caveman

name	caveman
description	Token compression via caveman mode: ~65% output reduction, caveman-compress, cavecrew subagents

Caveman Mode Skill

When to activate

• You want to dramatically reduce token usage across a long session
• Context window is filling up and you need to extend the session's useful life
• You're running a cost-sensitive workload (many parallel agents, batch processing)
• Claude's responses are verbose and you want terse, fragment-style output
• You want to compress existing memory or CLAUDE.md files to reduce input tokens

When NOT to use

• Security warnings or irreversible action confirmations — these need full sentences
• Multi-step sequences where fragment ambiguity could cause misread actions
• Onboarding new team members to a codebase — clarity beats brevity here
• Writing documentation that external people will read

Instructions

Caveman mode is an established token-compression technique with a dedicated implementation at github.com/JuliusBrussee/caveman. This skill is a pointer — use the original repo, do not duplicate it.

What it does

Caveman mode instructs Claude to output compressed, fragment-style prose:

Level	Rule	Example
lite	Drop filler and hedging, keep articles and full sentences	"The function handles edge cases."
full	Drop articles, fragments OK, short synonyms	"func handles edge cases"
ultra	Abbreviate prose words, strip conjunctions, arrows for causality	"fn→edge cases handled"

Benchmarked results (March 2026, arxiv.org/abs/2604.00025):

• ~65% output token reduction
• 26-point accuracy improvement on benchmarks (brevity sharpens reasoning)
• 100% technical accuracy maintained

caveman-compress sub-skill

Rewrites .md memory and CLAUDE.md files to caveman prose — ~46% input token savings every session because compressed files are re-read on every context load.

cavecrew subagents

Haiku-based subagents running in caveman mode — ~60% fewer tokens than vanilla agents for simple classification, extraction, and routing tasks.

caveman-shrink MCP middleware

Compresses MCP tool descriptions before they enter Claude's context — reduces MCP overhead by ~30% without changing tool behaviour.

Example

Activating caveman mode in a session:

Use caveman mode (full level) for this session. Drop articles, use fragments,
short synonyms. Auto-revert to normal prose for: security warnings,
irreversible action confirmations, multi-step sequences.

Using caveman-compress on a memory file:

/caveman-compress .claude/memory/project-context.md

Using cavecrew for a classification task:

Spawn a cavecrew subagent (Haiku, caveman full) to classify these 200 support
tickets into 5 categories. Return only: ticket_id, category.

---

Reference: github.com/JuliusBrussee/caveman — the authoritative caveman implementation. UitKit references this work; it is not duplicated here.

---