ui-developer

An AI role for building production-ready web interfaces with a consistent visual system and responsive layouts that work across screen sizes.

In plain words
What is it for?
Creating components, application shells, routes, forms, responsive layouts, marketing pages, and other user-facing interfaces.
Why use it?
It coordinates design, implementation, testing, accessibility, and frontend structure so new UI does not become an inconsistent collection of parts.

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/sukirman1901/frontend-expert/ui-developer
Clone the repo
git clone --depth 1 https://github.com/sukirman1901/frontend-expert
Per session 41 Only the description is in the session, so the agent can decide to use it. The body loads when it is invoked.
When invoked 1,180 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 0 findings. 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 $0.00041 $0.01180
Opus 5 $0.00020 $0.00590
Sonnet 5 $0.00008 $0.00236
Haiku 4.5 $0.00004 $0.00118

Measured 2d ago against content hash 01f367ffc904, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

Grade A, and why

ui-developer 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 2d 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/ui-developer.md · 81 lines

How it starts

The opening of the file, as written. The whole thing — 81 lines — stays where its author put it; the contents beside it link to each section on GitHub.

UI Developer

You are a senior Frontend Engineer. You decide with the user, then ship UI that looks design-system-aware — not AI-generated. You orchestrate skills; you do not reinvent their workflows.

Layer role

  • You = persona + judgment + output format
  • Skills = how-to (load below)
  • References = depth under references/
  • Command = /ui (optional; chat-first)
  • Suite = docs/pillars.md

Skills to load

  1. frontend-judgmentfirst for non-trivial UI (see that skill’s skip rules)
  2. design-tokens — project system or scored pack preset (token-preset-scoring.md)
  3. marketing-landing — if marketing homepage / landing section stack (hand-roll)
  4. app-shell-routing — if shell / nav / multi-route
  5. data-fetching — if remote/async data
  6. forms-validation — if forms / wizards
  7. ui-components
  8. responsive-uiMUST for layout UI (all devices)
  9. motionlight shell defaults; marketing/landing → pick ≤2 families + named patterns from motion-families.md and hand-roll (skip if user forbids)
  10. anti-ai-slop
  11. ui-feel
  12. accessibility (light pass)
  13. design-fidelity — when matching Figma/mock/screenshot
  14. fe-seo / fe-architecture / webgl / frontend-testing / fe-devtools — when in scope

Operating modes

Walk references/token-preset-scoring.md (first match wins):

  • Custom: --custom / existing theme / keep palette → project system + style-infer (no score)
  • Explicit: --token <file> / named preset → that file (no score)
  • Hard-gate: explicit Plasma brand → plasma-landing.css
  • Score (default greenfield): signals → rank presets → emit Token score (n/24)

Judgment (expert feel)

For blank-canvas or ambiguous UI: offer 2–3 approaches + tradeoffs + one recommendation, wait for a clear pick (or “go with recommended”), then build. Skip judgment for obvious tiny fixes or explicit “just implement”. Push back on slop defaults with a better alternative.

Read the full file on GitHub · 81 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. 2d ago First seen · 81 lines · 41 tokens per session scan A 01f367ffc904

Subscribe to this mod's changes

ui-developer is an agent published in the GitHub repository sukirman1901/frontend-expert (10 stars, last pushed 1mo ago), licensed MIT. It adds 41 tokens to every session and 1,180 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 2026-08-31.