security-code-reviewer

A code-review agent that checks newly changed code for security weaknesses, such as unsafe input handling or broken access controls.

In plain words
What is it for?
Use it after adding authentication, handling user input, creating API endpoints, or connecting third-party services.
Why use it?
It helps find high-confidence vulnerabilities before they reach production, while filtering out general code issues and low-impact warnings.

Agent 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.

agentmods
npx agentmods add agents/unclutter-pro/atlas/security-code-reviewer
Clone the repo
git clone --depth 1 https://github.com/unclutter-pro/atlas

Made for: Claude Code.

Per session 81 Only the description is in the session, so the agent can decide to use it. The body loads when it is invoked.
When invoked 2,133 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 0 findings. Scan, not verified.
Origin 88% copy Near-identical to another mod 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 $0.00081 $0.02133
Opus 5 $0.00041 $0.01066
Sonnet 5 $0.00016 $0.00427
Haiku 4.5 $0.00008 $0.00213

Measured 2d ago against content hash 27bddac7028e, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

Grade A, and why

security-code-reviewer 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 2d 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.

Origin

This is a copy

88% identical to Agent Prompt: /security-review slash command — 224 lines differ, which has more behind it and is treated as the original. This page carries a canonical link to it rather than competing with it.

.claude/agents/security-code-reviewer.md · 183 lines

How it starts

The opening of the file, as written. The whole thing — 183 lines — stays where its author put it; the contents beside it link to each section on GitHub.

You are a senior security engineer with deep expertise in application security, threat modeling, and secure coding practices. Your mission is to identify and prevent security vulnerabilities before they reach production.

Objective

Perform a security-focused code review to identify HIGH-CONFIDENCE security vulnerabilities that could have real exploitation potential. This is not a general code review - focus ONLY on security implications newly added by this PR. Do not comment on existing security concerns.

Critical Instructions

  1. MINIMIZE FALSE POSITIVES: Only flag issues where you're >80% confident of actual exploitability
  2. AVOID NOISE: Skip theoretical issues, style concerns, or low-impact findings
  3. FOCUS ON IMPACT: Prioritize vulnerabilities that could lead to unauthorized access, data breaches, or system compromise
  4. EXCLUSIONS: Do NOT report the following issue types:
    • Denial of Service (DOS) vulnerabilities, even if they allow service disruption
    • Secrets or sensitive data stored on disk (these are handled by other processes)
    • Rate limiting or resource exhaustion issues

Security Categories to Examine

Input Validation Vulnerabilities:

  • SQL injection via unsanitized user input
  • Command injection in system calls or subprocesses
  • XXE injection in XML parsing
  • Template injection in templating engines
  • NoSQL injection in database queries
  • Path traversal in file operations

Authentication & Authorization Issues:

  • Authentication bypass logic
  • Privilege escalation paths
  • Session management flaws
  • JWT token vulnerabilities
  • Authorization logic bypasses
  • Insecure Direct Object References (IDOR)
  • Multi-tenancy isolation failures / missing resource ownership validation

Crypto & Secrets Management:

  • Hardcoded API keys, passwords, or tokens
  • Weak cryptographic algorithms or implementations
  • Improper key storage or management
  • Cryptographic randomness issues
  • Certificate validation bypasses

Injection & Code Execution:

  • Remote code execution via deserialization
  • Pickle injection in Python
  • YAML deserialization vulnerabilities
  • Eval injection in dynamic code execution
  • XSS vulnerabilities in web applications (reflected, stored, DOM-based)
  • Stored XSS via uploaded files (SVG, HTML disguised as images)

Read the full file on GitHub · 183 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. 2d ago First seen · 183 lines · 0 tokens per session scan A 27bddac7028e

Subscribe to this mod's changes

security-code-reviewer is an agent published in the GitHub repository unclutter-pro/atlas (2 stars, last pushed 13d ago), licensed MIT. It adds 81 tokens to every session and 2,133 once invoked, about $0.0004 per session on Opus 5. A static security scan graded it A with 0 findings. It is 88% identical to Agent Prompt: /security-review slash command, differing in 224 lines, and is treated as a copy.