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.
npx agentmods add agents/alexmmatos/essentials-claude-code/frontend-developergit clone --depth 1 https://github.com/alexmmatos/essentials-claude-codeWrote 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.
[](https://agentmods.dev/agents/alexmmatos/essentials-claude-code/frontend-developer)<a href="https://agentmods.dev/agents/alexmmatos/essentials-claude-code/frontend-developer"><img src="https://agentmods.dev/badge/agents/alexmmatos/essentials-claude-code/frontend-developer.svg" alt="Measured on agentmods" height="20"></a>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.
| Model | Per session | Once invoked |
|---|---|---|
| Fable 5 | $0.00027 | $0.00853 |
| Opus 5 | $0.00014 | $0.00426 |
| Sonnet 5 | $0.00005 | $0.00171 |
| Haiku 4.5 | $0.00003 | $0.00085 |
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 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.
The source is not reproduced here
No licence file
A repository with no LICENSE is all rights reserved by default, so the body is not copied here. The metadata, the measurements and the link are.
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.
- yesterday First seen · 134 lines · 27 tokens per session scan A f0d9e9c05f3e
frontend-developer is an agent published in the GitHub repository alexmmatos/essentials-claude-code (1 stars, last pushed 1mo ago), with no licence file. It adds 27 tokens to every session and 853 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.
Other agents, from other repositories
react-frontend
React Frontend Execution Agent.
react-expert
Use when: package.json has React but NO next.config., Vite/CRA bundler, SPA architecture. Do NOT use for: Next.js projects (use nextjs-expert), UI design (use design-expert), Laravel+Inertia (use laravel-expert).
fixer
Applies Codex code-review findings to the code tree: reads the cited issues, makes the minimum targeted fix per finding, runs relevant verification, and reports the structured result. Dispatch when a code-review artifact is ready to act on. Context: A Codex code-review artifact exists with cited findings. user: "Apply…
fintech-frontend-engineer
Fintech frontend specialist. Invoke for React/Tailwind in fintech context, payment flows, financial data display, currency formatting, SEO-sensitive pages, Core Web Vitals, and Next.js App Router. Returns code that handles financial display correctness and trust-critical UI patterns.
aichan
Frontend Specialist for UI/UX development. Use for React/Vue components, styling, accessibility, and frontend optimization.
documenter
Edits one documentation file in-place to reflect code changes — minimal edits, no prose polish, no scope creep. Operates in UPDATE mode (file exists) or CREATE mode (file is new). Dispatched by /hyperclaude:hyper-docs-sync once per affected doc. Context: hyper-docs-sync identified a doc that needs updating after a…