deductive-chain

deductive-chain is a skill for Claude Code, Codex from yogsoth-ai/stress-test. It costs 24 tokens per session (157 once invoked), scanned A, original, Apache-2.0.

A step-by-step method for drawing logical conclusions from a starting statement. It records each inference so the reasoning can be checked.

In plain words
What is it for?
Use it to work through claims, arguments, or rule-based problems and show how each conclusion follows from the previous one.
Why use it?
It makes hidden assumptions and reasoning gaps easier to spot. The result is more traceable than an unsupported conclusion.

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/yogsoth-ai/stress-test/deductive-chain
Any agent
npx skills add yogsoth-ai/stress-test --skill deductive-chain
Clone the repo
git clone --depth 1 https://github.com/yogsoth-ai/stress-test

Made for: Claude Code, Codex.

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 deductive-chain

README.md
[![agentmods](https://agentmods.dev/badge/skills/yogsoth-ai/stress-test/deductive-chain.svg)](https://agentmods.dev/skills/yogsoth-ai/stress-test/deductive-chain)
Your own site
<a href="https://agentmods.dev/skills/yogsoth-ai/stress-test/deductive-chain"><img src="https://agentmods.dev/badge/skills/yogsoth-ai/stress-test/deductive-chain.svg" alt="Measured on agentmods" height="20"></a>
Per session 24 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 157 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 $0.00024 $0.00157
Opus 5 $0.00012 $0.00078
Sonnet 5 $0.00005 $0.00031
Haiku 4.5 $0.00002 $0.00016

Measured 5d ago against content hash 032125f14d18, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

Grade A, and why

deductive-chain 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 5d 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/deductive-chain/SKILL.md · 27 lines

What it actually says

Deductive Chain

Subagent that takes a premise and derives logical consequences through valid inference steps, producing a traceable chain.

Available SOPs

Optional, no fixed order; the final leaf is always a sop.

SOP When to use
spawn-agent Spawn a customized CC subagent with full MCP tool access. Used by SOPs that declare execution: subagent.
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. 5d ago First seen · 27 lines · 24 tokens per session scan A 032125f14d18

Subscribe to this mod's changes

deductive-chain is a skill published in the GitHub repository yogsoth-ai/stress-test (2 stars, last pushed 2mo ago), licensed Apache-2.0. It adds 24 tokens to every session and 157 once invoked, about $0.0001 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.