fable-domain

fable-domain is a skill for Claude Code, Codex from Sahir619/fable-method. It costs 113 tokens per session (2,384 once invoked), scanned A, original, MIT.

A workflow for creating a practical coding-agent skill for a specialised subject area. It discusses the subject, researches real sources, and produces instructions, a process diagram, safety checks, and a small test.

In plain words
What is it for?
Use it to add a new subject area to the Fable method and create its workflow, domain-specific adaptations, failure-case test, and smoke test.
Why use it?
It helps turn unfamiliar subject knowledge into repeatable guidance that a less capable agent can follow and verify.

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 fable plugin — 5 skills shipped together

Good fit Use it to add a new subject area to the Fable method and create its workflow, domain-specific adaptations, failure-case test, and smoke test.

Compare 6 skills from other repositories ↓
Install with agentmods
npx agentmods add skills/sahir619/fable-method/fable-domain
About the project

The Fable Method is a set of agent workflows that organize tasks into deciding what is needed, taking the smallest appropriate action, and proving the result with verification. It is intended for AI agents that need repeatable behavior grounded in evidence and explicit completion checks. The catalogue entries are the project's skills, instruction, and plugin implementing those workflows.

Sahir619/fable-method · 2,309 stars · on GitHub

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 Sahir619/fable-method --skill fable-domain
Clone the repo
git clone --depth 1 https://github.com/Sahir619/fable-method

Made for: Claude Code, Codex.

Or install fable, the plugin that ships this one along with the rest of its 5 skills.

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-domain

README.md
[![agentmods](https://agentmods.dev/badge/skills/sahir619/fable-method/fable-domain/github.svg)](https://agentmods.dev/skills/sahir619/fable-method/fable-domain)
Your own site
<a href="https://agentmods.dev/skills/sahir619/fable-method/fable-domain"><img src="https://agentmods.dev/badge/skills/sahir619/fable-method/fable-domain/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-domain

Your own site · 80×15
<a href="https://agentmods.dev/skills/sahir619/fable-method/fable-domain"><img src="https://agentmods.dev/badge/skills/sahir619/fable-method/fable-domain.svg" alt="Reviewed on agentmods" width="80" height="20"></a>
Per session 113 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 2,384 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. Third-party audits
  • NVIDIA SkillSpector pass 7 Sept 2026
How audits are shown
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 $0.00113 $0.02384
Opus 5.5 $0.00045 $0.00954
Sonnet 5.5 $0.00023 $0.00477
Haiku 4.5 $0.00011 $0.00238

Measured 27d ago against content hash ba96c5ae2c3c, method: parsed. Prices are Anthropic first-party input rates as of 2026-10-07, from the pricing page.

Security

Grade A, and why

fable-domain 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 27d 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-domain/SKILL.md · 72 lines

How it starts

The opening of the file, as written. The whole thing — 72 lines — stays where its author put it; the contents beside it link to each section on GitHub.

fable-domain

The fable-method ships domain adapters that translate its loop into a sector's nouns. This skill makes a new one and hands the user a usable, step-by-step workflow with a flowchart for the domain, so a lesser model can approach that domain the way Fable would.

Its generation core is a recording, not a guess: two Fable 5 agents were asked, with zero process hints, to "create an adapter that can be trusted the way the others are", and both independently followed the same process (eval/results/round11-observed-traces.json). Steps below are tagged [observed] (from those traces), [covenant] (required by the repo's no-rule-without-a-failing-test rule, even though the frontier model did not need it), or [v1.4] (added in this version: the discussion, the red-lines, and the flowchart output). The reason the covenant and v1.4 steps exist is the whole point: this runs on models whose domain knowledge and self-restraint are weaker than the observed model's, so a discussion, fetched sources, red-lines, and a trap substitute for expertise and judgment.

What it produces (the bundle; all four, or not done)

  1. A domain workflow with a flowchart [v1.4]. The step-by-step approach for this domain, distilled from the discussion and research, plus a mermaid flowchart, the same shape as this method's own references/flowcharts.md. This is the user-facing "here are the steps, in order" artifact. It lives in the adapter's Workflow section (see TEMPLATE.md).
  2. The adapter, conforming to references/domains/TEMPLATE.md, every named regulation/policy/figure carrying a fetched source in its Sources section.
  3. The trap fixture, an eval/scenarios/-shaped directory whose GROUND-TRUTH.md defines the task, the trap (the sector's central fraud), scoring caps, and ideal behavior.
  4. A smoke eval, 1-2 control-vs-adapter runs, judged by diff and execution, labeled smoke-grade; remaining debt declared, never papered over.

Stage 1: Discuss [v1.4]

Read the full file on GitHub · 72 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. 27d ago Changed · -2 tokens per session ba96c5ae2c3c
  2. 2mo ago First seen · 72 lines · 115 tokens per session scan A 3acc502d17b8

Subscribe to this mod's changes

fable-domain is a skill published in the GitHub repository Sahir619/fable-method (2,309 stars, last pushed 27d ago), licensed MIT. It adds 113 tokens to every session and 2,384 once invoked, about $0.0005 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.