← All skills

ruby4

100 / 100 · Low risk

Fine to try.

By MadBomber/experiments (GitHub) · coding · 11 stars · scanned at commit 8139ff6

Enforces idiomatic Ruby 4.0 code generation. This skill should be used whenever writing, reviewing, or refactoring Ruby code in a Ruby 4.0+ project. It ensures modern idioms (hash shorthand, `it` block param, endless methods, Data.define, pattern matching) are used by default and prevents generation of removed APIs (RJIT, pipe-based open, ObjectSpace._id2ref, old Ractor API, SortedSet, full CGI) and pre-4.0 patterns that have cleaner modern equivalents.

Works with any agent that supports SKILL.md skills.

What this skill can do

We found nothing in the files we read that matches our rules. That does not prove the skill is safe: see the limits of static scanning.

Install

Paste this into your terminal. It downloads exactly the version we scanned, not whatever is newest.

if [ -e ~/.agents/skills/'ruby4' ] || [ -L ~/.agents/skills/'ruby4' ]; then echo 'A skill folder named ruby4 already exists — not replacing it' >&2; false; else d=$(mktemp -d) && git clone --quiet --filter=blob:none --no-checkout 'https://github.com/MadBomber/experiments' "$d" && git -C "$d" checkout --quiet '8139ff68e8895b544661aa2ba8b53268d68652bc' -- 'ai_misc/skills/ruby4' && mkdir -p ~/.agents/skills && cp -R "$d"/'ai_misc/skills/ruby4' ~/.agents/skills/'ruby4' && rm -rf "$d"; fi

Codex reads ~/.agents/skills directly. For Claude Code, Cursor, Copilot, Gemini CLI, Antigravity or OpenCode, also link it. For Claude Code: ln -s ~/.agents/skills/'ruby4' ~/.claude/skills/'ruby4' (other agents: ~/.cursor/skills, ~/.copilot/skills, ~/.gemini/skills, ~/.gemini/config/skills, ~/.config/opencode/skills). Or install through the finder skill, which does both.

Badge for your README

The badge for MadBomber/experiments shows the score of its lowest-scoring skill.

[![SkillTrust](https://zalavijaysinh.github.io/skilltrust/badges/MadBomber/experiments.svg)](https://zalavijaysinh.github.io/skilltrust/repos/MadBomber/experiments/)

Score history