modernize-harden

modernize-harden is a command for Claude Code from ronmkr/PromptBook. It costs 21 tokens per session (641 once invoked), scanned A, original, Apache-2.0.

A security review command for older code that looks for common weaknesses, exposed secrets, and risky dependencies, then writes findings and proposed fixes for review.

In plain words
What is it for?
Use it to inspect a legacy component, record vulnerabilities with severity and location, and prepare targeted fixes for the most serious findings.
Why use it?
It helps developers understand and prioritise security problems without changing the existing code automatically.

Command for Claude Code

Written for Claude Code: argument-hint in frontmatter. Also seen: mentions subagents; positional $N argument.

Good fit Use it to inspect a legacy component, record vulnerabilities with severity and location, and prepare targeted fixes for the most serious findings.

Compare 6 commands from other repositories ↓
Install with agentmods
npx agentmods add commands/ronmkr/promptbook/modernize-harden
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/ronmkr/PromptBook

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 modernize-harden

README.md
[![agentmods](https://agentmods.dev/badge/commands/ronmkr/promptbook/modernize-harden/github.svg)](https://agentmods.dev/commands/ronmkr/promptbook/modernize-harden)
Your own site
<a href="https://agentmods.dev/commands/ronmkr/promptbook/modernize-harden"><img src="https://agentmods.dev/badge/commands/ronmkr/promptbook/modernize-harden/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 modernize-harden

Your own site · 80×15
<a href="https://agentmods.dev/commands/ronmkr/promptbook/modernize-harden"><img src="https://agentmods.dev/badge/commands/ronmkr/promptbook/modernize-harden.svg" alt="Reviewed on agentmods" width="80" height="20"></a>
Per session 21 Only the description is in the session, so the agent can decide to use it. The body loads when it is invoked.
When invoked 641 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 $0.00021 $0.00641
Opus 5 $0.00010 $0.00320
Sonnet 5 $0.00004 $0.00128
Haiku 4.5 $0.00002 $0.00064

Measured 9d ago against content hash 200e1dcc6a09, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-09, from the pricing page.

Security

Grade A, and why

modernize-harden 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 9d 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/standard/code-modernization/commands/modernize-harden.md · 65 lines

How it starts

The opening of the file, as written. The whole thing — 65 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Run a security hardening pass on legacy/$1: find vulnerabilities, rank them, and produce a reviewable patch for the critical ones.

This command never edits legacy/ — it writes findings and a proposed patch to analysis/$1/. The user reviews and applies (or not).

Scan

Spawn the security-auditor subagent:

"Adversarially audit legacy/$1 for security vulnerabilities. Cover what's relevant to the stack: injection (SQL/NoSQL/OS command/template), broken auth, sensitive data exposure, access control gaps, insecure deserialization, hardcoded secrets, vulnerable dependency versions, missing input validation, path traversal. For each finding return: CWE ID, severity (Critical/High/Med/Low), file:line, one-sentence exploit scenario, and recommended fix. Run any available SAST tooling (npm audit, pip-audit, OWASP dependency-check) and include its raw output."

Triage

Write analysis/$1/SECURITY_FINDINGS.md:

  • Summary scorecard (count by severity, top CWE categories)
  • Findings table sorted by severity
  • Dependency CVE table (package, installed version, CVE, fixed version)

Remediate

For each Critical and High finding, draft a minimal, targeted fix. Do not edit legacy/ — write all fixes as a single unified diff to analysis/$1/security_remediation.patch, with a comment line above each hunk citing the finding ID it addresses (# SEC-001: parameterize the query).

Add a Remediation Log section to SECURITY_FINDINGS.md mapping each finding ID → one-line summary of the proposed fix and the patch hunk that implements it.

Verify

Spawn the security-auditor again to review the patch against the original code:

"Review analysis/$1/security_remediation.patch against legacy/$1. For each hunk: does it fully remediate the cited finding? Does it introduce new vulnerabilities or change behavior beyond the fix? Return one verdict per hunk: RESOLVES / PARTIAL / INTRODUCES-RISK, with a one-line reason."

Add a Patch Review section to SECURITY_FINDINGS.md with the verdicts. If any hunk is PARTIAL or INTRODUCES-RISK, revise the patch and re-review.

Read the full file on GitHub · 65 lines

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. 9d ago First seen · 65 lines · 21 tokens per session scan A 200e1dcc6a09

Subscribe to this mod's changes

modernize-harden is a command published in the GitHub repository ronmkr/PromptBook (2 stars, last pushed 3mo ago), licensed Apache-2.0. It adds 21 tokens to every session and 641 once invoked, about $0.0001 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 2026-08-31.