ck

ck is a skill for Claude Code from zhaixin244-wq/fnw. It costs 45 tokens per session (1,283 once invoked), scanned B, a copy of ck, MIT.

A persistent project-memory tool for Claude Code. It stores structured project context, tracks sessions and Git activity, and provides commands for registering and updating that context.

In plain words
What is it for?
Use it to initialize project context, preserve it between sessions, and record ongoing development work.
Why use it?
It reduces the need to repeat a project’s background, goals, technology choices, and constraints in every coding session.

Skill for Claude Code

Written for Claude Code: SessionStart hook event. Also seen: reads .claude/ paths; mentions CLAUDE.md; mentions Claude Code.

Good fit Use it to initialize project context, preserve it between sessions, and record ongoing development work.

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Install with agentmods
npx agentmods add skills/zhaixin244-wq/fnw/ck
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 zhaixin244-wq/fnw --skill ck
Clone the repo
git clone --depth 1 https://github.com/zhaixin244-wq/fnw

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 ck

README.md
[![agentmods](https://agentmods.dev/badge/skills/zhaixin244-wq/fnw/ck/github.svg)](https://agentmods.dev/skills/zhaixin244-wq/fnw/ck)
Your own site
<a href="https://agentmods.dev/skills/zhaixin244-wq/fnw/ck"><img src="https://agentmods.dev/badge/skills/zhaixin244-wq/fnw/ck/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 ck

Your own site · 80×15
<a href="https://agentmods.dev/skills/zhaixin244-wq/fnw/ck"><img src="https://agentmods.dev/badge/skills/zhaixin244-wq/fnw/ck.svg" alt="Reviewed on agentmods" width="80" height="20"></a>
Per session 45 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 1,283 The whole file, excluding the scripts and references it only reads on demand.
Security scan B 1 finding. A grade says what 26 rules found in the file — not that it is safe.
Origin 91% 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 $0.00045 $0.01283
Opus 5 $0.00023 $0.00642
Sonnet 5 $0.00009 $0.00257
Haiku 4.5 $0.00005 $0.00128

Measured 7d ago against content hash b0eecbd9841e, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-11, from the pricing page.

Security

Grade B, and why

ck scanned grade B with 1 finding 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 7d ago.

The scan reads SKILL.md. This mod also ships 9 executable files (commands/forget.mjs, commands/info.mjs, commands/init.mjs, …), listed below but not scanned — reading those needs a real analyzer, not pattern matching.

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.

Reads agent configuration directoriesmediumAgent snooping

.claude/, .codex/, .gemini/ hold keys, settings and other credentials a mod has no legitimate need for.

`~/.claude/settings.json` to auto-load project context on session start:
Origin

This is a copy

91% identical to ck — 29 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.

.claude/skills/ck/SKILL.md · 148 lines

How it starts

The opening of the file, as written. The whole thing — 148 lines — stays where its author put it; the contents beside it link to each section on GitHub.

ck — Context Keeper

You are the Context Keeper assistant. When the user invokes any /ck:* command, run the corresponding Node.js script and present its stdout to the user verbatim. Scripts live at: ~/.claude/skills/ck/commands/ (expand ~ with $HOME).


Data Layout

~/.claude/ck/
├── projects.json              ← path → {name, contextDir, lastUpdated}
└── contexts/<name>/
    ├── context.json           ← SOURCE OF TRUTH (structured JSON, v2)
    └── CONTEXT.md             ← generated view — do not hand-edit

Commands

/ck:init — Register a Project

node "$HOME/.claude/skills/ck/commands/init.mjs"

The script outputs JSON with auto-detected info. Present it as a confirmation draft:

Here's what I found — confirm or edit anything:
Project:     <name>
Description: <description>
Stack:       <stack>
Goal:        <goal>
Do-nots:     <constraints or "None">
Repo:        <repo or "none">

Wait for user approval. Apply any edits. Then pipe confirmed JSON to save.mjs --init:

echo '<confirmed-json>' | node "$HOME/.claude/skills/ck/commands/save.mjs" --init

Confirmed JSON schema: {"name":"...","path":"...","description":"...","stack":["..."],"goal":"...","constraints":["..."],"repo":"..." }


/ck:save — Save Session State

This is the only command requiring LLM analysis. Analyze the current conversation:

  • summary: one sentence, max 10 words, what was accomplished
  • leftOff: what was actively being worked on (specific file/feature/bug)
  • nextSteps: ordered array of concrete next steps
  • decisions: array of {what, why} for decisions made this session
  • blockers: array of current blockers (empty array if none)
  • goal: updated goal string only if it changed this session, else omit

Show a draft summary to the user: "Session: '<summary>' — save this? (yes / edit)" Wait for confirmation. Then pipe to save.mjs:

echo '<json>' | node "$HOME/.claude/skills/ck/commands/save.mjs"

JSON schema (exact): {"summary":"...","leftOff":"...","nextSteps":["..."],"decisions":[{"what":"...","why":"..."}],"blockers":["..."]} Display the script's stdout confirmation verbatim.

Read the full file on GitHub · 148 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. 7d ago First seen · 148 lines · 45 tokens per session scan B b0eecbd9841e

Subscribe to this mod's changes

ck is a skill published in the GitHub repository zhaixin244-wq/fnw (29 stars, last pushed 3mo ago), licensed MIT. It adds 45 tokens to every session and 1,283 once invoked, about $0.0002 per session on Opus 5. A static security scan graded it B with 1 finding (reads agent configuration directories). It is 91% identical to ck, differing in 29 lines, and is treated as a copy.