ck-learn

ck-learn is a skill for Claude Code, Codex from Fredrik-C/ContextKing. It costs 28 tokens per session (666 once invoked), scanned A, original, no licence file.

A way to save useful knowledge about a codebase, such as domain rules, design decisions, traps, and links between modules.

In plain words
What is it for?
Use it to record notes that future work can retrieve when navigating or changing the repository.
Why use it?
It prevents important discoveries from being lost when a coding session ends or another developer works on the project.

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/fredrik-c/contextking/ck-learn
Any agent
npx skills add Fredrik-C/ContextKing --skill ck-learn
Clone the repo
git clone --depth 1 https://github.com/Fredrik-C/ContextKing

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 ck-learn

README.md
[![agentmods](https://agentmods.dev/badge/skills/fredrik-c/contextking/ck-learn.svg)](https://agentmods.dev/skills/fredrik-c/contextking/ck-learn)
Your own site
<a href="https://agentmods.dev/skills/fredrik-c/contextking/ck-learn"><img src="https://agentmods.dev/badge/skills/fredrik-c/contextking/ck-learn.svg" alt="Measured on agentmods" height="20"></a>
Per session 28 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 666 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 0 findings. Scan, not verified.
Origin unknown 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 $0.00028 $0.00666
Opus 5 $0.00014 $0.00333
Sonnet 5 $0.00006 $0.00133
Haiku 4.5 $0.00003 $0.00067

Measured 3d ago against content hash abf33a77d034, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

Grade A, and why

ck-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 3d 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.

skills/ck-learn/SKILL.md · 72 lines

The source is not reproduced here

No licence file

A repository with no LICENSE is all rights reserved by default, so the body is not copied here. The metadata, the measurements and the link are.

Read it on GitHub

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. 3d ago First seen · 72 lines · 28 tokens per session scan A abf33a77d034

Subscribe to this mod's changes

ck-learn is a skill published in the GitHub repository Fredrik-C/ContextKing (22 stars, last pushed 10d ago), with no licence file. It adds 28 tokens to every session and 666 once invoked, about $0.0001 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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