Whetstone

Small, sharp, agent-agnostic skills that keep an AI agent's work honest.

A whetstone doesn't make a tool — it keeps its edge true. Whetstone is a growing collection of
tiny open-source skills for AI agents: not frameworks, but disciplines that keep an agent's
work on-track, high-quality, and easy to hand off.

What a Whetstone skill is

Small and self-contained. One folder, one job. No build step, no install, no runtime.
Agent-agnostic. Works as a plain prompt in any agent — Claude, OpenAI, Gemini, Cursor, a
local model — and as a skill / slash command where those exist. Nothing assumes a particular
platform; every capability degrades gracefully.
Prompt-first, optional tooling. The discipline lives in plain language. Any helper script is
optional, zero-dependency, and never required.
Honest by construction. Checks are anchored to structure and substance, not vibes — a green
light has to mean something.
Plain words over jargon. If a reader has to learn a new token for an idea they already know,
that's a defect, not concision.

The skills

Skill	What it does
Throughline	Keep the thread of work intact — within a session (an emoji-tagged task list with one ⭐️ goal anchor) and across sessions or agents (a plain-markdown handoff the next agent re-derives before trusting).
Session Measurement	Score an agent session by session and read the trend across versions — so a model / frame / skill change shows up as a real regression or improvement, not a vibe. Six honest counts per session, plain-markdown trend table (optional charts), any agent.
more coming	—

Use one

Each skill is a self-contained folder. Drop it where your tool reads skills/commands
(Claude Code, Cursor, …), or just paste the relevant file into any agent as a prompt. Start with
each skill's own README.md.

Install as a Claude plugin

Whetstone is also a Claude plugin marketplace, so you can install these skills directly in Claude
Code or Cowork:

/plugin marketplace add jovesun-lab/whetstone
/plugin install session-measurement@whetstone
/plugin install throughline@whetstone

Installed skills are enabled by default and trigger automatically when relevant. Pull future
updates with /plugin marketplace update whetstone.

Token footprint

Built to be cheap to keep installed and modest to use (approximate, tokenizer-dependent):

Installed, idle: ~250 tokens — only the trigger description sits in context.
A session that writes one handoff: ~3–5k tokens (skill body + a command + the template + the handoff it writes).
Optional validator: 0 model tokens — it's a script.

On progressive-disclosure hosts (Claude Code, Cursor) you pay the ~250 baseline and spend the rest only when it actually fires — and the trigger is scoped so short, one-pass tasks don't load it at all.

License

Every Whetstone skill is MIT unless noted otherwise. Free to use, modify, embed, redistribute.

Whetstone is by guxcom. Feedback, issues, and PRs welcome on any skill.