essential

essential is a plugin for Claude Code from PolicyEngine/policyengine-claude. Its manifest loads nothing; the 5 skills it bundles cost 956 tokens per session together, scanned A, original, MIT.

A beginner guide to PolicyEngine, a web platform for exploring tax and government benefit policies.

In plain words
What is it for?
Use it to learn PolicyEngine’s basic concepts, user interface, and country-specific policy information.
Why use it?
It gives new users the background needed to understand the platform and use its web application.

Plugin for Claude Code

Written for Claude Code: a Claude Code plugin manifest.

Good fit Use it to learn PolicyEngine’s basic concepts, user interface, and country-specific policy information.

Compare 6 plugins from other repositories ↓
Install in Claude Code
/plugin marketplace add PolicyEngine/policyengine-claude
/plugin install essential
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/PolicyEngine/policyengine-claude

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 essential

README.md
[![agentmods](https://agentmods.dev/badge/plugins/policyengine/policyengine-claude/essential/github.svg)](https://agentmods.dev/plugins/policyengine/policyengine-claude/essential)
Your own site
<a href="https://agentmods.dev/plugins/policyengine/policyengine-claude/essential"><img src="https://agentmods.dev/badge/plugins/policyengine/policyengine-claude/essential/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 essential

Your own site · 80×15
<a href="https://agentmods.dev/plugins/policyengine/policyengine-claude/essential"><img src="https://agentmods.dev/badge/plugins/policyengine/policyengine-claude/essential.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 5 skills cost 956 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

essential 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.

.claude-plugin/marketplace.json#essential · 27 lines

What it actually says

{
  "name": "essential",
  "description": "Essential PolicyEngine knowledge for all users - understanding the platform, using the web app, and basic concepts",
  "category": "getting-started",
  "version": "4.0.2",
  "keywords": [
    "beginner",
    "users",
    "guide",
    "basics"
  ],
  "author": {
    "name": "PolicyEngine",
    "url": "https://github.com/PolicyEngine"
  },
  "license": "MIT",
  "skills": [
    "./skills/policyengine-user-guide",
    "./skills/policyengine-us",
    "./skills/policyengine-uk",
    "./skills/policyengine-canada",
    "./skills/policyengine-writing"
  ],
  "commands": [],
  "agents": [],
  "source": "./"
}
Contents

What it installs

The manifest is a name and a version. 5 skills travel with it, and installing the plugin installs all of them — 956 tokens a session between them. Each is measured on its own page, and each can be installed alone.

Files

What ships with it

1 file beside marketplace.json#essential 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 Changed d451c40b85e3
  2. 1mo ago First seen · 27 lines scan A 0acdd19663a3

Subscribe to this mod's changes

essential is a plugin published in the GitHub repository PolicyEngine/policyengine-claude (32 stars, last pushed 2d 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 2026-09-03.

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