teach

teach is a skill for Claude Code from JustineDevs/premortem. It costs 15 tokens per session (1,779 once invoked), scanned A, a copy of teach, Apache-2.0.

A structured way to learn a new skill or concept through lessons, reference notes, resources, and learning records.

In plain words
What is it for?
Studying a topic, building quick-reference documents, and recording what you have learned.
Why use it?
It keeps learning materials and progress in one place across multiple sessions.

Skill for Claude Code

Written for Claude Code: disable-model-invocation in frontmatter. Also seen: installed under .agents/ (shared by several agents).

Good fit Studying a topic, building quick-reference documents, and recording what you have learned.

Compare 6 skills from other repositories ↓
Install with agentmods
npx agentmods add skills/justinedevs/premortem/teach
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 JustineDevs/premortem --skill teach
Clone the repo
git clone --depth 1 https://github.com/JustineDevs/premortem

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.

agentmods badge for teach

README.md
[![agentmods](https://agentmods.dev/badge/skills/justinedevs/premortem/teach/github.svg)](https://agentmods.dev/skills/justinedevs/premortem/teach)
Your own site
<a href="https://agentmods.dev/skills/justinedevs/premortem/teach"><img src="https://agentmods.dev/badge/skills/justinedevs/premortem/teach/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 teach

Your own site · 80×15
<a href="https://agentmods.dev/skills/justinedevs/premortem/teach"><img src="https://agentmods.dev/badge/skills/justinedevs/premortem/teach.svg" alt="Reviewed on agentmods" width="80" height="20"></a>
Per session 15 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 1,779 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 84% 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 $0.00015 $0.01779
Opus 5 $0.00008 $0.00890
Sonnet 5 $0.00003 $0.00356
Haiku 4.5 $0.00002 $0.00178

Measured 9d ago against content hash d36496c90da9, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-12, from the pricing page.

Security

Grade A, and why

teach 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 9d 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

84% identical to teach — 13 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.

.agents/skills/engineering/productivity/teach/SKILL.md · 132 lines

How it starts

The opening of the file, as written. The whole thing — 132 lines — stays where its author put it; the contents beside it link to each section on GitHub.

The user has asked you to teach them something. This is a stateful request - they intend to learn the topic over multiple sessions.

Teaching Workspace

Treat the current directory as a teaching workspace. The state of their learning is captured in this directory in several files:

  • MISSION.md: A document capturing the reason the user is interested in the topic. This should be used to ground all teaching. Use the format in MISSION-FORMAT.md.
  • ./reference/*.html: A directory of reference materials. These are the compressed learnings from the lessons - cheat sheets, reference algorithms, syntax, yoga poses, glossaries. They are the raw units of learning. They should be beautiful documents which print out well, and are designed for quick reference.
  • RESOURCES.md: A list of resources which can be explored to ground your teaching in contextual knowledge, or to acquire knowledge and wisdom. Use the format in RESOURCES-FORMAT.md.
  • ./learning-records/*.md: A directory of learning records, which capture what the user has learned. These are loosely equivalent to architectural decision records in software development - they capture non-obvious lessons and key insights that may need to be revised later, or drive future sessions. These should be used to calculate the zone of proximal development. They are titled 0001-<dash-case-name>.md, where the number increments each time. Use the format in LEARNING-RECORD-FORMAT.md.
  • ./lessons/*.html: A directory of lessons. A lesson is a single, self-contained HTML output that teaches one tightly-scoped thing tied to the mission. This is the primary unit of teaching in this workspace.
  • NOTES.md: A scratchpad for you to jot down user preferences, or working notes.

Philosophy

To learn at a deep level, the user needs three things:

  • Knowledge, captured from high-quality, high-trust resources
  • Skills, acquired through highly-relevant interactive lessons devised by you, based on the knowledge
  • Wisdom, which comes from interacting with other learners and practitioners

Read the full file on GitHub · 132 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. 9d ago First seen · 132 lines · 15 tokens per session scan A d36496c90da9

Subscribe to this mod's changes

teach is a skill published in the GitHub repository JustineDevs/premortem (2 stars, last pushed 1mo ago), licensed Apache-2.0. It adds 15 tokens to every session and 1,779 once invoked, about $0.0001 per session on Opus 5. A static security scan graded it A with 0 findings. It is 84% identical to teach, differing in 13 lines, and is treated as a copy.

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