caveman-learn

caveman-learn is a skill for Claude Code, Codex from mrDesign-ww/vault-os. It costs 92 tokens per session (1,062 once invoked), scanned A, original, MIT.

A consent-based skill for reducing an AI coding agent's token use after a measurement report. Tokens are the text units an AI model reads and produces.

In plain words
What is it for?
Use it to review token sinks, trim oversized CLAUDE.md configuration, or move recurring context to Cavemem when the user approves.
Why use it?
It identifies where context costs tokens and requires approval for each proposed edit, then checks whether the change actually reduced measured usage.

Skill for Claude CodeCodex

Written for no agent in particular: nothing here depends on one. Also seen: mentions CLAUDE.md; mentions AGENTS.md.

Good fit Use it to review token sinks, trim oversized CLAUDE.md configuration, or move recurring context to Cavemem when the user approves.

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Install with agentmods
npx agentmods add skills/mrdesign-ww/vault-os/caveman-learn
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 mrDesign-ww/vault-os --skill caveman-learn
Clone the repo
git clone --depth 1 https://github.com/mrDesign-ww/vault-os

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 caveman-learn

README.md
[![agentmods](https://agentmods.dev/badge/skills/mrdesign-ww/vault-os/caveman-learn/github.svg)](https://agentmods.dev/skills/mrdesign-ww/vault-os/caveman-learn)
Your own site
<a href="https://agentmods.dev/skills/mrdesign-ww/vault-os/caveman-learn"><img src="https://agentmods.dev/badge/skills/mrdesign-ww/vault-os/caveman-learn/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 caveman-learn

Your own site · 80×15
<a href="https://agentmods.dev/skills/mrdesign-ww/vault-os/caveman-learn"><img src="https://agentmods.dev/badge/skills/mrdesign-ww/vault-os/caveman-learn.svg" alt="Reviewed on agentmods" width="80" height="20"></a>
Per session 92 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 1,062 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 $0.00092 $0.01062
Opus 5 $0.00046 $0.00531
Sonnet 5 $0.00018 $0.00212
Haiku 4.5 $0.00009 $0.00106

Measured 7d ago against content hash 45ddfdee4121, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-12, from the pricing page.

Security

Grade A, and why

caveman-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 7d ago.

The scan reads SKILL.md. This mod also ships 1 executable file (tests/skill-file.test.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.

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.

shell/claude/skills/caveman-learn/SKILL.md · 70 lines

What it actually says

You are the Caveman Learn editing skill. The "caveman learn" command MEASURES where an agent's tokens go; you are the consent-gated half that turns its findings into edits — with the user approving each one. You never claim a saving you have not measured, and you never make the agent dumber.

Read the plan first:

  1. Run: caveman learn report --json Parse the caveman.learn.v1 JSON. Show the Cave Score, its four components, and the ranked token sinks. For each sink state its class and basis. Behavioral sinks are observations — present their numbers as fact and their suggestion softly. Do not turn a behavioral finding into an imperative.

Then, only for the sinks the user chooses to act on, run the consent loop by class.

REDUCIBLE (a heavy CLAUDE.md, a never-invoked skill):

  • Run: caveman learn apply <sink_id> --dry-run (this materializes a candidate; it does not edit anything).
  • Propose a concrete diff and show before -> after tokens/turn.
  • Ask the user yes or no. On yes, apply the edit with your own file tools.
  • Re-run caveman learn report --json (or recount the touched file) to confirm the reduction. This is the net-token-negative gate: if after is not below before, revert and report. Never keep an edit that does not reduce tokens/turn.

RECURRING_CONTEXT (a heavy block re-established across sessions; fix kind cavemem_offload): move it into cavemem so it is recalled compactly instead of re-pasted every turn. The candidate carries only a LOCATOR — never the block body.

  • Run: caveman learn apply <sink_id> and read the candidate JSON it writes under ~/.caveman/candidates/. Take only the locator, the numbers, and the proposed pointer text. Do not trust any body from the candidate; there is none.
  • Re-read the real block locally yourself: open the locator's rel_path, go to its jsonl_line, re-segment that turn the same way (split the text on blank lines, in order), pick block_index, and verify that sha256 of the raw block equals the locator's content_sha256. If it does not match, the file changed since the scan — abort this item.
  • Store it: caveman mem remember -- "" and capture the returned id. The -- ends option parsing so a block that opens with a --- rule is stored verbatim instead of being read as a flag.
  • Measure the gate honestly. before = the block's tokens/turn (it loaded every turn). after = the pointer's tokens/turn plus the recall cost. Get the recall cost by running caveman mem recall "" and reading tokens_added on the hit. If after is not below before, run caveman mem forget , leave the source untouched, and stop.
  • Trim the source and write the pointer. Remove the block from its CLAUDE.md or AGENTS.md section (or, for content the user pastes by hand, tell them what to stop pasting), and write the candidate's proposed pointer text where it was. The pointer names the recall path: caveman mem recall "" for the compact form, and caveman mem recover for the byte-exact original.
  • Never make the agent dumber: before you finish, confirm that caveman mem recall "" returns a hit AND a pointer is in place. If recall returns nothing, or you did not write a pointer, REVERT (caveman mem forget and restore the source). Removing context without a working recall path is the one failure this guard exists to block.
  • Re-measure and report the confirmed reduction and the recall path.

LOAD_BEARING: never touch. It appears in the report only so the score stays honest.

Binding rules:

  • Consent per edit. No "apply all" that hides the individual diffs.
  • Every edit is reversible: report exactly what you changed. An offload undoes with caveman mem forget plus restoring the trimmed source.
  • inferred only. Never present a local number as verified, and never attach a currency.
  • The analyzer (caveman learn) is read-only. You are the only writer, and only after a yes.
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. 7d ago First seen · 70 lines · 92 tokens per session scan A 45ddfdee4121

Subscribe to this mod's changes

caveman-learn is a skill published in the GitHub repository mrDesign-ww/vault-os (2 stars, last pushed 5d ago), licensed MIT. It adds 92 tokens to every session and 1,062 once invoked, about $0.0005 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 2026-09-05.

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