caveman is a skill and proxy for coding agents that shortens unnecessary explanatory prose so agents use fewer tokens while leaving code, commands, paths, and error messages unchanged. It is for people using coding agents who want terse responses and lower token use, including with Claude-based workflows. The catalogue entries contain its skills, commands, agents, instructions, and plugins.
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.
npx skills add JuliusBrussee/caveman --skill caveman-compressgit clone --depth 1 https://github.com/JuliusBrussee/cavemanWrote 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.
[](https://agentmods.dev/skills/juliusbrussee/caveman/caveman-compress)<a href="https://agentmods.dev/skills/juliusbrussee/caveman/caveman-compress"><img src="https://agentmods.dev/badge/skills/juliusbrussee/caveman/caveman-compress/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.
<a href="https://agentmods.dev/skills/juliusbrussee/caveman/caveman-compress"><img src="https://agentmods.dev/badge/skills/juliusbrussee/caveman/caveman-compress.svg" alt="Reviewed on agentmods" width="80" height="20"></a>- Socket pass
- Snyk pass
- NVIDIA SkillSpector pass
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.
| Model | Per session | Once invoked |
|---|---|---|
| Fable 5.1 | $0.00054 | $0.01312 |
| Opus 5.5 | $0.00022 | $0.00525 |
| Sonnet 5.5 | $0.00011 | $0.00262 |
| Haiku 4.5 | $0.00005 | $0.00131 |
Grade C, and why
caveman-compress scanned grade C with 1 finding against 26 rules in 11 categories — prompt injection, anti-refusal, data exfiltration, privilege escalation, supply chain, agent snooping, system-prompt leakage, SSRF and excessive agency — measured 11d ago.
A static scan of the body, not an audit. Every finding is printed with the line that produced it so you can judge whether it matters here. A mod is markdown that instructs an agent; that is exactly why what it instructs is worth reading.
Reaches for credential fileshighPrivilege escalation
SSH keys, cloud credentials, git-credentials, .npmrc, /etc/shadow: reading these is how a config file becomes a credential leak.
> **Data leaves the machine.** Compression sends the file's full text to the model provider that `scripts/compress.py` is configured for: the `claude` CLI, the Anthropic API, or an OpenAI-compatible endpoint. Files whose Copies of this mod
1 near-identical copy found in the catalogue:
- caveman-compress — 100% identical, 7 lines differ
How it starts
The opening of the file, as written. The whole thing — 115 lines — stays where its author put it; the contents beside it link to each section on GitHub.
Caveman Compress
Purpose
Data leaves the machine. Compression sends the file's full text to the model provider that
scripts/compress.pyis configured for: theclaudeCLI, the Anthropic API, or an OpenAI-compatible endpoint. Files whose names look like secrets (.env,credentials,secrets,.netrc, …) are refused before they are read. Don't compress a file the provider shouldn't see.
Compress natural language files (CLAUDE.md, todos, preferences) into caveman-speak to reduce input tokens. Compressed version overwrites original. Human-readable backup saved as <filename>.original.md, but NOT beside the source file — it lives in an out-of-tree data dir ($XDG_DATA_HOME/caveman-compress/backups/<parent-dir-name>/, or %LOCALAPPDATA%\caveman-compress\backups\<parent-dir-name>\ on Windows) so skill auto-loaders don't re-ingest it as a live file.
Trigger
/caveman-compress <filepath> or when user asks to compress a memory file.
Requires an explicit filepath. If the user pastes raw text instead of naming a file, do NOT improvise an inline compression — ask them for the filepath to compress, or offer to save the pasted text to a file first. Writing your own reasoning/commentary about the request into the compressed output (e.g. "User passed text directly, not a filepath...") is the exact failure this guards against — never let that leak into a saved file.
Process
-
The compression scripts live in
scripts/(adjacent to this SKILL.md). If the path is not immediately available, search forscripts/__main__.pynext to this SKILL.md. -
From the directory containing this SKILL.md, run:
python3 -m scripts <absolute_filepath>
- The CLI will:
- detect file type (no tokens)
- call Claude to compress
- validate output (no tokens)
- if errors: cherry-pick fix with Claude (targeted fixes only, no recompression)
- retry up to 2 times
- if still failing after 2 retries: report error to user, leave original file untouched
- Return result to user
What ships with it
7 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.
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.
- 11d ago Changed · +5 lines · +11 tokens per session scan A → C dd5388f08531
- 1mo ago First seen · 110 lines · 43 tokens per session scan A 377b0b8682d9
caveman-compress is a skill published in the GitHub repository JuliusBrussee/caveman (114,861 stars, last pushed today), licensed Apache-2.0. It adds 54 tokens to every session and 1,312 once invoked, about $0.0002 per session on Opus 5.5. A static security scan graded it C with 1 finding (reaches for credential files). No closer match exists in the catalogue, so it is treated as the original; first seen 2026-08-30.
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pinecone-research
Agent RAG and long-term memory with Pinecone.
llm-wiki
Karpathy's LLM Wiki: build/query interlinked markdown KB.
qmd
Hybrid local search over notes, docs, and transcripts.
strategic-compact
Suggests manual context compaction at logical intervals to preserve context through task phases rather than arbitrary auto-compaction. Use when a session is approaching a context limit and a task phase is a natural place to compact.