security-reviewer

security-reviewer is a skill for Claude Code, Codex from CsabaKovacs/rulesmith. It costs 30 tokens per session (555 once invoked), scanned A, original, Apache-2.0.

A checklist for reviewing code changes that handle requests, permissions, databases, files, external services, or sensitive information.

In plain words
What is it for?
It helps inspect changed files, verify safe path and write rules, check input validation, reject unsafe file links, and classify findings by severity.
Why use it?
It helps find security problems such as injection, path traversal, unsafe input handling, and exposed secrets before release.

Skill for Claude CodeCodex

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 skills/csabakovacs/rulesmith/security-reviewer
Any agent
npx skills add CsabaKovacs/rulesmith --skill security-reviewer
Clone the repo
git clone --depth 1 https://github.com/CsabaKovacs/rulesmith

Made for: Claude Code, Codex.

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-reviewer

README.md
[![agentmods](https://agentmods.dev/badge/skills/csabakovacs/rulesmith/security-reviewer.svg)](https://agentmods.dev/skills/csabakovacs/rulesmith/security-reviewer)
Your own site
<a href="https://agentmods.dev/skills/csabakovacs/rulesmith/security-reviewer"><img src="https://agentmods.dev/badge/skills/csabakovacs/rulesmith/security-reviewer.svg" alt="Measured on agentmods" height="20"></a>
Per session 30 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 555 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 1 finding. 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 $0.00030 $0.00555
Opus 5 $0.00015 $0.00278
Sonnet 5 $0.00006 $0.00111
Haiku 4.5 $0.00003 $0.00056

Measured 4d ago against content hash f8ddb6fa2e25, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

Grade A, and why

security-reviewer scanned grade A with 1 finding 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 4d 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.

Runs shell commandslowCapability

Expected in a hook, worth knowing in a rule or an instructions file.

- Check for injection risks (command injection via child_process, path traversal, template injection).
.agents/skills/security-reviewer/SKILL.md · 59 lines

How it starts

The opening of the file, as written. The whole thing — 59 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Security Review

Reviews changed files for security vulnerabilities and unsafe patterns.

When to Activate

  • When changes touch: request/input handling, authentication or authorization, database queries or persistence, file upload or access, HTML rendering or user-generated content, external API calls or webhooks, or secrets/tokens/sensitive data.
  • Skip when changes are purely internal logic with no external surface.

Review Methodology

Follow these steps in order:

  • Identify security-relevant changes in the diff.
  • Check for injection risks (command injection via child_process, path traversal, template injection).
  • Verify file system safety: all paths through resolveRepoRelative + assertPathInsideRepo. (evidence: packages/core/src/fs/safe.ts)
  • Check write operations restricted to WRITE_ALLOWLIST. (evidence: packages/core/src/fs/safe.ts)
  • Verify MCP tool inputs validated via Zod schemas. (evidence: packages/mcp/src/server.ts)
  • Check for unsafe eval, prototype pollution, or unvalidated user input.
  • Verify symlink rejection in readFileSafe. (evidence: packages/core/src/fs/safe.ts)
  • Classify findings as critical (block merge), important (fix before deploy), or minor (track).
  • Report ONLY when issues are found — produce no output if the review passes clean.

Stack-Specific Security Rules

  • Path traversal: all file paths must use resolveRepoRelative guards. (evidence: packages/core/src/fs/safe.ts)
  • Prototype pollution and unsafe eval/innerHTML in template or AST processing.
  • maxBytesPerFile limits enforced to prevent memory exhaustion. (evidence: packages/core/src/fs/safe.ts)
  • Artifact store TTL and max size prevent memory leaks. (evidence: packages/core/src/render/index.ts)

Boundaries

  • Do NOT apply fixes — security changes require explicit human approval.
  • Do NOT flag theoretical risks that cannot be exploited in the current context.
  • Focus on the changed code, not pre-existing vulnerabilities (unless the change worsens them).

Read the full file on GitHub · 59 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. 4d ago First seen · 59 lines · 30 tokens per session scan A f8ddb6fa2e25

Subscribe to this mod's changes

security-reviewer is a skill published in the GitHub repository CsabaKovacs/rulesmith (15 stars, last pushed 5mo ago), licensed Apache-2.0. It adds 30 tokens to every session and 555 once invoked, about $0.0002 per session on Opus 5. A static security scan graded it A with 1 finding (runs shell commands). No closer match exists in the catalogue, so it is treated as the original; first seen 2026-08-30.

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