Is the RubyCritic Code Quality Analysis skill free?

Yes. The skill itself is free from esparkman/claude-rubycritic-skill. SkillProof publishes the install command and an independent test verdict at no cost.

How do I install RubyCritic Code Quality Analysis?

Copy the install command from this page, run it in your terminal, and restart Claude Code. Skills live in ~/.claude/skills/ (global) or .claude/skills/ inside a project.

Can I use RubyCritic Code Quality Analysis with Cursor, Copilot, Gemini CLI, Codex or other AI tools?

The SKILL.md format is native to Claude (Claude Code, Desktop, claude.ai). The instructions inside adapt to other assistants: Cursor rules, GitHub Copilot instructions, Windsurf rules, Custom GPTs, AGENTS.md for OpenAI Codex, and GEMINI.md for Google Gemini CLI — our conversion guides cover each, and the free converter on the tools page does the wrapping for you.

RubyCritic Code Quality Analysis

Wraps the RubyCritic gem to grade Ruby/Rails files A-F and prioritize refactoring by churn.

by esparkman · esparkman/claude-rubycritic-skill

Tested · Didn't pass

Read why it failed Download source ↗

Test report

Verdict: Tested · Didn't pass
Tested: Jul 15, 2026
Environment: Claude Code 2.x (agent harness)
Upstream re-checked: Aug 10, 2026 · df63209

The skill's own first Implementation step ('gem install rubycritic') fails outright on any pre-3.2 Ruby: rubycritic's simplecov dependency now requires Ruby >=3.2, and this was reproduced live on system Ruby 2.6.10 with a hard ERROR from gem. SKILL.md never mentions a Ruby-version requirement anywhere, so the exact 'legacy codebase' use case it advertises is the one most likely to hit this wall unwarned.

Scored on four weighted criteria — install, triggering, output vs. baseline, docs. How scoring works

Installs cleanly 5/5
Triggers reliably 5/5
Output vs. baseline 4/10
Docs & honesty 3/5

What RubyCritic Code Quality Analysis does

Runs and interprets RubyCritic analysis on Ruby/Rails codebases: A-F file grades, complexity/duplication/smell metrics, churn-based prioritization, and branch comparisons. Triggers on requests to analyze Ruby code quality, review a Ruby PR, or find technical debt in a Rails project.

How to install RubyCritic Code Quality Analysis

git clone https://github.com/esparkman/claude-rubycritic-skill.git
cd claude-rubycritic-skill
mkdir -p ~/.claude/skills
cp -r skills/rubycritic-skill ~/.claude/skills/rubycritic-skill

Skills live in ~/.claude/skills/ (global) or .claude/skills/ (per-project). Restart Claude Code after installing.

Commands — how to trigger RubyCritic Code Quality Analysis

/rubycritic-code-quality-analysis Wraps the RubyCritic gem to grade Ruby/Rails files A-F and prioritize refactoring by churn.

It also activates on plain-language prompts like these:

Can you grade the code quality of my Rails app's models directory?
Find the most technical-debt-heavy Ruby files in this legacy codebase
Review this Ruby pull request and flag any code quality regressions

Frequently asked questions

Is the RubyCritic Code Quality Analysis skill free?: Yes. The skill itself is free from esparkman/claude-rubycritic-skill. SkillProof publishes the install command and an independent test verdict at no cost.
Does RubyCritic Code Quality Analysis work with Claude Code?: We tested it with Claude Code 2.x (agent harness) on Jul 15, 2026. Verdict: Tested · Didn't pass. The skill's own first Implementation step ('gem install rubycritic') fails outright on any pre-3.2 Ruby: rubycritic's simplecov dependency now requires Ruby >=3.2, and this was reproduced live on system Ruby 2.6.10 with a hard ERROR from gem. SKILL.md never mentions a Ruby-version requirement anywhere, so the exact 'legacy codebase' use case it advertises is the one most likely to hit this wall unwarned.
How do I install RubyCritic Code Quality Analysis?: Copy the install command from this page, run it in your terminal, and restart Claude Code. Skills live in ~/.claude/skills/ (global) or .claude/skills/ inside a project.
Can I use RubyCritic Code Quality Analysis with Cursor, Copilot, Gemini CLI, Codex or other AI tools?: The SKILL.md format is native to Claude (Claude Code, Desktop, claude.ai). The instructions inside adapt to other assistants: Cursor rules, GitHub Copilot instructions, Windsurf rules, Custom GPTs, AGENTS.md for OpenAI Codex, and GEMINI.md for Google Gemini CLI — our conversion guides cover each, and the free converter on the tools page does the wrapping for you.