security-scan

security-scan is a command for coding agents from postrv/narsil-mcp. It costs 9 tokens per session (292 once invoked), scanned A, original, Apache-2.0.

A repository security-audit command that gathers findings about vulnerabilities, web-application risks, dependencies, and licenses. A repository is a project's tracked source files and configuration.

In plain words
What is it for?
Use it to scan a selected repository, check OWASP Top 10 web risks, find dependency CVEs, review licenses, and organize findings by severity.
Why use it?
It brings several security checks into one review, so problems are less likely to be missed across code, third-party packages, and licensing. It also provides extra context and fixes for critical findings.

Command

Part of the narsil-plugin plugin — 1 skill, 5 commands shipped together

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.

agentmods
npx agentmods add commands/postrv/narsil-mcp/security-scan
Clone the repo
git clone --depth 1 https://github.com/postrv/narsil-mcp

Or install narsil-plugin, the plugin that ships this one along with the rest of its 1 skill, 5 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 security-scan

README.md
[![agentmods](https://agentmods.dev/badge/commands/postrv/narsil-mcp/security-scan.svg)](https://agentmods.dev/commands/postrv/narsil-mcp/security-scan)
Your own site
<a href="https://agentmods.dev/commands/postrv/narsil-mcp/security-scan"><img src="https://agentmods.dev/badge/commands/postrv/narsil-mcp/security-scan.svg" alt="Measured on agentmods" height="20"></a>
Per session 9 Only the description is in the session, so the agent can decide to use it. The body loads when it is invoked.
When invoked 292 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 0 findings. Scan, not verified.
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 $0.00009 $0.00292
Opus 5 $0.00005 $0.00146
Sonnet 5 $0.00002 $0.00058
Haiku 4.5 $0.00001 $0.00029

Measured 5d ago against content hash 9abb0713755a, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

Grade A, and why

security-scan 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 5d 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.

narsil-plugin/commands/security-scan.md · 36 lines

What it actually says

Security Scan

Run a comprehensive security audit on the repository specified by the user. If no repository is specified, first use list_repos to show available repositories and ask which one to scan.

Workflow

Execute the following steps:

  1. Get security overview: Use get_security_summary to get an overview of the security posture

  2. Scan for vulnerabilities: Use scan_security with severity_threshold="medium" to find medium and above findings

  3. Check OWASP Top 10: Use check_owasp_top10 to check for web application vulnerabilities

  4. Check dependencies: Use check_dependencies to find known CVEs in dependencies

  5. Check licenses: Use check_licenses to identify license compliance issues

  6. Summarize findings: Present a summary organized by:

    • Critical/High severity findings (immediate attention needed)
    • Medium severity findings (should address soon)
    • Dependency vulnerabilities with available fixes
    • License issues
  7. For each critical finding: Use explain_vulnerability to provide context and suggest_fix to show remediation

Arguments

If $ARGUMENTS is provided, use it as the repository name. Otherwise, list available repositories first.

Repository to scan: $ARGUMENTS

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. 5d ago First seen · 36 lines · 9 tokens per session scan A 9abb0713755a

Subscribe to this mod's changes

security-scan is a command published in the GitHub repository postrv/narsil-mcp (181 stars, last pushed 3mo ago), licensed Apache-2.0. It adds 9 tokens to every session and 292 once invoked, about $0.0000 per session on Opus 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 2026-08-30.