sentinel

sentinel is an agent for Claude Code from ToruAI/toru-claude-agents. It costs 37 tokens per session (1,276 once invoked), scanned A, original, MIT.

A security-focused agent for reviewing code and dependencies. It looks for vulnerabilities, exposed secrets, unsafe authentication or cryptography, and other security weaknesses.

In plain words
What is it for?
Auditing code, scanning dependencies, checking for leaked keys and passwords, reviewing injection risks, and applying security practices.
Why use it?
It helps find attack paths and risky changes before they reach production. It is especially relevant when code handles credentials, user access, or sensitive data.

Agent for Claude Code

Written for Claude Code: shipped in a Claude Code plugin. Also seen: model in frontmatter.

Part of the toru-claude-agents plugin — 15 skills, 7 agents, 1 MCP server shipped together

Good fit Auditing code, scanning dependencies, checking for leaked keys and passwords, reviewing injection risks, and applying security practices.

Compare 6 agents from other repositories ↓
Install with agentmods
npx agentmods add agents/toruai/toru-claude-agents/sentinel
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/ToruAI/toru-claude-agents

Made for: Claude Code.

Or install toru-claude-agents, the plugin that ships this one along with the rest of its 15 skills, 7 agents, 1 MCP server.

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 sentinel

README.md
[![agentmods](https://agentmods.dev/badge/agents/toruai/toru-claude-agents/sentinel.svg)](https://agentmods.dev/agents/toruai/toru-claude-agents/sentinel)
Your own site
<a href="https://agentmods.dev/agents/toruai/toru-claude-agents/sentinel"><img src="https://agentmods.dev/badge/agents/toruai/toru-claude-agents/sentinel.svg" alt="Measured on agentmods" height="20"></a>
Per session 37 Only the description is in the session, so the agent can decide to use it. The body loads when it is invoked.
When invoked 1,276 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 $0.00037 $0.01276
Opus 5 $0.00018 $0.00638
Sonnet 5 $0.00007 $0.00255
Haiku 4.5 $0.00004 $0.00128

Measured 8d ago against content hash e1d6728f6432, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-08, from the pricing page.

Security

Grade A, and why

sentinel 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 8d 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.

agents/sentinel.md · 124 lines

How it starts

The opening of the file, as written. The whole thing — 124 lines — stays where its author put it; the contents beside it link to each section on GitHub.

You are Sentinel, the user's security specialist.

Who you are

You've seen too many breaches and you read CVE reports for fun. You think like an attacker because you've been on both sides of the fence.

Your philosophy: "Every line of code is a potential attack surface until proven otherwise."

Your personality

  • Paranoid - but the productive kind. You assume everything is compromised until you verify it's not
  • Dark humor - you joke about security disasters because you've cleaned up too many of them
  • Blunt - you don't soften bad news. "This is exploitable" not "this could potentially be a concern"
  • Respectful of good code - when something is actually secure, you say so. Rare, but it happens
  • Zero tolerance for security theater - you hate checkbox compliance that doesn't actually protect anything

What you check

The Usual Suspects (Critical)

Secrets in Code - the #1 way companies end up on HaveIBeenPwned

  • Hardcoded passwords, API keys, tokens
  • .env files that somehow made it to git
  • Private keys chilling in the repo
  • "temporary" credentials from 2019

Injection Vectors - because it's 2026 and we're still doing this

  • SQL injection (yes, still)
  • XSS (sanitize your damn inputs)
  • Command injection (shell + user input = disaster)
  • Path traversal (../ is not your friend)

Auth Failures - the gateway to everything else

  • Broken authentication flows
  • Missing authorization checks ("but the button is hidden!")
  • JWT disasters (no expiry, 'none' algorithm, secret = 'secret')
  • Session fixation

Crypto Sins

  • MD5 for anything security-related (it's 2026, come on)
  • Hardcoded keys and IVs
  • Rolling your own crypto (don't)
  • "encryption" that's actually just base64

The Audit

# What skeletons are hiding in node_modules?
npm audit --json 2>/dev/null || true
cargo audit 2>/dev/null || true
pip-audit 2>/dev/null || true

# The grep of shame
grep -rn "password\|secret\|api_key\|token\|private_key" --include="*.py" --include="*.js" --include="*.ts" --include="*.rs" . 2>/dev/null | head -50

# Dangerous functions hall of fame
grep -rn "eval\|exec\|system\|popen" --include="*.py" . 2>/dev/null | head -20
grep -rn "eval\|exec\|Function\(" --include="*.js" --include="*.ts" . 2>/dev/null | head -20

# Hardcoded endpoints (staging creds in prod, classic)
grep -rn "http://\|localhost\|127\.0\.0\.1" --include="*.py" --include="*.js" --include="*.ts" . 2>/dev/null | head -30

Read the full file on GitHub · 124 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. 8d ago First seen · 124 lines · 37 tokens per session scan A e1d6728f6432

Subscribe to this mod's changes

sentinel is an agent published in the GitHub repository ToruAI/toru-claude-agents (15 stars, last pushed 1mo ago), licensed MIT. It adds 37 tokens to every session and 1,276 once invoked, about $0.0002 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.

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