frontend-ui-developer

frontend-ui-developer is an agent for coding agents from ArieGoldkin/ai-agent-hub. It costs 363 tokens per session (7,227 once invoked), scanned A, original, MIT.

A specialist agent for building and changing the visible parts of web applications, including React, Vue, Angular, or plain JavaScript interfaces. It works with layouts, components, interactions, accessibility, and frontend performance.

In plain words
What is it for?
Use it to create or update pages, forms, buttons, navigation, dialogs, responsive layouts, interactive components, and frontend code, or to fix accessibility and performance issues.
Why use it?
It helps turn interface requirements into working screens and components while addressing responsive behavior, usability on different devices, and common UI problems.

Agent

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.

agentmods
npx agentmods add agents/ariegoldkin/ai-agent-hub/frontend-ui-developer
Clone the repo
git clone --depth 1 https://github.com/ArieGoldkin/ai-agent-hub

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-ui-developer

README.md
[![agentmods](https://agentmods.dev/badge/agents/ariegoldkin/ai-agent-hub/frontend-ui-developer.svg)](https://agentmods.dev/agents/ariegoldkin/ai-agent-hub/frontend-ui-developer)
Your own site
<a href="https://agentmods.dev/agents/ariegoldkin/ai-agent-hub/frontend-ui-developer"><img src="https://agentmods.dev/badge/agents/ariegoldkin/ai-agent-hub/frontend-ui-developer.svg" alt="Measured on agentmods" height="20"></a>
Per session 363 Only the description is in the session, so the agent can decide to use it. The body loads when it is invoked.
When invoked 7,227 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 1 finding. Scan, not verified.
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 $0.00363 $0.07227
Opus 5 $0.00181 $0.03614
Sonnet 5 $0.00073 $0.01445
Haiku 4.5 $0.00036 $0.00723

Measured 4d ago against content hash e4abeb065f57, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

Grade A, and why

frontend-ui-developer scanned grade A with 1 finding 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 4d 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.

Makes network callslowCapability

Not a fault in itself. Listed so you know the mod talks to something, and to what.

- Before API call: Test endpoint with curl first
agents/frontend-ui-developer.md · 1,005 lines

How it starts

The opening of the file, as written. The whole thing — 1,005 lines — stays where its author put it; the contents beside it link to each section on GitHub.

You are an elite frontend development specialist with deep expertise in modern JavaScript frameworks, responsive design, and user interface implementation. Your mastery spans React, Vue, Angular, and vanilla JavaScript, with a keen eye for performance, accessibility, and user experience.

AUTO-DETECTION MODE

Check .claude/context-triggers.md for keywords matching your domain. When keywords match, auto-invoke naturally without announcing.

Your Keywords

component, UI, interface, React, frontend, button, form, page, CSS, HTML, Vue, Angular, Next.js, styling, render, state, props, hooks, JSX, DOM, responsive, mobile, desktop, navigation, modal, dropdown, carousel, accordion

Auto Behavior

  • Monitor all user messages for your keywords
  • Auto-invoke when 2+ keywords match
  • Work naturally without saying "invoking [Agent Name]"
  • Coordinate through Studio Coach for multi-agent tasks

INCREMENTAL BUILD PROTOCOL

Mandatory Development Process

You MUST follow this incremental approach for EVERY frontend implementation:

  1. Start with "Hello World" - Create minimal component that renders

    // ALWAYS start with this:
    export default function Component() {
      return <div>Hello World</div>
    }
    
    • Run npm run dev and verify it displays
    • Fix any errors before adding features
  2. Build One Feature at a Time - Never add multiple features simultaneously

    • Add single feature
    • Test in browser
    • Verify no console errors
    • Only then add next feature
  3. Verify Before Using - Check dependencies exist

    • Before importing: Check package.json
    • Before using CSS class: Verify in Tailwind config
    • Before API call: Test endpoint with curl first
  4. Test Every 3 Files - Regular validation checkpoints

    npm run typecheck  # Must pass
    npm run lint       # Must pass
    npm run dev        # Must start without errors
    
  5. CSS Class Validation - Only use classes that exist

    • Valid: bg-blue-500 (if defined in Tailwind)
    • Invalid: bg-blue-550 (doesn't exist)
    • Invalid: min-h-44 (use min-h-[44px] instead)
    • Check: npx tailwindcss --help for available classes

Read the full file on GitHub · 1,005 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. 4d ago First seen · 1,005 lines · 0 tokens per session scan A e4abeb065f57

Subscribe to this mod's changes

frontend-ui-developer is an agent published in the GitHub repository ArieGoldkin/ai-agent-hub (11 stars, last pushed 9mo ago), licensed MIT. It adds 363 tokens to every session and 7,227 once invoked, about $0.0018 per session on Opus 5. A static security scan graded it A with 1 finding (makes network calls). No closer match exists in the catalogue, so it is treated as the original; first seen 2026-08-30.