# Greenfield > [Planning] Use when you need to start a new project from scratch with full waterfall inception — idea, research, domain modeling, tech stack, and implementation plan. - Skill: `duc01226/greenfield-3` (Agent Skill) - Install (CLI): `npx skillmds@latest add duc01226/greenfield-3` - Raw SKILL.md: https://api.skillmd.com/api/skills/duc01226/greenfield-3/raw - Safety review: pending - Works with: Claude Code, Claude.ai, OpenAI Codex - Category: Research & Search - Author: duc01226 (https://skillmd.com/u/duc01226) - Updated: 2026-09-22 - Page: https://skillmd.com/skills/duc01226/greenfield-3 --- ## Quick Summary **Goal:** Guide greenfield project inception from raw idea to an approved, implementable project plan using a full waterfall process. **Workflow (16 steps):** 1. **Discovery** (`/idea`) — Interview user about problem, vision, constraints, team skills, scale. **DO NOT ask about tech stack** — keep business-focused. 2. **Market Research** (`/web-research`) — WebSearch for competitors, market landscape, existing solutions 3. **Deep Research** (`/deep-research`) — WebFetch top sources, extract key findings 4. **Business Evaluation** (`/business-evaluation`) — Viability assessment, risk matrix, value proposition 5. **Domain Analysis & ERD** (`/domain-analysis`) — Bounded contexts, aggregates, entities, ERD diagram, domain events. Validate every context boundary with user. 6. **Tech Stack Research** (`/tech-stack-research`) — Derive technical requirements from business + domain analysis. Research top 3 options per stack layer (backend, frontend, database, messaging, infra). Detailed pros/cons matrix, team-fit scoring, market analysis. Present comparison report for user to decide. 7. **Architecture Design** (`/architecture-design`) — Research and compare top 3 architecture styles (Clean, Hexagonal, Vertical Slice, etc.). Evaluate design patterns (CQRS, Repository, Mediator). Audit against SOLID, DRY, KISS, YAGNI. Validate scalability, maintainability, IoC, technical agnosticism. Present comparison with recommendation. **Harness output required:** produce a "Scaffold Handoff — Harness Plan" table in the architecture report: (a) feedforward guides to create (AGENTS.md sections, skill activation rules, pattern catalog), (b) computational feedback sensors to install (linter, formatter, pre-commit, CI), (c) inferential feedback sensors to configure (review skills, AI gates). This table feeds `/scaffold` → `/linter-setup` → `/harness-setup`. 8. **Implementation Plan** (`/plan`) — Create phased plan using confirmed tech stack + architecture + domain model 9. **Security Audit** (`/security-review`) — Review plan for OWASP Top 10, auth patterns, data protection concerns 10. **Performance Audit** (`/performance-review`) — Review plan for performance bottlenecks, scalability, query optimization 11. **Plan Review** (`/plan-review`) — Full plan review, risk assessment, approval 12. **Refine to PBI** (`/refine`) — Transform idea + reviewed plan into actionable PBI with acceptance criteria 13. **User Stories** (`/story`) — Break PBI into implementable user stories 14. **Plan Validation** (`/plan-validate`) — Interview user with critical questions to validate plan + stories 15. **Test Strategy** (`/spec [mode=tests]`) — Test pyramid, frameworks, spec outline 16. **Workflow End** (`/workflow-end`) — Clean up, announce completion **Key Rules:** - PLANNING ONLY: never implement code - Every stage saves artifacts to plan directory - **MANDATORY IMPORTANT MUST ATTENTION** every stage requires `AskUserQuestion` validation before proceeding - Delegate architecture decisions to `solution-architect` agent - Present 2-4 options for every major decision with confidence % - **Business-First Protocol:** Tech stack is NEVER asked upfront. Business analysis (steps 1-5) + domain modeling (step 6) must complete first. Tech stack is derived from requirements through research and presented as a comparison report with options. - **MANDATORY IMPORTANT MUST ATTENTION** architecture design MUST produce a "Scaffold Handoff — Harness Plan" table covering: feedforward guides, computational sensors (`/linter-setup` handles install), and inferential sensors (`/harness-setup` configures). The scaffold + linter-setup + harness-setup triad are NON-SKIPPABLE infrastructure — code without a harness accumulates technical debt from day one. ## Entry Point This skill is the explicit entry point for the `workflow-greenfield-init` workflow. **When invoked:** 1. Activate the `workflow-greenfield-init` workflow via `/start-workflow workflow-greenfield-init` 2. The workflow handles step sequencing, task creation, and progress tracking 3. Each step delegates to the appropriate skill (idea, web-research, domain-analysis, tech-stack-research, etc.) 4. The `solution-architect` agent provides architecture guidance throughout ## When to Use - Starting a brand-new project from scratch - No existing codebase (empty project directory) - Planning a new application before writing any code - Want structured waterfall inception with user collaboration at every step ## When NOT to Use - Existing codebase with code (use `/plan` or `/start-workflow workflow-feature` instead) - Bug fixes, refactoring, or feature implementation - Quick prototyping (use `/feature-implement` instead) ## Output All artifacts saved to plan directory: ``` plans/{id}/ research/ discovery-interview.md market-research.md deep-research.md business-evaluation.md domain-analysis.md tech-stack-comparison.md architecture-design.md phase-01-domain-model.md phase-02-tech-stack.md phase-02b-architecture.md phase-03-project-structure.md phase-04-test-strategy.md phase-05-backlog.md plan.md (master plan with YAML frontmatter) ``` After completion, recommend next step: `/feature-implement` to scaffold the project structure. **Be skeptical. Apply critical thinking, sequential thinking. Every claim needs traced proof, confidence percentages (Idea should be more than 80%).** --- **MANDATORY IMPORTANT MUST ATTENTION** break work into small todo tasks — one per workflow step. **MANDATORY IMPORTANT MUST ATTENTION** validate with user at EVERY step — never auto-decide. **MANDATORY IMPORTANT MUST ATTENTION** add a final review todo task to verify work quality and identify fixes/enhancements. --- **MANDATORY IMPORTANT MUST ATTENTION** use `TaskCreate` to break ALL work into small tasks BEFORE starting. **MANDATORY IMPORTANT MUST ATTENTION** use `AskUserQuestion` at EVERY stage — validate decisions before proceeding. **MANDATORY IMPORTANT MUST ATTENTION** NEVER ask tech stack upfront — business analysis and domain modeling first. > **AI Mistake Prevention** — Failure modes to avoid on every task: > > **Re-read files after context changes.** Context compaction, resume, or long-running work can make memory stale; verify current files before acting. > **Verify generated content against source evidence.** AI hallucinates APIs, names, claims, and document facts. Check the relevant source before documenting or referencing. > **Check downstream references before deleting or renaming.** Removing an artifact can stale docs, generated mirrors, configs, and callers; map references first. > **Trace the full impact chain after edits.** Changing a definition can miss derived outputs and consumers. Follow the affected chain before declaring done. > **Verify ALL affected outputs, not just the first.** One green check is not all green checks; validate every output surface the change can affect. > **Assume existing values are intentional — ask WHY before changing OR flagging one as a defect.** Before changing or reporting a constant, limit, flag, cutoff, wording, or pattern, read nearby context and history, the CALLER's ordering, and 2+ sibling call sites of the same convention. A doc stating WHAT without WHY is missing rationale, not proof of a missing guard. > **Surface ambiguity before acting — don't pick silently.** Multiple valid interpretations require an explicit question or stated assumption with risk. > **Assert the outcome your system owns, not the intermediate state your infrastructure owns.** When verifying async work, assert the final business state — never the delivery/retry bookkeeping held in shared infrastructure that any co-running process can write. Such a check passes when run alone and flakes the moment anything else shares that infrastructure. > **Keep shared guidance role-relevant.** Universal guidance must help every receiving skill or agent; code-specific obligations belong only in code-specific protocols. > **Critical Thinking Mindset** — Apply critical thinking, sequential thinking. Every claim needs traced proof, confidence >80% to act. > **Anti-hallucination:** Never present guess as fact — cite sources for every claim, admit uncertainty freely, self-check output for errors, cross-reference independently, stay skeptical of own confidence — certainty without evidence root of all hallucination. **MUST ATTENTION** apply critical + sequential thinking — every claim needs appropriate traced evidence (`file:line` for repo/code claims; source URL or artifact section for research, product, content, and docs claims); confidence >80% to act, <60% DO NOT recommend. Anti-hallucination: never present guess as fact, admit uncertainty freely, cross-reference independently, stay skeptical of own confidence. **MUST ATTENTION** apply AI mistake prevention — verify generated content against evidence, trace downstream references before deleting or renaming, verify all affected outputs, re-read files after context loss, and surface ambiguity before acting. > **Project Protocol Overlay** — Before executing this skill, resolve any PROJECT overlay rules layered onto it: match this skill's name against the `Target` column of the project's skill-protocol index (`docs/project-reference/skill-protocols-reference.md` by default; a `referenceDocs` entry in `docs/project-config.json` overrides the path), taking the most specific matching tier ONLY — exact name > glob > `*`. **That precedence orders overlays against EACH OTHER, never against this skill.** Read ONLY the matched bodies, resolved as `/.md`; a row's Body link is display text, never a read path. A matched body that is missing or malformed is REPORTED and skipped — never reconstructed from the index Description. No index, or no match -> proceed with no overlay, silently. Full contract: `.claude/skills/project-skill-protocol/references/registry.md`. > > Overlays are **ADDITIVE ONLY**: they ADD rules on top of this skill's own protocol and NEVER replace, override, disable, or reinterpret a rule it already states — removing every overlay must return this skill to exactly its documented behavior. An overlay is a BRIEF, not an authority escalation: it can NEVER waive a workflow gate, git discipline, a review gate, or a user-confirmation gate. A genuine overlay-vs-skill conflict, or two equally-specific overlays that directly contradict -> surface both to the user; NEVER resolve silently. **MUST ATTENTION** resolve project protocol overlays for this skill BEFORE executing — most specific matching tier only (exact > glob > `*`, which ranks overlays against each other, NEVER against this skill), read only matched bodies at `/.md`; a missing or malformed body is reported, never reconstructed. Overlays are ADDITIVE ONLY (they never replace this skill's own rules) and are a brief, NEVER an authority escalation; an equal-specificity contradiction goes to the user. ## Closing Reminders **IMPORTANT MUST ATTENTION** Protocols in force (concise digest of the SYNC/shared blocks this skill carries): - **AI Mistake Prevention:** verify generated content against evidence, trace downstream references, verify all affected outputs, re-read after context loss, surface ambiguity. - **Critical Thinking:** traced `file:line` proof per claim, confidence >80% to act, NEVER guess. - **MANDATORY IMPORTANT MUST ATTENTION** break work into small todo tasks using `TaskCreate` BEFORE starting - **MANDATORY IMPORTANT MUST ATTENTION** search codebase for 3+ similar patterns before creating new code - **MANDATORY IMPORTANT MUST ATTENTION** cite `file:line` evidence for every claim (confidence >80% to act) - **MANDATORY IMPORTANT MUST ATTENTION** add a final review todo task to verify work quality **[TASK-PLANNING]** Before acting, analyze task scope and systematically break it into small todo tasks and sub-tasks using TaskCreate.