fable-security

fable-security is a skill for Claude Code, Codex from imMamdouhaboammar/get-fable. It costs 126 tokens per session (1,888 once invoked), scanned A, original, MIT.

A security review skill that examines how attackers could move through trust boundaries, authentication, APIs, and untrusted input. It also checks for exposed secrets and assesses reported vulnerabilities.

In plain words
What is it for?
Use it to review login and access-control changes, inspect APIs for injection, cross-site request forgery (CSRF), or cross-origin (CORS) risks, check credentials, and assess supply-chain or sandbox changes.
Why use it?
It helps find security problems that a secret scan or general checklist can miss, including flaws in permissions, data flow, and failure handling.

Skill for Claude CodeCodex

Written for Claude Code and Codex: shipped in a Claude Code plugin, but also agents/openai.yaml present.

Part of the get-fable plugin — 78 skills, 1 agent, 5 hooks shipped together

Good fit Use it to review login and access-control changes, inspect APIs for injection, cross-site request forgery (CSRF), or cross-origin (CORS) risks, check credentials, and assess supply-chain or sandbox changes.

Compare 6 skills from other repositories ↓
Install with agentmods
npx agentmods add skills/immamdouhaboammar/get-fable/fable-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 imMamdouhaboammar/get-fable --skill fable-security
Clone the repo
git clone --depth 1 https://github.com/imMamdouhaboammar/get-fable

Made for: Claude Code, Codex.

Or install get-fable, the plugin that ships this one along with the rest of its 78 skills, 1 agent, 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 fable-security

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

Your own site · 80×15
<a href="https://agentmods.dev/skills/immamdouhaboammar/get-fable/fable-security"><img src="https://agentmods.dev/badge/skills/immamdouhaboammar/get-fable/fable-security.svg" alt="Reviewed on agentmods" width="80" height="20"></a>
Per session 126 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 1,888 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 $0.00126 $0.01888
Opus 5 $0.00063 $0.00944
Sonnet 5 $0.00025 $0.00378
Haiku 4.5 $0.00013 $0.00189

Measured 4d ago against content hash cde853d3b47d, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-09, from the pricing page.

Security

Grade A, and why

fable-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 4d 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/fable-security/SKILL.md · 204 lines

How it starts

The opening of the file, as written. The whole thing — 204 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Fable Security

Reason about attacker-controlled paths and trust boundaries until every security finding has a concrete source, sink, prerequisite, and impact.

Mission

Security review is not a secret scan plus a generic checklist. It asks what an attacker can control, which privilege/data boundary that input can cross, what enforcement must hold, and whether the changed code preserves that property under failure and concurrency.

A clean scanner is evidence about scanner coverage, not a proof that the design is secure.

Activate When

  • authentication, authorization, sessions, tokens, permissions, tenancy, or privileged actions change;
  • untrusted input reaches parsers, queries, templates, files, URLs, shells, webhooks, or deserializers;
  • secrets/credentials or cryptographic material are handled;
  • a diff changes trust boundaries, network exposure, storage access, package/install logic, or sandboxing;
  • a reported vulnerability/finding needs validation or severity calibration;
  • repository/package supply-chain behavior needs security review.

Do Not Activate When

  • the task is only functional verification with no security question (fable-verify);
  • a generic maintainability review has no trust-boundary impact (fable-review);
  • a vulnerability is already validated and the user wants only a bounded fix (fable-execute, while preserving security acceptance).

Security Work Classification

Mode Primary question
Threat model what assets/actors/boundaries/abuse paths exist?
Security diff review what security property changed in this diff?
Finding validation can attacker-controlled data actually reach a sensitive sink?
Repository audit which exposed surfaces deserve deeper inspection?
Secret hygiene can sensitive values enter source/logs/artifacts?
Supply-chain/package can dependency/install/build boundaries be abused?

Protocol

Stage 1 — Define assets, actors, and trust boundaries

Identify:

  • protected assets/data/operations;
  • authenticated/unauthenticated/privileged actors;
  • tenant/user ownership boundaries;
  • external systems/webhooks/plugins;
  • process/filesystem/network privilege transitions.

Read the full file on GitHub · 204 lines

Files

What ships with it

8 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. 4d ago First seen · 204 lines · 126 tokens per session scan A cde853d3b47d

Subscribe to this mod's changes

fable-security is a skill published in the GitHub repository imMamdouhaboammar/get-fable (3 stars, last pushed 4d ago), licensed MIT. It adds 126 tokens to every session and 1,888 once invoked, about $0.0006 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 2026-09-05.

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