# House Builder > The house v2 build session — implement ONE plan unit from a kickoff brief, self-review it, reconcile that unit's docs, and report back through the house records. Use when you have been handed a kickoff brief for a single unit in a repo the house kernel tracks (it has a `.house/` dir). Do NOT use to drive a whole slice (that is house-orchestrator), to shape new work (house-shaper), or for non-build chat. - Skill: `argent-gnome/house-builder` (Agent Skill) - Install (CLI): `npx skillmds@latest add argent-gnome/house-builder` - Raw SKILL.md: https://api.skillmd.com/api/skills/argent-gnome/house-builder/raw - Safety review: pending - Works with: Claude Code, Claude.ai, OpenAI Codex - Category: Docs & Writing - Author: argent-gnome (https://skillmd.com/u/argent-gnome) - Updated: 2026-09-17 - Page: https://skillmd.com/skills/argent-gnome/house-builder --- # house-builder — one unit, over shared state You are spun up to implement **one plan unit**, then torn down. The orchestrator owns sequencing and the merge decision; you own building that unit well and reporting honestly. **Compose — do not reimplement.** **Doctrine — read on-demand, never preloaded:** `$HOME/.claude/skills/house-orchestrator/references/doctrine.md`, covering the composition contract (§7) while you build, hygiene (§8) at teardown, and reconcile (§9). ## 1. Preflight — validate the brief, never guess Check the brief against `cli/schema/kickoff.yaml`: every `required` field present, in the right shape. Any field missing or unusable ⇒ stop and finalize `--result NEEDS_CONTEXT`, naming the offenders as `missing_inputs`. **Never guess a missing input** — a brief you had to interpret is a brief that will be interpreted differently at the merge gate. Then resolve the brief's `stack:` against `.house/gates.yml`. **An absent or unknown stack key is also `NEEDS_CONTEXT`** — name the missing key. Guessing a stack's gates is how a run silently applies the wrong lenses and still reports green; that fail-open is closed. **You build; you do not decide the slice.** The brief's `scope_guards` are binding: work you find outside them is reported, not done. ## 2. The loop, per task **TDD's iron law:** write the failing test first, watch it fail for the right reason, then the minimal code that passes. **The build stays green at every task boundary** — a shared signature change updates its call sites in the SAME task; never leave the target broken for a later task to repair. ``` house task done --slice [--evidence-cmd ""] house task block --slice --note "" house unit heartbeat --note "" ``` The CLI runs the evidence command and **refuses the tick unless it is green. That refusal is the contract, not an obstacle** — routing around it (hand-editing `tasks.yaml`, weakening the command) is the single move that turns every downstream record into a lie. ## 3. Discriminating tests For every spec rule you touch, at least one input where **the rule and the nearest plausible-wrong implementation disagree** — a boundary, a non-monotone case, a divergent path. A suite that only exercises inputs where right and wrong agree is a coverage gap wearing a green tick. ## 4. Proof obligations - **Destructive and migrating changes are exercised against real prior data** — a store populated under the *previous* schema. A fresh install passing is NOT proof; it is precisely the case that cannot fail. - **CI-red taxonomy.** *Infra-only* = the job never executed (no steps, a startup failure, a budget block) — read the run's actual status, never a piped exit code, and re-run the full local bar before anything merges. *Code-red* = a step ran and failed: fix it, never merge through. **When unsure, treat it as code-red.** A repo with no hosted CI (ADR-0003) runs `.house/gates.yml` as its bar — not a waiver. - Never normalize a broken gate. "It's always red" is a finding to surface, not a condition to route past. ## 5. Stack gates Before self-review, run **every** `gates:` entry for your brief's stack, in order, out of `.house/gates.yml`. All green, or the unit does not finalize DONE. Report the real command output, not a summary of it. ## 6. Self-review, then finalize Review this unit against the plan yourself: does each task do what it said; did every folded plan-check commitment actually get built rather than quietly re-waived; does the spec/plan text still describe what shipped? Dispatch the doctrine §9 reconcile-subagent for this unit's docs, then: ``` house unit finalize --result --note "" ``` Your report is already incremental — heartbeats and ticks wrote it as you went — so a builder that dies mid-unit is re-dispatchable from its own record. **Absence of a finalized record is UNKNOWN, never DONE.** STOP and report rather than self-resolve at: **any plan deviation or genuine ambiguity · a red gate · any irreversible or outward-facing action.** Surface it — the orchestrator and the user decide, not you.