chrome-ext-develop

chrome-ext-develop is a skill for Claude Code from masayan1126/masayan-uni-code-plugins. It costs 48 tokens per session (208 once invoked), scanned A, original, MIT.

A development guide for building Chrome extensions, which are small programs that add features to the Chrome browser, and preparing them for Chrome Web Store submission.

In plain words
What is it for?
Use it to create a new Chrome extension, define its requirements, research competing extensions, and prepare its store description and image specifications.
Why use it?
It brings extension development, requirements planning, competitor research, and store materials into one workflow.

Skill for Claude Code

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

Part of the chrome-ext-toolkit plugin — 2 skills, 2 commands shipped together

Good fit Use it to create a new Chrome extension, define its requirements, research competing extensions, and prepare its store description and image specifications.

Compare 6 skills from other repositories ↓
Install with agentmods
npx agentmods add skills/masayan1126/masayan-uni-code-plugins/develop
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 masayan1126/masayan-uni-code-plugins --skill develop
Clone the repo
git clone --depth 1 https://github.com/masayan1126/masayan-uni-code-plugins

Made for: Claude Code.

Or install chrome-ext-toolkit, the plugin that ships this one along with the rest of its 2 skills, 2 commands.

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 chrome-ext-develop

README.md
[![agentmods](https://agentmods.dev/badge/skills/masayan1126/masayan-uni-code-plugins/develop/github.svg)](https://agentmods.dev/skills/masayan1126/masayan-uni-code-plugins/develop)
Your own site
<a href="https://agentmods.dev/skills/masayan1126/masayan-uni-code-plugins/develop"><img src="https://agentmods.dev/badge/skills/masayan1126/masayan-uni-code-plugins/develop/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 chrome-ext-develop

Your own site · 80×15
<a href="https://agentmods.dev/skills/masayan1126/masayan-uni-code-plugins/develop"><img src="https://agentmods.dev/badge/skills/masayan1126/masayan-uni-code-plugins/develop.svg" alt="Reviewed on agentmods" width="80" height="20"></a>
Per session 48 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 208 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 original 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 $0.00048 $0.00208
Opus 5.5 $0.00019 $0.00083
Sonnet 5.5 $0.00010 $0.00042
Haiku 4.5 $0.00005 $0.00021

Measured 1mo ago against content hash 37800f6f229e, method: parsed. Prices are Anthropic first-party input rates as of 2026-10-07, from the pricing page.

Security

Grade A, and why

chrome-ext-develop 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/chrome-ext-toolkit/skills/develop/SKILL.md · 21 lines

What it actually says

Chrome Extension Development Skill

Chrome拡張機能の開発から、Chrome Web Storeへの申請準備までを一貫してサポートするスキルです。

対応タスク

  • 新規Chrome拡張機能の開発
  • 競合調査と要件定義
  • ストア申請用アセット(説明文、画像仕様)の作成

関連ファイル

Files

What ships with it

3 files 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. 1mo ago First seen · 21 lines · 48 tokens per session scan A 37800f6f229e

Subscribe to this mod's changes

chrome-ext-develop is a skill published in the GitHub repository masayan1126/masayan-uni-code-plugins (5 stars, last pushed 7mo ago), licensed MIT. It adds 48 tokens to every session and 208 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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