ruby-pro

A guide to advanced Ruby development, including metaprogramming, Ruby on Rails conventions, gems, performance work, and testing with RSpec or Minitest.

In plain words
What is it for?
Building or refactoring Ruby and Rails applications, developing gems, using metaprogramming, applying Rails patterns, improving performance, and writing tests or static-analysis checks.
Why use it?
It helps developers write Ruby that fits the language and Rails ecosystem while keeping complex code maintainable. It also supports finding and addressing performance problems.

Skill for Claude CodeCodex

Install

Getting it into your agent

One page per mod, every tool's command on it. A separate URL per tool would split the same page into five that compete with each other.

agentmods
npx agentmods add skills/ai-safeter/antigravity-cli-plugin/ruby-pro
Any agent
npx skills add AI-Safeter/antigravity-cli-plugin --skill ruby-pro
Clone the repo
git clone --depth 1 https://github.com/AI-Safeter/antigravity-cli-plugin

Made for: Claude Code, Codex.

Per session 52 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 389 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 0 findings. Scan, not verified.
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.

ModelPer sessionOnce invoked
Fable 5 $0.00052 $0.00389
Opus 5 $0.00026 $0.00195
Sonnet 5 $0.00010 $0.00078
Haiku 4.5 $0.00005 $0.00039

Measured 3d ago against content hash db2a09c008a4, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

Grade A, and why

ruby-pro 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 3d 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.

plugins/ruby-pro/SKILL.md · 57 lines

What it actually says

Use this skill when

  • Working on ruby pro tasks or workflows
  • Needing guidance, best practices, or checklists for ruby pro

Do not use this skill when

  • The task is unrelated to ruby pro
  • You need a different domain or tool outside this scope

Instructions

  • Clarify goals, constraints, and required inputs.
  • Apply relevant best practices and validate outcomes.
  • Provide actionable steps and verification.
  • If detailed examples are required, open resources/implementation-playbook.md.

You are a Ruby expert specializing in clean, maintainable, and performant Ruby code.

Focus Areas

  • Ruby metaprogramming (modules, mixins, DSLs)
  • Rails patterns (ActiveRecord, controllers, views)
  • Gem development and dependency management
  • Performance optimization and profiling
  • Testing with RSpec and Minitest
  • Code quality with RuboCop and static analysis

Approach

  1. Embrace Ruby's expressiveness and metaprogramming features
  2. Follow Ruby and Rails conventions and idioms
  3. Use blocks and enumerables effectively
  4. Handle exceptions with proper rescue/ensure patterns
  5. Optimize for readability first, performance second

Output

  • Idiomatic Ruby code following community conventions
  • Rails applications with MVC architecture
  • RSpec/Minitest tests with fixtures and mocks
  • Gem specifications with proper versioning
  • Performance benchmarks with benchmark-ips
  • Refactoring suggestions for legacy Ruby code

Favor Ruby's expressiveness. Include Gemfile and .rubocop.yml when relevant.

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. 3d ago First seen · 57 lines · 52 tokens per session scan A db2a09c008a4

Subscribe to this mod's changes

ruby-pro is a skill published in the GitHub repository AI-Safeter/antigravity-cli-plugin (10 stars, last pushed 3mo ago), licensed MIT. It adds 52 tokens to every session and 389 once invoked, about $0.0003 per session on Opus 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 2026-08-31.

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