What is plugin-development?

A toolkit for creating, checking, and publishing Claude Code plugins. Plugins are add-ons that extend what Claude Code can do.

Use it when developing, validating, or distributing Claude Code plugins.

It provides a defined process for building plugins and checking that their files, documentation, and security meet the required rules.

plugin-development — Plugin for Claude Code by kossakovsky/cc-plugins

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.

Clone the repo

git clone --depth 1 https://github.com/kossakovsky/cc-plugins

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.

README.md

[![agentmods](https://agentmods.dev/badge/plugins/kossakovsky/cc-plugins/plugin-development/github.svg)](https://agentmods.dev/plugins/kossakovsky/cc-plugins/plugin-development)

Your own site

<a href="https://agentmods.dev/plugins/kossakovsky/cc-plugins/plugin-development"><img src="https://agentmods.dev/badge/plugins/kossakovsky/cc-plugins/plugin-development/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.

Your own site · 80×15

<a href="https://agentmods.dev/plugins/kossakovsky/cc-plugins/plugin-development"><img src="https://agentmods.dev/badge/plugins/kossakovsky/cc-plugins/plugin-development.svg" alt="Reviewed on agentmods" width="80" height="20"></a>

Per session not measured What this adds to a session before it is invoked.

When invoked not measured The manifest loads nothing itself; its 1 skill, 8 commands, 1 agent, 2 hooks cost 142 tokens a session between them.

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.

Security

Grade A, and why

plugin-development 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/plugin-development/.claude-plugin/plugin.json · 22 lines

What it actually says

{
  "name": "plugin-development",
  "version": "1.3.0",
  "description": "A comprehensive toolkit for creating, validating, and distributing Claude Code plugins",
  "author": {
    "name": "kossakovsky"
  },
  "homepage": "https://github.com/kossakovsky/cc-plugins",
  "repository": "https://github.com/kossakovsky/cc-plugins",
  "license": "MIT",
  "keywords": [
    "claude-code",
    "plugins",
    "developer-tools",
    "plugin-development",
    "plugin-authoring",
    "scaffold",
    "scaffolding",
    "validation"
  ]
}

Contents

What it installs

The manifest is a name and a version. 1 skill, 8 commands, 1 agent, 2 hooks travel with it, and installing the plugin installs all of them — 142 tokens a session between them. Each is measured on its own page, and each can be installed alone.

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.

1mo ago First seen · 22 lines scan A 7ced75c3608f

Subscribe to this mod's changes

plugin-development is a plugin published in the GitHub repository kossakovsky/cc-plugins (3 stars, last pushed 7mo ago), licensed MIT. Its token cost is not measured: this kind of file is read by the harness, not the model. 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.

Building agents

humanizer

Rewrite AI-sounding text so it reads like the writer without changing what it says.

blader/humanizer · not measured

nextjs

Official Next.js skills: adopt and optimize Cache Components, adopt Partial Prefetching, and verify runtime behavior against a running dev server.

vercel/next.js · not measured

themes-example

themes-example. An open-source AI agent that brings the power of Gemini directly into your terminal.

google-gemini/gemini-cli · not measured

claude-plugins-official marketplace

Directory of popular Claude Code extensions including development tools, productivity plugins, and MCP integrations.

anthropics/claude-plugins-official · not measured

knowledge-work-plugins marketplace

Plugin marketplace listing 123 plugins: noibu, productivity, enterprise-search, cowork-plugin-management, sales.

anthropics/knowledge-work-plugins · not measured

code-modernization

Guided modernization for any legacy codebase: start with /modernize, get an assessment, an interactive map, the business rules mined from the code, and a plan you approve, then an upgrade, a rewrite or a rebuild with independent proof that the new code behaves like the old. Includes security hardening, a one-page…