frontend

A rulebook router for frontend work, including web interfaces, user experience, React applications, performance, and visual quality.

In plain words
What is it for?
Use it when building, styling, redesigning, reviewing, or visually testing a web page or component, including React setup and performance work.
Why use it?
It directs the agent to the relevant design, branding, usability, and performance guidance instead of leaving those decisions to improvised defaults.

Skill for Claude CodeCodex

Install

Getting it into your agent

One page per mod, every tool's command on it. A separate URL per tool would split the same page into five that compete with each other.

agentmods
npx agentmods add skills/code-yeongyu/lazycodex/frontend
Any agent
npx skills add code-yeongyu/lazycodex --skill frontend
Clone the repo
git clone --depth 1 https://github.com/code-yeongyu/lazycodex

Made for: Claude Code, Codex.

Per session 183 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 4,454 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 1 finding. Scan, not verified.
Origin original No closer match found in the catalogue.
Token cost

What it costs to keep this loaded

Counted locally with the o200k_base tokenizer, which is exact for GPT models; Claude uses its own tokenizer and its counts differ. Treat this as one consistent yardstick across the catalogue rather than a bill. Prices are per million input tokens.

ModelPer sessionOnce invoked
Fable 5 $0.00183 $0.04454
Opus 5 $0.00092 $0.02227
Sonnet 5 $0.00037 $0.00891
Haiku 4.5 $0.00018 $0.00445

Measured 2d ago against content hash cb3a0ca65af2, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

Grade A, and why

frontend scanned grade A with 1 finding against 26 rules in 11 categories — prompt injection, anti-refusal, data exfiltration, privilege escalation, supply chain, agent snooping, system-prompt leakage, SSRF and excessive agency — measured 2d ago.

A static scan of the body, not an audit. Every finding is printed with the line that produced it so you can judge whether it matters here. A mod is markdown that instructs an agent; that is exactly why what it instructs is worth reading.

Makes network callslowCapability

Not a fault in itself. Listed so you know the mod talks to something, and to what.

description: "MUST USE for frontend/web UI/UX/visual work: building, styling, redesigning pages/components, React setup, performance audits, visual QA, taste, and polish. Routes four rulesets: design taste router and bra
plugins/omo/skills/frontend/SKILL.md · 148 lines

How it starts

The opening of the file, as written. The whole thing — 148 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Frontend

This file is a router, not a rulebook. The rules live in four rulesets under references/; your first job is to load the smallest set of files that covers the request, state which you loaded in one sentence, then execute under their guidance. Loading nothing and freestyling produces the generic AI-slop output this skill exists to prevent; loading everything wastes context and creates contradictory instructions.

The bar is not clean-and-correct — it is work a senior designer at Linear, Stripe, or Supabase would ship. Correct-but-flat is a failure, not a finish. Protect the surface as hard as you protect the build: design is a first-class deliverable, not a one-shot decision you lock and walk away from.

Phase 0 — Route (before any UI work)

Request involves… Read
ANY UI implementation, styling, redesign, mockup, or visual decision references/design/README.md FIRST. It enforces two mandatory gates — the Design System Gate (a DESIGN.md must exist before any component is written) and the React Dev Tooling Gate (react-grab / react-scan / react-doctor installed by default) — then routes to the taste and brand references below.
Interaction or motion work — micro-interactions, animated components, transitions, gestures, hover/press/state feedback, "make it feel alive" ALSO references/design/interaction-skill.md. The beui.dev catalog is the mandatory interaction reference: find the nearest pattern, read its real source through the file's curl recipe, and adapt the mechanism to DESIGN.md motion tokens. It stacks on the routed style skill — never replaces it.
Writing or modifying frontend code, OR auditing performance / SEO / accessibility / quality ALSO references/perfection/README.md. Lighthouse 100 in every category, measured on real Playwright Chromium (never the lighthouse CLI), achieved through architecture — never by dropping animations or hiding content.
Looking up a concrete style, color palette, font pairing, chart type, landing-page structure, or UX guideline — or generating a project design system from keywords references/ui-ux-db/README.md. A searchable CSV database with a CLI; a lookup tool, not a posture. Load on demand; design stays the source of truth for taste and the DESIGN.md contract.
ANY implementation or redesign that creates or updates DESIGN.md — plus explicit operating-layer asks (personas, critique, debt, handoff, synthetic user testing) references/designpowers/README.md + references/designpowers/lane-c-review.md. An internal frontend ruleset, not a separate skill: lane-c is the Phase Final flatness/critique reviewer, and its accessibility-constraints and accepted-debt language fills the required DESIGN.md sections. Load other lanes only when their phase applies.

Read the full file on GitHub · 148 lines

Files

What ships with it

60 files beside SKILL.md in the same directory: the scripts, references and assets a skill reads on demand. Not counted in the per-session cost; read them before you install if any of them is executable.

Changes

What this file has done since we first saw it

Hashed on every crawl. A supply-chain change to an agent config is a question of when, not whether, so the history is kept rather than the latest state alone.

  1. 2d ago First seen · 148 lines · 183 tokens per session scan A cb3a0ca65af2

Subscribe to this mod's changes

frontend is a skill published in the GitHub repository code-yeongyu/lazycodex (3,350 stars, last pushed 23d ago), licensed MIT. It adds 183 tokens to every session and 4,454 once invoked, about $0.0009 per session on Opus 5. A static security scan graded it A with 1 finding (makes network calls). No closer match exists in the catalogue, so it is treated as the original; first seen 2026-08-30.

Related

Other skills, from other repositories

general-video

Author or edit a custom HyperFrames composition when no specialized workflow fits, or when BRIEF.md sets flow: companion. Use for longer or multi-scene pieces, brand and sizzle reels, montages, static loops, static title cards, footage remixes, and freeform builds. Use motion-graphics instead for a short unnarrated…

heygen-com/hyperframes · 92 tokens

use-agent-browser-for-airi

Test AIRI display-model imports with agent-browser across stage-tamagotchi Electron, stage-web, and stage-pocket mobile web layouts. Use when uploading and verifying contributor-supplied Live2D ZIP, VRM, or MMD ZIP/PMX/PMD files through AIRI's model selector, including onboarding bypass, format-specific import…

moeru-ai/airi · 87 tokens

opencli-sitemap-author

Use when creating or maintaining OpenCLI site sitemaps: agent-facing navigation, page-state, action, workflow, API-reference, pitfall, and fallback knowledge for a website. Use after browser exploration discovers durable site context, when a sitemap is stale, or when promoting local site knowledge into the repo.

jackwener/OpenCLI · 67 tokens

debug-optimize-lcp

Guides debugging and optimizing Largest Contentful Paint (LCP) using Chrome DevTools MCP tools. Use this skill whenever the user asks about LCP performance, slow page loads, Core Web Vitals optimization, or wants to understand why their page's main content takes too long to appear. Also use when the user mentions…

ChromeDevTools/chrome-devtools-mcp · 99 tokens

pinchtab-mcp

Use this skill when a task requires browser automation through PinchTab's MCP server connected to a remote browser instance. Covers navigation, element interaction, data extraction, form filling, multi-step flows, and session management via MCP tools.

pinchtab/pinchtab · 52 tokens

mintlify-preview

Run the public Mintlify product docs site locally for live preview. Use when previewing or iterating on docs under docs/ (.mdx/.md pages, docs.json nav), or when the user says "start the docs", "run mintlify", "preview the docs site".

latitude-dev/latitude-llm · 69 tokens