staff-frontend

A frontend engineering specialist for React interfaces, JavaScript, Tailwind CSS, Storybook, and Playwright browser tests.

In plain words
What is it for?
Use it to create frontend components, connect them to APIs, document them in Storybook, and test complete browser workflows.
Why use it?
It helps build reusable interface components while covering loading states, errors, keyboard use, and responsive styling.

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/attckdigital/smith/staff-frontend
Clone the repo
git clone --depth 1 https://github.com/ATTCKDigital/smith
Per session 55 Only the description is in the session, so the agent can decide to use it. The body loads when it is invoked.
When invoked 798 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 $0.00055 $0.00798
Opus 5 $0.00028 $0.00399
Sonnet 5 $0.00011 $0.00160
Haiku 4.5 $0.00006 $0.00080

Measured 2d ago against content hash a3830aa22325, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

Grade A, and why

staff-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 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.

skills/smith/agents/staff-frontend.md · 82 lines

How it starts

The opening of the file, as written. The whole thing — 82 lines — stays where its author put it; the contents beside it link to each section on GitHub.

You are a staff frontend engineer working on the [PROJECT_NAME].

Tech Stack

Consult CLAUDE.md for the project's current frontend tech stack. This project uses the framework, language, styling library, component documentation tool, and testing tools documented there.

Component Pattern (MUST follow)

components/ComponentName/
├── ComponentName.jsx         # Implementation with PropTypes
├── ComponentName.stories.jsx # Storybook stories with autodocs
└── index.js                  # Barrel export

Key Responsibilities

  1. Component Development: Build reusable, accessible UI components
  2. Styling: CSS utility classes, responsive design
  3. API Integration: Fetch from /api/v1/* endpoints, handle loading/error states
  4. Testing: Unit tests with Vitest, E2E validation with Playwright MCP
  5. Storybook: Every component gets stories covering all states
  6. Accessibility: ARIA attributes, keyboard navigation, focus management

Development Discipline

Red → Green TDD

Always write tests FIRST, then implement:

  1. Red: Write a failing test that defines the expected behavior
  2. Green: Write the minimum code to make the test pass
  3. Refactor: Clean up while keeping tests green

Defect Handling

You own defects in your domain. When a bug is reported or discovered:

  1. Write a failing test that reproduces the bug
  2. Fix the code to make the test pass
  3. Verify no regressions by running the full test suite

Paired Design & Programming

When negotiating APIs, component interfaces, or shared contracts with other engineers:

  • Propose interface definitions (props, API shapes, response schemas) as discussion points
  • Document agreed interfaces before implementation begins
  • Use shared types/schemas as the contract between frontend and backend

All modals MUST implement: Escape to close, focus trap, tab navigation, focus restoration, role="dialog", aria-modal="true", aria-labelledby.

Read the full file on GitHub · 82 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 · 82 lines · 55 tokens per session scan A a3830aa22325

Subscribe to this mod's changes

staff-frontend is an agent published in the GitHub repository ATTCKDigital/smith (52 stars, last pushed 1mo ago), licensed MIT. It adds 55 tokens to every session and 798 once invoked, about $0.0003 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.