learn

learn is a skill for Claude Code, Codex from john-wilmes/claude-agentic-coding-playbook. It costs 51 tokens per session (1,262 once invoked), scanned A, original, MIT.

A skill for saving a non-obvious bug, workaround, or useful development pattern as structured knowledge for later sessions.

In plain words
What is it for?
Use it when someone asks to remember a lesson or when a session reveals a reusable fix, configuration detail, security issue, or coding convention.
Why use it?
Without a shared record, useful lessons can be forgotten or rediscovered repeatedly. This captures them in a persistent knowledge store or project memory file.

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/john-wilmes/claude-agentic-coding-playbook/learn
Any agent
npx skills add john-wilmes/claude-agentic-coding-playbook --skill learn
Clone the repo
git clone --depth 1 https://github.com/john-wilmes/claude-agentic-coding-playbook

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 learn

README.md
[![agentmods](https://agentmods.dev/badge/skills/john-wilmes/claude-agentic-coding-playbook/learn.svg)](https://agentmods.dev/skills/john-wilmes/claude-agentic-coding-playbook/learn)
Your own site
<a href="https://agentmods.dev/skills/john-wilmes/claude-agentic-coding-playbook/learn"><img src="https://agentmods.dev/badge/skills/john-wilmes/claude-agentic-coding-playbook/learn.svg" alt="Measured on agentmods" height="20"></a>
Per session 51 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 1,262 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 5.1 $0.00051 $0.01262
Opus 5 $0.00026 $0.00631
Sonnet 5 $0.00010 $0.00252
Haiku 4.5 $0.00005 $0.00126

Measured 5d ago against content hash ac114680c530, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-05, from the pricing page.

Security

Grade A, and why

learn 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.

profiles/combined/skills/learn/SKILL.md · 140 lines

How it starts

The opening of the file, as written. The whole thing — 140 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Learn

Capture a lesson as a structured knowledge entry that persists across sessions and projects.

Steps

Install Root Discovery

INSTALL_ROOT=$(bash ~/.claude/scripts/skills/find-install-root.sh)

0. Check prerequisites

Check if knowledge-db.js is available:

ls ${INSTALL_ROOT}/.claude/hooks/knowledge-db.js 2>/dev/null

If not found, fall back to writing the lesson directly to the project memory file (lessons-learned.md in the project memory directory). Skip steps that reference knowledge-db.js and instead append the structured entry to the memory file using the Edit tool.

1. Identify the lesson

If $ARGUMENTS is provided, use it as the lesson description. Otherwise, review what happened in the current session and ask the user what they want to capture.

Skip trivial or session-specific facts. Good candidates:

  • Non-obvious bugs and their root causes
  • Workarounds for tool or platform issues
  • Patterns that save significant time
  • Configuration gotchas that cause silent failures
  • Security issues encountered

2. Classify the entry

Based on the lesson, determine:

Category (pick one):

  • gotcha — surprising behavior, silent failure, or common mistake
  • pattern — reusable approach or best practice
  • workaround — temporary fix for a known issue
  • config — configuration requirement or setting
  • security — security-related finding
  • performance — optimization or bottleneck insight
  • convention — project-specific conventions, coding standards, naming patterns, or workflow preferences that should be remembered for future sessions in the same project
  • reference — factual reference information: API endpoints, config keys, schema details, version constraints, or external service behaviors
  • decision — architectural or design decisions with rationale; records why a particular approach was chosen over alternatives, to prevent re-debating settled questions

Tool: The primary tool, library, or platform (e.g., git, npm, docker, amplify, vitest).

Read the full file on GitHub · 140 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. 5d ago First seen · 140 lines · 51 tokens per session scan A ac114680c530

Subscribe to this mod's changes

learn is a skill published in the GitHub repository john-wilmes/claude-agentic-coding-playbook (4 stars, last pushed 5mo ago), licensed MIT. It adds 51 tokens to every session and 1,262 once invoked, about $0.0003 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.