react-expert

react-expert is an agent for Claude Code from spjoshis/claude-code-plugins. It costs 47 tokens per session (970 once invoked), scanned A, original, no licence file.

A React development specialist covering React 18 and newer, hooks, performance, state management, Next.js, TypeScript, testing, and production application patterns.

In plain words
What is it for?
Use it to build, improve, test, and troubleshoot production React or Next.js applications.
Why use it?
It helps developers make consistent choices when building and scaling React applications across the interface, data, and testing layers.

Agent for Claude Code

Written for Claude Code: a Claude Code subagent (agents/*.md). Also seen: model in frontmatter.

Good fit Use it to build, improve, test, and troubleshoot production React or Next.js applications.

Compare 6 agents from other repositories ↓
Install with agentmods
npx agentmods add agents/spjoshis/claude-code-plugins/react-expert
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.

Clone the repo
git clone --depth 1 https://github.com/spjoshis/claude-code-plugins

Made for: Claude Code.

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 react-expert

README.md
[![agentmods](https://agentmods.dev/badge/agents/spjoshis/claude-code-plugins/react-expert.svg)](https://agentmods.dev/agents/spjoshis/claude-code-plugins/react-expert)
Your own site
<a href="https://agentmods.dev/agents/spjoshis/claude-code-plugins/react-expert"><img src="https://agentmods.dev/badge/agents/spjoshis/claude-code-plugins/react-expert.svg" alt="Measured on agentmods" height="20"></a>
Per session 47 Only the description is in the session, so the agent can decide to use it. The body loads when it is invoked.
When invoked 970 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 0 findings. A grade says what 26 rules found in the file — not that it is safe.
Origin unknown 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 5.1 $0.00047 $0.00970
Opus 5 $0.00023 $0.00485
Sonnet 5 $0.00009 $0.00194
Haiku 4.5 $0.00005 $0.00097

Measured 4d ago against content hash 47fc881ef331, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-07, from the pricing page.

Security

Grade A, and why

react-expert 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.

plugins/react-development/agents/react-expert.md · 146 lines

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.

Read it on GitHub

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 · 146 lines · 47 tokens per session scan A 47fc881ef331

Subscribe to this mod's changes

react-expert is an agent published in the GitHub repository spjoshis/claude-code-plugins (6 stars, last pushed 7mo ago), with no licence file. It adds 47 tokens to every session and 970 once invoked, about $0.0002 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.

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