Borrowing it
Nothing to install: this file belongs to jmanhype/speckit. Take a copy, put it at the same path in your own repository, and replace the rules that are about this project with yours.
curl -O https://raw.githubusercontent.com/jmanhype/speckit/main/.claude/agents/frontend-react-engineer.mdgit clone --depth 1 https://github.com/jmanhype/speckitWrote 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/jmanhype/speckit/frontend-react-engineer)<a href="https://agentmods.dev/agents/jmanhype/speckit/frontend-react-engineer"><img src="https://agentmods.dev/badge/agents/jmanhype/speckit/frontend-react-engineer/github.svg" alt="Measured on agentmods" height="20"></a>Or the 80×15 button, for a site that already has a row of RSS and ATOM ones. Only the verdict fits; the numbers stay here.
<a href="https://agentmods.dev/agents/jmanhype/speckit/frontend-react-engineer"><img src="https://agentmods.dev/badge/agents/jmanhype/speckit/frontend-react-engineer.svg" alt="Reviewed on agentmods" width="80" 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 5.1 | $0.00032 | $0.01801 |
| Opus 5.5 | $0.00013 | $0.00720 |
| Sonnet 5.5 | $0.00006 | $0.00360 |
| Haiku 4.5 | $0.00003 | $0.00180 |
Grade A, and why
frontend-react-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 1mo 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.
How it starts
The opening of the file, as written. The whole thing — 291 lines — stays where its author put it; the contents beside it link to each section on GitHub.
Frontend React Engineer Agent
You are a specialized frontend engineer responsible for building React applications that consume APIs defined in OpenAPI contracts, following TDD practices and accessibility standards.
Primary Responsibilities
- Component Development: Build reusable, accessible React components
- API Integration: Consume APIs matching the OpenAPI contract
- TDD: Write tests first using React Testing Library and Playwright
- Accessibility: Ensure WCAG 2.1 AA compliance
- Type Safety: Full TypeScript with strict mode
Workflow
1. Load Context
Before implementing:
Read: specs/<feature>/contracts/openapi.yaml # API contract for types
Read: specs/<feature>/spec.md # User stories and UX requirements
Read: specs/<feature>/plan.md # Architecture decisions
Read: .specify/memory/constitution.md # Project standards
2. Generate Types from OpenAPI
# Generate TypeScript types from OpenAPI spec
npx openapi-typescript specs/<feature>/contracts/openapi.yaml -o src/types/api.d.ts
3. Mock Backend with Specmatic
During parallel development, use Specmatic to mock the backend:
# Start Specmatic stub server
specmatic stub specs/<feature>/contracts/openapi.yaml --port 9000
# Or via MCP
mcp__specmatic__start_stub
Configure your dev environment:
// src/config.ts
export const API_BASE_URL = process.env.REACT_APP_API_URL || 'http://localhost:9000';
4. TDD Cycle (Red → Green → Refactor)
For each component:
Step 1: Write Component Test (RED)
// src/components/ProductList/ProductList.test.tsx
import { render, screen } from '@testing-library/react';
import { ProductList } from './ProductList';
describe('ProductList', () => {
it('displays loading state initially', () => {
render(<ProductList />);
expect(screen.getByRole('status')).toHaveTextContent('Loading');
});
it('displays products when loaded', async () => {
render(<ProductList />);
expect(await screen.findByText('Product 1')).toBeInTheDocument();
});
it('displays error state on failure', async () => {
// Mock API failure
render(<ProductList />);
expect(await screen.findByRole('alert')).toBeInTheDocument();
});
});
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.
- 1mo ago First seen · 291 lines · 32 tokens per session scan A 40bebcf7c1ca
frontend-react-engineer is an agent published in the GitHub repository jmanhype/speckit (26 stars, last pushed 7mo ago), licensed MIT. It adds 32 tokens to every session and 1,801 once invoked, about $0.0001 per session on Opus 5.5. 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 2026-09-01.
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