Check

check — drift report

Pure diagnostic. Reports violations grouped by severity. Writes nothing. The user decides the remedy.

Plan artifacts drifting silently from code is the #1 failure mode. check is the detector. Run it after each build and before each ship — drift caught here is a diff; drift caught in prod is a LESSONS.md bug row.

OWNERSHIP

Owns: the drift report (delivered inline — does NOT write a file). Reads: PLAN.md, SPEC.md, ARD.md (whatever exists), CONTEXT.md, the codebase. MUST NOT write anything. NEVER invokes fix skills — only suggests them.

WHEN (user-invoked)

• After a build completes a task or a plan.
• Before a ship / merge / PR.
• User asks "check drift", "audit the spec", "does the code still match", "is the plan still accurate".
• Invoked by the verify discipline as the final plan-level drift check.

STEP 0 — LOAD

1. Resolve the active plan per §6. If none, "no plan, nothing to check." Stop.
2. Read whatever exists: PRD.md, ARD.md, SPEC.md, PLAN.md, CONTEXT.md.
3. Parse invocation args:
   • §V -> check invariants only (default)
   • §I -> check interfaces
   • §T -> audit task status vs code
   • --all -> all three

CHECK §V — invariants

For each V<n> in SPEC.md/ARD.md:

1. Translate the invariant into a verifiable claim about the code.
2. Grep / read the relevant files.
3. Classify:
   • HOLD — the code satisfies the invariant.
   • VIOLATE — the code breaks the invariant (cite file:line).
   • UNVERIFIABLE — no test covers the invariant's path.
4. Record the address + file:line evidence.

CHECK §I — interfaces

For each §I item:

1. Locate the implementation.
2. Classify:
   • MATCH — shape in code = shape in spec.
   • DRIFT — impl exists, shape differs (cite file:line).
   • MISSING — impl absent.
   • EXTRA — code exposes a surface not in §I.

CHECK §T — tasks

For each T<n> in PLAN.md:

1. If [x]: verify the claimed work is present in the code. If not -> STALE.
2. If ~: note as in-progress.
3. If [ ]: note as pending.

REPORT

Caveman. Grouped by severity. Example:

## §V drift
V2 VIOLATE: auth/mw.go:47 uses `<` not `<=`. see LESSONS.md B.1.
V5 UNVERIFIABLE: no test covers every req path.

## §I drift
I.api DRIFT: POST /x returns `{result}` not `{id}`. route.go:112.
I.cmd MISSING: `foo bar` absent from cli/*.go.

## §T drift
T3 STALE: status [x], no middleware file exists.

## summary
2 violate. 1 missing. 1 stale. 1 unverifiable.
next: spec skill with `bug:` or fix code at cited lines.

REMEDY HINTS (not actions)

End the report with a one-line hint per class. NEVER invoke the fixes.

• VIOLATE / DRIFT -> invoke the spec skill with bug: <V.n> or fix the code.
• MISSING -> invoke the build skill on §T.n if a task exists; else the spec skill with amend §T.
• STALE -> the spec skill with amend §T to uncheck.
• EXTRA -> the spec skill with amend §I to document, or delete the code.
• UNVERIFIABLE -> the tdd discipline to write the missing test.

BOUNDARIES

• MUST write nothing. No artifact edits. No code edits.
• MUST NOT invoke fix skills. Report only.
• MUST cite file:line for every VIOLATE / DRIFT / STALE finding.
• MUST run on the main thread — no subagents.
• MUST give a binary verdict per item: holds or drifts. No scores, no grades.
• MUST use caveman for the report.