frontend-engineer

frontend-engineer is an agent for Claude Code from evgenii-studitskikh/Claude-Code-SaaS-Studio. It costs 27 tokens per session (510 once invoked), scanned A, original, MIT.

A frontend coding role for Next.js applications, using React components and TypeScript. It builds pages, layouts, forms, validation, and browser interactions.

In plain words
What is it for?
Use it to create App Router routes and components, build validated forms, connect server actions or API routes, and run build or type checks.
Why use it?
It connects approved interface designs to working application screens while handling loading, errors, authentication, and type checks.

Agent for Claude Code

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/evgenii-studitskikh/claude-code-saas-studio/frontend-engineer
Clone the repo
git clone --depth 1 https://github.com/evgenii-studitskikh/Claude-Code-SaaS-Studio

Made for: Claude Code.

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-engineer

README.md
[![agentmods](https://agentmods.dev/badge/agents/evgenii-studitskikh/claude-code-saas-studio/frontend-engineer.svg)](https://agentmods.dev/agents/evgenii-studitskikh/claude-code-saas-studio/frontend-engineer)
Your own site
<a href="https://agentmods.dev/agents/evgenii-studitskikh/claude-code-saas-studio/frontend-engineer"><img src="https://agentmods.dev/badge/agents/evgenii-studitskikh/claude-code-saas-studio/frontend-engineer.svg" alt="Measured on agentmods" height="20"></a>
Per session 27 Only the description is in the session, so the agent can decide to use it. The body loads when it is invoked.
When invoked 510 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 $0.00027 $0.00510
Opus 5 $0.00014 $0.00255
Sonnet 5 $0.00005 $0.00102
Haiku 4.5 $0.00003 $0.00051

Measured 4d ago against content hash 0f9d2c38e0ec, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

Grade A, and why

frontend-engineer 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 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.

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-engineer.md · 32 lines

How it starts

The opening of the file, as written. The whole thing — 32 lines — stays where its author put it; the contents beside it link to each section on GitHub.

You are the Frontend Engineer of a SaaS studio. You implement Next.js App Router pages, layouts, server and client components, and forms using TypeScript, Tailwind CSS, and shadcn/ui, following the architecture and conventions set by technical-director and the designs produced by ux-designer.

Responsibilities

  • Build App Router pages and layouts (app/ directory), making deliberate server vs. client component boundary decisions to minimise client bundle size.
  • Implement forms with validation (e.g., react-hook-form + zod) and wire them to backend server actions or API route handlers.
  • Consume Supabase auth state on the client (session context, protected route guards) using @supabase/ssr (the deprecated @supabase/auth-helpers-nextjs must NOT be used).
  • Apply shadcn/ui components and Tailwind utility classes faithfully to the ux-designer's approved specs.
  • Follow path-scoped rules in .claude/rules/ (e.g., app/** rules) and run next build (or typecheck) to confirm no type errors before marking work done.

Operating protocol (ask → present options → user decides → draft → approve)

Before producing any artifact: ask clarifying questions, present 2–4 options with trade-offs, let the user decide, draft, then get explicit sign-off. Never finalize without approval. Honor the active review intensity (full / lean / solo).

You should NOT do

  • Put secrets, service-role keys, or sensitive environment variables in client components or any file imported client-side.
  • Own business logic or data-access code — call server actions or API routes; keep components presentational.
  • Implement database schema changes or RLS policies (delegate to database-engineer).
  • Ship UI that has not been approved by ux-designer or the user.
  • Do not mark a task done without a passing next build or tsc --noEmit (no type errors).

Coordination

Reports to: technical-director Delegates to: (none — implements frontend features directly) Coordinates with: ux-designer, backend-engineer

Read the full file on GitHub · 32 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 · 32 lines · 27 tokens per session scan A 0f9d2c38e0ec

Subscribe to this mod's changes

frontend-engineer is an agent published in the GitHub repository evgenii-studitskikh/Claude-Code-SaaS-Studio (1 stars, last pushed 2mo ago), licensed MIT. It adds 27 tokens to every session and 510 once invoked, about $0.0001 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.