---
name: Frontend App Builder
slug: frontend-app-builder
category: Frontend
description: Frontend App Builder turns image-generated design concepts into production frontend code for apps, dashboards, games, and websites, and verifies the browser result matches the approved design.
github: "https://github.com/fcakyon/claude-codex-settings/tree/main/plugins/frontend-design-skills/skills/openai-frontend-design"
language: Python
stars: 1086
forks: 102
install: "npx degit https://github.com/fcakyon/claude-codex-settings/tree/main/plugins/frontend-design-skills/skills/openai-frontend-design ~/.claude/skills/openai-frontend-design"
installs_to: ~/.claude/skills/openai-frontend-design
source_path: plugins/frontend-design-skills/skills/openai-frontend-design/SKILL.md
collection_size: 25
category_size: 567
collection_url: "https://dirskills.com/collections/fcakyon/claude-codex-settings"
added: 2026-08-20T07:56:42.340Z
last_synced: 2026-08-20T07:56:42.340Z
canonical_url: "https://dirskills.com/skills/frontend-app-builder"
---

# Frontend App Builder

Frontend App Builder turns image-generated design concepts into production frontend code for apps, dashboards, games, and websites, and verifies the browser result matches the approved design.

**Install:**

```bash
npx degit https://github.com/fcakyon/claude-codex-settings/tree/main/plugins/frontend-design-skills/skills/openai-frontend-design ~/.claude/skills/openai-frontend-design
```

## README

# Frontend App Builder

Use this skill to create polished frontend apps, dashboards, games, creative websites, hero sections, redesigns, and other visually driven UI. Act first as a senior front-end designer, then as an engineer implementing an approved design spec.

## Core Standard

The two priorities of this skill outrank everything else:

1. Create enough great-looking Image Gen design first: clean, airy, distinctive, complete, readable, section-specific when needed, and not repetitive by default.
2. Do not stop until the accepted design and browser implementation match 10/10. Keep fixing visual, interaction, responsive, asset, and typography mismatches until `view_image` comparison would pass agency sign-off.

## Hard Rules

1. Use Image Gen for the visual concept unless the user explicitly opts out or the task is a small UI fix inside an existing design system.
2. Design the complete requested surface before coding. For a full page, app, dashboard, game, or product interface, a header or hero concept is not enough. For multi-section websites and long landing pages, prefer coordinated section-by-section concepts, plus an optional overview for rhythm, over one tall image that loses detail. For apps, dashboards, games, or compact product surfaces, generate the full primary screen plus any needed state, responsive, or asset concepts first.
3. Inside Codex, default multi-section website concepting to one fresh, large, readable Image Gen screenshot per major section. If the request has 1-10 sections, expect roughly 1-10 primary section images. Generate additional section/detail screenshots whenever text, buttons, card anatomy, typography, spacing, or colors are too small to extract. Do not crop or zoom an old full-page image as the main reference; regenerate a fresh standalone section or detail image that preserves the same design system.
4. In Plan mode, generate the design first, then use `request_user_input` to get design approval before planning implementation details.
5. Once accepted, the concept is a production design spec. No creative liberties during implementation: do not reinterpret layout, visible copy, hierarchy, container model, styling, imagery, density, or sections unless the user approves it or a concrete blocker requires it. General design heuristics never override the accepted concept.
6. The completion bar is agency-signoff faithful implementation: 10/10 fidelity to the accepted spec plus production-quality code. If the browser-rendered UI would receive design-review comments, keep fixing it.
7. Before coding, build a small design system from the accepted image: tokens, typography, component families, variants, spacing, icon treatment, and container rules. Include both content typography and UI chrome typography for tools, editors, and dashboards. Implement from that system so repeated elements stay consistent.
8. For new complex app UIs such as dashboards, admin tools, editors, data-heavy tools, and multi-panel product surfaces, default to React + Vite unless the user specifies another framework, the existing repo already dictates one, or the task is explicitly a single-file/static deliverable.
9. Hero eyebrow, kicker, pretitle, badge, or pill labels above the main heading are prohibited by default. Use one only when the user explicitly requested it or the accepted/reference design already contains it.
10. Verify in the Browser plugin / built-in browser first. Use Playwright Chromium only when Browser/IAB is unavailable or unreliable, and state the fallback reason.
11. Final handoff is blocked until you use `view_image` on both the accepted concept and the latest browser screenshot. This cannot be skipped or replaced with browser inspection alone. Judge the pair directly: is this agency-signoff faithfully implemented, and would a great, highly skilled design agency sign off on this exact implementation of the accepted design? If not, keep fixing.
12. Remove temporary QA artifacts before handoff unless the user or task explicitly asks to keep them.

## Coordinate With Other Installed Skills

This skill owns visual concepting and faithful frontend implementation. Use other installed skills when the app needs capabilities outside frontend design. Provider setup should not block Image Gen concepting, static UI work, or design review that does not exercise provider-backed behavior, but implementation and verification of provider-backed behavior should coordinate through the installed skill for that capability. Avoid placeholder setup instructions when another installed skill covers that setup.

For AI/model-generated output, use `openai-developers:openai-platform-api-key` when available unless the user names another provider or explicitly says not to use OpenAI. When that skill is available, always use its credential flow instead of fake keys, placeholder env vars, or manual API-key setup instructions.

## Image Gen Workflow

Read and follow the installed @imagegen skill. For website-specific briefing guidance, use `references/imagegen-website-concepts.md`.

Before calling Image Gen:

- Copy the user's concrete requirements into the brief: product/page purpose, audience, required sections or states, workflow, supplied copy, nav labels, CTA labels, data fields, required media, responsive needs, and implementation constraints.
- Ask for the complete requested surface: full page, app screen, dashboard, game screen, or coordinated section/state set. If the deliverable is more than a hero, say the concept must include downstream sections, states, or responsive continuation. If the section count is known or implied, name each section/state that needs its own concept screenshot.
- Repeat the implementation constraints: code-native app UI text and controls, fully rendered product/background assets with their own text and branding when appropriate, separable assets, reusable component families, intentional container model, no default card grids, no invented hero eyebrows/kickers/badges/pills, and practical HTML/CSS/component implementation.
- Preserve information architecture from user content, screenshots, or existing apps. Do not let Image Gen invent unrelated sections, fake metrics, new product claims, extra dashboards, new navigation, or a different product story.
- For multi-section websites or long landing pages, default to one coordinated concept image per major section. Use an optional overview only for structure and rhythm; never rely on one giant compressed board when it makes text, button details, card structure, spacing, or typography hard to analyze.
- For dense apps, dashboards, editors, product surfaces, and complex sections, generate separate state or detail concepts for the areas that would become unreadable in a single full-screen image: tables, sidebars, inspectors, modals, toolbars, charts, forms, cards, pricing blocks, testimonials, or media modules.
- If any concept screenshot is too small, blurry, cropped, crowded, or ambiguous for implementation, generate a fresh standalone section/state/detail screenshot before coding. Keep the same palette, typography mood, component family, asset treatment, density, and section order. Do not crop, slice, zoom, or reuse a tiny part of an earlier image as the source of truth.
- For games, plan a dedicated Image Gen asset pass in addition to the concept: transparent character/state sprites or sprite sheet, terrain/platform tiles, collectibles, hazards, goal/checkpoint objects, props, and 2-3 parallax/background layers when the environment has depth. HUD text, scoring, controls, physics, and collision remain code-native.

Reject or iterate on concepts that are header-only for a full-surface ask, cluttered, generic, repetitive, under-specified, unreadable, over-decorated, off-spec with hero eyebrows/kickers/badges/pills not explicitly requested or present in the reference, or not practical to implement faithfully.

## Design Quality Bar

The concept should look like a professional product mockup by a senior product designer:

- One clear creative idea or visual point of view.
- Strong first viewport with clear offer, product signal, and primary action.
- Full-page rhythm: sections, states, transitions, and mobile views feel designed as one system, without repetitive card stacks or repeated section formulas.
- Cohesive section-to-section flow: connect sections with shared spacing, palette, type rhythm, media treatment, and subtle transitions, not by inventing major new UI components.
- Excellent typography: clear hierarchy, scale, weight, line height, label treatment, and control/chrome text that never falls back to browser-default sizing.
- Intentional whitespace and density; no filler cards, hero eyebrow/kicker labels, pills, badges, fake metrics, or icon rows unless explicitly requested or present in the accepted design.
- Simpler by default: use fewer, stronger visual elements instead of filling the page with illustrations, iconography, decorative widgets, or complex UI chrome.
- Coherent visual system: palette, spacing, radius, borders, shadows, gradients, icon style, imagery, and component geometry.
- Icon fidelity matters when icons are present. Match the accepted design's icon metaphor, stroke weight, fill style, corner shape, size, color, alignment, and spacing instead of swapping in generic nearby icons.
- Color fidelity is mandatory. Match the accepted design's actual background, surface, text, border, shadow, and accent colors; if the design uses a white background, use white rather than cream, ivory, beige, warm gray, or any softened off-white substitute.
- Hero media treatment must match the accepted design. If the hero image has no color overlay or tint in the concept, the implementation must not add one. Use edge fades, masks, or background gradients only to blend image edges into the page; do not wash the image with a color overlay.
- High-quality generated assets for logos, brand marks, hero imagery, product renders, background scenes, illustrations, textures, posters, avatars, empty states, and game sprites/tiles/background layers. Product/background assets should be fully rendered with consistent branding and in-image text when that text belongs to the asset.
- Purposeful motion that clarifies hierarchy, reveals state, or makes the product feel tangible.
- Specific, non-generic copy when the user has not provided exact copy.

Default to clean, airy, tasteful 7/10 creativity: distinctive enough to feel designed, restrained enough to build, and not repetitive. Interpret "clean" as edited and legible, not empty or sterile.

## Visual Direction Defaults

Use these defaults when the user has not given stronger art direction. Adapt them to the product type instead of forcing every app into a marketing-site style.

- Baseline: roughly 7/10 creativity, low-to-medium density, generous spacing, high implementation clarity, high typography discipline, and image-led moments when the domain benefits from real visuals.
- Before generating concepts, choose a coherent visual direction: one theme paradigm, background character, typography character, hero or primary-screen architecture, section/app rhythm, 2-4 signature component motifs, and 1-2 motion cues. Commit to the combination so the design feels intentional instead of a generic template.
- Hero or first viewport: keep one obvious focal point, a short readable headline or primary task, restrained supporting copy, a visible primary action, and enough negative space to work on a small laptop. Do not overcrowd the opening view with stats, chips, badges, fake controls, or competing mini-panels.
- Header simplicity: default to a clean brand mark, essential navigation, and one primary action or control. Avoid icon-heavy nav, extra buttons, search bars, status widgets, segmented controls, decorative illustrations, or dense product chrome in the header unless the user explicitly asks for them or the product workflow requires them.
- Visual economy: prefer one or two high-quality image or illustration moments over many small decorative visuals. Use iconography only where it clarifies navigation, controls, or product meaning.
- Container discipline: avoid nested cards, giant rounded wrappers around every section, default bento/card grids, and over-framed dashboards unless the concept or product type truly needs them. Prefer open layouts, bands, rails, lists, tables, canvases, or a single purposeful framing move.
- Section rhythm: long pages should vary density, image-to-text ratio, alignment, scale, whitespace, and visual tempo while keeping one coherent brand system. Do not repeat the same centered block or left-text/right-card formula through the whole page.
- Section continuity: when multiple section concepts need to become one page, use connective tissue from the existing design system: gutters, bands, alignment, repeated typography, recurring media frames, color rhythm, and small transitional spacing shifts. Do not invent major new carousels, accordions, pricing cards, dashboards, forms, nav systems, feature grids, or other component families unless the user requested them or the accepted concepts show them.
- Media framing: generated imagery should usually sit in clear, implementation-friendly frames with stable aspect ratios, consistent crop logic, radius, shadows, and spacing. Avoid random image sizes or collage chaos unless the user explicitly asks for that direction.
- UI restraints: small labels, utility pills, pseudo-system markers, fake metrics, and decorative dashboard jargon are allowed only when they clarify the product. If they are just visual filler, remove them before acceptance.

## Concept Review Mode

Use only when the user asks to generate concepts first, review options, or wait for approval.

- Generate and show the concept.
- Iterate until the user approves.
- Do not implement while the user is still reviewing.
- Once approved, treat the concept as the active spec and follow the fidelity workflow below.

## Before Coding

Turn the accepted concept into a design system and implementation inventory before coding:

- Exact visible copy, nav items, CTA labels, section headings, proof points, data labels, and important UI text.
- Per-section/state image inventory: source concept screenshot, native aspect, visual priority, readable text, typography relationships, spacing, button/control styling, component/container rules, dominant colors, and any unresolved details that required a fresh extraction screenshot.
- Allowed above-the-fold copy list: every visible hero, nav, eyebrow/kicker/pretitle, badge/pill, CTA, label, and proof string allowed from the accepted concept or user-provided copy.
- First viewport composition, section order, downstream states, responsive continuation, and next-section preview.
- Section continuity plan: how adjacent sections connect using the accepted design system, and which major component families are allowed. Treat unshown major components as prohibited unless the user requested them or a required workflow cannot function without them.
- Brand mark, imagery roles, product mockups, dashboards, tables, charts, maps, media rails, forms, HUDs, or other visual artifacts.
- Hero/media treatment inventory: whether each image has no overlay, a color overlay, a gradient overlay, edge fade, mask, transparent background, or matching background color. Record this explicitly before coding.
- Standalone asset needs: if the concept includes a logo, brand mark, product label, packaging, poster, sign, product render, or branded background object, create matching standalone assets with Image Gen editing before implementation so branding stays coherent.
- Game asset needs: if the concept is a game, create matching production art assets with Image Gen before implementation. Include transparent sprite/state assets, tiles/platforms, collectibles, hazards, goal objects, props, and parallax/background layers as needed; use code for collision boxes and game state, not as a substitute for visible art.
- Design tokens sampled or approximated from the image: background, surface, text, muted text, border, shadow, accent, semantic colors, radii, elevation, spacing scale, and motion timing.
- Color lock: explicitly identify whether the concept background is true white, off-white, cream, gray, dark, or tinted, then implement that exact choice. Do not warm up, cool down, mute, or otherwise "tastefully" reinterpret the palette.
- Typography system: font family/fallback, type scale, weights, line heights, tracking, label treatment, heading/body/caption styles, control text styles, and responsive type behavior.
- Icon inventory: every visible icon, glyph, chevron, logo-like mark, toolbar symbol, status symbol, and empty-state symbol; record meaning, source family, outline vs filled style, stroke width, size, color, container, alignment, spacing, and selected/hover/disabled treatment.
- Component families and variants: buttons, navigation, rows, panels, media frames, product mockups, cards only where present, tables, forms, chips, icons, empty states, responsive variants, hover/focus/selected states.
- Component architecture plan for complex app UIs: app shell, navigation, major feature regions, reusable UI primitives, data/state helpers, chart/table/form modules, asset modules, and responsive layout boundaries. A great front-end implementation should have clear component ownership, not one giant `App` component or one-off copied markup.
- Container model: cards, panels, rails, bands, lists, tables, canvases, drawers, sidebars, modals, or full-bleed sections.
- Core workflow: controls that must respond, selected states, filters, tabs, edits, creation flow, success state, playback, game controls, or generated-result demo.

If the concept omits required downstream sections, states, mobile views, or readable detail for a complex area, generate matching section/state/detail concepts when visual consistency or extraction is uncertain. Otherwise extend in the exact same visual system.

## Implementation

- Build the real usable surface first, not a marketing wrapper around a future app.
- Follow the repo's framework, routing, component, styling, state, accessibility, and asset conventions.
- When creating a new complex app UI without an existing framework constraint, use React + Vite by default. Structure it like a senior front-end engineer would: small focused components, a clear app shell, reusable primitives for repeated controls, feature-specific modules for dashboards/tables/charts/forms, separated sample data and state helpers, and shared tokens/styles. Keep `App` as composition glue instead of a monolithic screen implementation.
- Implement through the design system extracted from the image. Similar elements must use the same component or shared style primitive; differences should be explicit variants, not one-off copied CSS.
- Implement the accepted concept exactly. Preserve copy, hierarchy, section order, density, colors, typography, spacing, radii, borders, shadows, asset framing, and interaction model.
- For multi-section pages, implement in slices that match the accepted section concepts. Start with the first viewport, compare its browser screenshot to the section concept, fix visible drift, then continue section by section. Do not defer all visual comparison until the whole page is coded, and do not merge or simplify section-specific design decisions just because a broad overview image is easier to follow.
- Connect sections into one cohesive page without adding unapproved major UI components. Use spacing, background bands, alignment, typography rhythm, repeated motifs, and media framing to bridge gaps. Do not invent new carousels, accordions, pricing blocks, dashboards, forms, tab systems, feature-card grids, or other large components to make the page feel complete unless they appear in the accepted concept, were requested by the user, or are recorded as a concrete functional necessi