build

What the source does

• FilesystemNone observedNo reads or writes in the source
• NetworkNone observedNo outbound calls in the source
• ShellNone observedNo commands run in the source
• DependenciesPinnedNothing floats
• SecretsNone foundNo keys in source

Five audit layers

Gates applied: no behavioural pass.

Audit 0.4.1 · source sha 4ddfda34b42a · 21 Oct 2026Report an issue or request a re-scan

• Publisherjuliusbrussee GitHub userOwner of the repository this skill is read from
• Source folderjuliusbrussee/cavekit/skills/buildThe exact folder we audited
• LicenceMITAs the repository states it
• Commit pinned for this verdict4ddfda34b42aA new audit runs when the source changes
• Repository statusNot archivedLast push 67 days ago
• Sandboxed runNot runSkills are read, not executed; layer L4 is skipped

Its description: Plan-then-execute implementation against SPEC.md. Native single-thread loop, no sub-agents. On test or build failure, auto-invokes the backprop skill before retrying — a failed verification always considers whether a…

---
name: build
description: |
  Plan-then-execute implementation against SPEC.md. Native single-thread
  loop, no sub-agents. On test or build failure, auto-invokes the backprop
  skill before retrying — a failed verification always considers whether
  a new §V invariant would prevent recurrence. Triggers when the user asks
  to build, implement, execute the spec, or tackle a specific §T task
  (`build §T.3`, `build --next`, `implement next task`, `run the build`).
  Expects SPEC.md to exist; if not, defers to the spec skill.
---

# build — implement spec

Single-thread native plan→execute. You are main Claude. No swarm.

## LOAD

1. Read `SPEC.md`. If missing → tell user to invoke the spec skill first. Stop.
2. Read `FORMAT.md` once if not loaded.
3. Read §R if present — external facts the build must honor, ⊥ re-derive or contradict.
4. Parse invocation args:
   - `§T.n` → that task only
   - `--next` → lowest-numbered row with status `.` or `~`
   - `--all` or empty → every `.` row in §T order

High blast radius (shared module, auth, data, money, public §I)? Run `/review` first. Trivial & reversible? Skip planning ceremony, just do step EXECUTE.

## PLAN

Native plan mode — you delegate to it, you do not reinvent task breakdown. For chosen task(s):

1. Cite every §V invariant that applies. Plan must respect all.
2. Cite every §I interface touched. Plan must preserve shape.
3. List files to create / edit.
4. **Verification contract** — name the EXACT test(s) / acceptance criteria that
   prove each §V touched. Which test, not "add tests". "Do TDD" alone backfires;
   the spec says *what to check*. Each §V touched → a named test that fails first.
5. Name verification command (test, build, lint) — this is the external oracle. Green = done; ⊥ "looks done".

Show plan. Wait for user OK unless auto mode.

## EXECUTE

Per task in order:

1. Flip §T.n status cell `.` → `~`. Just write to SPEC.md.
2. Edit code per plan.
3. Run verification command.
4. **Pass** → flip `~` → `x`. Next task.
5. **Fail** → invoke backprop skill. Do NOT retry blindly.

## FAIL → BACKPROP

On test/build failure:

1. Read failure output.
2. Ask: is failure (a) my code bug, (b) spec wrong, or (c) unspecified edge case?
3. If (a) → fix code, re-run. No spec change.
4. If (b) or (c) → invoke spec skill with `bug: <cause>` first, let it update §V and §B, then resume build against updated spec.

Rule: never silently fix root-cause without considering backprop. §B is the memory that stops recurrence.

## WRITE POLICY

- Only flip §T status. No other SPEC.md edits from build.
- Other spec edits → invoke spec skill.
- Commit after each §T completes. Message: `T<n>: <goal line>` + §V cites.

## VERIFICATION

Task `x` only if:
- Verification command (the oracle) exits 0.
- Every §V touched has its named test from the verification contract, and it passes.
- No §V invariant regressed (run full test suite at end).

## NON-GOALS

- No sub-agents. No parallel workers. Main thread only.
- No progress dashboards. `cat SPEC.md | grep §T` is the dashboard.
- No speculative work beyond chosen task scope.

Excerpt, first 3,111 characters of SKILL.md, verbatim from the audited commit. It is text from someone else’s repository, quoted so you can judge it before your agent reads it.

git clone https://github.com/juliusbrussee/cavekit
git -C cavekit checkout 4ddfda34b42a

Works in

1. 2026-10-21
   ✓SAFE B 89 / 100

   first audit · source 4ddfda34b42a

Questions about build

• github.com/juliusbrussee/cavekit/tree/main/skills/build — the audited source at commit 4ddfda34b42a and every finding aboveObserved · 21 Oct 2026

Spotted something wrong? Report a correction · Methodology