A frontend workflow for designing interface components, writing browser-based end-to-end tests, checking accessibility, and reviewing visual changes. Frontend code is the part of an application users see and interact with.

Use it to create components, write Playwright tests, run WCAG accessibility checks, or review a frontend visually.

It brings interface building and verification tasks together, helping catch interaction, accessibility, and visual problems before release.

How matteocervelli/llms configures Claude Code

Reuse

Borrowing it

Nothing to install: this file belongs to matteocervelli/llms. 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/matteocervelli/llms/main/.claude/skills/frontend/SKILL.md

Clone the repo

git clone --depth 1 https://github.com/matteocervelli/llms

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.

README.md

[![agentmods](https://agentmods.dev/badge/skills/matteocervelli/llms/frontend.svg)](https://agentmods.dev/skills/matteocervelli/llms/frontend)

Your own site

<a href="https://agentmods.dev/skills/matteocervelli/llms/frontend"><img src="https://agentmods.dev/badge/skills/matteocervelli/llms/frontend.svg" alt="Measured on agentmods" height="20"></a>

Per session 72 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.

When invoked 2,686 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.

Model	Per session	Once invoked
Fable 5.1	$0.00072	$0.02686
Opus 5	$0.00036	$0.01343
Sonnet 5	$0.00014	$0.00537
Haiku 4.5	$0.00007	$0.00269

Measured 3d ago against content hash 4ad9bb38ad71, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-06, from the pricing page.

Security

Grade A, and why

frontend 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.

The scan reads SKILL.md. This mod also ships 14 executable files (scripts/design-lint.sh, templates/e2e/api-mocking.ts, templates/e2e/auth-setup.ts, …), listed below but not scanned — reading those needs a real analyzer, not pattern matching.

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.

.claude/skills/frontend/SKILL.md · 258 lines

How it starts

The opening of the file, as written. The whole thing — 258 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Frontend — Design, Build & Verify

Unified frontend skill for visual design, component creation, E2E testing, accessibility audits, and visual review. Composes five design dimensions with tech-specific implementations.

Usage

/frontend                        # Show dimensions, suggest next action
/frontend design                 # 6 design dimensions + 9-phase workflow
/frontend component <name>       # Create UI component with variants, tests, preview
/frontend e2e                    # Write Playwright E2E tests (page object model)
/frontend a11y                   # WCAG 2.1 AA accessibility audit
/frontend review                 # Gemini visual review (screenshot + code)
/frontend verify                 # Quick verification decision tree

Workflow

Step 1: Determine Mode

Parse $ARGUMENTS for explicit subcommand. If no arguments:

Check for recent frontend file changes (*.html, *.css, *.ts, *.tsx, *.jinja2, *.scss)
If changes found → suggest /frontend verify
If new project → suggest /frontend design
Otherwise → show all modes

Step 1.5: Load Design System

Before routing to any subcommand, check for a persistent design system file:

Look for .design/system.md in the project root (search from CWD upward, stop at git root)
If found: read it and announce → Design system loaded: [list the Mode + Typography + Color + Depth values]
Treat the loaded values as hard constraints throughout the session — do not contradict them without explicitly noting you're changing a decision and logging it

On /frontend design Phase 1 completion:

Create .design/system.md if it does not exist (use the Design Brief output as seed)
If it exists: update only the fields changed in this session; preserve existing Decisions Log entries
Note: .design/system.md should be committed to version control (it is a project artifact)

After each design phase (typography, color, spatial, etc.):

Update the corresponding section in .design/system.md with the decisions made

Read the full file on GitHub · 258 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.

3d ago First seen · 258 lines · 72 tokens per session scan A 4ad9bb38ad71

Subscribe to this mod's changes

frontend is a skill published in the GitHub repository matteocervelli/llms (25 stars, last pushed 3mo ago), licensed MIT. It adds 72 tokens to every session and 2,686 once invoked, about $0.0004 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.

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llms: Skill for Claude Code