sigil-security

sigil-security is a plugin for Claude Code from NOMARJ/sigil. Its manifest loads nothing; the 6 skills, 2 agents, 2 hooks it bundles cost 484 tokens per session together, scanned A, original, Apache-2.0.

A command-line security scanner for AI-agent code, repositories, packages, and agent tools, with a workflow that places suspicious items in quarantine for review.

In plain words
What is it for?
Use it to scan projects and agent tooling, review findings, and isolate items that need approval.
Why use it?
It helps find malicious code and supply-chain risks before untrusted components are used.

Plugin for Claude Code

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.

Claude Code
/plugin marketplace add NOMARJ/sigil
agentmods
npx agentmods add plugins/nomarj/sigil/claude-code
Clone the repo
git clone --depth 1 https://github.com/NOMARJ/sigil

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 sigil-security

README.md
[![agentmods](https://agentmods.dev/badge/plugins/nomarj/sigil/claude-code.svg)](https://agentmods.dev/plugins/nomarj/sigil/claude-code)
Your own site
<a href="https://agentmods.dev/plugins/nomarj/sigil/claude-code"><img src="https://agentmods.dev/badge/plugins/nomarj/sigil/claude-code.svg" alt="Measured on agentmods" 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 6 skills, 2 agents, 2 hooks cost 484 tokens a session between them.
Security scan A 0 findings. Scan, not verified.
Origin original No closer match found in the catalogue.
Security

Grade A, and why

sigil-security 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 today.

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/claude-code/.claude-plugin/plugin.json · 38 lines

What it actually says

{
  "name": "sigil-security",
  "version": "1.1.0",
  "description": "Automated security auditing CLI for AI agent code. Scan repos, packages, and agent tooling for malicious patterns with quarantine-first workflow.",
  "author": {
    "name": "NOMARK",
    "email": "[email protected]",
    "url": "https://github.com/NOMARJ/sigil"
  },
  "homepage": "https://github.com/NOMARJ/sigil",
  "repository": "https://github.com/NOMARJ/sigil",
  "license": "Apache-2.0",
  "keywords": [
    "security",
    "scanner",
    "ai",
    "agent",
    "supply-chain",
    "malware",
    "audit",
    "quarantine",
    "mcp",
    "threat-intelligence"
  ],
  "skills": "./skills/",
  "agents": "./agents/",
  "hooks": "./hooks/hooks.json",
  "mcpServers": {
    "sigil": {
      "command": "npx",
      "args": ["-y", "@nomark/sigil-mcp-server"],
      "env": {
        "SIGIL_BINARY": "sigil"
      }
    }
  }
}
Contents

What it installs

The manifest is a name and a version. 6 skills, 2 agents, 2 hooks travel with it, and installing the plugin installs all of them — 484 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.

  1. today First seen · 38 lines scan A d8a3aa9efeaf

Subscribe to this mod's changes

sigil-security is a plugin published in the GitHub repository NOMARJ/sigil (5 stars, last pushed today), licensed Apache-2.0. 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 2026-09-04.