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catalyst: Skill for Claude Code

.claude/skills/frontend-dev-guidelines/SKILL.md

frontend-dev-guidelines is a skill for Claude Code from dwalleck/catalyst. It costs 76 tokens per session (2,746 once invoked), scanned A, a copy of frontend-dev-guidelines, MIT.

A set of coding guidelines for React and TypeScript front ends, which are the browser-facing parts of web applications. It covers component structure, data loading, navigation, styling with MUI, and performance.

In plain words
What is it for?
Use it when creating React components, pages, or features; fetching data with TanStack Query; setting up TanStack Router navigation; styling with MUI; or improving front-end performance.
Why use it?
It gives developers consistent patterns for building and organizing front-end code. This helps avoid ad hoc loading behavior, scattered files, and common TypeScript or performance problems.

Skill for Claude Code

Written for Claude Code: installed under .claude/.

This is dwalleck/catalyst's own configuration. It tells Claude Code how to work on catalyst itself, so it is not a mod to install elsewhere. Copy it as a starting point and replace the rules that are about this project. Everything catalyst configures →

Needs its repository: it reads a path above its own folder, which exists only inside the repository. The line is import { featureApi } from '../api/featureApi';.

not rated 11repo 11mo ago A scan 76 tokens copy · 95% MIT
View source ↗ dwalleck/catalyst
Reuse

Borrowing it

Nothing to install: this file belongs to dwalleck/catalyst. Take a copy, put it at the same path in your own repository, and replace the rules that are about this project with yours.

Copy the file
curl -O https://raw.githubusercontent.com/dwalleck/catalyst/main/.claude/skills/frontend-dev-guidelines/SKILL.md
Clone the repo
git clone --depth 1 https://github.com/dwalleck/catalyst

Made for: Claude Code.

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-dev-guidelines

README.md
[![agentmods](https://agentmods.dev/badge/skills/dwalleck/catalyst/frontend-dev-guidelines/github.svg)](https://agentmods.dev/skills/dwalleck/catalyst/frontend-dev-guidelines)
Your own site
<a href="https://agentmods.dev/skills/dwalleck/catalyst/frontend-dev-guidelines"><img src="https://agentmods.dev/badge/skills/dwalleck/catalyst/frontend-dev-guidelines/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-dev-guidelines

Your own site · 80×15
<a href="https://agentmods.dev/skills/dwalleck/catalyst/frontend-dev-guidelines"><img src="https://agentmods.dev/badge/skills/dwalleck/catalyst/frontend-dev-guidelines.svg" alt="Reviewed on agentmods" width="80" height="20"></a>
Per session 76 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 2,746 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 95% 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 5.1 $0.00076 $0.02746
Opus 5.5 $0.00030 $0.01098
Sonnet 5.5 $0.00015 $0.00549
Haiku 4.5 $0.00008 $0.00275

Measured 1mo ago against content hash 646f2fb6e25c, method: parsed. Prices are Anthropic first-party input rates as of 2026-10-07, from the pricing page.

Security

Grade A, and why

frontend-dev-guidelines 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 1mo 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

95% identical to frontend-dev-guidelines — 2 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.

.claude/skills/frontend-dev-guidelines/SKILL.md · 399 lines

How it starts

The opening of the file, as written. The whole thing — 399 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 · 399 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. 1mo ago First seen · 399 lines · 76 tokens per session scan A 646f2fb6e25c

Subscribe to this mod's changes

frontend-dev-guidelines is a skill published in the GitHub repository dwalleck/catalyst (11 stars, last pushed 11mo ago), licensed MIT. It adds 76 tokens to every session and 2,746 once invoked, about $0.0003 per session on Opus 5.5. A static security scan graded it A with 0 findings. It is 95% identical to frontend-dev-guidelines, differing in 2 lines, and is treated as a copy.

FrontendLanguagesTypeScript
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