What problem does it solve? Design decisions about state machines, data models, or page layouts are hard to reason about on paper, and committing to an untested design wastes implementation effort. This Skill builds disposable, runnable prototypes that answer a specific design question through hands-on interaction. ## Core Features & Use Cases - Logic Prototypes: Build a minimal screen-clearing terminal app with a pure state-transition module to push a data model or state machine through hard cases like duplicate actions, out-of-order events, and boundary conditions. - UI Prototypes: Generate 3-5 structurally different UI variants on a single route, switchable via a ?variant= URL param and a floating bottom bar, so users can compare layouts against real app data. - Use Case: Before building a task management feature, prototype the reducer in a terminal app to verify it handles concurrent cancellation correctly, then fold the validated logic module into production and delete the scaffolding. ## Quick Start Ask the AI to prototype the state machine for your feature as an interactive terminal app so you can test edge cases before implementing it.