improve-code

name	improve-code
description	Surface deepening opportunities in a codebase — shallow modules, seam leaks, missing locality — and grill through whichever one you pick. Architecture-pattern aware (monolith / distributed / serverless).
disable-model-invocation	true

Improve Code

/improve-code [path] [--arch=monolith|distributed|serverless] — Read-only audit → HTML report of deepening opportunities (shallow modules → deep) → grilling loop on user's pick. No code mods in audit. Invocation implies read-only git approval (status/diff/log); no git write without separate confirmation.

Vocabulary (use exactly — no "component/service/API/boundary")

Module — interface + implementation (function/class/package/slice). Interface — everything a caller must know: signature, invariants, ordering, errors, config, perf. Implementation — module body. Depth — behaviour per unit of interface; deep = small interface + lots of behaviour, shallow = interface ≈ implementation. Seam — alter behaviour without editing in that place; where the interface lives. Adapter — concrete thing at a seam (role, not substance). Leverage — callers' gain from depth. Locality — maintainers' gain (change/bugs/knowledge concentrate).

Principles

Depth is a property of the interface, not implementation. Deletion test: delete it — complexity vanishes (pass-through) or concentrates across N callers (earning keep)? Interface is the test surface: testing past it = wrong shape. One adapter = hypothetical seam, two = real — don't introduce unless something varies.

Architecture pattern

Auto-detect (package layout, Dockerfile/compose, framework, entry points) or --arch. Print at report top with confidence. Tunes seam-vs-leak: monolith — HTTP in logic = leak, seam is in-process. distributed — inter-service HTTP = seam; flag only within-service. serverless — function boundary = seam; downweight "shallow". Low-confidence → default monolith, note in header.

Scope

Path arg → scan that only. Else count source files (exclude .git/, node_modules/, dist/, build/, vendor/, lockfiles, generated): ≤500 → whole repo; >500 → git diff vs base (origin/main, origin/master, main, master in order; fallback HEAD~1..HEAD; if no HEAD~1, HEAD). Zero → ✅ NOTHING TO REVIEW, stop.

Exclusions (auto-skip)

Tests (*.test.*, *.spec.*, __tests__/, tests/, *_test.go), migrations (migrations/, *.migration.*), scripts (scripts/, bin/), config (.config/, *.config.*, root *.json/yaml/toml), generated (generated/, dist/, build/, .next/, gen/, header markers), vendored (vendor/, node_modules/, third_party/). Unclassifiable modules → skip silently.

Flow

1. Context

Glossary: first of docs/glossary.md / terminology.md / domain.md (case-insensitive) = domain vocabulary. None → note, proceed without. ADRs: docs/adr/ or docs/decisions/, read any in touched area, don't re-litigate; surface conflicts only if friction warrants reopening, mark in card. Pattern: auto-detect or --arch, print with confidence.

2. Explore

Spawn one subagent_type=Explore. Walk scope organically, feel friction, no rigid heuristics. Look for: concept-bouncing across small modules (no locality); shallow modules; pure-for-testability extracts where bugs hide in call sites (no locality); seam leaks; untested/hard-to-test-through-interface; cross-layer calls the pattern says should be seamed. Apply deletion test to suspects.

3. Report (HTML)

Self-contained HTML to $TMPDIR (fallback /tmp/%TEMP%): improve-code-<timestamp>.html. Open it (open/xdg-open/start). Tell user absolute path. Tailwind via CDN for layout, Mermaid via CDN for graph-shaped, hand-built divs/SVG for editorial. Each candidate: before/after visualisation.

Card: Files | Problem (vocab terms) | Solution (plain English) | Benefits (leverage+locality+testability) | Before/After | Strength (Strong/Worth exploring/Speculative badge). Glossary vocab for domain, this skill's for architecture. End with Top recommendation. Don't propose interfaces yet. Ask: "Which would you like to explore?"

4. Grilling

Run /brainstorm on picked candidate — design tree: constraints, dependencies, deepened shape, behind-seam, surviving tests. Inline: new term → add to docs/glossary.md (create lazily if none); sharpened term → update; load-bearing rejection → offer ADR only if hard-to-reverse + surprising + real trade-off.

Sub-agent contract (Explore)

No user prompts, no escalation, assume-and-proceed on low-risk reversible ambiguity (record assumptions), missing context → "insufficient context" notes, findings only in final response.

Failure handling

Explore timeout → retry once stricter + contract; still blocked → 🔄 CHANGES_NEEDED + missing-context list. HTML write fails → Markdown in terminal + note. No opener → print path. Not a repo → skip adaptive scope, scan whole/path arg, note reduced confidence.

Out of scope (YAGNI)

No proposing interfaces in Phase 3, code mods, running tests/build/lint, numerical scoring, cross-run tracking, perf/security/correctness bugs (→ /review-changes, /debug), forcing layers on layerless code (✅ NOTHING TO REVIEW — no architectural layering detected, stop), auto-creating ADRs, spawning >1 Explore.

Edge cases

Empty repo → ✅ NOTHING TO REVIEW. No docs/ → skip glossary/ADR, note. No pattern signals → default monolith, note. Single-file path → 0-1 candidates. No pick → end after report.