Dag Slim

/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-.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: : — cut , replace with — 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: , (# 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: : — . ceiling: . upgrade: (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.

Source & license

This open-source skill is cataloged on AgentStack and links to its original source — we do not rehost the code.

• Author: AbyssCN
• Source: AbyssCN/oh-my-dag
• License: MIT

Install and usage instructions live in the source repository linked above.