AILang/skills/audit/SKILL.md

---
name: audit
description: Use at milestone close OR when baseline drift is suspected. Runs architect drift review against the design/ ledger (spine design/INDEX.md) plus the three regression scripts (bench/check.py, bench/compile_check.py, bench/cross_lang.py). Mandatory at every milestone close; deferral requires an explicit Gitea backlog issue naming the reason and the re-run date.
---

# audit — milestone-tidy

> **Violating the letter of these rules is violating the spirit.**

## Overview

Without a scheduled clean-up step, codebases grow by accretion: every
iteration adds, none tear out, and deferred drift compounds across
milestones. This skill is the cleanup step. It runs after the last
iteration of a milestone closes and before the next milestone starts.

## When to Use / Skipping

**Mandatory** at every milestone close. Skipping requires an explicit
Gitea backlog issue naming:
- the blocking sibling milestone (if any),
- the reason for deferral,
- the date the audit will be re-run.

"We want to keep moving" is not a valid reason. Conventions require
deferred audits to compound, which is the failure mode the skill
prevents.

Also triggered manually when baseline drift is suspected outside a
milestone close (e.g. the bencher reports an unexplained metric
shift).

## The Iron Law

```
TIDY IS NON-OPTIONAL AT MILESTONE CLOSE
BENCH EXIT CODE 2 = FIX INFRASTRUCTURE FIRST, NEVER REPORT AS REGRESSION
NO BASELINE UPDATE WITHOUT A PAIRED RATIFY STATEMENT IN THE AUDIT COMMIT BODY
```

## The Process

### Step 1 — Architect drift review

Dispatch `ailang-architect` with the milestone scope (commit range
from the previous milestone-close to `HEAD`):

```
For milestone <X>: read `design/INDEX.md`, walk to its contracts;
`git log <prev-close>..HEAD --format=full` for the milestone's iter
and audit commit bodies; `git diff <prev-close>..HEAD` for the diff;
report drift.
```

Architect produces a prioritised drift list (see
`skills/audit/agents/ailang-architect.md` output format).

### Step 2 — Bench-regression check

Run the three scripts in this order:

```bash
bench/check.py && bench/compile_check.py && bench/cross_lang.py
```

The exit code is the gate:

| Exit | Classification | Action |
|------|----------------|--------|
| `0` | Green | All metrics within tolerance vs. `bench/baseline*.json`. Audit can close. |
| `1` | Drift / regression | At least one metric regressed past tolerance. Treat like a drift item. |
| `2` | Infrastructure failure | Bench-output format changed, fixture missing, or harness can't spawn. **Fix the infrastructure FIRST**, re-run. Never claim a regression on exit 2. |

### Step 3 — Classify and report

Combine architect drift items + bench results into one report to
the orchestrator (me). Each item is one of:
- **fix** (specific iter scoped, plan + implement)
- **ratify** (`--update-baseline` on the firing script + an explicit
  ratify statement in the audit commit body naming the iter that
  intentionally moved the metric and why)
- **carry-on** (architect found nothing actionable, bench green)

### Step 4 — Resolve

The orchestrator picks per item:
- **fix path:** dispatch `planner` + `implement` for a tidy iteration.
  The implement skill leaves the fix in the working tree; the Boss
  commits per the iter's pattern (suggested subject:
  `iter <X>.tidy: <fix>`).
- **ratify path:** run `--update-baseline` on the firing script. The
  audit-close commit carries both the updated baseline JSON and a
  ratify paragraph in its body naming the iter that moved the
  metric and the language reason (semantic cost, intentional
  trade-off).
- **carry-on path:** the audit-close commit body says
  `Milestone-<X> tidy (clean)` and ratifies whatever the bench
  drove. Audit commits always exist at milestone close — they
  carry the architect findings, the bench numbers, and the
  resolution.

## Handoff Contract

`audit` hands to the orchestrator:

| Field | Content |
|-------|---------|
| `drift_items` | prioritised list (path + 1-line justification) from architect |
| `bench_exit_code` | `0` / `1` / `2` |
| `bench_numbers` | raw figures from the three scripts (verbatim) |
| `recommendation` | per-item: `fix` / `ratify` / `carry-on` |

The orchestrator decides the per-item outcome; `audit` does not
self-resolve.

## Common Rationalisations

| Excuse | Reality |
|--------|---------|
| "Tidy can wait until next week, let's keep moving" | CLAUDE.md is explicit: tidy at milestone close is non-optional. Deferral compounds; next milestone adds its own drift. |
| "Bench red, just bump the baseline, the regression is expected" | "Expected" is exactly the claim that needs evidence. Localise the regression, then either optimise OR ratify with a paragraph in the audit commit body naming the iter and reason. |
| "Drift item is trivial, ignore it" | Trivial drift left open trains future-me to treat the architect's findings as advisory. Six items in, six items out. |
| "Bench scripts are hanging, skip them this milestone" | Exit code 2 = fix infrastructure FIRST. No skipping. |
| "Architect report is empty, fast-close" | Empty report is a possible outcome. Run the bench scripts anyway. Both gates must pass. |

## Red Flags — STOP

- Skipping any of the three bench scripts
- Bumping baseline without a paired ratify statement in the audit commit body
- Treating exit code 2 as a regression to fix
- Closing a milestone with drift items in `pending` state
- "We'll re-run after the holidays" without a dated backlog issue

## Cross-references

- **Upstream pattern:** standalone — this is project-specific
  discipline.
- **Agents dispatched:**
  - `skills/audit/agents/ailang-architect.md` — drift review
  - `skills/audit/agents/ailang-bencher.md` — bench-regression
    diagnostics if a metric needs localising
- **Hand-off target:** orchestrator (me), or `planner` + `implement`
  for a tidy iteration.
- **Project source:** former CLAUDE.md sections "Iter cycle / Tidy-iter
  at family boundaries" and "Performance regressions" are superseded
  by this file.