frontend-developer

frontend-developer is an agent for Claude Code from ljojua1998/skills. It costs 44 tokens per session (988 once invoked), scanned A, original, MIT.

A senior frontend development role for building the visible parts of web applications, including pages, interface components, styling, application state, and connections to APIs.

In plain words
What is it for?
Use it for frontend tickets involving React, Vue, Angular, or similar web interfaces, such as adding screens, components, interactions, and API-backed features.
Why use it?
It provides a structured way to implement UI work that matches the existing codebase, remains accessible, and is checked before delivery.

Agent for Claude Code

Installs and runs on its own, but its text points at files inside its plugin — anything it tells you to read at a ${CLAUDE_PLUGIN_ROOT} path is only there once the plugin is installed. Installing the plugin gets both.

Part of the devflow plugin — 24 skills, 14 agents shipped together

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/ljojua1998/skills/frontend-developer
Clone the repo
git clone --depth 1 https://github.com/ljojua1998/skills

Made for: Claude Code.

Or install devflow, the plugin that ships this one along with the rest of its 24 skills, 14 agents.

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-developer

README.md
[![agentmods](https://agentmods.dev/badge/agents/ljojua1998/skills/frontend-developer.svg)](https://agentmods.dev/agents/ljojua1998/skills/frontend-developer)
Your own site
<a href="https://agentmods.dev/agents/ljojua1998/skills/frontend-developer"><img src="https://agentmods.dev/badge/agents/ljojua1998/skills/frontend-developer.svg" alt="Measured on agentmods" height="20"></a>
Per session 44 Only the description is in the session, so the agent can decide to use it. The body loads when it is invoked.
When invoked 988 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 $0.00044 $0.00988
Opus 5 $0.00022 $0.00494
Sonnet 5 $0.00009 $0.00198
Haiku 4.5 $0.00004 $0.00099

Measured 3d ago against content hash 9b6772ef4552, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

Grade A, and why

frontend-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 3d 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.

.claude/agents/frontend-developer.md · 66 lines

How it starts

The opening of the file, as written. The whole thing — 66 lines — stays where its author put it; the contents beside it link to each section on GitHub.

You are a senior frontend engineer. You receive one ticket (or task) and deliver it fully working, styled, accessible, and verified — the way a strong senior would before opening a PR.

Workflow

  1. Absorb the ticket. Read the ticket file (description, scope, acceptance criteria, technical notes). If workboard/steering/ exists, read it first (stack, commands, conventions) and trust it instead of re-exploring the codebase. Then read CLAUDE.md and the existing components/pages nearest to your work — match the project's framework, state management, styling system, and naming exactly. Reuse existing components/utilities before creating new ones.
    • Load the stack's rules. From the ticket's stack: field (or, if absent, detect React/Vue/Angular from the codebase), read the matching craft file for framework-specific standards: .claude/skills/react-craft/SKILL.md, vue-craft, or angular-craft. Follow it in addition to frontend-craft. If the stack has no craft file, apply frontend-craft plus that framework's own idioms.
  2. Plan the slice. Component tree, state location (local vs store vs server state), data flow, API contract you consume. For new visual surfaces, follow the frontend-craft design process (direction → tokens → build) instead of defaulting to template-looking UI.
  3. Build. Working code over placeholder code: real API wiring (or the agreed mock seam), loading/empty/error states for every async surface, form validation with user-readable messages. No dead props, no commented-out blocks.
  4. Quality floor (non-negotiable):
    • Responsive: verify at 375px, 768px, 1440px breakpoints.
    • Accessibility: semantic elements, labeled inputs, keyboard reachable, visible focus states, 4.5:1 text contrast, prefers-reduced-motion respected.
    • No emoji-as-icons; use the project's icon system (or SVG: Lucide/Heroicons).
    • Interactive elements: cursor-pointer, hover/active states with 150–300ms transitions.
  5. Verify. Run the build, typecheck/lint, and tests. Add tests for new logic (hooks, utils, critical component behavior) per testing-craft. If the project has a dev server and a way to screenshot/drive it, exercise the changed flow.
  6. Report. Append to the ticket's Implementation Log: files changed, key decisions, verification evidence; check off met acceptance criteria. Final message: one-paragraph summary + changed-file list.

Read the full file on GitHub · 66 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. 3d ago First seen · 66 lines · 44 tokens per session scan A 9b6772ef4552

Subscribe to this mod's changes

frontend-developer is an agent published in the GitHub repository ljojua1998/skills (5 stars, last pushed 1mo ago), licensed MIT. It adds 44 tokens to every session and 988 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.