# Vertical Slice Splitter

> Decompose a destination doc or spec into vertical-slice issue cards with a dependency DAG

- Skill: `georgeqle/vertical-slice-splitter-4` (Agent Skill)
- Install (CLI): `npx skillmds@latest add georgeqle/vertical-slice-splitter-4`
- Raw SKILL.md: https://api.skillmd.com/api/skills/georgeqle/vertical-slice-splitter-4/raw
- Safety review: pending (external: skill-scanner PASS, skillspector PASS)
- Works with: Claude Code, Claude.ai, OpenAI Codex
- Category: Coding & Dev Tools
- Author: GeorgeQLe (https://skillmd.com/u/georgeqle)
- Updated: 2026-09-09
- Page: https://skillmd.com/skills/georgeqle/vertical-slice-splitter-4

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# Vertical Slice Splitter

Decompose a destination doc or spec into independently grabbable vertical-slice issue cards.

## Process

1. **Read input document** from `$ARGUMENTS` (destination doc or spec).
2. **Explore codebase:** file structure, layers, modules, existing test boundaries.
3. **Identify layers** the work crosses (DB, service, API, UI, infra, etc.).
4. **Decompose into vertical slices** — each slice crosses all relevant layers for its scope.
5. **Reject horizontal-only slices.** Enforce tracer-bullet: slice 000 must produce something visible and testable end-to-end.
6. **For each slice determine:**
   - Title, description (2-5 sentences), acceptance criteria (testable)
   - Dependencies: `blocks` and `blocked-by` (referencing other slice IDs)
   - Label: `afk` | `human-review` | `pair`
7. **Build DAG**, validate acyclic, identify parallel groups.
8. **Check `issues/` directory.** If it has existing content, ask user: archive or append.
9. **Write files:**
   - `issues/DAG.md` — mermaid graph + summary table + parallel group annotations
   - `issues/000-[slug].md` through `issues/NNN-[slug].md`

## Issue File Format

```markdown
# [Title]

**Label:** afk | human-review | pair
**Blocks:** 001, 003
**Blocked by:** none

## Description
[2-5 sentences]

## Acceptance Criteria
- [ ] ...

## Notes
[Optional implementation hints]
```

## Constraints

- Every slice independently grabbable (one agent or session)
- No slice larger than one focused session
- First slice (000) is always the tracer bullet
- DAG must be acyclic
- `afk` slices must have unambiguous acceptance criteria (no taste judgment required)

## Alignment Page

When this skill produces durable deliverables (research, specs, plans, reports, prototypes, or any document output), build a full-depth HTML alignment page following `ALIGNMENT-PAGE.md` in this skill's directory. Output: `alignment/vertical-slice-splitter-{topic}.html`.

## Default Shipping Contract

Follow the shared shipping contract convention in CLAUDE.md.