What is ruby-skills CLAUDE.md?

A project instruction guide for a Ruby version-management plugin. It describes when to run tests, how the plugin is organized, and how to verify Ruby detection and version switching.

It is for maintaining shell scripts and Ruby version detection, running required checks, and understanding the plugin's files and skills.

It gives the coding agent project-specific rules for testing changes and checking that the plugin still works.

How st0012/ruby-skills configures Claude Code

Reuse

Borrowing it

Nothing to install: this file belongs to st0012/ruby-skills. 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/st0012/ruby-skills/master/CLAUDE.md

Clone the repo

git clone --depth 1 https://github.com/st0012/ruby-skills

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/st0012/ruby-skills/claude-md/github.svg)](https://agentmods.dev/instructions/st0012/ruby-skills/claude-md)

Your own site

<a href="https://agentmods.dev/instructions/st0012/ruby-skills/claude-md"><img src="https://agentmods.dev/badge/instructions/st0012/ruby-skills/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/st0012/ruby-skills/claude-md"><img src="https://agentmods.dev/badge/instructions/st0012/ruby-skills/claude-md.svg" alt="Reviewed on agentmods" width="80" height="20"></a>

Per session 1,197 This file is loaded in full into every session.

When invoked 1,197 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	$0.01197	$0.01197
Opus 5.5	$0.00479	$0.00479
Sonnet 5.5	$0.00239	$0.00239
Haiku 4.5	$0.00120	$0.00120

Measured 2mo ago against content hash 4d9ac8a982f0, method: parsed. Prices are Anthropic first-party input rates as of 2026-10-07, from the pricing page.

Security

Grade A, and why

ruby-skills 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 2mo 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 · 156 lines

How it starts

The opening of the file, as written. The whole thing — 156 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Ruby Skills - Development Guide

For Claude: When to Run Tests

Run these tests automatically when:

You modify any .sh script in the plugin
You change detection logic in detect.sh or detect-all-managers.sh
Before committing changes
When debugging issues reported by the user

Minimum verification before any commit:

Run detect.sh and verify it outputs valid key=value pairs
Test that ACTIVATION_COMMAND actually switches Ruby versions

Project Structure

This repository is a plugin marketplace containing one plugin:

ruby-skills/                            # Marketplace root
├── .claude-plugin/
│   └── marketplace.json                # Marketplace definition
├── plugins/
│   └── ruby-skills/                    # Plugin
│       ├── .claude-plugin/plugin.json
│       ├── hooks/
│       │   ├── hooks.json
│       │   └── session-start.sh
│       └── skills/
│           ├── ruby-version-manager/
│           │   ├── SKILL.md
│           │   ├── detect.sh
│           │   ├── detect-all-managers.sh
│           │   └── set-preference.sh
│           ├── ruby-resource-map/
│           │   └── SKILL.md            # Authoritative resource map
│           └── ruby-test-frameworks/
│               └── SKILL.md            # minitest vs test-unit divergences
├── CLAUDE.md                           # This file
└── README.md                           # User documentation

Test Suite

Test 1: Basic Detection

When to run: After any change to detect.sh or detect-all-managers.sh

cd /path/to/ruby/project
/path/to/ruby-skills/plugins/ruby-skills/skills/ruby-version-manager/detect.sh

Verify:

Output contains VERSION_MANAGER=<manager> (not empty or "none" if manager is installed)
Output contains ACTIVATION_COMMAND=<command> (not empty)
Output contains VERSION_AVAILABLE=true (if the Ruby version is installed)

Test 2: Activation Command Works

When to run: After any change to activation logic

Read the full file on GitHub · 156 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.

2mo ago First seen · 156 lines · 1,197 tokens per session scan A 4d9ac8a982f0

Subscribe to this mod's changes

ruby-skills CLAUDE.md is an instructions file published in the GitHub repository st0012/ruby-skills (124 stars, last pushed 4mo ago), licensed MIT. It adds 1,197 tokens to every session, about $0.0048 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.

Languages Ruby

ruby-skills CLAUDE.md next to 6 instructions from other repositories
Mod	Type	Stars	Last push	Licence	Scan	Tokens	Works with
ruby-skills CLAUDE.mdst0012/ruby-skills	Instructions file	124	4mo ago	MIT	A	1,197	Claude Code
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vscode oss-third-party-notices.instructions.mdmicrosoft/vscode	Instructions file	195k	yesterday	MIT	A	5,516	GitHub Copilot
vscode copilot-instructions.mdmicrosoft/vscode	Instructions file	195k	yesterday	MIT	A	3,093	GitHub Copilot
deepseek-harness AGENTS.mddeepseek-ai/deepseek-harness	Instructions file	274k	2d ago	MIT	A	4,313	Codex, OpenCode

ruby-skills: Instructions file for Claude Code