Borrowing it
Nothing to install: this file belongs to mtnyilmaz/agents. Take a copy, put it at the same path in your own repository, and replace the rules that are about this project with yours.
curl -O https://raw.githubusercontent.com/mtnyilmaz/agents/main/.agents/skills/security-engineer/SKILL.mdgit clone --depth 1 https://github.com/mtnyilmaz/agentsWrote 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.
[](https://agentmods.dev/skills/mtnyilmaz/agents/security-engineer)<a href="https://agentmods.dev/skills/mtnyilmaz/agents/security-engineer"><img src="https://agentmods.dev/badge/skills/mtnyilmaz/agents/security-engineer/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.
<a href="https://agentmods.dev/skills/mtnyilmaz/agents/security-engineer"><img src="https://agentmods.dev/badge/skills/mtnyilmaz/agents/security-engineer.svg" alt="Reviewed on agentmods" width="80" height="20"></a>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.
| Model | Per session | Once invoked |
|---|---|---|
| Fable 5.1 | $0.00063 | $0.00483 |
| Opus 5.5 | $0.00025 | $0.00193 |
| Sonnet 5.5 | $0.00013 | $0.00097 |
| Haiku 4.5 | $0.00006 | $0.00048 |
Grade A, and why
security-engineer 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 1mo 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.
What it actually says
Security Engineer
Expert in application security for this monorepo.
Reference Documentation
Read the full security guide before making security-related decisions:
.agents/rules/security-patterns.md— Complete security architecture (input validation, auth, rate limiting, CORS, headers, XSS, SQL injection, secrets, file uploads, audit trail).agents/rules/auth-patterns.md— Authentication flows, RBAC roles, multi-app session.agents/rules/config-patterns.md— Secrets management, environment variables.agents/rules/api-patterns.md— API middleware chain, request validation
Quick Security Checklist
Before approving any code:
- Input validated with Zod on both client AND server
- Auth middleware checks session/JWT before route handler
- RBAC middleware checks role for protected routes
- No secrets in code, logs, or error responses
- No
anytypes — useunknownand narrow - No
$queryRawUnsafe— use parameterized queries only - No
dangerouslySetInnerHTMLwithout DOMPurify - No
console.log— use@repo/logger(it redacts sensitive fields) - Rate limiting on auth endpoints (login, register, forgot-password)
- Soft delete — never hard delete user data
Security Patterns by Area
Authentication — see .agents/rules/security-patterns.md and .agents/rules/auth-patterns.md
Rate Limiting — see .agents/rules/security-patterns.md (Rate Limiting section)
CORS & Headers — see .agents/rules/security-patterns.md (CORS and HTTP Security Headers sections)
File Uploads — see .agents/rules/security-patterns.md (File Upload Security section)
Audit Trail — see .agents/rules/security-patterns.md (Audit Trail section)
What ships with it
1 file beside SKILL.md in the same directory: the scripts, references and assets a skill reads on demand. Not counted in the per-session cost; read them before you install if any of them is executable.
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.
- 1mo ago First seen · 39 lines · 63 tokens per session scan A b0d848c88077
security-engineer is a skill published in the GitHub repository mtnyilmaz/agents (6 stars, last pushed 5mo ago), licensed MIT. It adds 63 tokens to every session and 483 once invoked, about $0.0003 per session on Opus 5.5. 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.
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