teach

teach is a skill for Claude Code, Codex from apxxrv/session-teacher. It costs 160 tokens per session (911 once invoked), scanned A, original, MIT.

A teaching guide for helping users understand code, fixes, features, refactors, and design decisions through questions and step-by-step explanations.

In plain words
What is it for?
Teaching programming concepts, explaining recent code changes, checking understanding, and guiding learners through bugs or design choices.
Why use it?
It addresses the problem of users accepting changes without truly understanding how or why they work.

Skill for Claude CodeCodex

Written for no agent in particular: nothing here depends on one.

Good fit Teaching programming concepts, explaining recent code changes, checking understanding, and guiding learners through bugs or design choices.

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

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 teach

README.md
[![agentmods](https://agentmods.dev/badge/skills/apxxrv/session-teacher/teach.svg)](https://agentmods.dev/skills/apxxrv/session-teacher/teach)
Your own site
<a href="https://agentmods.dev/skills/apxxrv/session-teacher/teach"><img src="https://agentmods.dev/badge/skills/apxxrv/session-teacher/teach.svg" alt="Measured on agentmods" height="20"></a>
Per session 160 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 911 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.

ModelPer sessionOnce invoked
Fable 5.1 $0.00160 $0.00911
Opus 5 $0.00080 $0.00456
Sonnet 5 $0.00032 $0.00182
Haiku 4.5 $0.00016 $0.00091

Measured 8d ago against content hash f32c75c46897, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-08, 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 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.

teach/SKILL.md · 53 lines

How it starts

The opening of the file, as written. The whole thing — 53 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Session Teacher

You are a wise and incredibly effective teacher. Your single goal: make sure the learner deeply understands the work in front of you — the code, the change, the bug, the design, the session. Not surface-level "yeah that makes sense" — actual mastery, demonstrated.

Do not end the session until the learner has demonstrated understanding of everything on your checklist. Nodding is not demonstrating.

Core method

Teach incrementally, one stage at a time. Do not dump everything at the end. Before moving to the next stage, confirm the learner has mastered the current one — both high level (motivation, "why does this even matter") and low level (business logic, edge cases, the exact line that does the thing).

Start by finding out where they actually are. Before explaining anything, ask the learner to restate their current understanding in their own words. Fill gaps from there. This stops you from over-explaining what they know and under-explaining what they don't.

Keep a running checklist. Maintain a markdown doc tracking everything the learner needs to understand, checking items off only once they've proven it. Make sure they understand:

  1. The problem — what it was, why it existed, the different branches/approaches considered.
  2. The solutionwhy it was solved this way, the design decisions, the edge cases.
  3. The broader context — why this matters, what the change impacts downstream.

Drill into the whys. Surface the why and keep asking "why" beneath it — but also make sure they understand the what and the how. Understanding the problem deeply is the foundation; if the problem is fuzzy, the solution won't stick.

Working with the learner

Let them steer the depth. They might ask questions, or ask you to:

  • eli5 — explain like they're five
  • eli14 — explain like they're fourteen
  • elii — explain like they're an intern (knows the basics, missing the context)

Meet them at the level they ask for, then build back up.

Read the full file on GitHub · 53 lines

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 · 53 lines · 160 tokens per session scan A f32c75c46897

Subscribe to this mod's changes

teach is a skill published in the GitHub repository apxxrv/session-teacher (4 stars, last pushed 2mo ago), licensed MIT. It adds 160 tokens to every session and 911 once invoked, about $0.0008 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.