plan-feature

name	plan-feature
description	Pre-implementation planning — interview to clarify scope, then compile into a PRD. Triggers "help me figure out", "vague scope", "define requirements" (discovery phase); "PRD", "requirements document", "product spec", "feature spec", "write requirements" (PRD phase).
context	fork
agent	planner

Plan Feature

Two-phase pre-implementation planning: clarify requirements via interview, then compile a complete PRD.

Phase 1: Discovery

Help clarify requirements and scope through structured questioning.

Interview Framework

The interview is a fog-of-war walk across four quadrants of the unknown. Open by listing the known knowns (what the user has already decided), then work the questions below to surface known unknowns (open questions they're aware of), unknown knowns (constraints they hold but haven't said — the questions in 2–4 exist to shake these loose), and close by hunting unknown unknowns ("what would surprise us mid-build? what reference implementation should we read first?"). A discovery that ends with all four quadrants visited produces a PRD that doesn't get re-planned in week two.

1. Understand the Goal

• What problem are you solving?
• Who is this for?
• What does success look like?

2. Define Scope

• What must be included (MVP)?
• What's nice to have (future)?
• What's explicitly out of scope?

3. Identify Constraints

• Timeline constraints?
• Technical constraints?
• Resource constraints?

4. Clarify Details

• What are the inputs/outputs?
• What are the edge cases?
• What are the error scenarios?

5. Validate Understanding

• Summarize back what you heard
• Confirm priorities
• Identify open questions

Output

## Discovery Summary: [Feature/Project]

### Goal
[Clear statement of what we're building and why]

### Requirements
**Must Have (MVP)**
- [ ] Requirement 1
- [ ] Requirement 2

**Nice to Have**
- [ ] Feature A
- [ ] Feature B

**Out of Scope**
- Not doing X
- Not doing Y

### Technical Approach
[High-level approach]

### Open Questions
- [ ] Need to clarify: ...
- [ ] Decision needed: ...

### Next Steps
1. [First action]
2. [Second action]

Remember

• Ask, don't assume
• Summarize frequently
• Document decisions
• Store requirements as learnings

---

Phase 2: PRD Compilation

Structured 6-phase process to produce a complete PRD from a feature idea, including user stories, task breakdown, and parallel execution plan.

Workflow

Phase 1: Clarifying Questions

Ask 5-8 targeted questions to fill gaps. Use smart defaults so the user can skip.

## Clarifying Questions

1. **Target users?** [default: existing app users]
2. **Platform scope?** [default: web only]
3. **Auth required?** [default: yes, existing auth]
4. **Performance targets?** [default: <3s LCP, <100ms INP]
5. **Accessibility level?** [default: WCAG 2.1 AA]
6. **Data persistence?** [default: existing database]
7. **Mobile responsive?** [default: yes]
8. **Analytics needed?** [default: basic events]

Press enter to accept all defaults, or answer specific questions.

Phase 2: Scope Definition

Define what is IN and OUT of scope.

## Scope

### In Scope
- [feature 1]
- [feature 2]

### Out of Scope
- [explicitly excluded 1]
- [explicitly excluded 2]

### Assumptions
- [assumption 1]
- [assumption 2]

Phase 3: User Stories

Write user stories with acceptance criteria.

## User Stories

### US-1: [Title]
**As a** [role]
**I want** [capability]
**So that** [benefit]

**Acceptance Criteria:**
- [ ] Given [context], when [action], then [result]
- [ ] Given [context], when [action], then [result]

**Priority:** P1 | P2 | P3
**Complexity:** trivial | small | medium | large | epic

Phase 4: Task Breakdown

Break into implementable tasks with metadata.

## Tasks

### T-1: [Title]
- **Description:** [what to implement]
- **User Story:** US-1
- **Priority:** 1 (1=highest, 5=lowest)
- **Complexity:** medium
- **Estimated Tokens:** 15000
- **Dependencies:** none
- **Blocks:** T-2, T-3
- **Verification:** [how to verify completion]

### T-2: [Title]
- **Dependencies:** T-1
- ...

Phase 5: Parallel Batch Detection

Analyze task dependencies to find parallel execution groups using topological sorting.

## Execution Plan

### Batch 1 (parallel) — estimated: 25k tokens
- T-1: Setup data models
- T-4: Create UI scaffolding
- T-7: Write test fixtures

### Batch 2 (parallel, depends on Batch 1) — estimated: 40k tokens
- T-2: Implement API endpoints (depends: T-1)
- T-5: Build form components (depends: T-4)

### Batch 3 (sequential) — estimated: 20k tokens
- T-3: Integration wiring (depends: T-2, T-5)

### Batch 4 (parallel) — estimated: 15k tokens
- T-6: E2E tests (depends: T-3)
- T-8: Documentation (depends: T-3)

Total estimated tokens: 100k
Estimated context windows: 2

Phase 6: Final PRD

Compile everything into the final document.

# PRD: [Feature Name]

## Overview
[1-2 paragraph summary]

## Goals
- [measurable goal 1]
- [measurable goal 2]

## Scope
[from Phase 2]

## User Stories
[from Phase 3]

## Technical Design
### Architecture
[high-level approach]

### Data Model
[key entities and relationships]

### API Surface
[endpoints or interfaces]

## Task Breakdown
[from Phase 4]

## Execution Plan
[from Phase 5]

## Success Metrics
- [metric 1: target value]
- [metric 2: target value]

## Risks
| Risk | Likelihood | Impact | Mitigation |
|------|-----------|--------|------------|
| [risk] | Low/Med/High | Low/Med/High | [approach] |

## Timeline
- Phase 1: [dates] — [deliverable]
- Phase 2: [dates] — [deliverable]

Smart Defaults

When the user provides minimal input, apply these defaults:

• Platform: Web — detect from package.json (next → Next.js / satus, react-router → RR / novus)
• Auth: Existing auth system
• Performance: LCP <3s, INP <100ms, CLS <0.1
• Accessibility: WCAG 2.1 AA
• Testing: Unit + integration, no E2E unless requested
• Styling: Project's existing system (Tailwind if detected)

Task Sizing Reference

See docs/enhanced-todos.md for the complexity/token sizing reference table.

---

Phase 3: Close (plan → durable record)

A PRD is a build plan while building and a rationale record once shipped — closing flips it from one to the other. When the feature lands (merged, gates green), rewrite the PRD instead of letting it rot as a stale plan:

• Keep the why: the problem, the principles, the invariants that must never break, the approaches tried and rejected.
• Cut every paragraph that restates what the code does — point at the code instead; it is the source of truth for how.
• Record every divergence from the plan (dropped tasks, renamed seams, assumptions that broke). Divergences are the most valuable content: they're exactly what a future reader would otherwise re-derive the hard way.
• Archive it where the project keeps finished plans (e.g. docs/prd/done/), and promote anything decision-shaped into an ADR via /context-doc.

If the plan lives as GitHub issues (/project), the close pass is the closing comment on the epic: what shipped, what diverged, and why.