Prototype

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

Pick a branch

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

• "Does this logic / state model feel right?" (business logic, state transitions, data shape, or an API before it is written: anything that looks reasonable on paper but only feels wrong once pushed through real cases) → LOGIC.md, a shareable HTML demo that drives the model.
• "What should this look like?" (a page, a layout, options for a screen) → UI.md, one treatment or a set of variants rendered on a real route.

The two branches produce very different artifacts, so getting this wrong wastes the whole prototype. If the question is genuinely ambiguous and the user is not 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