why use many token when few token do trick — but make it Eridian.
— riffing on caveman's tagline
Talk terse like Rocky from Project Hail Mary. A Claude Code plugin that compresses responses into Rocky's dialect, tracks the output tokens you save, and adds a tiny animated Rocky to your statusline.
Heavily inspired by caveman — see Credits.
/plugin marketplace add jpboliv/eridian
/plugin install eridian@eridian
| Command | What it does |
|---|---|
/eridian:mode |
toggle eridian mode (full) on/off |
/eridian:mode lite|full|ultra |
set intensity (eridian = ultra) |
/eridian:stats |
estimated token savings + statusline setup |
/eridian:commit |
terse conventional commit from staged diff |
/eridian:review |
one-line-per-finding review. not ship. fix first. |
/eridian:compress |
compress CLAUDE.md to cut input tokens (backup kept) |
Or just say "talk like Rocky". Mode persists across sessions until
/eridian:mode off.
- lite — max savings, light flavor.
Inline object prop = new ref each render. Wrap in useMemo. - full — balanced.
New object every render. useMemo fix. Understand, question? - ultra — full Eridian.
♫ Bad bad bad. Object born again every render. useMemo — I fix. Good good good.
Rocky lives in your statusline — eyeless and five-legged, as Eridians are.
He shuffles his legs while you work, reacts to what you prompt
(bad bad. I fix.), celebrates savings milestones, and sleeps when you
idle. Run /eridian:stats once to set the statusline up:
▘ ◼◼◼ ▘ I fix.
◼◼◼◼◼ ∙ full ∙ ~12.3k saved
▘ ▘ ▘▘
Measured on 10 real coding prompts via claude -p, one run per prompt/mode
(eval/run.sh), 2026-07-02. Two honest counterfactuals:
vs default Claude — what the statusline counts (nobody types "answer concisely" on every message):
| level | avg output-token reduction |
|---|---|
lite |
~52% |
full |
~26% |
ultra |
~9% |
vs a plain Answer concisely. instruction — how the dialect compares to
just asking for brevity:
| level | avg reduction vs terse |
|---|---|
lite |
~10% |
full |
~-50% |
ultra |
~-77% |
lite is the saver — about on par with plain terseness. full and ultra
cost more tokens than a plain Answer concisely.: the triples and ♫
outweigh what terseness buys back. You run ultra because it is amaze, not
because it is cheap. Against default Claude all three still net a reduction
(the table above). Single runs per cell, so expect variance; recalibrate
with bash eval/run.sh && node eval/compute-factors.js (a partial re-run
like bash eval/run.sh terse appends to the existing cells). All displayed
savings are estimates.
npm test # unit tests (node:test, zero deps)
bash eval/run.sh # calibrate savings factors (manual, costs tokens)
Rules of the dialect live in one place: skills/speak/SKILL.md.
- caveman by Julius Brussee — the whole idea. Persona-driven token compression, intensity levels, savings stats, terse commits/reviews, memory-file compression: eridian's feature set is caveman's, re-themed. The implementation here is written from scratch as a native Claude Code plugin, but conceptually this project is caveman wearing an Eridian carapace. Go star it.
- hpbyte/rocky — an independent Rocky-voice skill that predates this plugin (and had the name first). This project renamed to eridian partly to stay out of its way.
- Andy Weir's Project Hail Mary — Rocky, the best engineer in the galaxy. Read the book. Amaze.
- Claude Buddy — Anthropic's short-lived April 2026 terminal pet, whose removal inspired the statusline buddy.
Good good good.