security

A set of security rules for QAuth authentication and OAuth flows, covering passwords, secrets, rate limits, error messages, timing, and dependency checks.

In plain words
What is it for?
Implementing or reviewing login and token flows, rate limiting, secret handling, security audits, vulnerability fixes, and OWASP API security controls.
Why use it?
It provides specific safeguards for code that handles accounts, login credentials, tokens, and other sensitive data.

Skill for Claude CodeCodex

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 skills/qauth-labs/qauth/security
Any agent
npx skills add qauth-labs/qauth --skill security
Clone the repo
git clone --depth 1 https://github.com/qauth-labs/qauth

Made for: Claude Code, Codex.

Per session 63 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 2,067 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 0 findings. Scan, not verified.
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 $0.00063 $0.02067
Opus 5 $0.00032 $0.01033
Sonnet 5 $0.00013 $0.00413
Haiku 4.5 $0.00006 $0.00207

Measured 2d ago against content hash 1b09947b0438, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

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 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.

.claude/skills/security/SKILL.md · 122 lines

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.

Read the full file on GitHub · 122 lines

Files

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.

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 · 122 lines · 63 tokens per session scan A 1b09947b0438

Subscribe to this mod's changes

security is a skill published in the GitHub repository qauth-labs/qauth (24 stars, last pushed 7d ago), licensed Apache-2.0. It adds 63 tokens to every session and 2,067 once invoked, about $0.0003 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.