feynman

feynman is a skill for Claude Code, Codex from neurofoo/agent-skills. It costs 41 tokens per session (551 once invoked), scanned A, original, MIT.

A learning method that explains a subject in simple words, finds gaps in that explanation, fills them, and then improves the result. It is known as the Feynman Technique.

In plain words
What is it for?
Use it to learn a new concept, test your understanding, prepare to teach, create an analogy, and identify questions that still need answers.
Why use it?
It reveals whether you really understand an idea instead of relying on vague explanations or memorized terms.

Skill for Claude CodeCodex

Part of the learning-skills plugin — 3 skills, 7 commands shipped together

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/neurofoo/agent-skills/feynman
Any agent
npx skills add neurofoo/agent-skills --skill feynman
Clone the repo
git clone --depth 1 https://github.com/neurofoo/agent-skills

Made for: Claude Code, Codex.

Or install learning-skills, the plugin that ships this one along with the rest of its 3 skills, 7 commands.

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 feynman

README.md
[![agentmods](https://agentmods.dev/badge/skills/neurofoo/agent-skills/feynman.svg)](https://agentmods.dev/skills/neurofoo/agent-skills/feynman)
Your own site
<a href="https://agentmods.dev/skills/neurofoo/agent-skills/feynman"><img src="https://agentmods.dev/badge/skills/neurofoo/agent-skills/feynman.svg" alt="Measured on agentmods" height="20"></a>
Per session 41 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 551 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 $0.00041 $0.00551
Opus 5 $0.00020 $0.00275
Sonnet 5 $0.00008 $0.00110
Haiku 4.5 $0.00004 $0.00055

Measured 5d ago against content hash ea0e7a0ba3c8, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

Grade A, and why

feynman 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.

feynman/SKILL.md · 99 lines

How it starts

The opening of the file, as written. The whole thing — 99 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Feynman Technique

Apply the full Feynman learning technique to deeply understand a concept.

Instructions

Work through all four steps of the Feynman technique. Be honest about gaps—they're the point.

Output Format

Concept: [What are we trying to understand?]


Step 1: Explain It Simply

Explain as if teaching someone with no background in this field

Simple Explanation

[Write a plain-language explanation. Use everyday words. Avoid jargon. Aim for a bright 12-year-old to understand.]

Analogy

[Create an analogy using something familiar to illustrate the concept]


Step 2: Identify Gaps

Where did the explanation get fuzzy, hand-wavy, or require jargon?

Gaps Found

Gap What I Said What I'm Not Sure About
1 [vague part] [the underlying question]
2 [vague part] [the underlying question]
3 [vague part] [the underlying question]

Jargon Used

Term Can I Explain It Simply?
[term] Yes / No / Partially

Step 3: Fill the Gaps

Research or think through each gap

Gap 1: [Topic]

  • The question: [What wasn't clear?]
  • The answer: [What I learned]
  • Now I can explain it as: [Simple version]

Step 4: Refined Explanation

Rewrite the complete explanation with gaps filled and simpler language

Final Simple Explanation

[The improved, complete explanation in plain language]

Improved Analogy

[A refined or new analogy that better captures the concept]

Key Takeaways

  1. [Core insight 1]
  2. [Core insight 2]
  3. [Core insight 3]

Test Question If someone asked me to explain this in 30 seconds, I'd say:

[Elevator pitch version]

Guidelines

  • Don't pretend to understand—gaps are valuable
  • Use analogies from everyday life
  • If you need jargon, define it simply
  • Shorter is usually better
  • The "explain to a child" bar is high—take it seriously

$ARGUMENTS

Read the full file on GitHub · 99 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. 5d ago First seen · 99 lines · 41 tokens per session scan A ea0e7a0ba3c8

Subscribe to this mod's changes

feynman is a skill published in the GitHub repository neurofoo/agent-skills (111 stars, last pushed 7mo ago), licensed MIT. It adds 41 tokens to every session and 551 once invoked, about $0.0002 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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