Frontend App Builder

Use this skill to turn a frontend application request into a working, visually checked app. For new apps, dashboards, games, websites, product interfaces, tools, redesigns, and other visually driven UI work from scratch, act first as a senior front-end designer unless the user explicitly says not to use Image Gen for concepting: create a concrete visual direction, use the installed @imagegen skill to produce an overall interface, screen, dashboard, game, website, or hero concept, then implement the concept in code as faithfully as possible. Aim for high-taste, agency-quality, minimal design rather than maximal visual spectacle, except when the product or game genre calls for richer art direction. Use additional generated assets when they materially improve the implemented UI or are needed to match the generated concept. For app interfaces, implement the main functionality with believable local state and real interactions so the user can click through the core idea instead of only viewing a static mockup. The accepted concept is an implementation contract, not a moodboard: do not redesign, simplify, rename, reorder, or substitute it unless the user explicitly asks for a change. Keep working until the running app matches the generated concept closely enough to pass a professional design-agency inspection and the core workflow has been verified, or until you hit a concrete blocker that you report clearly. Always run the app and verify the result in a browser; use the Browser plugin / built-in app browser first whenever it is available, and only fall back to Playwright with Chromium when Browser/IAB is unavailable or demonstrably unreliable for the needed check.

Workflow

1. Read the existing app structure, scripts, styling system, and asset locations before editing.
2. Use a concept-first image generation pass for new apps, dashboards, games, websites, product interfaces, tools, redesigns, and visually described UI from scratch unless the user explicitly instructs you not to use Image Gen for concepting.
3. If the user asks to generate a concept first, review concepts, or hold implementation until approval, enter Concept Review Mode: generate and show the concept, iterate with the user until they are happy, and do not implement yet.
4. For concept-first implementation work, read and follow the installed @imagegen skill, then write a concise design-director brief and generate the overall app, dashboard, game, website, screen, redesign, or hero concept before implementation.
5. Choose one generated image as the accepted layout concept and keep its exact path visible in your notes. If multiple images were generated, label the rest as supporting assets and do not let them redefine the page structure.
6. Reject or iterate on generated concepts that are cluttered, overly decorative, under-specified, or trying to show too many product ideas at once.
7. Before coding, create a concept-to-implementation inventory from the accepted concept: native concept size/aspect, first-viewport composition, headline line breaks, nav/header geometry, brand mark, palette, type scale, panel/card topology, row counts, chart axes, drawers/rails, footer/status regions, asset roles, data/copy values, visible control states, and mobile continuation.
8. Define the minimum implementation plan, core interaction path, and asset list needed for the complete screen, page, or flow. Every visible concept element should map to code, an imagegen asset, or a clearly named intentional deviation.
9. If the accepted concept only shows part of the page or a single state, infer the remaining sections, states, and responsive views from the concept's visual language and implement them in the same design system.
10. Use the imagegen built-in tool path for missing visual assets such as logos, brand marks, hero imagery, product scenes, illustrations, textures, mockups, thumbnails, and empty-state art.
11. Treat the accepted concept as the visual spec. Extract layout, spacing, typography, palette, imagery, component shapes, interaction model, and responsive implications before coding.
12. Complete the inline preservation checklist below before coding; map every visible concept element to an implementation choice.
13. Implement the design in the app using the repo's existing framework, routing, component, styling, state, data, accessibility, and asset conventions.