Borrowing it
Nothing to install: this file belongs to qauth-labs/qauth. 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/qauth-labs/qauth/main/.claude/skills/security/SKILL.mdgit clone --depth 1 https://github.com/qauth-labs/qauthWrote 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/qauth-labs/qauth/security)<a href="https://agentmods.dev/skills/qauth-labs/qauth/security"><img src="https://agentmods.dev/badge/skills/qauth-labs/qauth/security/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/qauth-labs/qauth/security"><img src="https://agentmods.dev/badge/skills/qauth-labs/qauth/security.svg" alt="Reviewed on agentmods" width="80" height="20"></a>- NVIDIA SkillSpector warn
SkillSpector: 1 finding, up to medium
These are SkillSpector’s own severities. On a checked sample its high-severity flags on skills were ~96% false positives — a documented command, a public API, a “never do X” rule — so we show them as a caution to read, not a verdict. Why →
- medium Prompt Injection · line 20 Large whitespace padding was detected (a block of blank lines or a long run of spaces). This can push injected instructions below or to the right of the visible area so a human reviewer never sees them while the agent still reads them. Manual review of the hidden content is recommended.Fix: Remove the large whitespace padding (blank-line blocks or long space runs) and review any content hidden below or to the right of it. Keep skill files compact and reviewable so no instructions can be
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 | $0.02067 |
| Opus 5.5 | $0.00025 | $0.00827 |
| Sonnet 5.5 | $0.00013 | $0.00413 |
| Haiku 4.5 | $0.00006 | $0.00207 |
Grade A, and why
security 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.
How it starts
The opening of the file, as written. The whole thing — 122 lines — stays where its author put it; the contents beside it link to each section on GitHub.
Security (QAuth)
Standards-aligned security for QAuth: authentication, authorization, rate limiting, timing-safe operations, secrets, and dependency hygiene. Use this skill when implementing or reviewing security-sensitive code, handling CVEs, or aligning with OWASP and related standards.
When to Use This Skill
- Implementing or changing auth flows (login, token, PKCE, JWT)
- Adding rate limits, error handling, or audit logging
- Handling secrets, keys, or environment configuration
- Reviewing code for OWASP API Security risks
- Addressing dependency vulnerabilities (npm/pnpm audit, CVE)
Quick Reference
| Concern | QAuth pattern |
|---|---|
| Passwords | Argon2id via @node-rs/argon2; never store plaintext; validate strength (zxcvbn) |
| Timing | Constant-time comparison for PKCE (crypto.timingSafeEqual); minimum response time on login/token/refresh |
| Rate limiting | Per-route and global via @fastify/rate-limit; Redis store; env-driven limits |
| Errors | Generic messages for auth failures (no user enumeration); domain errors from @qauth-labs/shared-errors |
| Secrets | Keys in env/secrets manager; never in images or logs; see ADR-001 for JWT keys |
| Audit | Log auth/token events to audit_logs (success/failure, IP, userAgent, metadata) |
| Dependencies | Run pnpm audit (or npm audit); fix or document exceptions; track CVEs |
OWASP API Security Top 10:2023 — Checklist
- API1 Broken Object Level Authorization: Check object IDs against current user/realm; validate every access by ID.
- API2 Broken Authentication: Strong auth (OAuth 2.1 + PKCE, JWT with Ed25519); no default/weak creds; rate limit auth endpoints.
- API3 Broken Object Property Level Authorization: Don't over-expose or mass-assign; validate input and response shape.
- API4 Unrestricted Resource Consumption: Rate limit (global + per-route); limit payload size; timeouts.
- API5 Broken Function Level Authorization: Enforce admin vs user; validate scope and client type.
- API6 Unrestricted Access to Sensitive Business Flows: Rate limit login, token, register, resend-verification; consider CAPTCHA/MFA for sensitive flows.
- API7 SSRF: Validate and allowlist URLs when fetching remote resources; no user-controlled URLs to internal services.
- API8 Security Misconfiguration: Secure defaults; no debug in production; HTTPS; lock headers (CORS, etc.).
- API9 Improper Inventory Management: Document endpoints; version APIs; remove or protect deprecated/debug routes.
- API10 Unsafe Consumption of APIs: Validate and sanitize data from third-party APIs; don't trust upstream blindly.
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 · 122 lines · 63 tokens per session scan A 1b09947b0438
security is a skill published in the GitHub repository qauth-labs/qauth (26 stars, last pushed today), licensed Apache-2.0. It adds 63 tokens to every session and 2,067 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 2026-08-30.
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