dag-slim

name	dag-slim
tier	core
runtime	on-demand
trigger	mention
description	Over-engineering-only review as a DAG: two passes, GLOBAL first (one strong reviewer hunts cross-file dedup/collapse/layer/couple — the -50% win), then LOCAL per-file hunks concurrently (delete/stdlib/native/yagni). One line per finding: what to cut, what replaces it. Trigger: what can we delete / over-engineered? / simplify review / 精简审查 / dag-slim. Skip: correctness/security bugs (/dag-review) / deepening candidates (/dag-deepen) / behavioral lazy mode (/ponytail).
metadata	{"source":"oh-my-dag","version":"1.0.0","methodology":"DietrichGebert/ponytail (MIT) ponytail-review, v2 全局>局部 discipline; vocab from design-vocab.ts"}
disable-model-invocation	true

/dag-slim — over-engineering-only diff review

Finds what to DELETE, never what to fix. Every reviewer prompt carries the shared DESIGN_VOCAB + PONYTAIL_DISCIPLINE blocks (src/harness/review/design-vocab.ts, single source — same vocabulary as /dag-deepen, opposite direction). The best outcome is fewer concepts, not just fewer lines.

Usage

bun run scripts/dag-slim.ts \
  [--base main]         # diff base (default main)
  [--staged]            # review staged changes instead
  [--paths "a,b"]       # limit diff to pathspecs
  [--model M]           # local-pass leaf model  (env OMD_SLIM_MODEL > OMD_LEAF_MODEL)
  [--global-model M]    # global-pass model, stronger slot (env OMD_SLIM_GLOBAL_MODEL > OMD_REVIEW_FIND_MODEL)
  [--no-global|--no-local]  # run only one pass
  [--verify]            # reuse the dag-review refute layer over the findings
  [--out p]             # artifact path (default /tmp/omd-slim-<ts>.md)

Exit 2 on empty diff. Terse stdout: one line per finding, Global group first.

Two passes — GLOBAL runs FIRST

Per-hunk golfing finds pennies; the system-level pass finds the -50%. Pass 1 is ONE reviewer on a stronger model slot seeing the whole changed surface + what it touches. Pass 2 splits the diff per file into a pre-built ConductorPlan (one inproc leaf per file-chunk + a dedup synth node) and fans out concurrently.

pass	kind	hunts	replacement
global	dedup:	same logic hand-rolled in N places	one shared util (biggest win)
global	collapse:	parallel implementations of one concept	merge to one
global	layer:	module/indirection/wrapper nobody needs	deletion-test it, drop the layer
global	couple:	local-"minimal" choice that created coupling/duplication	the globally-coherent alternative
local	delete:	dead code, unused flexibility, speculative feature	nothing
local	stdlib:	hand-rolled thing Bun/std ships	name the function
local	native:	dep or app code doing what the platform does	name the feature
local	yagni:	abstraction with one impl, config nobody sets, layer with one caller	inline it

Format: <kind>: <file:line> — cut <what>, replace with <what> — one line per finding, no prose. Nothing to cut → Lean already. Ship.

Guardrails (from PONYTAIL_DISCIPLINE — violating these = false positive)

• A documented DEFER, a contract surface, a deliberate extension seam is chosen architecture, not a finding — planned ≠ speculative.
• Fewer lines, never fewer cases: a suggestion may not drop an edge case, type, validation, or error path — that is a bug, not a simplification.
• A single smoke test / assert self-check is the ponytail minimum, not bloat.
• dedup:/collapse: only merge things that are genuinely ONE concept — merging lookalikes manufactures coupling.
• Findings ≠ ground truth: the caller adjudicates (same discipline as /dag-review).

The ponytail: marker + omd-debt

Deliberate shortcuts are marked in code as // ponytail: <ceiling>, <upgrade trigger> (# and /* prefixes too). Those markers are NOT dag-slim findings — they are tracked debt. Harvest the ledger with:

bun run scripts/omd-debt.ts [--paths "src,scripts"]   # pure scan, zero LLM; exit 3 = clean

One row per marker: <file>:<line> — <what>. ceiling: <x>. upgrade: <y> (missing trigger → - = rot risk).

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Family: /ponytail (behavioral lazy mode) · omd-debt (shortcut ledger). Correctness/security → /dag-review; what to DEEPEN → /dag-deepen.