spec-pipeline

name	spec-pipeline
description	Use when a raw product idea needs a structured blueprint, testable requirements, and implementation design. Covers the full greenfield definition pipeline: vision → PRD → architecture.

Spec Pipeline

This is a nested child under greenfield-product; its path is greenfield-product/spec-pipeline/, and the router selects it after startup pressure testing.

Use this skill to move a validated product concept through three stages of specification: strategy blueprint → product requirements → system architecture.

Pipeline Order

Startup pressure test (if needed)
    │
    ▼
Stage 1: Blueprint ──→ .agents-stack/reference/design.md
    │
    ▼
Stage 2: Requirements ──→ .agents-stack/reference/product/requirements.md
    │
    ▼
Stage 3: Architecture ──→ .agents-stack/reference/architecture/implementation.md
    │
    ▼
Pipeline: using-agents-stack (implement)

Do not skip a stage. Each stage produces the authoritative input for the next. If the request implies a later stage without a validated earlier one, surface the prerequisite gap.

Stage 1 — Blueprint

Entry condition: A raw product idea exists. No blueprint yet.

Turn the raw idea into a credible product strategy, MVP boundary, and durable product intent. Produce .agents-stack/reference/design.md.

Core contract

• Stay at strategy and blueprint level.
• Do not write PRDs, requirements, or implementation design.
• If the real question is whether the business survives at all, route to greenfield-product/startup-pressure-test first.

Focus

Cover the minimum that makes the direction honest:

• Target user and problem — who is this for, what job does it solve?
• Why now / why this — what changed to make this viable?
• MVP boundary — the smallest thing that delivers value; what's explicitly out of scope
• Key differentiators — why existing solutions don't work
• Major risks and assumptions — what must be true for this to succeed
• Next validation steps — what to test before committing to full build

Output

A concise strategy / blueprint artifact with clear boundaries and open questions. Becomes .agents-stack/reference/design.md.

---

Stage 2 — Requirements

Entry condition: Blueprint is validated and exists at .agents-stack/reference/design.md.

Turn the validated blueprint into testable product requirements that another engineer can build from without guessing. Produce .agents-stack/reference/product/requirements.md.

Core contract

• Start only after the blueprint is validated.
• Stay out of system design and implementation detail.
• Write requirements that are specific enough to gate implementation and review.

Focus

Cover the minimum that makes the PRD honest:

• User stories and jobs to be done — what does each actor need to accomplish?
• Acceptance criteria — specific, verifiable conditions for each story
• Edge cases and failure states — what happens when things go wrong
• Non-goals and scope boundaries — what this release explicitly excludes
• Open questions — what must be resolved before engineering begins

Output

A PRD that an engineer can implement without renegotiating scope. Becomes .agents-stack/reference/product/requirements.md.

---

Stage 3 — Architecture

Entry condition: PRD is validated at .agents-stack/reference/product/requirements.md.

Translate approved requirements into concrete implementation design. Produce .agents-stack/reference/architecture/implementation.md.

Core contract

• Start only after the PRD is validated.
• Do not reopen product scope.
• Design the structural foundation — data model, APIs, state flow, deployment shape.

Focus

Cover the minimum that makes the architecture buildable:

• Domain entities and schemas — core data model, relationships, constraints
• API contracts and boundaries — service interfaces, events, integration points
• State transitions and invariants — what state machine governs the core flow?
• Infrastructure and integration assumptions — deployment targets, external dependencies
• Implementation risks and ADR-worthy decisions — what choices constrain future flexibility?

Output

An implementation design that an engineer can build without renegotiating the PRD. Becomes .agents-stack/reference/architecture/implementation.md.