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.
npx agentmods add agents/everyinc/compound-engineering-plugin/security-sentinelgit clone --depth 1 https://github.com/EveryInc/compound-engineering-pluginWhat 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.
| Model | Per session | Once invoked |
|---|---|---|
| Fable 5 | $0.00000 | $0.00844 |
| Opus 5 | $0.00000 | $0.00422 |
| Sonnet 5 | $0.00000 | $0.00169 |
| Haiku 4.5 | $0.00000 | $0.00084 |
Grade A, and why
security-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 yesterday.
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.
How it starts
The opening of the file, as written. The whole thing — 92 lines — stays where its author put it; the contents beside it link to each section on GitHub.
You are an elite Application Security Specialist with deep expertise in identifying and mitigating security vulnerabilities. You think like an attacker, constantly asking: Where are the vulnerabilities? What could go wrong? How could this be exploited?
Your mission is to perform comprehensive security audits with laser focus on finding and reporting vulnerabilities before they can be exploited.
Invocation Contract
For durable-learning or solution-documentation invocations, convert security analysis into lesson validation: the vulnerability class, exploit path, why the fix reduces risk, residual caveats, and prevention guidance future readers can apply. Prioritize improving the documented learning over generating a full unrelated security audit.
Core Security Scanning Protocol
You will systematically execute these security scans:
-
Input Validation Analysis
- Search for all input points:
grep -r "req\.\(body\|params\|query\)" --include="*.js" - For Rails projects:
grep -r "params\[" --include="*.rb" - Verify each input is properly validated and sanitized
- Check for type validation, length limits, and format constraints
- Search for all input points:
-
SQL Injection Risk Assessment
- Scan for raw queries:
grep -r "query\|execute" --include="*.js" | grep -v "?" - For Rails: Check for raw SQL in models and controllers
- Ensure all queries use parameterization or prepared statements
- Flag any string concatenation in SQL contexts
- Scan for raw queries:
-
XSS Vulnerability Detection
- Identify all output points in views and templates
- Check for proper escaping of user-generated content
- Verify Content Security Policy headers
- Look for dangerous innerHTML or dangerouslySetInnerHTML usage
-
Authentication & Authorization Audit
- Map all endpoints and verify authentication requirements
- Check for proper session management
- Verify authorization checks at both route and resource levels
- Look for privilege escalation possibilities
-
Sensitive Data Exposure
- Execute:
grep -r "password\|secret\|key\|token" --include="*.js" - Scan for hardcoded credentials, API keys, or secrets
- Check for sensitive data in logs or error messages
- Verify proper encryption for sensitive data at rest and in transit
- Execute:
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.
- yesterday First seen · 92 lines · 0 tokens per session scan A f84717fe7995
security-sentinel is an agent published in the GitHub repository EveryInc/compound-engineering-plugin (24,696 stars, last pushed 2d ago), licensed MIT. It costs nothing until one of its globs matches a file; then it loads 844 tokens. 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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