Ultra-compressed communication mode. Cuts output tokens 65% (measured) by speaking like caveman while keeping full technical accuracy. Supports intensity levels: lite, full (default), ultra, wenyan-lite, wenyan-full, wenyan-ultra. Use when user says "caveman mode", "talk like caveman", "use caveman", "less tokens", "be brief", or invokes /caveman. Also auto-triggers when token efficiency is requested.
Collected from public GitHub. Every version is saved exactly as it was and never changes. Install it at an exact version with the mdr tool, and every file is checked before it reaches your agent. The main file is checked against the SHA-256 fingerprint recorded here, and the others against the fingerprints GitHub keeps for its source commit. The automatic checks below grade the latest version, and the same checks always give the same file the same grade.
What the file says
Respond terse like smart caveman. All technical substance stay. Only fluff die.
## Persistence
ACTIVE EVERY RESPONSE. No revert after many turns. No filler drift. Still active if unsure. Off only: "stop caveman" / "normal mode".
Default: **full**. Switch: `/caveman lite|full|ultra|wenyan-lite|wenyan-full|wenyan-ultra|off`.
## Rules
Drop: articles (a/an/the), filler (just/really/basically/actually/simply), pleasantries (sure/certainly/of course/happy to), hedging. Fragments OK. Short synonyms (big not extensive, fix not "implement a solution for"). No tool-call narration, no decorative tables/emoji, no dumping long raw error logs unless asked — quote shortest decisive line. Standard well-known tech acronyms OK (DB/API/HTTP); never invent new abbreviations (cfg/impl/req/res/fn) — tokenizer split them same as full word: zero token saved, reader still decode. Full word cheaper AND clearer. No causal arrows (→) either — own token, save nothing. Technical terms exact. Code blocks unchanged. Errors quoted exact.
Never drop not/never/no/only/except — flip meaning worse than any token saved. Numbers, units exact.
…
The line at the top of this page pins the label git:20260804.0abefec, which is what most people want. This one pins the sha256 fingerprint of the contents instead, so it survives a label being moved. Either way the exact version is written to mdr.lock, and mdr install downloads and checks those contents again, so it installs them exactly or stops with an error.
A 17 of 17 checks passed. Fixed automatic checks with no AI involved, so the same checks give the same answer every run.
pass: Frontmatter block present
pass: Frontmatter declares a name
pass: Frontmatter declares a description
pass: Size between 200 bytes and 200 KB (6216 bytes)
pass: No zero-width or bidi control characters
pass: No instruction hidden inside an HTML comment
pass: No link to an exfiltration or paste host
pass: No credential-shaped string
pass: No instruction to send local credentials anywhere
pass: No text hidden with inline styles
pass: No prompt-injection phrasing
pass: No curl or wget piped into a shell
pass: No recursive delete of root, home or parent
pass: No instruction to read or print local credentials
pass: No base64 blob over 200 characters
pass: No link to a raw IP address
pass: No script tag
Source
GitHub
chinkan/rustfox · 11 stars · license MIT · pushed 2026-11-03 · branch main
API
GET https://markdownregistry.com/api/v1/artifacts/art_r2ikjxkaquvweizf
GET https://markdownregistry.com/api/v1/resolve?ref=chinkan/rustfox/caveman
GET https://markdownregistry.com/api/v1/blob/daf9cec496ebd039809d8236f99f17fa1b4beaadf8ce4e2d532d0da51d70afce
Your AI assistant does the legwork. You hear about the deals worth your word. Hand yours the standing instructions at modelranch.com and it joins the network that reads files like this one.
chinkan/rustfox · .agents/skills/brainstorming/SKILL.md · You MUST use this before any creative work - creating features, building components, adding functionality, or modifying…
chinkan/rustfox · .agents/skills/cavecrew/SKILL.md · Decision guide for delegating to caveman-style subagents. Tells the main thread WHEN to spawn `cavecrew-investigator`…
chinkan/rustfox · .agents/skills/caveman-compress/SKILL.md · Compress natural language memory files (CLAUDE.md, todos, preferences) into caveman format to save input tokens…
chinkan/rustfox · .agents/skills/caveman-help/SKILL.md · Quick-reference card for all caveman modes, skills, and commands. One-shot display, not a persistent mode. Trigger…
chinkan/rustfox · .agents/skills/caveman-review/SKILL.md · Ultra-compressed code review comments. Cuts noise from PR feedback while preserving the actionable signal. Each comment…
chinkan/rustfox · .agents/skills/caveman-stats/SKILL.md · Show real token usage and estimated savings for the current session. Reads directly from the Claude Code session log —…
chinkan/rustfox · .agents/skills/code-review/SKILL.md · Review the changes since a fixed point (commit, branch, tag, or merge-base) along two axes: Standards (does the code…
chinkan/rustfox · .agents/skills/codebase-design/SKILL.md · Shared vocabulary for designing deep modules. Use when the user wants to design or improve a module's interface, find…
chinkan/rustfox · .agents/skills/design-an-interface/SKILL.md · Generate multiple radically different interface designs for a module using parallel sub-agents. Use when user wants to…
chinkan/rustfox · .agents/skills/diagnosing-bugs/SKILL.md · Diagnosis loop for hard bugs and performance regressions. Use when the user says "diagnose"/"debug this", or reports…
hoangnguyen0403/agent-skills-standard · .agents/skills/caveman/SKILL.md · Ultra-compressed communication mode. Cuts token usage ~75% by speaking like caveman while keeping full technical…
bug-ops/zeph · .zeph/skills/caveman/SKILL.md · Switch to ultra-compressed, telegraphic output. Use when the user asks for terse, brief, minimal, "caveman", or…
eltmon/overdeck · src/lib/caveman/skills/caveman/SKILL.md · Ultra-compressed communication mode. Cuts token usage ~75% by speaking like caveman while keeping full technical…
