why use many token when few do trick
Your AI coding agent bills by the word and writes like it knows that.
Caveman make it stop. Brain still big. Mouth small. Bill small.
See it · Install · Numbers · Skill · Proxy · Wrap · Docs · Privacy · License
| 🗣️ Normal agent · 69 tokens |  Caveman agent · 19 tokens |
|---|---|
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Same diagnosis. Same fix. Same useMemo. The only thing that died was the throat-clearing.
Code, commands, file paths, and exact error messages never get cavemanned. Only the prose around them does.
┌──────────────────────────────────────────────────┐
│ output tokens saved (skill) ██████░░░ 65% │
│ input tokens saved (proxy) ███░░░░░░ 33% │
│ code changed ░░░░░░░░░ 0% │
│ vibes █████████ OOG │
└──────────────────────────────────────────────────┘
Caveman no make brain smaller. Caveman make mouth smaller.
Caveman come in two sizes.
Small rock: the skill. A rule file that makes your agent answer in caveman. MIT, free forever, works in 30+ agents (Claude Code, Codex, Gemini, Cursor, Windsurf, Cline, Copilot, more). One command:
npx skills add JuliusBrussee/cavemanType /caveman if your agent doesn't wake up on its own. That the whole install. One rock.
Big rock: the proxy. Runs on your machine, between your agent and the AI provider, and shrinks what the agent reads before every call. Everything it squeezes gets a backup on your disk, so the agent can always pull the original back. MIT CLI, BSL-1.1 runtime:
npm install -g @caveman-ai/cli && caveman setup --install
caveman claude # or codex · gemini · aider · kilo · qwen · opencode · hermes · openclaw · piThey stack. Most people start with the small rock and graduate.
More doors into the cave · full installer, Windows, single agents, uninstall
The full installer wires up Claude Code hooks and the statusline badge, finds every supported agent on your machine, and skips agents you no have. Safe to re-run. Needs Node.js 22.13+.
curl -fsSL https://raw.githubusercontent.com/JuliusBrussee/caveman/v2.6.0/install.sh | bashWindows, PowerShell 5.1+:
irm https://raw.githubusercontent.com/JuliusBrussee/caveman/v2.6.0/install.ps1 | iexJust one agent:
# Claude Code
claude plugin marketplace add JuliusBrussee/caveman && claude plugin install caveman@caveman
# Gemini CLI
gemini extensions install https://github.com/JuliusBrussee/caveman
# Qwen Code CLI, then its Caveman wrapper
npm i -g @qwen-code/qwen-code
caveman qwen
# Codex, Cursor, Windsurf, Cline, and other skills-compatible agents
npx skills add JuliusBrussee/caveman --skill '*' -a codex --yes # replace codex with your agent profileInstall broke? Open your agent in this repo and say: "Read CLAUDE.md and INSTALL.md, install caveman for me." Agent read repo, agent fix own brain. Snake eat tail.
Changed your mind: npx -y github:JuliusBrussee/caveman -- --uninstall
The full 30+ agent matrix, dry runs, flags, and verification live in INSTALL.md.
A token is what AI billing counts, roughly three quarters of a word. Your agent pays for every token it writes and every token it reads. Reading is usually the bigger bill. The skill cuts the writing. The proxy cuts the reading.
Ten ordinary coding prompts through the real Claude API, with the skill and without. Same model, same questions. Output tokens per reply:
| Task | Normal | Caveman | Saved |
|---|---|---|---|
| Implement React error boundary | 3454 | 456 | 87% |
| Set up PostgreSQL connection pool | 2347 | 380 | 84% |
| Explain git rebase vs merge | 702 | 292 | 58% |
| Refactor callback to async/await | 387 | 301 | 22% |
| Average across all ten prompts | 1214 | 294 | 65% |
Best row and worst row both up there on purpose. Caveman wins big when the agent would have written an essay, and barely at all when the answer was already mostly code.
All ten prompts · regenerate with uv run python benchmarks/run.py
| Task | Normal | Caveman | Saved |
|---|---|---|---|
| Explain React re-render bug | 1180 | 159 | 87% |
| Fix auth middleware token expiry | 704 | 121 | 83% |
| Set up PostgreSQL connection pool | 2347 | 380 | 84% |
| Explain git rebase vs merge | 702 | 292 | 58% |
| Refactor callback to async/await | 387 | 301 | 22% |
| Architecture: microservices vs monolith | 446 | 310 | 30% |
| Review PR for security issues | 678 | 398 | 41% |
| Docker multi-stage build | 1042 | 290 | 72% |
| Debug PostgreSQL race condition | 1200 | 232 | 81% |
| Implement React error boundary | 3454 | 456 | 87% |
| Average | 1214 | 294 | 65% |
Important
Before you multiply 65% by your invoice: the skill only shortens output. Input and reasoning tokens don't change, and the skill's own rules cost about 1 to 1.5k input tokens every turn. Whole-session savings land lower than the table. On work that was already terse, you can lose money. Speed and readability are the product. The discount is the bonus. Full accounting in docs/HONEST-NUMBERS.md.
Maintainer note. If you read one linked doc, read that one. I wrote it after #550, where someone's Cursor A/B went the wrong way and I couldn't reproduce it. Caveman is a shorter agent, not free money. Measure your own setup before you tell your boss anything.
Your agent rereads logs, test output, diffs, and half your repo all day. The proxy shrinks that stream before it reaches the provider. Pinned 54-run Claude Code benchmark, provider-reported input tokens, three runs per case:
| Case | Direct Claude Code | Through caveman | Change |
|---|---|---|---|
| CSV outlier hunt | 165,823 | 74,484 | -55.1% |
| Log needle in haystack | 148,807 | 74,068 | -50.2% |
| YAML config drift | 132,124 | 71,027 | -46.2% |
| Test output failure | 150,377 | 108,514 | -27.8% |
| Deployment JSON drift | 147,975 | 108,939 | -26.4% |
| Dashboard HTML alert | 140,687 | 154,641 | +9.9% |
| Total | 885,793 | 591,673 | -33.2% |
All 18 of 18 exact-answer checks passed, so the squeeze cost nothing in correctness. Method, confidence intervals, and limits: docs/WRAP-BENCHMARK.md.
Maintainer note. The HTML row is red and it stays red. That case had no compression transform, so caveman paid its own overhead and won nothing back. The day I hide a red row is the day you should stop trusting the green ones.
Browsing too: a focused question against a 200-row table costs 121 tokens through caveman's view of the page, against 15,704 for the Playwright ARIA baseline. That's 129.8× smaller (browse/BENCHMARK.md).
One rule file, one talking style, plus a small toolbox. /caveman lite|full|ultra|wenyan-lite|wenyan-full|wenyan-ultra sets intensity. /caveman off or normal mode turns it off.
Everything in the box · commit messages, reviews, subagents, work patterns
| Tool / command | What you get |
|---|---|
/caveman [lite|full|ultra|wenyan-lite|wenyan-full|wenyan-ultra|off] |
Shorter replies at the intensity you choose. |
cavecrew-investigator, cavecrew-builder, cavecrew-reviewer |
Compressed subagent presets for locating, editing, and reviewing code. |
/caveman-commit |
Terse Conventional Commit messages. |
/caveman-review |
One-line, actionable review findings. |
/caveman-compress <file> |
Smaller Markdown memory files, with the original backed up. |
/caveman-stats |
Local session token usage and estimated savings in Claude Code. |
/caveman-help |
One-screen reminder of every mode and command. |
investigate-first, lean-build, surgical-patch, safe-refactor, migration, verify-and-stop |
Work patterns that write less code, so the agent bills fewer tokens. Your agent picks these up on its own when a task fits. |
/caveman-setup, /caveman-discover, /caveman-learn, /caveman-manage, /caveman-optimize, /caveman-explore, /caveman-evidence-review |
Drive the caveman engine and proxy: set it up, find where tokens go, act on what it finds. |
One local process. Your agent talks to it, it talks to your provider. No Caveman server in the path, and your Claude Pro/Max login passes through to Anthropic untouched. Originals of everything it compresses sit in a SQLite file on your machine with a recovery handle, so the agent can always ask for the full version back.
What the engine keeps, by payload type · and the wrap stack diagram
detect() types each payload and routes it to a compressor that keeps what answers depend on:
| Detected type | Keeps | Target savings |
|---|---|---|
json |
keys, structure, error/message subtrees; collapses repetitive arrays | 70-90% |
log |
errors, stack traces, first/last lines; drops INFO and progress noise | 85-95% |
code |
imports, signatures, types; elides function bodies, syntax stays valid | 40-70% |
diff |
file/hunk headers and changed lines; elides repeated context | 60-80% |
search-result |
top/bottom hits plus diagnostic/security hits | 80-95% |
text / HTML |
headings, opening/closing context, important sections | 50-80% |
contextwindow.Pack() additionally fits candidate context into a token budget by BM25 relevance, recency, and error signal, returned in original order so chronology survives.
Any MCP host gets the same powers through five tools: caveman_compress, caveman_retrieve, caveman_stats, caveman_toon_encode, caveman_toon_decode.
Months of your agent history already sit on your disk. caveman learn reads it, locally, read-only, no account, and ranks your token sinks worst-first with a one-line fix behind each.
caveman learn # Claude Code + Codex + Gemini CLI + opencode; aider via CAVEMAN_AIDER_ROOT
caveman learn implement # hand the fixes to Claude Code or Codex, one diff at a time, applied only on your yes
implement re-measures after every change and reverts anything that didn't lower tokens per turn. Caveman never makes your agent dumber to make it cheaper.
caveman explore install # read-only FastContext subagent: finds code as path:line
caveman shrink -- pnpm test # compress noisy command output, byte-exact recoverable
caveman browse <url> # local Chrome over a compressed a11y tree
caveman mem remember|recall # durable memory; `mem recover <handle>` = original bytes
caveman trial -- claude # A/B a real session, then `trial report`
caveman toon encode|decode # the TOON re-encoder, standalone
caveman stats # what caveman actually did, by content typeCaveman eating its own tail. Every skill you install is prompt text your agent reloads on every call. caveman convert renders the skill body to PNG pages in place, and the model reads it as an image. On the caveman skill itself: 1,069 to 415 estimated tokens, a 61% cut.
caveman convert --dry-run # every installed skill, with the token math, no writes
caveman convert --agent claude # convert the profitable ones
caveman convert --revert # byte-identical restore from SKILL.orig.mdConvert only fires when pages beat the text. Any failure leaves the skill byte-identical and names the gate that said no.
caveman <agent> turns the proxy on for good and launches the agent. caveman wrap <agent> runs one session and leaves nothing behind. It never edits your config files.
| Agent | Vendor | How it's wrapped |
|---|---|---|
| Claude Code | Anthropic | env vars |
| OpenAI Codex CLI | OpenAI | env vars (API key) · ephemeral CODEX_HOME (ChatGPT login) |
| Gemini CLI | env vars | |
| Aider | OpenAI/Anthropic | env vars |
| Kilo Code | Kilo Code | KILO_CONFIG_CONTENT, your kilo.json untouched |
| Qwen Code | QwenLM | ephemeral system-settings overlay, source settings untouched |
| opencode | sst | inline config via env, your opencode.json untouched |
| Hermes Agent | Nous Research | --provider custom + env |
| OpenClaw | OpenClaw | ephemeral merged config, your config read-only |
| Pi | pi.dev | bundled native extension, your ~/.pi config untouched |
Fine print · tested versions, default loadout, SDK recipes
Tested against real sessions on Hermes v0.18.0, OpenClaw 2026.6.11, Pi 0.84.2, Kilo Code 7.5.6 (the CLI, not the editor extension), and Qwen Code 0.22.3. Persistent shortcuts are journaled and reversible with caveman disable <agent>.
OpenClaw, for the record, is a lobster. Lobster claw still sharp. Lobster mouth now small.
The default wrap hands the agent the five MCP tools, the browse server when Chrome resolves, command-output shrink on Claude, opencode, Gemini, Hermes, and OpenClaw, and pixel mode on new skill installs. Codex skips the shrink hook because its runtime rejects the rewrite (openai/codex#18491). Turn pieces off in ~/.caveman-cloud/config.json.
Agent not on the list? Point any provider SDK or framework (Vercel AI SDK, LangChain, LiteLLM, OpenAI Agents, CrewAI, PydanticAI) at the local proxy with a baseURL swap: integrations/recipes/. New native agent is usually one JSON profile in agents/profiles/.
One idea everywhere: agent do more with less.
Frozen ones still install and work. Their best ideas moved in here.
Caveman make token small. Caveman Cloud make it provable. Local numbers are inferred, pinned benchmarks benchmark_counterfactual, neither is an invoice. Live traffic behind eval gates with signed receipts earns verified. That's Cloud. Waitlist at caveman.so
Your agent still talks to the provider you chose. The skill and hooks run entirely on your machine, and nothing here needs an account.
The caveman CLI does send anonymous usage stats by default, and here's the honest why: caveman is free, one person maintains it, and those stats are how I find out which commands people actually use and how many tokens caveman actually saves in the wild. That's what keeps this thing free and pointed in the right direction. Fair trade, we think.
What it sends: which commands ran, plus token counts through and cut. What it never sends: your prompts, your code, your file paths, or anything that could identify you. It tells you all this the first time you run it.
Not into it? One command and it's off forever, no hard feelings:
caveman telemetry off # or set DO_NOT_TRACK=1Exact network, telemetry, and storage boundaries: SECURITY.md.
Split license. Skill and adoption surfaces are MIT. Engine-linked runtime is BSL-1.1 source-available, not OSI Open Source before Change Date.
MIT: the skill, Agent SDK and initializer, the CLI, both client SDKs, contracts, provider catalog, extension shell, and the thin cavemem clients. Free like mammoth on open plain.
BSL-1.1: Engine, Proxy, Cache Engine, rewriter, Browse, MCP server, shrink, cavemem Go core, and shared Go platform. New Engine-linked runtime modules default to BSL-1.1. Read it, fork it, self-host it for your own first-party traffic free, production included. Each version converts to Apache-2.0 on the earlier of 2030-06-21 or four years after it ships. Hosting it for third parties needs a commercial license.
engine/pixel embeds pxpipe (MIT) plus glyph atlases derived from Spleen 5×8 (BSD-2-Clause) and GNU Unifont (dual OFL-1.1 / GPLv2-with-font-exception); its NOTICE travels with that source.
"Caveman" and the rock logo are trademarks of Julius Brussee. "Powered by Caveman" is fine when true.
Caveman save you token, save you money. Star cost zero. Fair trade. ⭐
Docs: Technical manual · Install matrix · Honest numbers · Wrap benchmark · License · Contributing · Maintainer guide · Issues
MIT skill · BSL-1.1 engine. Few token. No lie.