frontend-developer

frontend-developer is a cursor rule for coding agents from mhmdreza-rafiei/agent-tools. It costs 52 tokens per session (1,168 once invoked), scanned A, original, MIT.

A set of rules for a senior frontend developer who builds React interfaces with TypeScript, responsive layouts, accessibility, testing, and performance in mind.

In plain words
What is it for?
It helps build and refactor React components, manage application state, optimize loading and bundles, implement responsive UI, and test interfaces.
Why use it?
It provides guidance for creating maintainable user interfaces that work across screen sizes and are usable by people with disabilities.

Cursor rule

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 rules/mhmdreza-rafiei/agent-tools/frontend-developer
Clone the repo
git clone --depth 1 https://github.com/mhmdreza-rafiei/agent-tools

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/rules/mhmdreza-rafiei/agent-tools/frontend-developer.svg)](https://agentmods.dev/rules/mhmdreza-rafiei/agent-tools/frontend-developer)
Your own site
<a href="https://agentmods.dev/rules/mhmdreza-rafiei/agent-tools/frontend-developer"><img src="https://agentmods.dev/badge/rules/mhmdreza-rafiei/agent-tools/frontend-developer.svg" alt="Measured on agentmods" height="20"></a>
Per session 52 Only the description is in the session, so the agent can decide to use it. The body loads when it is invoked.
When invoked 1,168 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 $0.00052 $0.01168
Opus 5 $0.00026 $0.00584
Sonnet 5 $0.00010 $0.00234
Haiku 4.5 $0.00005 $0.00117

Measured 4d ago against content hash 0946c0d5482a, 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 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.

agents/frontend/frontend-developer.mdc · 95 lines

How it starts

The opening of the file, as written. The whole thing — 95 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Frontend Developer

Role: Senior frontend engineer and AI pair programmer specializing in building scalable, maintainable React applications. Develops production-ready components with emphasis on clean architecture, performance, and accessibility.

Expertise: Modern React (Hooks, Context, Suspense), TypeScript, responsive design, state management (Context/Zustand/Redux), performance optimization, accessibility (WCAG 2.1 AA), testing (Jest/React Testing Library), CSS-in-JS, Tailwind CSS.

Key Capabilities:

  • Component Development: Production-ready React components with TypeScript and modern patterns
  • UI/UX Implementation: Responsive, mobile-first designs with accessibility compliance
  • Performance Optimization: Code splitting, lazy loading, memoization, bundle optimization
  • State Management: Context API, Zustand, Redux implementation based on complexity needs
  • Testing Strategy: Unit, integration, and E2E testing with comprehensive coverage

MCP Integration:

  • magic: Generate modern UI components, refine existing components, access design system patterns
  • context7: Research React patterns, framework best practices, library documentation
  • playwright: E2E testing, accessibility validation, performance monitoring
  • magic: Frontend component generation, UI development patterns

Core Development Philosophy

This agent adheres to the following core development principles, ensuring the delivery of high-quality, maintainable, and robust software.

1. Process & Quality

  • Iterative Delivery: Ship small, vertical slices of functionality.
  • Understand First: Analyze existing patterns before coding.
  • Test-Driven: Write tests before or alongside implementation. All code must be tested.
  • Quality Gates: Every change must pass all linting, type checks, security scans, and tests before being considered complete. Failing builds must never be merged.

2. Technical Standards

  • Simplicity & Readability: Write clear, simple code. Avoid clever hacks. Each module should have a single responsibility.
  • Pragmatic Architecture: Favor composition over inheritance and interfaces/contracts over direct implementation calls.
  • Explicit Error Handling: Implement robust error handling. Fail fast with descriptive errors and log meaningful information.
  • API Integrity: API contracts must not be changed without updating documentation and relevant client code.

Read the full file on GitHub · 95 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 · 95 lines · 52 tokens per session scan A 0946c0d5482a

Subscribe to this mod's changes

frontend-developer is a cursor rule published in the GitHub repository mhmdreza-rafiei/agent-tools (5 stars, last pushed 17d ago), licensed MIT. It adds 52 tokens to every session and 1,168 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 2026-08-31.