vercel-react

vercel-react is a skill for Claude Code from martineserios/thebrana. It costs 34 tokens per session (1,795 once invoked), scanned A, a copy of react-performance, MIT.

A set of 70 guidelines for making React and Next.js applications faster and more efficient.

In plain words
What is it for?
Use it when writing, reviewing, refactoring, or optimizing React components, Next.js pages, data fetching, bundle size, and rendering performance.
Why use it?
It highlights common causes of slow applications, such as waiting tasks in sequence, oversized bundles, unnecessary re-renders, and inefficient data loading.

Skill for Claude Code

Written for Claude Code: allowed-tools in frontmatter. Also seen: names the AskUserQuestion tool; mentions AGENTS.md.

Part of the brana plugin — 53 skills, 4 commands, 14 agents shipped together

Good fit Use it when writing, reviewing, refactoring, or optimizing React components, Next.js pages, data fetching, bundle size, and rendering performance.

Compare 6 skills from other repositories ↓
Install with agentmods
npx agentmods add skills/martineserios/thebrana/vercel-react
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.

Any agent
npx skills add martineserios/thebrana --skill vercel-react
Clone the repo
git clone --depth 1 https://github.com/martineserios/thebrana

Made for: Claude Code.

Or install brana, the plugin that ships this one along with the rest of its 53 skills, 4 commands, 14 agents.

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 vercel-react

README.md
[![agentmods](https://agentmods.dev/badge/skills/martineserios/thebrana/vercel-react/github.svg)](https://agentmods.dev/skills/martineserios/thebrana/vercel-react)
Your own site
<a href="https://agentmods.dev/skills/martineserios/thebrana/vercel-react"><img src="https://agentmods.dev/badge/skills/martineserios/thebrana/vercel-react/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.

agentmods 80×15 button for vercel-react

Your own site · 80×15
<a href="https://agentmods.dev/skills/martineserios/thebrana/vercel-react"><img src="https://agentmods.dev/badge/skills/martineserios/thebrana/vercel-react.svg" alt="Reviewed on agentmods" width="80" height="20"></a>
Per session 34 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 1,795 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 91% copy Near-identical to another mod 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 $0.00034 $0.01795
Opus 5.5 $0.00014 $0.00718
Sonnet 5.5 $0.00007 $0.00359
Haiku 4.5 $0.00003 $0.00179

Measured 1mo ago against content hash fe0beb81770d, method: parsed. Prices are Anthropic first-party input rates as of 2026-10-07, from the pricing page.

Security

Grade A, and why

vercel-react 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.

Origin

This is a copy

91% identical to react-performance — 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.

system/skills/acquired/vercel-react/SKILL.md · 152 lines

How it starts

The opening of the file, as written. The whole thing — 152 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Vercel React Best Practices

Comprehensive performance optimization guide for React and Next.js applications, maintained by Vercel. Contains 70 rules across 8 categories, prioritized by impact to guide automated refactoring and code generation.

When to Apply

Reference these guidelines when:

  • Writing new React components or Next.js pages
  • Implementing data fetching (client or server-side)
  • Reviewing code for performance issues
  • Refactoring existing React/Next.js code
  • Optimizing bundle size or load times

Rule Categories by Priority

Priority Category Impact Prefix
1 Eliminating Waterfalls CRITICAL async-
2 Bundle Size Optimization CRITICAL bundle-
3 Server-Side Performance HIGH server-
4 Client-Side Data Fetching MEDIUM-HIGH client-
5 Re-render Optimization MEDIUM rerender-
6 Rendering Performance MEDIUM rendering-
7 JavaScript Performance LOW-MEDIUM js-
8 Advanced Patterns LOW advanced-

Quick Reference

1. Eliminating Waterfalls (CRITICAL)

  • async-cheap-condition-before-await - Check cheap sync conditions before awaiting flags or remote values
  • async-defer-await - Move await into branches where actually used
  • async-parallel - Use Promise.all() for independent operations
  • async-dependencies - Use better-all for partial dependencies
  • async-api-routes - Start promises early, await late in API routes
  • async-suspense-boundaries - Use Suspense to stream content

2. Bundle Size Optimization (CRITICAL)

  • bundle-barrel-imports - Import directly, avoid barrel files
  • bundle-analyzable-paths - Prefer statically analyzable import and file-system paths to avoid broad bundles and traces
  • bundle-dynamic-imports - Use next/dynamic for heavy components
  • bundle-defer-third-party - Load analytics/logging after hydration
  • bundle-conditional - Load modules only when feature is activated
  • bundle-preload - Preload on hover/focus for perceived speed

Read the full file on GitHub · 152 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. 1mo ago First seen · 152 lines · 34 tokens per session scan A fe0beb81770d

Subscribe to this mod's changes

vercel-react is a skill published in the GitHub repository martineserios/thebrana (3 stars, last pushed 3d ago), licensed MIT. It adds 34 tokens to every session and 1,795 once invoked, about $0.0001 per session on Opus 5.5. A static security scan graded it A with 0 findings. It is 91% identical to react-performance, differing in 19 lines, and is treated as a copy.

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