prototype

name	prototype
description	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.

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. Build a tiny interactive terminal app that pushes the state machine through cases that are hard to reason about on paper.
• "What should this look like?" → 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 prototype code close to where it will actually be used so context is obvious, and name it so a casual reader can see it is temporary. Follow the project's existing routing and task-runner conventions.
2. One command to run. Whatever the project's existing task runner supports — pnpm <name>, python <path>, bun <path>, etc. The user must be able to start it without thinking.
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 and then delete it.
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. Delete or absorb when done. When the prototype has answered its question, delete it or fold the validated logic into production-quality code.

When done

The answer is the only durable output. Load /vault, then create or update a prototype artifact containing the question, the observed result, and the resulting decision. Link it to the governing wayfinding ticket, spec, or decision with vlt link. Keep prototype code temporary and keep durable prose in the vault.