PRD Pipeline (Per-Feature)

Three phases — decompose → per-feature PRD → cross-feature review. Consumes plans/{slug}/idea-brief.md, emits plans/{slug}/prd/ with one PRD per feature, a Mermaid navigation graph, and a master INDEX.

When to Use

• After running kta-idea-pipeline — idea-brief.md validated and feature_seeds: populated
• "I have an idea brief, write the PRDs"
• "Break my MVP scope into feature specs with screen lists"
• "Generate per-feature PRDs from this idea"
• Re-running on existing prd/ to refresh after idea-brief changes

How the pipeline works

The pipeline pre-fills ~60% of PRD fields with sensible defaults (Settings always has account/notifications/theme/about; Auth always has email + 1 social provider; etc.). The student picks from options offered by the skill instead of writing fields from scratch. There are no modes, no levels, no toggles — this is the natural flow.

Workflow

1. Phase 1 — Decompose — read references/phase-1-decompose.md. Read idea-brief.md, validate feature_seeds (5–8 items) present. AI proposes 4–8 features grouped by 5 user-journey buckets (Acquisition / Activation / Core Loop / Retention / Settings). Student edits/approves. Hard cap 8 — skill refuses 9th. Monetization is OUT OF SCOPE in this phase — refuse paywall/IAP/subscription/billing features and tell the student to defer to a later phase.
2. Phase 2 — Per-Feature PRD — read references/phase-2-feature-prd.md. Loop. Each feature gets one PRD using references/feature-prd-template.md. Screens nested inside (NOT separate PRDs per screen). Save plans/{slug}/prd/{NN}-{feature-slug}.md.
3. Phase 3 — Cross-Feature Review — read references/phase-3-cross-review.md. Generate Mermaid nav-graph.mmd (screens as nodes, navigation as edges). Surface shared components and naming conflicts. Write INDEX.md.
4. Phase 4 — Handoff (MANDATORY) — after INDEX.md is written, use AskUserQuestion to offer the next step. See "Handoff Prompt" section below.

Handoff Prompt (Phase 4)

Trigger condition (STRICT): fire ONLY after ALL feature PRDs from Phase 2 are written AND INDEX.md + nav-graph.mmd from Phase 3 are written. Do NOT fire mid-loop after a single feature PRD. Do NOT fire if any feature in the Phase 1 approved list is missing its {NN}-{feature-slug}.md file. The handoff is a Phase 3 boundary — confirm all PRD files exist on disk before proceeding.

Immediately after writing plans/{slug}/prd/INDEX.md (last file of Phase 3), surface the absolute path of the PRD directory in a one-line confirmation, then call AskUserQuestion:

header: "Next Step"
question: "PRDs written to {abs prd dir}. What next?"
multiSelect: false
options:
  - label: "Run design", description: "Auto-run kta-design-spec with PRD dir path"
  - label: "Pick feature", description: "Run kta-design-spec for ONE specific PRD only"
  - label: "Exit to read", description: "Stop here so I can read PRDs first"

Branching:

• If user picks "Run design" → invoke Skill tool with skill: "kta-design-spec" and args containing the absolute path of the PRD directory (e.g., args: "plans/{slug}/prd/"). Downstream skill takes over.
• If user picks "Pick feature" → emit a second AskUserQuestion with one option per feature PRD file (label = feature slug ≤17 chars, description = 1-line feature summary from PRD). On selection, invoke Skill tool with skill: "kta-design-spec" and args = absolute path of the chosen single PRD file.
• If user picks "Exit to read" → end the skill cleanly. Print the PRD dir path one more time. Do NOT proactively run any other skill.

This handoff is non-optional — every successful run of kta-prd-pipeline ends with this question. If INDEX.md failed to write, skip the handoff and surface the error instead.

Inputs

• plans/{slug}/idea-brief.md (required) — must include feature_seeds: 5–8 items
• Optional — student overrides on proposed feature list

Outputs

• plans/{slug}/prd/INDEX.md — master feature list with status + screen counts
• plans/{slug}/prd/nav-graph.mmd — Mermaid LR-flowchart of screen navigation
• plans/{slug}/prd/{NN}-{feature-slug}.md — one per feature (4–8 files)

Integration

• Previous stage — kta-idea-pipeline (provides idea-brief.md)
• Next stage — kta-design-spec (consumes per-feature PRDs to emit per-screen design specs)

Constraints

• Hard 8-feature cap — Phase 1 refuses 9th feature; student must consolidate or defer to V2
• 5 journey buckets are FIXED — no ad-hoc buckets, no Monetization bucket in this phase
• Screens always nested inside feature PRDs — NEVER emit per-screen PRDs
• No project-stack-specific defaults — generic patterns only (no Supabase / DRE-KT mentions in feature catalog)
• Skill emits markdown only, no code
• Validates feature_seeds exist in idea-brief before running — refuses with clear error otherwise
• Default working directory — plans/{slug}/
• Phase 4 handoff is mandatory AND fires ONLY after ALL feature PRDs + Phase 3 outputs (INDEX.md, nav-graph.mmd) are on disk. Never trigger mid-loop. Offers "Run design" (auto-chains to kta-design-spec with PRD dir), "Pick feature" (single-PRD design run), or "Exit to read"