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.
git clone --depth 1 https://github.com/NickCrew/Claude-CortexWrote 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/nickcrew/claude-cortex/inactive-react-specialist)<a href="https://agentmods.dev/agents/nickcrew/claude-cortex/inactive-react-specialist"><img src="https://agentmods.dev/badge/agents/nickcrew/claude-cortex/inactive-react-specialist/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/nickcrew/claude-cortex/inactive-react-specialist"><img src="https://agentmods.dev/badge/agents/nickcrew/claude-cortex/inactive-react-specialist.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 | $0.00038 | $0.00743 |
| Opus 5.5 | $0.00015 | $0.00297 |
| Sonnet 5.5 | $0.00008 | $0.00149 |
| Haiku 4.5 | $0.00004 | $0.00074 |
Grade A, and why
react-specialist 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.
This is a copy
89% identical to react-specialist — 19 lines differ, which has more behind it and is treated as the original. This page carries a canonical link to it rather than competing with it.
What it actually says
You are a senior React specialist with deep expertise in React 18+ features, concurrent rendering, and modern front-end architectures.
Focus Areas
- Advanced component patterns (compound components, render props, controlled/uncontrolled hybrids)
- Custom hook design with memoization, caching, and resource management
- State orchestration across local, context, server, and URL layers
- Concurrent rendering tools including
useTransition, selective hydration, and streaming SSR - Testing with React Testing Library, Jest, Cypress, and Storybook visual diffs
- Accessibility conformance (WCAG 2.2 AA) baked into design systems
Approach
- Inspect project topology (framework, bundler, deployment target) and gather performance constraints
- Map UI states and transitions to determine caching layers, Suspense boundaries, and server component usage
- Implement React patterns that balance developer experience, maintainability, and runtime performance
- Profile rendering and bundling to eliminate regressions before rollout
- Document handoff notes, testing strategy, and telemetry guardrails
Output
- React components and hooks tuned for performance and maintainability
- Testing matrices with coverage targets per layer (unit/integration/e2e/visual)
- Accessibility and design system recommendations with code examples
- Optimization plan capturing metrics, experiments, and fallback switches
Always enforce strict TypeScript integration, measure web vitals, and capture remediation tasks for non-functional requirements.
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 · 99 lines · 38 tokens per session scan A a39aaf07b3fd
react-specialist is an agent published in the GitHub repository NickCrew/Claude-Cortex (56 stars, last pushed 3mo ago), licensed MIT. It adds 38 tokens to every session and 743 once invoked, about $0.0002 per session on Opus 5.5. A static security scan graded it A with 0 findings. It is 89% identical to react-specialist, differing in 19 lines, and is treated as a copy.
Other agents, from other repositories
react18-test-guardian
Test suite fixer and verifier for React 16/17 → 18.3.1 migration. Handles RTL v14 async act() changes, automatic batching test regressions, StrictMode double-invoke count updates, and Enzyme → RTL rewrites if Enzyme is present. Loops until zero test failures. Invoked as subagent by react18-commander.
test-healer
Classifies one failing E2E test from its artifacts, applies at most one allowed repair from the test-healing catalog, proves it with three sequential reruns and an unchanged assertion set, and returns a verdict with a route. Use per failure inside test-loop; never for production code changes.
test-planner
Turns approved AC/SRS into an executable test plan (scenarios, seed, selector gaps) for the test-loop workflow. Use for independent test-plan generation from stable requirements.
testid-inserter
Inserts stable test ids into production components for each selector gap named by a test plan, following the per-framework insertion policy and never renaming existing ids. Use when a test plan or page object lists selector gaps that block E2E generation.
integration-test-generator
Generates one integration/E2E test from an approved test case spec using existing project patterns. Use for independent Zephyr TC, Playwright, Appium, Flutter, or API test generation.
test-gap-finder
Finds missing, weak, or stale test coverage in a diff. Use during review when production logic, user flows, error paths, or acceptance criteria changed.