A fundamentals-explanation command that reads current project or infrastructure sources and gives a detailed explanation of how they work.

Use it to understand a project, work area, or piece of infrastructure, including the subject currently being discussed.

It helps you catch up on an unfamiliar codebase or work area without relying on outdated notes or guesses.

ef — Command for Claude Code by danielmiessler/LifeOS

About the project

LifeOS is an AI-assisted personal operating system that records a person’s goals, values, context, and current situation to help move them toward a desired future state. It supports work such as building applications, starting businesses, and creative projects. Its catalogue entries extend the system through skills, hooks, agents, and commands.

danielmiessler/LifeOS · 19,747 stars · on GitHub · ourlifeos.ai

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.

Clone the repo

git clone --depth 1 https://github.com/danielmiessler/LifeOS

Made for: Claude Code.

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.

README.md

[![agentmods](https://agentmods.dev/badge/commands/danielmiessler/lifeos/ef/github.svg)](https://agentmods.dev/commands/danielmiessler/lifeos/ef)

Your own site

<a href="https://agentmods.dev/commands/danielmiessler/lifeos/ef"><img src="https://agentmods.dev/badge/commands/danielmiessler/lifeos/ef/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.

Your own site · 80×15

<a href="https://agentmods.dev/commands/danielmiessler/lifeos/ef"><img src="https://agentmods.dev/badge/commands/danielmiessler/lifeos/ef.svg" alt="Reviewed on agentmods" width="80" height="20"></a>

Per session 65 Only the description is in the session, so the agent can decide to use it. The body loads when it is invoked.

When invoked 190 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.

Model	Per session	Once invoked
Fable 5.1	$0.00065	$0.00190
Opus 5.5	$0.00026	$0.00076
Sonnet 5.5	$0.00013	$0.00038
Haiku 4.5	$0.00006	$0.00019

Measured 10d ago against content hash 5856f3655271, method: parsed. Prices are Anthropic first-party input rates as of 2026-10-07, from the pricing page.

Security

Grade A, and why

ef 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 10d 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.

LifeOS/install/commands/ef.md · 19 lines

What it actually says

ef — Explain fundamentals

Invoke the Explain skill's ExplainFundamentals intent on $ARGUMENTS:

Skill("Explain", "explain fundamentals $ARGUMENTS")

If $ARGUMENTS is empty, the area defaults to whatever this conversation has been working in; on a fresh session with nothing in play, the intent asks.

Full intent: ~/.claude/skills/Explain/Intents/ExplainFundamentals.md.

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.

10d ago First seen · 19 lines · 65 tokens per session scan A 5856f3655271

Subscribe to this mod's changes

ef is a command published in the GitHub repository danielmiessler/LifeOS (19,747 stars, last pushed 2d ago), licensed MIT. It adds 65 tokens to every session and 190 once invoked, about $0.0003 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 2026-10-28.

Learning and teaching Productivity ai ai-harness augmentation humans intent-engineering

ef next to 6 commands from other repositories
Mod	Type	Stars	Last push	Licence	Scan	Tokens	Works with
efdanielmiessler/LifeOS	Command	20k	2d ago	MIT	A	65	Claude Code
welcomefrankxai/Starlight-Intelligence-System	Command	10	today	MIT	A	42	Claude Code
daily-okrMark393295827/third-brain-v7-skills	Command	140	1mo ago	MIT	A	27	Claude Code
recapDojoCodingLabs/code-sensei	Command	15	1mo ago	MIT	A	16	Claude Code
start-12-4minicoohei/ai-agent-camp	Command	347	1mo ago	none	A	2	Claude Code
modesruvnet/flow-nexus	Command	106	yesterday	none	A	0	Claude Code
sessionruvnet/flow-nexus	Command	106	yesterday	none	A	0	Claude Code