vercel-react-best-practices

vercel-react-best-practices is a skill for Claude Code from FlorianBruniaux/starmapper. It costs 51 tokens per session (1,494 once invoked), scanned A, original, no licence file.

A set of React and Next.js performance guidelines from Vercel’s engineering team. React is a library for building user interfaces, while Next.js is a React framework for web applications.

In plain words
What is it for?
Use it when writing, reviewing, or changing React or Next.js code, especially MapLibre maps, data fetching, and bundle size.
Why use it?
It helps identify and avoid common causes of slow pages, large downloads, and inefficient data loading.

Skill for Claude Code

Written for Claude Code: allowed-tools in frontmatter. Also seen: installed under .agents/ (shared by several agents).

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 skills/florianbruniaux/starmapper/vercel-react-best-practices
Any agent
npx skills add FlorianBruniaux/starmapper --skill vercel-react-best-practices
Clone the repo
git clone --depth 1 https://github.com/FlorianBruniaux/starmapper

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 vercel-react-best-practices

README.md
[![agentmods](https://agentmods.dev/badge/skills/florianbruniaux/starmapper/vercel-react-best-practices.svg)](https://agentmods.dev/skills/florianbruniaux/starmapper/vercel-react-best-practices)
Your own site
<a href="https://agentmods.dev/skills/florianbruniaux/starmapper/vercel-react-best-practices"><img src="https://agentmods.dev/badge/skills/florianbruniaux/starmapper/vercel-react-best-practices.svg" alt="Measured on agentmods" height="20"></a>
Per session 51 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 1,494 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 0 findings. Scan, not verified.
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 $0.00051 $0.01494
Opus 5 $0.00026 $0.00747
Sonnet 5 $0.00010 $0.00299
Haiku 4.5 $0.00005 $0.00149

Measured 6d ago against content hash 75c171609158, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-06, from the pricing page.

Security

Grade A, and why

vercel-react-best-practices 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 6d 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.

.agents/skills/vercel-react-best-practices/SKILL.md · 164 lines

The source is not reproduced here

A licence we could not identify

The repository carries a LICENSE file, but it is custom or dual enough that GitHub cannot name it and neither can this catalogue. Unknown terms are not permission, so the body is not copied here. Read the licence at the source and decide for yourself.

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. 6d ago First seen · 164 lines · 51 tokens per session scan A 75c171609158

Subscribe to this mod's changes

vercel-react-best-practices is a skill published in the GitHub repository FlorianBruniaux/starmapper (83 stars, last pushed 4d ago), with no licence file. It adds 51 tokens to every session and 1,494 once invoked, about $0.0003 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.

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