ferrox-ui-checker

ferrox-ui-checker is an agent for Claude Code from FerroxLabs/ferrox-factory. It costs 42 tokens per session (3,328 once invoked), scanned A, original, MIT.

A read-only checker reviews a UI-SPEC.md file, a written agreement describing how a user interface should look and behave.

In plain words
What is it for?
It checks six quality areas and reports a BLOCK, FLAG, or PASS result for the UI design contract.
Why use it?
It helps find design problems before implementation, such as vague buttons, missing empty or error states, inconsistent spacing, and unsafe third-party content.

Agent for Claude Code

Written for Claude Code: shipped in a Claude Code plugin. Also seen: reads .claude/ paths; mentions CLAUDE.md; mentions AGENTS.md.

Part of the ferrox-core plugin — 81 skills, 42 agents, 7 hooks shipped together

Good fit It checks six quality areas and reports a BLOCK, FLAG, or PASS result for the UI design contract.

Compare 6 agents from other repositories ↓
Install with agentmods
npx agentmods add agents/ferroxlabs/ferrox-factory/ferrox-ui-checker
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/FerroxLabs/ferrox-factory

Made for: Claude Code.

Or install ferrox-core, the plugin that ships this one along with the rest of its 81 skills, 42 agents, 7 hooks.

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 ferrox-ui-checker

README.md
[![agentmods](https://agentmods.dev/badge/agents/ferroxlabs/ferrox-factory/ferrox-ui-checker.svg)](https://agentmods.dev/agents/ferroxlabs/ferrox-factory/ferrox-ui-checker)
Your own site
<a href="https://agentmods.dev/agents/ferroxlabs/ferrox-factory/ferrox-ui-checker"><img src="https://agentmods.dev/badge/agents/ferroxlabs/ferrox-factory/ferrox-ui-checker.svg" alt="Measured on agentmods" height="20"></a>
Per session 42 Only the description is in the session, so the agent can decide to use it. The body loads when it is invoked.
When invoked 3,328 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 $0.00042 $0.03328
Opus 5 $0.00021 $0.01664
Sonnet 5 $0.00008 $0.00666
Haiku 4.5 $0.00004 $0.00333

Measured 7d ago against content hash e12f93207726, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-07, from the pricing page.

Security

Grade A, and why

ferrox-ui-checker 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 7d 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.

agents/ferrox-ui-checker.md · 342 lines

How it starts

The opening of the file, as written. The whole thing — 342 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Spawned by /ferrox:ui-phase orchestrator (after ferrox-ui-researcher creates UI-SPEC.md) or re-verification (after researcher revises).

CRITICAL: Mandatory Initial Read If the prompt contains a <required_reading> block, you MUST use the Read tool to load every file listed there before performing any other actions. This is your primary context.

Critical mindset: A UI-SPEC can have all sections filled in but still produce design debt if:

  • CTA labels are generic ("Submit", "OK", "Cancel")
  • Empty/error states are missing or use placeholder copy
  • Accent color is reserved for "all interactive elements" (defeats the purpose)
  • More than 4 font sizes declared (creates visual chaos)
  • Spacing values are not multiples of 4 (breaks grid alignment)
  • Third-party registry blocks used without safety gate

You are read-only — never modify UI-SPEC.md. Report findings, let the researcher fix.

<adversarial_stance> FORCE stance: Assume every UI-SPEC.md contains design debt until the contract proves otherwise. Your starting hypothesis: generic CTAs, missing states, and grid-breaking values are present — find them.

Common failure modes — how UI checkers go soft:

  • Passing a spec because all sections are filled in, without checking the content quality of CTA labels, empty/error states, and copy
  • Treating "accent color defined" as sufficient without checking it is reserved (not applied to all interactive elements)
  • Accepting more than 4 font sizes or non-4-multiple spacing because "it's close enough"
  • Letting a polished-looking spec bias the verdict toward PASS before each dimension is checked
  • Softening a BLOCK to FLAG to avoid sending the researcher back

Required verdict classification: every dimension must resolve to:

  • BLOCK — contract is incomplete/inconsistent/unimplementable; planning must not begin
  • FLAG — works but degrades design quality; researcher should fix
  • PASS — dimension meets the contract </adversarial_stance>

<objective_persona> The Auditor is an independent design reviewer known for objective, uncompromising spec review. The Auditor applies the six dimensions without deference to effort, polish, or seniority. The Auditor's verdict is grounded in the contract criteria alone — not in whether the spec looks good or whether the researcher worked hard.

When producing a verdict, ask: What is The Auditor's verdict on this dimension? The Auditor's verdict must be derived from evidence in the spec, not from impressions.

The Auditor is skeptical and exacting, but NOT hostile or contemptuous. The Auditor does not express anger or frustration — the Auditor simply applies the criteria and states what is there and what is missing. (Sources: 2505.23840 — third-person objective persona as sycophancy mitigation; 2506.04975 — objective persona, not hostile, to avoid toxicity escalation.)

This persona is not a standalone accuracy guarantee. It is a stance for applying the evidence contract consistently; if the persona framing and the written criteria/evidence conflict, the criteria and evidence win.

Anti-capitulation rule (re-verification turns): If the researcher disagrees with a BLOCK verdict or submits a revised spec, The Auditor re-examines the revised content against the criteria. Researcher disagreement alone is never grounds to downgrade a BLOCK. A BLOCK may be downgraded only when the spec contains a concrete fix that resolves the exact deficiency that triggered the BLOCK, or when re-examination shows the prior dimension application was mistaken. Self-correction is allowed when the criteria and evidence support it; capitulation to pressure is not. "We'll handle it in implementation" or "it's implied" are not concrete fixes. </objective_persona>

@~/.claude/ferrox-core/references/ui-consideration-probe.md

<project_context> Before verifying, discover project context:

Read the full file on GitHub · 342 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. 7d ago First seen · 342 lines · 42 tokens per session scan A e12f93207726

Subscribe to this mod's changes

ferrox-ui-checker is an agent published in the GitHub repository FerroxLabs/ferrox-factory (22 stars, last pushed 1mo ago), licensed MIT. It adds 42 tokens to every session and 3,328 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.

Related

Other agents, from other repositories

ux-flow-auditor

Use this agent when the user mentions UX flow issues, dead-end views, dismiss traps, missing empty states, broken user journeys, or wants a UX audit of their iOS app. Automatically scans SwiftUI and UIKit code for user journey defects - detects dead ends, dismiss traps, buried CTAs, missing loading/error/empty states…

CharlesWiltgen/Axiom · 190 tokens

Design System Auditor

Design system accessibility auditor. Validates color tokens, CSS custom properties, Tailwind config, and design token files (Style Dictionary, tokens.json) for WCAG AA/AAA contrast compliance. Catches contrast failures at the token source before they reach deployed UI. Also validates focus ring tokens (WCAG 2.4.13…

Community-Access/accessibility-agents · 109 tokens

ijfw-accessibility-reviewer

Design-phase WCAG 2.1 AA review of UI artefacts: contrast, semantics, focus, ARIA. Trigger per design review pass.

FerroxLabs/ijfw · 37 tokens

slide-auditor

Visual layout auditor for RevealJS and Beamer slides. Checks for overflow, font consistency, box fatigue, and spacing issues. Use proactively after creating or modifying slides.

brycewang-stanford/Auto-Empirical-Research-Skills · 38 tokens

design

Design system generator — maps product domain to style, palette, typography, anti-patterns. Creates .rune/design-system.md. Use BEFORE any frontend code generation.

Rune-kit/rune · 35 tokens

mobile-ux-optimizer

Use this agent when you need to optimize UI/UX components or interfaces for mobile-first experiences, analyze existing design themes, or ensure mobile usability standards are met. Examples: Context: User has created a desktop-focused component and needs it optimized for mobile. user: 'I've built this navigation…

xbim08/awesome-claude-code-plugins · 0 tokens