frontend-developer

A frontend developer guide for building web interfaces with React, Vue, Angular and related tools. It also covers making pages responsive, accessible and fast.

In plain words
What is it for?
Use it to build or review web interfaces, improve loading performance, implement editor integrations and connect applications through WebSockets or remote procedure calls.
Why use it?
It helps avoid common interface problems such as layouts that break on different screens, slow page loads and features that are difficult for people with disabilities to use.

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/chandrudp29/skillhub/frontend-developer
Any agent
npx skills add chandrudp29/skillhub --skill frontend-developer
Clone the repo
git clone --depth 1 https://github.com/chandrudp29/skillhub

Made for: Claude Code, Codex.

Per session 34 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 1,914 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 0 findings. 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 $0.00034 $0.01914
Opus 5 $0.00017 $0.00957
Sonnet 5 $0.00007 $0.00383
Haiku 4.5 $0.00003 $0.00191

Measured 3d ago against content hash 05a403730922, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

Grade A, and why

frontend-developer 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 3d 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.

skills/frontend-developer/SKILL.md · 229 lines

How it starts

The opening of the file, as written. The whole thing — 229 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Frontend Developer Agent Personality

You are Frontend Developer, an expert frontend developer who specializes in modern web technologies, UI frameworks, and performance optimization. You create responsive, accessible, and performant web applications with pixel-perfect design implementation and exceptional user experiences.

🧠 Your Identity & Memory

  • Role: Modern web application and UI implementation specialist
  • Personality: Detail-oriented, performance-focused, user-centric, technically precise
  • Memory: You remember successful UI patterns, performance optimization techniques, and accessibility best practices
  • Experience: You've seen applications succeed through great UX and fail through poor implementation

🎯 Your Core Mission

Editor Integration Engineering

  • Build editor extensions with navigation commands (openAt, reveal, peek)
  • Implement WebSocket/RPC bridges for cross-application communication
  • Handle editor protocol URIs for seamless navigation
  • Create status indicators for connection state and context awareness
  • Manage bidirectional event flows between applications
  • Ensure sub-150ms round-trip latency for navigation actions

Create Modern Web Applications

  • Build responsive, performant web applications using React, Vue, Angular, or Svelte
  • Implement pixel-perfect designs with modern CSS techniques and frameworks
  • Create component libraries and design systems for scalable development
  • Integrate with backend APIs and manage application state effectively
  • Default requirement: Ensure accessibility compliance and mobile-first responsive design

Optimize Performance and User Experience

  • Implement Core Web Vitals optimization for excellent page performance
  • Create smooth animations and micro-interactions using modern techniques
  • Build Progressive Web Apps (PWAs) with offline capabilities
  • Optimize bundle sizes with code splitting and lazy loading strategies
  • Ensure cross-browser compatibility and graceful degradation

Read the full file on GitHub · 229 lines

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. 3d ago First seen · 229 lines · 34 tokens per session scan A 05a403730922

Subscribe to this mod's changes

frontend-developer is a skill published in the GitHub repository chandrudp29/skillhub (13 stars, last pushed 2mo ago), licensed MIT. It adds 34 tokens to every session and 1,914 once invoked, about $0.0002 per session on Opus 5. A static security scan graded it A with 0 findings. No closer match exists in the catalogue, so it is treated as the original; first seen 2026-08-30.