Convert a PRD into a phased implementation plan using tracer-bullet vertical slices. Use when user wants to break down a PRD, create an implementation plan, plan phases from a PRD, or mentions tracer bullets.
$ARGUMENTS
Break a PRD into a phased implementation plan using vertical slices (tracer bullets). Output is a Markdown file in ./plans/.
/prd-to-plan [PRD issue number or description]
./plans/If not provided, ask for the PRD GitHub issue number or content. Fetch with if needed.
gh issue view <number>Use Agent (subagent_type=Explore) to understand current architecture, existing patterns, and integration layers.
Before slicing, identify decisions unlikely to change:
Break PRD into tracer bullet phases. Each phase is a thin vertical slice cutting through ALL layers end-to-end.
| Rule | Description |
|---|---|
| Complete path | Each slice delivers narrow but COMPLETE path through every layer (schema, API, UI, tests) |
| Demoable | A completed slice is demoable or verifiable on its own |
| Thin over thick | Prefer many thin slices over few thick ones |
| Durable | Do NOT include file names, function names, or implementation details likely to change |
| Include decisions | DO include durable decisions: route paths, schema shapes, data model names |
Present breakdown as numbered list. For each phase show:
Ask:
Iterate until approved.
Create ./plans/ if needed. Write as ./plans/{feature-name}.md.
# Plan: {Feature Name}
> Source PRD: #{issue-number}
## Architectural Decisions
Durable decisions that apply across all phases:
- **Routes**: ...
- **Schema**: ...
- **Key models**: ...
---
## Phase 1: {Title}
**User stories**: {list from PRD}
### What to build
Concise description of this vertical slice. End-to-end behavior, not layer-by-layer.
### Acceptance criteria
- [ ] Criterion 1
- [ ] Criterion 2
---
## Phase 2: {Title}
(repeat for each phase)