What is frontend-fidelity?

A set of frontend tools for recreating a web app’s interface accurately. One part extracts information from the original app, another turns it into buildable specifications, and a third checks the implementation against the original.

Use it when reverse-engineering a web app, preparing a frontend rebuild, documenting a design system, or checking whether a new implementation matches the original.

It gives frontend work a process for recording how an existing interface looks and works, then finding differences after it is rebuilt. This helps catch visual or behavioral drift.

frontend-fidelity — Plugin for Claude Code by big-emotion

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.

Clone the repo

git clone --depth 1 https://github.com/big-emotion/agent-atelier

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/plugins/big-emotion/agent-atelier/frontend-fidelity/github.svg)](https://agentmods.dev/plugins/big-emotion/agent-atelier/frontend-fidelity)

Your own site

<a href="https://agentmods.dev/plugins/big-emotion/agent-atelier/frontend-fidelity"><img src="https://agentmods.dev/badge/plugins/big-emotion/agent-atelier/frontend-fidelity/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.

Your own site · 80×15

<a href="https://agentmods.dev/plugins/big-emotion/agent-atelier/frontend-fidelity"><img src="https://agentmods.dev/badge/plugins/big-emotion/agent-atelier/frontend-fidelity.svg" alt="Reviewed on agentmods" width="80" height="20"></a>

Per session not measured What this adds to a session before it is invoked.

When invoked not measured The manifest loads nothing itself; its 3 skills cost 115 tokens a session between them.

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.

Security

Grade A, and why

frontend-fidelity 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 2mo 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.

plugins/frontend-fidelity/.claude-plugin/plugin.json · 14 lines

What it actually says

{
  "name": "frontend-fidelity",
  "displayName": "Frontend Fidelity",
  "version": "0.2.0",
  "description": "Pixel-fidelity pipeline for frontend work: reverse-ui extracts a complete reproduction kit from any web app, blueprint turns it into a buildable frontend spec, validate-fidelity catches drift between spec, implementation, and the original.",
  "author": {
    "name": "Big Emotion"
  },
  "homepage": "https://github.com/big-emotion/agent-atelier",
  "repository": "https://github.com/big-emotion/agent-atelier",
  "license": "MIT",
  "keywords": ["frontend", "design-system", "reverse-engineering", "ui", "fidelity"]
}

Contents

What it installs

The manifest is a name and a version. 3 skills travel with it, and installing the plugin installs all of them — 115 tokens a session between them. Each is measured on its own page, and each can be installed alone.

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.

2mo ago First seen · 14 lines scan A 854aa9989088

Subscribe to this mod's changes

frontend-fidelity is a plugin published in the GitHub repository big-emotion/agent-atelier (3 stars, last pushed 24d ago), licensed MIT. Its token cost is not measured: this kind of file is read by the harness, not the model. 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 2026-08-31.

CI and CD Claude Code Design and UX Frontend atlassian claude-code-plugin conventional-commits developer-tooling

frontend-fidelity next to 6 plugins from other repositories
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frontend-fidelitybig-emotion/agent-atelier	Plugin	3	24d ago	MIT	A	—	Claude Code
arn-sparkAppsVortex/arness	Plugin	34	yesterday	MIT	A	—	Claude Code
frontend-designharnessprotocol/harness-kit	Plugin	10	2d ago	Apache-2.0	A	—	Claude Code
cyxj-image-studiochenyuxiaojin/xiaochen-skills	Plugin	8	5d ago	MIT	A	—	Claude Code
figbyjunyoung/claude-product-skills	Plugin	5	3d ago	MIT	A	—	Claude Code
visual-genwidnyana/eyay-toolkits	Plugin	8	13d ago	MIT	A	—	Claude Code
excalidraw-diagramswidnyana/eyay-toolkits	Plugin	8	13d ago	MIT	A	—	Claude Code