---
name: Prototype
slug: prototype-3
category: Frontend
description: Prototype builds throwaway code to answer a design question. Use it to sanity-check state logic or explore what a UI should look like, with the prototype kept close to the code it is testing.
github: "https://github.com/tt-a1i/matt-skills-with-to-goal/tree/main/skills/engineering/prototype"
language: Shell
stars: 29
forks: 7
install: "npx degit https://github.com/tt-a1i/matt-skills-with-to-goal/tree/main/skills/engineering/prototype ~/.claude/skills/prototype"
installs_to: ~/.claude/skills/prototype
source_path: skills/engineering/prototype/SKILL.md
collection_size: 40
category_size: 567
collection_url: "https://dirskills.com/collections/tt-a1i/matt-skills-with-to-goal"
added: 2026-08-12T04:44:21.727Z
last_synced: 2026-08-12T04:44:21.727Z
canonical_url: "https://dirskills.com/skills/prototype-3"
---

# Prototype

Prototype builds throwaway code to answer a design question. Use it to sanity-check state logic or explore what a UI should look like, with the prototype kept close to the code it is testing.

**Install:**

```bash
npx degit https://github.com/tt-a1i/matt-skills-with-to-goal/tree/main/skills/engineering/prototype ~/.claude/skills/prototype
```

## README

# 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 task runner — `pnpm <name>`, `python <path>`, `bun <path>`, etc. 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.** Fold any validated decision into the real code, then capture the prototype itself as a **primary source**: commit it to a throwaway branch, out of main, and leave a context pointer to that branch on the implementation issue. Capture the answer too — the verdict and the question it settled — in the issue or a commit. The main branch keeps only the validated decision.