frontend-mastery

frontend-mastery is a skill for Claude Code, Codex from subhansh-dev/agent-maxxing. It costs 30 tokens per session (1,378 once invoked), scanned A, original, MIT.

A set of rules for building user interfaces that are clear, consistent, accessible, and suited to their audience. It covers interaction choices, visual quality, and frontend implementation habits.

In plain words
What is it for?
Use it to design controls, choose icons, organise workflows, match the interface to its product, and keep frontend work consistent with an existing design.
Why use it?
It helps prevent interfaces that look polished but are confusing, inconsistent, or awkward to use.

Skill for Claude CodeCodex

Written for no agent in particular: nothing here depends on one. Also seen: mentions Codex.

Good fit Use it to design controls, choose icons, organise workflows, match the interface to its product, and keep frontend work consistent with an existing design.

Compare 6 skills from other repositories ↓
Install with agentmods
npx agentmods add skills/subhansh-dev/agent-maxxing/04-frontend-mastery
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.

Any agent
npx skills add subhansh-dev/agent-maxxing --skill 04-frontend-mastery
Clone the repo
git clone --depth 1 https://github.com/subhansh-dev/agent-maxxing

Made for: Claude Code, Codex.

Wrote this? Show the measurements

A badge with what this costs and how it scanned, read live from this page, so it follows the numbers instead of freezing them. Markdown for a README, HTML for a documentation site or a project page.

agentmods badge for frontend-mastery

README.md
[![agentmods](https://agentmods.dev/badge/skills/subhansh-dev/agent-maxxing/04-frontend-mastery/github.svg)](https://agentmods.dev/skills/subhansh-dev/agent-maxxing/04-frontend-mastery)
Your own site
<a href="https://agentmods.dev/skills/subhansh-dev/agent-maxxing/04-frontend-mastery"><img src="https://agentmods.dev/badge/skills/subhansh-dev/agent-maxxing/04-frontend-mastery/github.svg" alt="Measured on agentmods" height="20"></a>

Or the 80×15 button, for a site that already has a row of RSS and ATOM ones. Only the verdict fits; the numbers stay here.

agentmods 80×15 button for frontend-mastery

Your own site · 80×15
<a href="https://agentmods.dev/skills/subhansh-dev/agent-maxxing/04-frontend-mastery"><img src="https://agentmods.dev/badge/skills/subhansh-dev/agent-maxxing/04-frontend-mastery.svg" alt="Reviewed on agentmods" width="80" height="20"></a>
Per session 30 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 1,378 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 0 findings. A grade says what 26 rules found in the file — not that it is safe.
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 5.1 $0.00030 $0.01378
Opus 5 $0.00015 $0.00689
Sonnet 5 $0.00006 $0.00276
Haiku 4.5 $0.00003 $0.00138

Measured 5d ago against content hash 84817141e0d0, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-08, from the pricing page.

Security

Grade A, and why

frontend-mastery 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 5d 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.

system-prompts/04-frontend-mastery/SKILL.md · 106 lines

How it starts

The opening of the file, as written. The whole thing — 106 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Frontend Mastery — Design & UI Patterns

Extracted from Codex GPT-5.5 (11,104 lines) and Claude Design (9,199 lines).

Build with Empathy

  • If working with an existing design or given a design framework in context, pay careful attention to existing conventions and ensure consistency.
  • Think deeply about the audience and use that to decide features, layout, components, visual style, on-screen text, and interaction patterns. Using your application should feel rich and sophisticated.
  • Tailor the frontend design for the domain: SaaS/CRM tools should feel quiet, utilitarian, and work-focused. Games can be more illustrative, expressive, animated, and playful.
  • Common workflows should be ergonomic and efficient, yet comprehensive.

Design Instructions

  • Use icons in buttons for tools, swatches for color, segmented controls for modes, toggles/checkboxes for binary settings, sliders/steppers/inputs for numeric values, menus for option sets, tabs for views.
  • Do not use rounded rectangular UI elements with text inside if you could use a familiar symbol or icon instead. Build tooltips for unfamiliar icons.
  • Use lucide icons inside buttons whenever one exists. If a library is enabled in an existing application, use icons from that library.
  • Build feature-complete controls, states, and views that a target user would naturally expect.
  • Do not use visible, in-app text to describe the application's features, functionality, keyboard shortcuts, styling, or how to use the application.
  • Should not make a landing page unless absolutely required; build the actual usable experience as the first screen.

Hero Pages

  • When making a hero page, use a relevant image, generated bitmap image, or immersive full-bleed interactive scene as the background with text over it that is not in a card.
  • Never use a split text/media layout where a card is one side and text is on another side.
  • Never put hero text or the primary experience in a card.
  • Never use a gradient/SVG hero page.
  • Do not create an SVG hero illustration when a real or generated image can carry the subject.
  • For landing-page heroes, make the H1 the brand/product/place/person name or a literal offer/category; put descriptive value props in supporting copy, not the headline.

Read the full file on GitHub · 106 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. 5d ago First seen · 106 lines · 30 tokens per session scan A 84817141e0d0

Subscribe to this mod's changes

frontend-mastery is a skill published in the GitHub repository subhansh-dev/agent-maxxing (2 stars, last pushed 1mo ago), licensed MIT. It adds 30 tokens to every session and 1,378 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 2026-09-03.