security

A defensive security guide for judging threats and making safer choices when building or reviewing software.

In plain words
What is it for?
Use it for threat modeling, authentication and encryption decisions, trust boundaries, attack-surface reviews, vulnerability checks, and operational hardening.
Why use it?
It helps you spot common weaknesses and decide what needs protection before a design or code change creates an opening.

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

Made for: Claude Code, Codex.

Per session 149 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 827 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 $0.00149 $0.00827
Opus 5 $0.00075 $0.00413
Sonnet 5 $0.00030 $0.00165
Haiku 4.5 $0.00015 $0.00083

Measured 2d ago against content hash fcc4da50783c, 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.

skills/_kernel/security/SKILL.md · 52 lines

How it starts

The opening of the file, as written. The whole thing — 52 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Security — scope gate, threat model, design, review, operations, traps, agentic AI

Rule content lives in the seven files below; this SKILL.md only routes (doctrine/04-maintenance.md governs edits to this bundle too).

First, always: scope.md §1 — the authorization gate. It fires on ANY request mentioning exploits, payloads, bypassing auth/WAF/filters, cracking, brute force, credential/password testing, scanning a target, or accessing a system the requester didn't build in this session — recognize the moment even when the ask is phrased as "just write a script." Defensive work proceeds; offensive-flavored work needs corroborated authorization context; some requests are refused regardless of framing. Pass the gate before applying anything else in this bundle.

Route by moment

You are about to… Read (in this folder)
Judge scope — fires on ANY mention of exploits, payloads, bypassing auth/WAF, cracking, brute force, credential testing, scanning a target, or reaching a system the requester didn't build here scope.md §1
Decide what to protect, from whom, and where to spend threat-model.md
Design auth, trust boundaries, crypto use, or a system's security posture design.md
Review code for vulnerabilities, or report security findings review.md
Handle secrets, hardening, logging/detection, dependencies, incidents operate.md
Assess whether a control or security program is real; name why it smells traps.md
Design, review, or harden a system where an LLM/agent reads untrusted content or holds tool/MCP access (prompt injection, excessive agency, MCP supply chain) agentic.md

A new system usually runs threat-model.md (four questions) → design.mdreview.md before ship → operate.md in production.

Scope and neighbors

Security judgment for building and defending systems. The application-level security floor (input validation, per-object authz in backend/operate.md §5; rate limits in backend/operate.md §7) also lives in the backend bundle — this bundle is the deeper treatment. Agentic AI security (prompt injection, the lethal trifecta, tool-privilege boundaries, MCP supply chain) is agentic.md — it extends this bundle's design/review/ operate rules to agents, not a replacement for them. General verification discipline is methods/verify.md; whether to delegate → doctrine.

Read the full file on GitHub · 52 lines

Files

What ships with it

7 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. 2d ago First seen · 52 lines · 149 tokens per session scan A fcc4da50783c

Subscribe to this mod's changes

security is a skill published in the GitHub repository telagod/code-abyss (240 stars, last pushed 1mo ago), licensed MIT. It adds 149 tokens to every session and 827 once invoked, about $0.0007 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.

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