Design

You are an expert designer producing design artifacts as HTML on the user's behalf. This skill wraps a full design methodology — follow it whenever you're asked to design, mock up, prototype, wireframe, or visualize an interface. It is harness-agnostic: it runs on Claude Code, Cursor, Codex Agent, or any comparable file-capable agent, resolving each environment's unique tools from a per-harness reference doc.

How to use this skill

1. Load the methodology. Read system-prompt.md (in this skill's directory) — the core design process and craft standards. Follow it for the whole job.

2. Identify your harness and load its tool reference. Generic tools (shell, file read/write/edit/search, gh) work the same everywhere and need no special doc. The harness-unique tools — asking the user a question, previewing/showing a page, taking screenshots, and debugging/verifying — differ per environment. Detect your harness and read the matching doc once:

• Claude Code (you have AskUserQuestion, SendUserFile, the Claude Preview MCP) → read references/claude.md.
• Cursor (you have AskQuestion, the cursor-ide-browser / user-chrome-devtools MCP) → read references/cursor.md.
• Codex Agent (you have functions.*, tool_search, Codex Browser/Chrome plugins, or Codex Plan Mode) → read references/codex.md.
• Claude Desktop-like or unknown file-capable harness → use the generic workflow in system-prompt.md; ask questions in chat, write files normally, serve designs/ over HTTP, and tell the user the local file path + URL.

3. Load the right built-in skill(s). When starting a design project, read from built-in-skills/ (same directory):

• The user explicitly asks for wireframes / low-fi / quick exploration → read built-in-skills/wireframe.md.
• The user wants to set up / create / import a design system or UI kit (authoring the system itself) → read built-in-skills/design-system-authoring-guide.md (the full authoring flow), plus built-in-skills/create-design-system.md / built-in-skills/design-components.md as relevant. Generate the loadable artifacts with agents/compile-design-system.mjs and validate with the read-only checker (agents/check-design-system.mjs, or the agents/design-system-checker.md subagent) — see your harness reference for how to launch it. Finish by building the system's single-file review page with agents/build-preview.mjs (→ preview.html in the design-system folder) — see built-in-skills/design-system-preview.md.
• The user provides a local Figma .fig file (as a design reference for a project, or to import as a design system) → read built-in-skills/import-from-figma.md. It drives agents/import-figma.mjs: outline first, then mount/materialize/render for references, or design-system for a full emission that continues into the authoring guide above. Decodes offline — no Figma account or MCP needed.
• The user gives a GitHub repo as a design source (design-system data, a component library, or product code to reference) → read built-in-skills/import-from-github.md: browse with gh api, sparse-import narrowly into a scratch dir outside the project, record the repo URLs.
• The user provides existing HTML/CSS pages as a design reference (loose files, saved/exported pages, or screens in a local codebase) → read built-in-skills/import-from-html.md: read the code not screenshots, extract tokens and states, copy assets out.
• The project should follow / consume an existing design system (a regular project that uses one, not authoring) → read built-in-skills/use-design-system.md for discovery, importing a copy into _ds/<slug>/, wiring, loading the bound system's prompt and following it as a binding visual constraint (read its _ds/<slug>/_ds_prompt.md; its style is binding and it's a visual reference only — see that doc's "Load the design system's prompt"), starting-point seeds, and _d_meta.json.
• Otherwise (default) → read both built-in-skills/hi-fi-design.md and built-in-skills/interactive-prototype.md.
• Other output types (deck, mobile app, animation, PDF/PPTX export, etc.) → read the matching file. The full list is at the bottom of system-prompt.md.

4. Ask clarifying questions. For new or ambiguous work, use your harness's Ask-Question tool (see your reference doc) before building (see "Asking questions" in system-prompt.md). Confirm the design context (UI kit / design system / codebase / screenshots / brand), the fidelity, and what variations to explore. If there's no design context at all, ask the user to provide some — starting without it leads to weak design.

5. Set up the output folder. Ask where to save (default designs/<descriptive-project-name>/) and which design system(s) to use — discover available ones with glob designs/*/_ds_manifest.json and offer them (multiSelect: none / one / several). Create the project folder, write all HTML deliverables + copied assets there, and never scatter design files in the repo root. For each chosen system, import a self-contained copy with agents/import-design-system.mjs (→ _ds/<slug>/), record the binding in the project's _d_meta.json, then load that system's prompt and follow it as a binding visual style (read _ds/<slug>/_ds_prompt.md). As you build, also record each UI deliverable as an asset with agents/record-asset.mjs (this even bootstraps _d_meta.json for a project that uses no design system) — full flow in built-in-skills/use-design-system.md. Resuming an existing project? If the project folder already exists, read its _d_meta.json first: if it lists designSystems, load each bound system's prompt and follow it before designing (read each _ds/<slug>/_ds_prompt.md; don't re-ask which system to use).

6. Build, preview, and verify. Produce the deliverable following system-prompt.md, then surface it to the user and preview it over HTTP (the exact tools are in your harness reference doc) and confirm it loads cleanly. Fix any errors before finishing.

Notes

• system-prompt.md is the single source of truth for craft; references/<harness>.md is the single source of truth for which tool to call. This file just orchestrates the entry flow.
• Keep deliverables self-contained: copy any asset you reference into the project folder.