| name | prototype |
| description | Use when the user wants to build, scaffold, or ship a working MVP from an idea. Covers scope, stack choice, minimal architecture, implementation handoff, validation, and deployment. Trigger on "build an MVP", "prototype this", "scaffold this project", "turn this idea into a working app", "launch this", or /prototype. Do not use when the user only wants to capture, explore, or stress-test an idea; use ideation for that. |
| user-invocable | true |
Prototype Workflow
Structured path from idea โ working MVP. Most side projects die in "where do I even start" โ this is the scaffolding. Discard it once momentum exists.
Boundary: use ideation when the user wants to think, compare, stress-test, or write planning artifacts. Use this skill when they want to build.
Ask โ Calibrate seriousness
Ask first. The answer changes everything.
"Is this a quick side project or something you want to take seriously?"
- Side project / weekend hack: skip formality, move fast, architecture is a one-liner, deployment is optional for now.
- Serious startup / real product: run all phases with full depth.
Cut โ Define the smallest usable v1
3 questions max. Don't proceed until all 3 have clear answers.
- Who is this for? (specific person/role, not "everyone")
- What's the one thing it does? (if you need "and", it's two products)
- What does "done" look like for v1? (the minimum that a real user could actually use)
If the user can't answer #2 without "and", help them cut.
Choose โ Pick the fastest credible stack
Recommend based on project type and stated skills. Offer 2 options with honest trade-offs โ don't just list everything.
Web app (default for solo dev speed):
- Next.js + Vercel โ fastest from zero to deployed, great DX, edge-ready
- SvelteKit + Vercel โ smaller bundle, less ecosystem, better if React fatigue
API / backend:
- Hono + Bun โ fast, minimal, TypeScript-first, great for side projects
- FastAPI โ Python, better if the user has ML or data science adjacent work
Mobile:
- Expo (React Native) โ ship to iOS + Android from one codebase, Vercel-style DX for mobile
CLI:
- Node.js + commander โ if the user knows JS
- Python + click or Typer โ if the user knows Python
Database (don't overcomplicate v1):
- Turso (libSQL) or Neon (Postgres) + Drizzle ORM โ serverless, free tier
- Supabase โ if auth + realtime + storage are needed out of the box
State the trade-off plainly: "Next.js is the default because it ships fastest. Use SvelteKit if bundle size is a constraint or you dislike React's mental model."
Shape โ Name the minimal architecture
One-paragraph overview only. No architecture astronautics.
Cover:
- Data model (3โ5 entities max for v1)
- Key routes or components
- Auth approach (no auth / magic link / OAuth โ pick based on audience)
If the user is over-engineering, say so: "You don't need a message queue for an MVP with 10 users."
Build โ Hand off or implement with acceptance criteria
Implementation must include:
- One-sentence product goal
- V1 scope and explicit non-goals
- Stack decision and rationale
- Data model
- Required routes/screens
- Validation commands
- Definition of done
Set up in order: repo โ CI if needed โ core feature โ README. If implementation is delegated or done later, pass the bullets above as the handoff; if implementing now, use them as the acceptance criteria.
Verify โ Prove the MVP is shippable
Before declaring done:
Skip items that don't apply to a side project, but report what was skipped.
Completion Criteria
Do not declare the prototype complete until:
- V1 scope is 3โ5 user-visible capabilities max.
- Stack choice includes one recommended option and one rejected alternative.
- Architecture names the core entities, routes/components, and auth choice.
- Implementation has either been completed or handed off with explicit acceptance criteria.
- Validation commands have run, or failures are reported honestly.
- Final response includes repo path, run command, and deployment URL if deployed.
