding or pre-build gate skill? If so, its "after-build" checklist is your pre-close gate. (Product-specific gates live inside the product repo; this skill stays generic and defers to them.)

Refuse to run (fail-closed)

Do not close mid-iteration — you lose skin AND flesh. REFUSE if: the test suite exists and is actually FAILING (an absent suite is not a failing one — see Step 0.4); an adversarial gate, if the repo has one, is pending or CHANGES-REQUIRED; or another agent/lane has uncommitted mid-slice work in paths you'd touch. Say what's blocking and stop.

Run the phases IN ORDER. Each has an exit test; never proceed past a failed exit.

Phase 1 — DISTILL (salvage gate: nothing dies before its lesson is banked)

1. Sweep this iteration's chat-born decisions into the repo's decision record (Step 0.1), each with its status and source. If the repo banks decisions nowhere yet, creating the record is part of this phase — a single DECISIONS.md at repo root is enough. A decision that exists only in a chat window does not exist; do not leave distilled decisions with no tracked home.
2. New invariants/rules discovered this iteration → the repo's contracts file, or lacking that the decision record — ideally each as a test. If neither exists, create the decision record and put them there. Delete the artifact, keep the invariant.
3. Session-only-capability check: did this iteration rely on anything living ONLY in a prompt, a scratchpad, or someone's memory? Promote it into the repo (code / skill / doc) or record its deliberate exclusion. Name each one explicitly — this is where pipelines die.
4. If the STRUCTURE changed, update — or, if none exists and the structure is now nontrivial, create — a short architecture/system note so it still describes reality. Bring any status board (e.g. a progress doc) current if the repo has one.

EXIT TEST: grep this iteration's key decisions and invariants inside the repo — every one findable in a tracked file. Anything findable only in chat = Phase 1 not done.

Phase 2 — SHED (ruthless deletion; git history is the ONLY archive)

1. Build a deletion inventory with evidence, one line each: path | why dead | what supersedes it. Cover superseded modules/specs, dead/empty dirs, dev residue (scratch files, mktemp-style junk, test rows in real-shaped stores), completed plan/TODO docs, and STALE DOCS — run a docs-vs-code contradiction pass; a doc that asserts what the code contradicts is worse than none.
2. Rules: git rm only. NO _archive/ dirs, NO .bak, NO old-/legacy- renames, NO commented-out corpses. Recovery = git history, one git revert away — that is the archive; a checkpoint commit before deleting makes it bulletproof.
3. Never shed the product's real DATA as if it were dev residue. User/customer state, saved sessions, real archives of user content look like clutter and are the product's soul. When a directory could be either, treat it as data and keep it; verify before any git rm.
4. Commit deletions in themed groups; each message says WHY + what supersedes it.
5. Post-deletion checks (all that apply must pass): if the repo has a test suite, it is green; dangling-reference grep for every deleted module/symbol is empty (an import of a deleted file crashes at startup — a real scar); the entry doc and skill docs reference no deleted path.

EXIT TEST: git status clean, no archive-shaped dirs exist, dangling grep empty, and the test suite green if one exists.

Phase 3 — TWO READINESS CHANNELS (different needs; verify separately)

Uploading and being-continuable are NOT the same problem. Conflating them is how a repo gets "pushed to the cloud" while its real state still lives in a chat log. Verify each on its own.

3a. Confirmed cloud upload (the TRANSPORT problem)

1. Secret scan on TRACKED files only (sk-ant / ghp_ / gho_ / github_pat / AKIA / xox[baprs] / consumer_secret / access_token / Bearer / BEGIN PRIVATE KEY / .env shapes). Any hit → stop, scrub, re-scan.
2. Check git remote. If there is NO remote, upload needs one the USER provides — adding a remote is a config change, so confirm it with the user or record "no remote yet — publish deferred" and skip to 3b rather than erroring on a bare git command.
3. With a remote: show git log @{u}..HEAD --oneline + diffstat (fall back to "all local commits" when there is no upstream yet) — exactly what will leave this machine.
4. Upload via the repo's confirmed-upload command (Step 0.2) after the user confirms; if the repo has none, git push after the diffstat and a yes. Never auto-push.

3b. Zero-context takeover (the KNOWLEDGE-COMPLETENESS problem) — the cold-start probe

1. Get ONE genuinely context-free reader onto the repo — in Claude Code: spawn a fresh subagent (Task tool); in Codex: run a fresh codex exec or a new session with no prior context; on any bare harness: open a new session and paste ONLY the repo path plus the questions, never this conversation. Give it only the repo path and: "Read this repo cold from its entry doc. Then answer: (1) what is this product, in one sentence; (2) where does the work stand (done / next); (3) what would you do next and why; (4) name three things you must never do here."
2. Grade its answers against the repo's canonical docs. If the repo has no entry/canonical doc at all, creating a minimal one (the product in one sentence, current state done/next, three never-dos) is part of this close — it is the artifact the probe grades. Do not run the probe against nothing.
3. Every wrong or missing answer is a TAKEOVER-DOC BUG, not the probe's fault. Fix (or create) the doc, re-run with a NEW fresh reader. Loop until a cold reader scores 4/4.

EXIT TEST: probe passes 4/4. Only then is "any new window / machine can continue" a tested fact.

Phase 4 — ONE-COMMAND BOOTSTRAP (rehearsed, not assumed)

1. Ensure the repo's bootstrap (Step 0.3) exists and is current — idempotent, safe to re-run: verify toolchain versions; wire sync/config; install deps; run the test suite if one exists; print the current status + the NAMES of any missing local secrets (never values, e.g. "config.local.json absent — needed only for live publish"); exit non-zero on any failure with a one-line reason. If no bootstrap exists yet, this is the iteration to create one.
2. REHEARSE it: clone the repo into a scratch dir (from the origin URL, or from the local repo path when there is no remote yet) and run the bootstrap there. It must end green with ZERO manual steps. Delete the rehearsal clone after.
3. The new-machine story must be one line and TRUE after this rehearsal: git clone <origin-url> <dir> && cd <dir> && <bootstrap command>. If no remote exists yet, note that this line is not yet true until the user sets one — don't publish it as if it works.

EXIT TEST: the rehearsal clone bootstraps green, untouched by hands.

Phase 5 — CLOSE + SEED (continuity)

1. Tag the iteration: git tag iter-<N>-<slug> (annotated, one-line summary). N = 1 + the count of existing iter-* tags (git tag --list "iter-*"); the first close is iter-1.
2. Update the status board / log with one line, if the repo has one: what was distilled, how many files shed, probe 4/4, bootstrap rehearsed.
3. Emit the NEXT-ITERATION SEED into chat: the open questions this iteration surfaced + a paste-ready kickoff prompt for the next slice (goal, acceptance, and a reminder to run the repo's grounding gate before building, if it has one).

Major iteration — when the STRUCTURE itself is replaced (same rules, bigger skin)

A structural overhaul — new architecture, new module tree, even "the old approach was wrong" — is still an ITERATION of one organism, not a restart. It keeps its git history, its decisions, its lessons; only the skin is new. History is unambiguous that restarts bleed: every time a project was reborn in a fresh repo, lesson-grade material was left behind. So:

• Grow the new structure IN THIS REPO alongside the old (strangler pattern): the new tree earns tests and ownership first; the old tree dies in Phase 2 only once nothing references it.
• Opening a NEW repo is the expensive exception, not the default — it requires a recorded decision stating why THIS history must be abandoned, approved before any files move.
• Same five phases; the deletion inventory is just larger and the cold-start probe matters more — the new structure's docs have never met a stranger.
• If the product's name or entry command changes, Phase 4's one-line story updates in the SAME iteration. Two live names is a two-truths bug.

Guardrails (non-negotiable)

• Phase order is the safety mechanism: NEVER shed (Phase 2) before distill (Phase 1) exits.
• Deletion needs evidence of supersession, not vibes. Genuinely unsure? Keep it ONE more iteration and record the doubt in the decision record — not in an archive dir.
• Push is a confirmed act, always. No auto-push, no bypassing the repo's upload step.
• The cold-start reader must be genuinely context-free (fresh subagent / codex exec / new session — repo only) or the probe is theater.
• If the repo runs multiple agents/lanes in parallel, don't touch another lane's uncommitted paths; hand off through its board if it has one.
• When this skill and the repo disagree about the repo's conventions, the repo wins.