javascript-coding-standards

javascript-coding-standards is a skill for Claude Code from systempromptio/systemprompt-marketplace. It costs 60 tokens per session (3,751 once invoked), scanned A, original, no licence file.

A set of JavaScript rules for systemprompt.io. It covers module style, Web Components, rendering approaches, state ownership, comments, and file-size limits.

In plain words
What is it for?
Writing or reviewing JavaScript in the systemprompt.io project according to its defined standards.
Why use it?
It gives the agent one reference for deciding how JavaScript should be written or reviewed, helping avoid disallowed patterns and inconsistent designs.

Skill for Claude Code

Written for Claude Code: shipped in a Claude Code plugin.

Part of the development plugin — 20 skills shipped together

Good fit Writing or reviewing JavaScript in the systemprompt.io project according to its defined standards.

Compare 6 skills from other repositories ↓
Install with agentmods
npx agentmods add skills/systempromptio/systemprompt-marketplace/javascript-coding-standards
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 systempromptio/systemprompt-marketplace --skill javascript-coding-standards
Clone the repo
git clone --depth 1 https://github.com/systempromptio/systemprompt-marketplace

Made for: Claude Code.

Or install development, the plugin that ships this one along with the rest of its 20 skills.

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 javascript-coding-standards

README.md
[![agentmods](https://agentmods.dev/badge/skills/systempromptio/systemprompt-marketplace/javascript-coding-standards/github.svg)](https://agentmods.dev/skills/systempromptio/systemprompt-marketplace/javascript-coding-standards)
Your own site
<a href="https://agentmods.dev/skills/systempromptio/systemprompt-marketplace/javascript-coding-standards"><img src="https://agentmods.dev/badge/skills/systempromptio/systemprompt-marketplace/javascript-coding-standards/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 javascript-coding-standards

Your own site · 80×15
<a href="https://agentmods.dev/skills/systempromptio/systemprompt-marketplace/javascript-coding-standards"><img src="https://agentmods.dev/badge/skills/systempromptio/systemprompt-marketplace/javascript-coding-standards.svg" alt="Reviewed on agentmods" width="80" height="20"></a>
Per session 60 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 3,751 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 $0.00060 $0.03751
Opus 5.5 $0.00024 $0.01500
Sonnet 5.5 $0.00012 $0.00750
Haiku 4.5 $0.00006 $0.00375

Measured 1mo ago against content hash bf571751f509, method: parsed. Prices are Anthropic first-party input rates as of 2026-10-07, from the pricing page.

Security

Grade A, and why

javascript-coding-standards 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.

plugins/development/skills/javascript-coding-standards/SKILL.md · 276 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. 1mo ago First seen · 276 lines · 60 tokens per session scan A bf571751f509

Subscribe to this mod's changes

javascript-coding-standards is a skill published in the GitHub repository systempromptio/systemprompt-marketplace (2 stars, last pushed 13d ago), with no licence file. It adds 60 tokens to every session and 3,751 once invoked, about $0.0002 per session on Opus 5.5. 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 2026-08-31.

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