axiom

axiom is a skill for Claude Code from Ghosteken/agent-harness. It costs 51 tokens per session (3,087 once invoked), scanned A, a copy of axiom, MIT.

A structured method for examining hidden assumptions behind a decision or conclusion and rebuilding the reasoning from verified basic facts.

In plain words
What is it for?
Use it to break down major decisions, test product or business assumptions, rank risks, and reason from first principles in English or Chinese.
Why use it?
It helps expose beliefs, conventions, and uncertain premises that may be causing a plan or judgment to fail.

Skill for Claude Code

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

Part of the agent-harness plugin — 173 skills, 13 commands, 12 agents shipped together

Good fit Use it to break down major decisions, test product or business assumptions, rank risks, and reason from first principles in English or Chinese.

Compare 6 skills from other repositories ↓
Install with agentmods
npx agentmods add skills/ghosteken/agent-harness/axiom
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 Ghosteken/agent-harness --skill axiom
Clone the repo
git clone --depth 1 https://github.com/Ghosteken/agent-harness

Made for: Claude Code.

Or install agent-harness, the plugin that ships this one along with the rest of its 173 skills, 13 commands, 12 agents.

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 axiom

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

Your own site · 80×15
<a href="https://agentmods.dev/skills/ghosteken/agent-harness/axiom"><img src="https://agentmods.dev/badge/skills/ghosteken/agent-harness/axiom.svg" alt="Reviewed on agentmods" width="80" height="20"></a>
Per session 51 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 3,087 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 100% copy Near-identical to another mod 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 $0.00051 $0.03087
Opus 5 $0.00026 $0.01543
Sonnet 5 $0.00010 $0.00617
Haiku 4.5 $0.00005 $0.00309

Measured 8d ago against content hash e708ecf306dd, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-11, from the pricing page.

Security

Grade A, and why

axiom 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 8d 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.

Origin

This is a copy

100% identical to axiom — 0 lines differ, which has more behind it and is treated as the original. This page carries a canonical link to it rather than competing with it.

archive/skills-community/axiom/SKILL.md · 261 lines

How it starts

The opening of the file, as written. The whole thing — 261 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Axiom — First-Principles Assumption Auditor / 第一性原理拆解器

Strip any question down to its irreducible truths, then rebuild from there. This is not framework fill-in-the-blank — it is assumption prosecution.

把任何问题强制剥离到"不可再拆的最小真相单元",再从那里重建。 不是框架填空,是假设审判。

Language Rule / 语言规则

Auto-detect the user's input language and respond entirely in that language throughout the session. If the user writes in Chinese, all phases, labels, and outputs must be in Chinese. If the user writes in English, all phases, labels, and outputs must be in English. Do NOT mix languages unless the user explicitly switches.


When to Use This Skill / 何时使用

  • A major life or career decision is on the table (quitting a job, starting a company, buying a house)
  • You want to stress-test a business direction or product hypothesis
  • You suspect a belief you hold might be wrong but can't articulate why
  • You need to cut through complexity and find the real bottleneck
  • Someone asks you to "think from first principles" or "break it down"

Trigger phrases (中文): 第一性原理 / 帮我想清楚 / 拆解一下 / 从底层分析 / 这个假设对吗 / 我在做一个决定 / 从根本上分析 / 底层逻辑 / 元问题 / 重新思考 / 有没有想错 / axiom

Trigger phrases (English): first principles / break it down / question my assumptions / think from scratch / challenge this belief / audit my reasoning / what am I missing / help me think clearly / axiom


What This Skill Does / 核心能力

  1. Problem Reframing / 问题澄清 — Confirms the question itself is correctly defined before touching assumptions
  2. Assumption Mining / 假设挖掘 — Systematically surfaces 8-12 hidden assumptions across three depth layers
  3. Assumption Classification / 假设分类 — Force-labels every assumption into one of four types with different challenge strategies
  4. Risk Ranking / 优先级排序 — Scores each assumption on Fragility × Impact and outputs a "Most Dangerous Top 3"
  5. Reconstruction / 重建 — Rebuilds conclusions from verified premises only, explicitly comparing "before vs after" cognitive shift

Read the full file on GitHub · 261 lines

Files

What ships with it

4 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. 8d ago First seen · 261 lines · 51 tokens per session scan A e708ecf306dd

Subscribe to this mod's changes

axiom is a skill published in the GitHub repository Ghosteken/agent-harness (2 stars, last pushed yesterday), licensed MIT. It adds 51 tokens to every session and 3,087 once invoked, about $0.0003 per session on Opus 5. A static security scan graded it A with 0 findings. It is 100% identical to axiom, differing in 0 lines, and is treated as a copy.