# Prototype

> Build a throwaway prototype to answer a design question. Use when the user wants to sanity-check whether a state model or logic feels right, or explore what a UI should look like.

- Skill: `leek/prototype` (Agent Skill, multi-file: 4 files)
- Install (CLI): `npx skillmds@latest add leek/prototype`
- Raw SKILL.md: https://api.skillmd.com/api/skills/leek/prototype/raw
- Safety review: pending
- Works with: Claude Code, Claude.ai, OpenAI Codex
- Category: AI & ML
- Author: leek (https://skillmd.com/u/leek)
- Updated: 2026-09-17
- Page: https://skillmd.com/skills/leek/prototype

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# Prototype

A prototype is **throwaway code that answers a question**. The question decides the shape.

## Pick a branch

Identify which question is being answered: from the user's prompt, the surrounding code, or by asking if the user is around:

- **"Does this logic / state model feel right?"** → [LOGIC.md](LOGIC.md). Build a single shareable HTML file (free-play buttons plus tabbed guided walkthroughs) that pushes the state machine through cases that are hard to reason about on paper, and that a non-developer can drive.
- **"What should this look like?"** → [UI.md](UI.md). Generate several radically different UI variations on a single route, switchable via a URL search param and a floating bottom bar.

The two branches produce very different artifacts: getting this wrong wastes the whole prototype. If the question is genuinely ambiguous and the user isn't reachable, default to whichever branch better matches the surrounding code (a backend module → logic; a page or component → UI) and state the assumption at the top of the prototype.

## Rules that apply to both

1. **Throwaway from day one, and clearly marked as such.** Locate the prototype code close to where it will actually be used (next to the module or page it's prototyping for) so context is obvious, but name it so a casual reader can see it's a prototype, not production. For throwaway UI routes, obey whatever routing convention the project already uses; don't invent a new top-level structure.
2. **Trivial to run.** A UI prototype starts from one command in the project's existing task runner: `php artisan <name>`, `composer <script>`, `pnpm <name>`, `python <path>`. A logic demo is a single HTML file the user double-clicks. Either way, no thinking required to start it.
3. **No persistence by default.** State lives in memory. Persistence is the thing the prototype is _checking_, not something it should depend on. If the question explicitly involves a database, hit a scratch DB or a local file with a clear "PROTOTYPE, wipe me" name.
4. **Skip the polish.** No tests, no error handling beyond what makes the prototype _runnable_, no abstractions. The point is to learn something fast.
5. **Surface the state.** After every action (logic) or on every variant switch (UI), print or render the full relevant state so the user can see what changed.
6. **Capture it when done.** Capture the prototype itself as a **primary source**: keep it as a clearly-named throwaway file (never a git branch), and leave a context pointer to it on the ticket via the tracker's Assets operation. Capture the answer too (the verdict and the question it settled) on the ticket. Fold only the validated *decision* onward: into the ticket's Resolution or the spec while charting, into real code once building. The codebase keeps the validated decision, never the prototype.