What is skillfold CLAUDE.md?

Repository instructions for Skillfold, a tool that declares, pins, installs, and checks reusable skills and rules for Claude Code. A lock file records exact versions so installations can be reproduced.

Use them to install or add skills, verify synchronization, list status, run tests and type checks, build the project, or follow its blog-writing process.

They provide the project's command reference and explain its structure, helping agents manage configuration and keep installed skills consistent.

How byronxlg/skillfold configures Claude Code

Reuse

Borrowing it

Nothing to install: this file belongs to byronxlg/skillfold. 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/byronxlg/skillfold/main/CLAUDE.md

Clone the repo

git clone --depth 1 https://github.com/byronxlg/skillfold

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.

README.md

[![agentmods](https://agentmods.dev/badge/instructions/byronxlg/skillfold/claude-md/github.svg)](https://agentmods.dev/instructions/byronxlg/skillfold/claude-md)

Your own site

<a href="https://agentmods.dev/instructions/byronxlg/skillfold/claude-md"><img src="https://agentmods.dev/badge/instructions/byronxlg/skillfold/claude-md/github.svg" alt="Measured on agentmods" height="20"></a>

Or the 80×15 button, for a site that already has a row of RSS and ATOM ones. Only the verdict fits; the numbers stay here.

Your own site · 80×15

<a href="https://agentmods.dev/instructions/byronxlg/skillfold/claude-md"><img src="https://agentmods.dev/badge/instructions/byronxlg/skillfold/claude-md.svg" alt="Reviewed on agentmods" width="80" height="20"></a>

Per session 1,869 This file is loaded in full into every session.

When invoked 1,869 The same file — it is already loaded in full.

Security scan A 0 findings. A grade says what 26 rules found in the file — not that it is safe.

Origin original No closer match found 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.

Model	Per session	Once invoked
Fable 5.1	$0.01869	$0.01869
Opus 5.5	$0.00748	$0.00748
Sonnet 5.5	$0.00374	$0.00374
Haiku 4.5	$0.00187	$0.00187

Measured 5d ago against content hash c4c0bb7aeecb, method: parsed. Prices are Anthropic first-party input rates as of 2026-10-07, from the pricing page.

Security

Grade A, and why

skillfold 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 5d 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.

CLAUDE.md · 114 lines

How it starts

The opening of the file, as written. The whole thing — 114 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Skillfold

Declarative skill manager for Claude config. Declare skills and rules in skillfold.yaml, pin exact revisions in skillfold.lock, install them into .claude/skills and .claude/rules.

GitHub

Repo: https://github.com/byronxlg/skillfold
Issues, PRs, releases, actions, and all other GitHub features are available for use
Every package change ships: a PR touching src/** (tests aside), library/** or skillfold.schema.json bumps package.json (semver, CONTRIBUTING.md) and adds the ## X.Y.Z CHANGELOG.md section in the same PR. Merging publishes to npm and creates the release (publish.yml); CI's release-check fails the PR otherwise. Work on the package is not done until npm view skillfold version shows it.

Operations

runbook/ - how the package, site and blog cron ship, what healthy means, and how to roll back (fleet standard, tier 3)

Quick Reference

Run the CLI: npx tsx src/cli.ts <command>
Install skills: npx tsx src/cli.ts install (--frozen for CI-exact installs)
Add a skill: npx tsx src/cli.ts add <source>
Verify sync: npx tsx src/cli.ts check
List status: npx tsx src/cli.ts list
Tests: npm test (node:test via tsx, no extra deps)
E2E (network): npm run test:e2e - @installed against real CLIs (@playwright/cli, hyperframes, skillfold) under npm, pnpm, workspaces, and -g
Type check: npm run typecheck (src + scripts)
Build: npm run build
Build the blog: npm run build:blog (regenerates site/blog/, output is gitignored, except the marker-fenced block in site/index.html which is committed)
Write a blog post: follow skills/blog-post/SKILL.md. The blog is current-events-first (news in the agent config / skill distribution / supply chain space), with an evergreen queue in docs/blog-todo.md as the quiet-week fallback. It is not a product blog.

Project Structure

src/
  cli.ts      - CLI entry point: arg parsing, command dispatch, output formatting
  manifest.ts - skillfold.yaml parsing, validation, comment-preserving add/remove edits
  source.ts   - source string parsing (local paths, github:, npm:) and @ref extraction
  skill.ts    - SKILL.md frontmatter parsing, skill directory reading, sha256 integrity hashing
  lock.ts     - skillfold.lock read/write and manifest-vs-lock diffing
  resolve.ts  - central resolver: manifest + lock -> concrete files, pin reuse, frozen mode
  github.ts   - GitHub ref -> SHA resolution and skill fetching (contents API, injectable fetch)
  npm.ts      - npm skill resolution: node_modules first, then registry via npm pack into cache
  installed.ts - @installed refs: installed package version from lockfiles / node_modules / global root
  cache.ts    - shared content cache (~/.cache/skillfold), keyed by SHA / exact version
  compose.ts  - composed skill generation (body concatenation, topological ordering)
  targets.ts  - install-target layouts (claude, codex, cursor) mapping targets to locations
  agentsmd.ts - managed rules block in AGENTS.md for the codex target
  install.ts  - sync into skillsDir (managed-dir safety, pruning) and offline check
  init.ts     - skillfold init scaffolding
  list.ts     - status table (ok / modified / not installed / not locked)
  search.ts   - npm registry search for skillfold-skill packages
  index.ts    - public API exports
  testutil.ts - test helpers (tmp dirs, fixture skills, fetch stub); excluded from build
library/      - 11 general-purpose skills published with the package (agentskills map)
site/         - static docs site deployed to GitHub Pages
  index.html    - landing page (page-specific CSS inline)
  assets/       - vendored fonts, base.css (shared chrome), blog.css
  blog/posts/   - blog sources: markdown + YAML frontmatter (the only committed blog files)
scripts/
  build-blog.ts - renders site/blog/posts/*.md into site/blog/, feed.xml,
                  sitemap.xml, robots.txt, and the marker-fenced block in index.html
skills/blog-post/ - repo-specific skill driving the weekly blog automation
docs/blog-todo.md - blog editorial state: news beats, fallback queue, rollouts, shipped log
docs/         - markdown docs (getting started, manifest, CLI, publishing)
skillfold.yaml         - this repo's own manifest (dogfood: blog-post skill and the conventions rule)
skillfold.schema.json  - JSON Schema for manifest validation and IDE autocompletion
action.yml             - GitHub Action wrapper for skillfold check

Read the full file on GitHub · 114 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.

5d ago Changed · +1 lines · +109 tokens per session c4c0bb7aeecb
1mo ago Changed · +2 lines · +97 tokens per session 0050fe21cbff
1mo ago Changed · +4 tokens per session bf135b9a47be
1mo ago Changed · -14 tokens per session 08918c39ed09
1mo ago Changed · +4 lines · +37 tokens per session 2bd7a0e672a7
1mo ago First seen · 107 lines · 1,636 tokens per session scan A 30206a6dfea1

Subscribe to this mod's changes

skillfold CLAUDE.md is an instructions file published in the GitHub repository byronxlg/skillfold (15 stars, last pushed 2d ago), licensed MIT. It adds 1,869 tokens to every session, about $0.0075 per session on Opus 5.5. A static security scan graded it A with 0 findings. No closer match exists in the catalogue, so it is treated as the original; first seen 2026-08-30.

Claude Code TypeScript agent-skills agents-md claude yaml

vscode buildNext.instructions.md

Working notes and architecture documentation for the new esbuild-based build system in build/next. Use when making changes to the new build pipeline (transpile/bundle commands, NLS plugin, source-map handling, resource copying, or self-hosting watch tasks).

microsoft/vscode · 9,715 tokens

skillfold: Instructions file for Claude Code

Borrowing it

Wrote this? Show the measurements

What it costs to keep this loaded

Grade A, and why

Nothing flagged

How it starts

Skillfold

GitHub

Operations

Quick Reference

Project Structure

What this file has done since we first saw it

Other instructions, from other repositories

vscode buildNext.instructions.md

next.js AGENTS.md

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