Cut the Token Bill on Both Ends

Every agentic session burns tokens in two directions. Agent talks back. Terminal pipes output in. Same context window, both ends leaking.

Run long enough and you hit the wall. Quality drops. Costs climb.

Two tools fixed most of it. One trims what the agent says. The other trims what flows back from the shell.

Same model. Same prompts. Lighter bill.

Two leaks in the same window

Biggest blocks in any session transcript: agent responses and tool output. Not your prompts.

• Agent responses: pleasantries, hedging, restatements, “Sure! Happy to help…”.
• Tool output: npm install logs, git status walls of text, grep dumps with full file paths.

Both pile up. Both push the useful signal away from the model.

Caveman trims the output

Caveman is a Claude Code skill. One command, /caveman full, and the agent drops articles, fillers, and pleasantries. Fragments are welcome. Technical terms stay exact.

Install:

curl -fsSL https://raw.githubusercontent.com/JuliusBrussee/caveman/main/install.sh | bash

What dies:

• Articles: a, an, the.
• Fillers: just, really, basically, actually, simply.
• Pleasantries: sure, of course, happy to.
• Hedging: might, perhaps, it depends.

What stays:

• Code blocks, exact errors, file paths, commands.
• Security warnings and destructive ops (skill auto-clarifies).

Same answer. A fraction of the prose.

Levels: lite, full, ultra. Start at full. Ultra reads like telegrams.

The agent does not lose intelligence when you take away its small talk.

RTK trims the input

RTK (Rust Token Killer) wraps the commands your agent runs. A hook rewrites git status into rtk git status. Transparent. Zero overhead.

Install:

brew install rtk
rtk init -g    # install the hook that auto-rewrites commands

The wrapped version strips noise before it reaches the agent. Color codes. Repeated separators. npm install banners. Verbose timestamps.

Same git status, raw vs wrapped:

$ rtk proxy git status
On branch main
Your branch is up to date with 'origin/main'.

Untracked files:
  (use "git add <file>..." to include in what will be committed)
	content/blog/new-draft.md

nothing added to commit but untracked files present (use "git add" to track)

$ rtk git status
* main...origin/main
? Untracked: 1 file
   content/blog/new-draft.md

Same information. Half the lines. On a busy repo the gap scales: dozens of untracked files, branch hints, instruction lines, all collapse to one block.

rtk gain              # see how many tokens it saved you
rtk gain --history    # per-command breakdown
rtk discover          # scan your Claude Code history for missed wins

Run rtk gain after real use to see your own savings. RTK reports 60-90% fewer tokens on common dev commands.

Output you never read is still output the model has to read.

Why the combo compounds

Each tool plugs one leak. Together they multiply.

A turn: prompt, think, run command, terminal output, read, answer. RTK shrinks the tool output. Caveman shrinks the answer. Smaller turns, more turns in the same window.

Compaction kicks in later. Cached top of conversation stays cheap. Only the new parts cost.

Real check on the $100/month Claude Max plan. Before both tools: I hit the weekly usage cap often, sometimes on a single project. After: multiple projects running in parallel and the cap rarely shows.

When not to compress

Both tools know when to step aside.

Caveman switches back to normal prose for:

• Security warnings and destructive operations.
• Multi-step sequences where fragments could be misread.
• When you ask the agent to clarify or repeat.

RTK never touches the payload. Strips noise around it. Errors and stack traces stay exact. If a filter ever eats something you need, bypass it for one call:

rtk proxy <cmd>   # raw output, no filtering

If an answer lands too terse, type normal mode.

Compression is for the chatter. Never for the substance.

Start with one, add the other

You do not need both on day one. Pick the leak that hurts more.

Agent writes long essays for every fix? Install Caveman first.

Every grep or npm install floods the window? Install RTK first.

Then add the second. They do not conflict.

Two tools. Two leaks. One context window that lasts twice as long.