Build throwaway prototypes that answer design questions about logic or UI.
npx skills add https://github.com/northguild/gmt --skill prototype-northguild
Please help me install this Agent Skill. Skill: prototype Source: https://github.com/northguild/gmt/tree/main/.agents/skills/prototype Command: npx skills add https://github.com/northguild/gmt --skill prototype-northguild
?variant= URL param and a floating bottom bar with arrow-key navigation. - Capture workflow: Fold validated decisions into real code while archiving the prototype on a throwaway branch as a primary source. - Use Case: Ask whether a checkout state machine handles the edge case where a payment fails after confirmation, and receive a shareable HTML demo with scenarios covering the happy path, the edge case, and an illegal transition. ## Quick Start Ask the assistant to prototype whether your state machine handles a specific edge case, or to generate three layout variants for an existing page.High-intent search queries and answers about installing and using this skill.
Build a single self-contained HTML file with the state logic isolated as a pure reducer or state machine module, plus free-play buttons and guided scenario walkthroughs. Anyone can open the file by double-clicking and push the model through edge cases without installing anything.
Render 3-5 structurally different variants on the same existing route, gated by a ?variant= URL search param, with a floating bottom bar to cycle between them. Keeping real data fetching and layout context makes variants easier to judge than isolated mockups.
Logic prototypes should be one plain HTML file with inline CSS and JS, no framework, bundler, or server, so they survive being emailed and opened by non-developers. UI prototypes follow the host project's existing framework and routing conventions.
Skip prototyping when the question is already answered or when the code would need tests, persistence, or error handling to be meaningful. A prototype answers one specific question; if it needs production concerns, it has stopped being a prototype.
Fold the validated decision into the real codebase, then commit the full prototype to a throwaway branch as a primary source with a pointer on the implementation issue. The main branch keeps only the validated decision, not the prototype shell.
HDeiblerAn example.
The-Vibe-CompanyBuild throwaway HTML or UI prototypes to answer design questions.
open-mercatoBuild clickable, commentable HTML prototypes for Open Mercato backend and backoffice flows.
ToanPV90Document architectural decisions with ADRs capturing context and trade-offs.