grimoire-core: Instructions file for Claude Code

CLAUDE.md

grimoire-core CLAUDE.md is an instructions file for Claude Code from jeffreytse/grimoire-core. It costs 884 tokens per session, scanned A, a copy of grimoire-core AGENTS.md, MIT.

Documentation for grimoire-core, a curated collection of skills for coding assistants across software development, business, science, health, and writing. Grimoire is the package manager that installs and manages these skill collections.

In plain words
What is it for?
Use it to understand grimoire-core’s package structure, skill paths, supported assistant tools, and available subject areas when selecting a matching skill.
Why use it?
It explains where skills live, how the package fits into the wider tool ecosystem, and which domains it covers.

Instructions file for Claude Code

Written for Claude Code: Claude Code plugin machinery. Also seen: mentions Claude Code; mentions Codex; mentions Gemini CLI.

This is jeffreytse/grimoire-core's own configuration. It tells Claude Code how to work on grimoire-core itself, so it is not a mod to install elsewhere. Copy it as a starting point and replace the rules that are about this project. Everything grimoire-core configures →

Reuse

Borrowing it

Nothing to install: this file belongs to jeffreytse/grimoire-core. Take a copy, put it at the same path in your own repository, and replace the rules that are about this project with yours.

Copy the file
curl -O https://raw.githubusercontent.com/jeffreytse/grimoire-core/main/CLAUDE.md
Clone the repo
git clone --depth 1 https://github.com/jeffreytse/grimoire-core

Made for: Claude Code.

Wrote this? Show the measurements

A badge with what this costs and how it scanned, read live from this page, so it follows the numbers instead of freezing them. Markdown for a README, HTML for a documentation site or a project page.

agentmods badge for grimoire-core CLAUDE.md

README.md
[![agentmods](https://agentmods.dev/badge/instructions/jeffreytse/grimoire-core/claude-md.svg)](https://agentmods.dev/instructions/jeffreytse/grimoire-core/claude-md)
Your own site
<a href="https://agentmods.dev/instructions/jeffreytse/grimoire-core/claude-md"><img src="https://agentmods.dev/badge/instructions/jeffreytse/grimoire-core/claude-md.svg" alt="Measured on agentmods" height="20"></a>
Per session 884 This file is loaded in full into every session.
When invoked 884 The same file — it is already loaded in full.
Security scan A 0 findings. Scan, not verified.
Origin 86% copy Near-identical to another mod in the catalogue.
Token cost

What it costs to keep this loaded

Counted locally with the o200k_base tokenizer, which is exact for GPT models; Claude uses its own tokenizer and its counts differ. Treat this as one consistent yardstick across the catalogue rather than a bill. Prices are per million input tokens.

ModelPer sessionOnce invoked
Fable 5.1 $0.00884 $0.00884
Opus 5 $0.00442 $0.00442
Sonnet 5 $0.00177 $0.00177
Haiku 4.5 $0.00088 $0.00088

Measured 6d ago against content hash 61ca95a28cf9, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-06, from the pricing page.

Security

Grade A, and why

grimoire-core CLAUDE.md scanned grade A with 0 findings against 26 rules in 11 categories — prompt injection, anti-refusal, data exfiltration, privilege escalation, supply chain, agent snooping, system-prompt leakage, SSRF and excessive agency — measured 6d ago.

A static scan of the body, not an audit. Every finding is printed with the line that produced it so you can judge whether it matters here. A mod is markdown that instructs an agent; that is exactly why what it instructs is worth reading.

Nothing flagged

None of the 26 patterns this scan looks for appear in this file: no shell pipes, no recursive deletes, no credential paths, no hidden text, no instruction-override or anti-refusal phrasing, no agent-config snooping. That is not a guarantee, it is the absence of the things that are checkable.

Origin

This is a copy

86% identical to grimoire-core AGENTS.md — 16 lines differ, which has more behind it and is treated as the original. This page carries a canonical link to it rather than competing with it.

CLAUDE.md · 102 lines

How it starts

The opening of the file, as written. The whole thing — 102 lines — stays where its author put it; the contents beside it link to each section on GitHub.

grimoire-core

The official skills package for the grimoire package manager. Multi-domain skill collection for AI assistants — works across Claude Code, Codex, Copilot, Gemini CLI, OpenCode, and more.

Role in the ecosystem: grimoire (CLI) manages packages; grimoire-core is the official package. Any git repo can be a grimoire package — grimoire-core is the curated, peer-reviewed one.

Skill Path Convention

All skill paths follow this pattern:

<domain>/<subdomain>/skills/<skill-name>/SKILL.md

If a task matches a skill, invoke it. Never implement directly when a skill applies.

Domains

Domain Sub-domains
meta (flat — no sub-domains)
engineering development, frontend, architecture, testing, reliability, devops, cloud, networking, security, data, ai, hardware, mobile, performance, project-management, product, documentation
business strategy, operations, leadership, entrepreneurship, hr
science biology, physics, chemistry, mathematics, earth-science, astronomy
health fitness, nutrition, mental-health, sleep, medicine
writing creative, technical, copywriting, academic, journalism
design ui-ux, graphic, branding, motion, product
marketing seo, content, social-media, paid-ads, growth, analytics
finance personal-finance, investing, accounting, real-estate, corporate
law contracts, ip, employment, privacy, corporate
film cinematography, directing, editing, screenwriting, production
music composition, production, mixing, theory, performance
art drawing, painting, digital-art, illustration, color-theory
sports training, coaching, nutrition, tactics, recovery
psychology cognitive, behavioral, social, clinical, positive
language learning, linguistics, translation, communication
education curriculum, teaching, e-learning, assessment, learning-science
cooking techniques, baking, flavor, nutrition, world-cuisine
travel planning, budgeting, cultural, adventure
home renovation, interior-design, gardening, organization, smart-home
parenting infant, toddler, school-age, teen
automotive maintenance, troubleshooting, buying, modifications, ev
pets dogs, cats, training, nutrition, health
fashion styling, wardrobe, design, sustainability, accessories
environment sustainability, ecology, climate, energy, policy
photography composition, lighting, editing, genres
productivity time-management, habits, focus, goals, tools

Read the full file on GitHub · 102 lines

Changes

What this file has done since we first saw it

Hashed on every crawl. A supply-chain change to an agent config is a question of when, not whether, so the history is kept rather than the latest state alone.

  1. 6d ago First seen · 102 lines · 884 tokens per session scan A 61ca95a28cf9

Subscribe to this mod's changes

grimoire-core CLAUDE.md is an instructions file published in the GitHub repository jeffreytse/grimoire-core (4 stars, last pushed 17d ago), licensed MIT. It adds 884 tokens to every session, about $0.0044 per session on Opus 5. A static security scan graded it A with 0 findings. It is 86% identical to grimoire-core AGENTS.md, differing in 16 lines, and is treated as a copy.

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