agentmods.dev

ck:frontend-development

A set of conventions for building React and TypeScript frontends with routing, data fetching, styling, and performance patterns. React is a JavaScript framework for assembling user interfaces from reusable components.

In plain words
What is it for?
Use it when creating React components and pages, fetching data, setting up routes, styling with MUI, and improving loading performance.
Why use it?
It gives developers consistent rules for organizing components, loading data, styling screens, and handling heavy content. This reduces ad-hoc frontend decisions across a project.

Skill for Claude CodeCodex

88 3d ago A scan 44 tokens copy · 92% MIT
View the source file manhvann/codexkit
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/manhvann/codexkit/frontend-development
Any agent
npx skills add manhvann/codexkit --skill frontend-development
Clone the repo
git clone --depth 1 https://github.com/manhvann/codexkit

Made for: Claude Code, Codex.

Per session 44 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 2,723 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 0 findings. Scan, not verified.
Origin 92% copy Near-identical to another mod 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 $0.00044 $0.02723
Opus 5 $0.00022 $0.01362
Sonnet 5 $0.00009 $0.00545
Haiku 4.5 $0.00004 $0.00272

Measured 2d ago against content hash d2ecde80ed80, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

Grade A, and why

ck:frontend-development scanned grade A with 0 findings 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.

Nothing flagged

None of the 26 patterns this scan looks for appear in this file: no shell pipes, no recursive deletes, no credential paths, no hidden text, no instruction-override or anti-refusal phrasing, no agent-config snooping. That is not a guarantee, it is the absence of the things that are checkable.

Origin

This is a copy

92% identical to frontend-dev-guidelines — 8 lines differ, which has more behind it and is treated as the original. This page carries a canonical link to it rather than competing with it.

.agents/skills/frontend-development/SKILL.md · 401 lines

How it starts

The opening of the file, as written. The whole thing — 401 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Frontend Development Guidelines

Purpose

Comprehensive guide for modern React development, emphasizing Suspense-based data fetching, lazy loading, proper file organization, and performance optimization.

When to Use This Skill

  • Creating new components or pages
  • Building new features
  • Fetching data with TanStack Query
  • Setting up routing with TanStack Router
  • Styling components with MUI v7
  • Performance optimization
  • Organizing frontend code
  • TypeScript best practices

Quick Start

New Component Checklist

Creating a component? Follow this checklist:

  • Use React.FC<Props> pattern with TypeScript
  • Lazy load if heavy component: React.lazy(() => import())
  • Wrap in <SuspenseLoader> for loading states
  • Use useSuspenseQuery for data fetching
  • Import aliases: @/, ~types, ~components, ~features
  • Styles: Inline if <100 lines, separate file if >100 lines
  • Use useCallback for event handlers passed to children
  • Default export at bottom
  • No early returns with loading spinners
  • Use useMuiSnackbar for user notifications

New Feature Checklist

Creating a feature? Set up this structure:

  • Create features/{feature-name}/ directory
  • Create subdirectories: api/, components/, hooks/, helpers/, types/
  • Create API service file: api/{feature}Api.ts
  • Set up TypeScript types in types/
  • Create route in routes/{feature-name}/index.tsx
  • Lazy load feature components
  • Use Suspense boundaries
  • Export public API from feature index.ts

Import Aliases Quick Reference

Alias Resolves To Example
@/ src/ import { apiClient } from '@/lib/apiClient'
~types src/types import type { User } from '~types/user'
~components src/components import { SuspenseLoader } from '~components/SuspenseLoader'
~features src/features import { authApi } from '~features/auth'

Read the full file on GitHub · 401 lines

Files

What ships with it

10 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 · 401 lines · 44 tokens per session scan A d2ecde80ed80

Subscribe to this mod's changes

ck:frontend-development is a skill published in the GitHub repository manhvann/codexkit (88 stars, last pushed 3d ago), licensed MIT. It adds 44 tokens to every session and 2,723 once invoked, about $0.0002 per session on Opus 5. A static security scan graded it A with 0 findings. It is 92% identical to frontend-dev-guidelines, differing in 8 lines, and is treated as a copy.

FrontendLanguages
Related

Other skills, from other repositories

systematic-debugging

Use when encountering any bug, test failure, or unexpected behavior, before proposing fixes.

obra/superpowers · 21 tokens

next-cache-components-adoption

Turn on Cache Components in a Next.js app and resolve the blocking routes it surfaces. Use when the user wants to enable, adopt, or migrate to Cache Components, flip the cacheComponents flag, work through a flood of blocking-prerender / instant validation errors, run the cache-components-instant-false codemod, or…

vercel/next.js · 95 tokens

babysit-pr

Babysit a GitHub pull request after creation by continuously polling review comments, CI checks/workflow runs, and mergeability state until the PR is merged/closed or user help is required. Diagnose failures, retry likely flaky failures up to 3 times, auto-fix/push branch-related issues when appropriate, and keep…

openai/codex · 114 tokens

imagegen

Generate or edit raster images when the task benefits from AI-created bitmap visuals such as photos, illustrations, textures, sprites, mockups, or transparent-background cutouts. Use when Codex should create a brand-new image, transform an existing image, or derive visual variants from references, and the output…

openai/codex · 113 tokens

cpu-profile-analysis

Analyze V8/Chrome CPU profiles (.cpuprofile) and DevTools trace files (Trace-.json). Use when: profiling performance, investigating slow functions, comparing code paths, finding bottlenecks, analyzing timeToRequest, understanding call trees from sampling profiler data, analyzing layout/paint/rendering, investigating…

microsoft/vscode · 71 tokens

next-cache-components-optimizer

Drive a Next.js route to instant navigation by setting up an agentic loop, under Cache Components / PPR, on initial load (hard navigation) and client-side navigation (soft navigation). Encode the goal as a failing @next/playwright instant() e2e and work it to green, one verified route at a time; the shipped test then…

vercel/next.js · 170 tokens