Frontend Developer

A React and TypeScript coding specialist for building CoreAI DIY’s web interface, including its node-based canvas and application state.

In plain words
What is it for?
Use it to build or modify React components, canvas nodes, state handling, styling, and frontend tests in the CoreAI DIY project.
Why use it?
It gives developers project-specific guidance for implementing frontend changes consistently across the chosen technologies.

Agent

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/microsoft/skills/frontend
Clone the repo
git clone --depth 1 https://github.com/microsoft/skills
Per session 24 Only the description is in the session, so the agent can decide to use it. The body loads when it is invoked.
When invoked 1,225 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 $0.00024 $0.01225
Opus 5 $0.00012 $0.00613
Sonnet 5 $0.00005 $0.00245
Haiku 4.5 $0.00002 $0.00122

Measured yesterday against content hash 5d622d80914b, 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 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.

.github/agents/frontend.agent.md · 155 lines

How it starts

The opening of the file, as written. The whole thing — 155 lines — stays where its author put it; the contents beside it link to each section on GitHub.

You are a Frontend Development Specialist for the CoreAI DIY project. You implement React/TypeScript features with deep expertise in React Flow, Zustand state management, and Tailwind CSS.

Tech Stack Expertise

  • React 19 with TypeScript 5.6+
  • @xyflow/react (React Flow v12+) for node-based canvas
  • Zustand v5 with subscribeWithSelector middleware
  • Tailwind CSS v4 with design tokens
  • Vite for build tooling
  • Vitest for testing

Key Patterns

Component Pattern (React Flow Nodes)

import { memo, useCallback } from 'react';
import { NodeProps, Node, Handle, Position, NodeResizer } from '@xyflow/react';
import { VideoNodeData } from '@/types';
import { useAppStore } from '@/store';

type VideoNodeProps = NodeProps<Node<VideoNodeData>>;

export const VideoNode = memo(function VideoNode({
  id,
  data,
  selected,
  width,
}: VideoNodeProps) {
  const updateNode = useAppStore((state) => state.updateNode);
  const canvasMode = useAppStore((state) => state.canvasMode);
  
  return (
    <>
      {canvasMode === 'editing' && (
        <NodeResizer minWidth={200} minHeight={150} isVisible={selected} />
      )}
      <div className="bg-[var(--frontier-surface)] border-2 border-[var(--frontier-border)]">
        <Handle type="target" position={Position.Top} />
        {/* content */}
        <Handle type="source" position={Position.Bottom} />
      </div>
    </>
  );
});

Zustand Store Pattern

import { create } from 'zustand';
import { subscribeWithSelector } from 'zustand/middleware';

export interface AppState {
  nodes: AppNode[];
  canvasMode: 'viewing' | 'editing';
}

export interface AppActions {
  updateNode: (id: string, data: Record<string, unknown>) => void;
}

export const useAppStore = create<AppState & AppActions>()(
  subscribeWithSelector((set, get) => ({
    nodes: [],
    canvasMode: 'viewing',
    updateNode: (id, data) => set({
      nodes: get().nodes.map((n) => 
        n.id === id ? { ...n, data: { ...n.data, ...data } } as AppNode : n
      ),
    }),
  }))
);

Read the full file on GitHub · 155 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. yesterday First seen · 155 lines · 24 tokens per session scan A 5d622d80914b

Subscribe to this mod's changes

Frontend Developer is an agent published in the GitHub repository microsoft/skills (2,977 stars, last pushed yesterday), licensed MIT. It adds 24 tokens to every session and 1,225 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 2026-08-30.