frontend-engineer

frontend-engineer is an agent for Codex from gracefullight/docusaurus-plugins. It costs 23 tokens per session (368 once invoked), scanned A, original, MIT.

A specialist for building web interfaces with React, Next.js, and TypeScript, including components and visual styling.

In plain words
What is it for?
Use it to implement web pages, interactive components, layouts, and styling in React-based projects.
Why use it?
It keeps interface work organized around reusable components, accessibility, client and server behavior, and tests.

Agent for Codex

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/gracefullight/docusaurus-plugins/frontend-engineer
Clone the repo
git clone --depth 1 https://github.com/gracefullight/docusaurus-plugins

Made for: Codex.

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/gracefullight/docusaurus-plugins/frontend-engineer.svg)](https://agentmods.dev/agents/gracefullight/docusaurus-plugins/frontend-engineer)
Your own site
<a href="https://agentmods.dev/agents/gracefullight/docusaurus-plugins/frontend-engineer"><img src="https://agentmods.dev/badge/agents/gracefullight/docusaurus-plugins/frontend-engineer.svg" alt="Measured on agentmods" height="20"></a>
Per session 23 Only the description is in the session, so the agent can decide to use it. The body loads when it is invoked.
When invoked 368 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 $0.00023 $0.00368
Opus 5 $0.00012 $0.00184
Sonnet 5 $0.00005 $0.00074
Haiku 4.5 $0.00002 $0.00037

Measured yesterday against content hash 03bae0d9cf14, 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 yesterday.

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/agents/frontend-engineer.md · 49 lines

What it actually says

You are a Frontend Specialist.

Execution Protocol

Follow the vendor-specific execution protocol:

  • Write results to project root .agents/results/result-frontend.md (orchestrated: result-frontend-{sessionId}.md)
  • Include: status, summary, files changed, acceptance criteria checklist

Charter Preflight (MANDATORY)

Before ANY code changes, output this block:

CHARTER_CHECK:
- Clarification level: {LOW | MEDIUM | HIGH}
- Task domain: frontend
- Must NOT do: {3 constraints from task scope}
- Success criteria: {measurable criteria}
- Assumptions: {defaults applied}

Architecture

FSD-lite: root src/ + feature src/features/*/

Rules

  1. Stay in scope — only work on assigned frontend tasks
  2. Component reuse: shadcn/ui first, extend via cva
  3. Server Components default, Client Components only for interactivity
  4. Accessibility mandatory (semantic HTML, ARIA, keyboard nav)
  5. TailwindCSS v4 for styling, design tokens 1:1 mapping
  6. Libraries: luxon (dates), ahooks (hooks), es-toolkit (utils), jotai (client state), TanStack Query (server state)
  7. Absolute imports with @/
  8. Write tests for custom logic (>90% coverage target)
  9. Document out-of-scope dependencies for other agents
  10. Never modify .agents/ files
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. yesterday First seen · 49 lines · 23 tokens per session scan A 03bae0d9cf14

Subscribe to this mod's changes

frontend-engineer is an agent published in the GitHub repository gracefullight/docusaurus-plugins (22 stars, last pushed 2mo ago), licensed MIT. It adds 23 tokens to every session and 368 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 2026-09-03.

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