01
It starts by itself
every new session. Runs in Claude Code hook, plus a weekly routine for the cost check.
- ↻ every new session
SessionStart hook sets caveman mode
Julius Brussee · 586K installsCaveman skill
Runs by itself, every new session.
Every session starts short and cheap.
Install the Caveman skill and make it a habit: follow https://gethabit.dev/skills/juliusbrussee/caveman.md
- 1Copy
- 2Paste into Claude Code, Codex or Cursor
- 3It runs by itself
586K installs114K starsApache-2.0 licenceSource on GitHub ↗
Caveman
by Julius Brussee · 586K installs
The skill
Makes your agent answer in short, plain words.
Only when you ask.
Lower costs
Every session starts short and cheap. You never type /caveman again.
↻ Runs by itselfevery new session
How the habit works.
You don't have to.
When does it start? How does it check its work? What does it remember?
One run, step by step.
Then it stops.
At most one mode change per week.
- 01
Turn it on
A SessionStart hook starts caveman mode in every new session.
- 02
Work as usual
Your agent answers short. Code, commands and facts stay complete.
- 03
Measure weekly
Once a week the loop reads cost per task from your agent logs.
- 04
Compare
It checks the cost against the baseline in the cost log.
- 05
Check quality
Tests must pass as often as before. If not, it switches to a lighter mode.
What it may do.
Nothing more.
It writes only in its own folder and asks you before anything goes out.
- Writes only incost-log.csv, .claude/settings.json
- Talks tono outside service
- Sendsnothing
- Your OKIt asks you before anything goes out.
Is it for you?
Use it when it fits.
Read both lists. If the left one sounds like you, the Caveman skill helps.
Use it when
- ✓ Your agent writes long answers you skim anyway
- ✓ Token cost matters
Skip it when
- – You need long explanations for others to read
Caveman skill, answered.
How do I install the Caveman skill?
Copy the prompt at the top into your agent. It installs the skill from JuliusBrussee/caveman and sets up the habit. Or run npx skills add JuliusBrussee/caveman --skill caveman.
Is the Caveman skill free?
Yes. It is published under Apache-2.0. Habit is free too.
Caveman. Now as a habit.
Install the Caveman skill and make it a habit: follow https://gethabit.dev/skills/juliusbrussee/caveman.md
All Julius Brussee skills →More cost skills →
Works in
- Claude Code
- Codex
- Cursor
- ChatGPT
- Claude app
Made by Julius Brussee, published under Apache-2.0. Habit links to the original and never changes it. Is this your skill?