claudia-security

claudia-security is a skill for Claude Code from reganomalley/claudia. It costs 89 tokens per session (797 once invoked), scanned A, original, MIT.

A security guidance skill covering common decisions about protecting software and user data. It explains choices involving login, permissions, secrets, encryption, isolated execution, and web or API security.

In plain words
What is it for?
It is for choosing authentication methods, storing passwords and API keys, protecting web requests, and evaluating security-related architecture decisions.
Why use it?
It helps avoid common security mistakes when designing an application, while making clear that it is not a formal security audit.

Skill for Claude Code

Written for Claude Code: shipped in a Claude Code plugin.

Part of the claudia plugin — 10 skills, 12 commands, 5 hooks shipped together

Good fit It is for choosing authentication methods, storing passwords and API keys, protecting web requests, and evaluating security-related architecture decisions.

Compare 6 skills from other repositories ↓
Install with agentmods
npx agentmods add skills/reganomalley/claudia/claudia-security
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.

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

Made for: Claude Code.

Or install claudia, the plugin that ships this one along with the rest of its 10 skills, 12 commands, 5 hooks.

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 claudia-security

README.md
[![agentmods](https://agentmods.dev/badge/skills/reganomalley/claudia/claudia-security/github.svg)](https://agentmods.dev/skills/reganomalley/claudia/claudia-security)
Your own site
<a href="https://agentmods.dev/skills/reganomalley/claudia/claudia-security"><img src="https://agentmods.dev/badge/skills/reganomalley/claudia/claudia-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.

agentmods 80×15 button for claudia-security

Your own site · 80×15
<a href="https://agentmods.dev/skills/reganomalley/claudia/claudia-security"><img src="https://agentmods.dev/badge/skills/reganomalley/claudia/claudia-security.svg" alt="Reviewed on agentmods" width="80" height="20"></a>
Per session 89 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 797 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 $0.00089 $0.00797
Opus 5 $0.00044 $0.00398
Sonnet 5 $0.00018 $0.00159
Haiku 4.5 $0.00009 $0.00080

Measured 10d ago against content hash ae1eb76bca1f, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-10, from the pricing page.

Security

Grade A, and why

claudia-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 10d 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.

skills/claudia-security/SKILL.md · 79 lines

How it starts

The opening of the file, as written. The whole thing — 79 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Claudia Security Domain

Overview

This skill provides security decision frameworks. It doesn't replace a security audit -- it helps you make informed choices and avoid common pitfalls.

Decision Trees

Authentication: Which Method?

What are you building?
├── API consumed by other services
│   ├── Internal only → API keys + mTLS
│   └── External/public → OAuth 2.0 client credentials
├── Web app with users
│   ├── Simple/small scale → Session-based auth (cookie + server session)
│   ├── SPA + API backend → JWT (short-lived) + refresh tokens (httpOnly cookie)
│   └── Enterprise/SSO needs → OIDC with identity provider (Auth0, Okta, Keycloak)
├── Mobile app
│   └── OAuth 2.0 + PKCE (always PKCE for public clients)
└── CLI tool
    └── OAuth 2.0 device flow or API key

Secrets: Where Do They Go?

What kind of secret?
├── API keys / tokens
│   ├── Development → .env file (gitignored) + dotenv library
│   ├── CI/CD → Pipeline secrets (GitHub Actions secrets, etc.)
│   └── Production → Secret manager (AWS SSM, Vault, Doppler)
├── Database credentials
│   ├── Local dev → .env or docker-compose env
│   └── Production → Secret manager + IAM roles where possible
├── Encryption keys
│   └── Always → KMS (AWS KMS, GCP KMS, Azure Key Vault)
└── User passwords
    └── Never store → bcrypt/argon2 hash only

Common Mistakes (and fixes)

Mistake Why It's Bad Fix
JWT in localStorage XSS can steal tokens httpOnly cookie for refresh, memory for access
Long-lived JWT (days/weeks) Stolen token = long compromise 15min access + rotating refresh tokens
Rolling your own auth You will miss something Use a library (Passport, NextAuth, Lucia)
Hardcoded secrets in code Ends up in git history .env + secret manager
CORS * in production Any site can call your API Whitelist specific origins
No rate limiting on auth Brute force attacks Rate limit login + lockout after N failures
MD5/SHA1 for passwords Fast to crack bcrypt (cost 12+) or argon2id
No CSRF protection Forged requests from other sites SameSite cookies + CSRF tokens

Read the full file on GitHub · 79 lines

Files

What ships with it

3 files 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. 10d ago First seen · 79 lines · 89 tokens per session scan A ae1eb76bca1f

Subscribe to this mod's changes

claudia-security is a skill published in the GitHub repository reganomalley/claudia (4 stars, last pushed 6mo ago), licensed MIT. It adds 89 tokens to every session and 797 once invoked, about $0.0004 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 2026-08-31.

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