benchmark

A performance-testing skill that checks how quickly web pages load, including measures called Core Web Vitals, and the size of their files.

In plain words
What is it for?
Use it to create performance baselines, compare pull requests, and track page-speed changes over time. It is triggered only when the user types /benchmark.
Why use it?
It helps detect when a code change makes a website slower by comparing results before and after each pull request, a proposed code change for review.

Skill for Claude CodeCodex

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/10xdev-startup/template-nodejs-express-next-supabase/benchmark
Any agent
npx skills add 10xdev-startup/template-nodejs-express-next-supabase --skill benchmark
Clone the repo
git clone --depth 1 https://github.com/10xdev-startup/template-nodejs-express-next-supabase

Made for: Claude Code, Codex.

Per session 88 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 4,998 The whole file, excluding the scripts and references it only reads on demand.
Security scan C 2 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 $0.00088 $0.04998
Opus 5 $0.00044 $0.02499
Sonnet 5 $0.00018 $0.01000
Haiku 4.5 $0.00009 $0.00500

Measured 2d ago against content hash 291051940f48, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

Grade C, and why

benchmark scanned grade C with 2 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 2d 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.

Downloads and executes remote codehighSupply chain

curl | sh runs whatever the server returns today, which is not necessarily what it returned when this was reviewed.

3. If `bun` is not installed: `curl -fsSL https://bun.sh/install | bash`

Makes network callslowCapability

Not a fault in itself. Listed so you know the mod talks to something, and to what.

3. If `bun` is not installed: `curl -fsSL https://bun.sh/install | bash`
.claude/skills/gstack/benchmark/SKILL.md · 441 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

Files

What ships with it

1 file beside SKILL.md in the same directory: the scripts, references and assets a skill reads on demand. Not counted in the per-session cost; read them before you install if any of them is executable.

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. 2d ago First seen · 441 lines · 88 tokens per session scan C 291051940f48

Subscribe to this mod's changes

benchmark is a skill published in the GitHub repository 10xdev-startup/template-nodejs-express-next-supabase (2 stars, last pushed 13d ago), with no licence file. It adds 88 tokens to every session and 4,998 once invoked, about $0.0004 per session on Opus 5. A static security scan graded it C with 2 findings (downloads and executes remote code, makes network calls). No closer match exists in the catalogue, so it is treated as the original; first seen 2026-08-31.

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