Vertical Slice Splitter

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

# [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.