awesome-agv: Skill for Claude Code

.agents/skills/ruby-idioms/SKILL.md

ruby-idioms is a skill for Claude Code from irahardianto/awesome-agv. It costs 0 tokens per session (779 once invoked), scanned A, original, MIT.

A guide to idiomatic Ruby, covering readable language features, pattern matching, immutable data objects, and error handling.

In plain words
What is it for?
Use it when writing or reviewing Ruby classes, methods, result objects, and domain errors.
Why use it?
It helps Ruby code follow common conventions and remain easier to understand and maintain.

Skill for Claude Code

Written for Claude Code: paths in frontmatter. Also seen: installed under .agents/ (shared by several agents).

This is irahardianto/awesome-agv's own configuration. It tells Claude Code how to work on awesome-agv itself, so it is not a mod to install elsewhere. Copy it as a starting point and replace the rules that are about this project. Everything awesome-agv configures →

Reuse

Borrowing it

Nothing to install: this file belongs to irahardianto/awesome-agv. 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/irahardianto/awesome-agv/main/.agents/skills/ruby-idioms/SKILL.md
Clone the repo
git clone --depth 1 https://github.com/irahardianto/awesome-agv

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.

agentmods badge for ruby-idioms

README.md
[![agentmods](https://agentmods.dev/badge/skills/irahardianto/awesome-agv/ruby-idioms/github.svg)](https://agentmods.dev/skills/irahardianto/awesome-agv/ruby-idioms)
Your own site
<a href="https://agentmods.dev/skills/irahardianto/awesome-agv/ruby-idioms"><img src="https://agentmods.dev/badge/skills/irahardianto/awesome-agv/ruby-idioms/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.

agentmods 80×15 button for ruby-idioms

Your own site · 80×15
<a href="https://agentmods.dev/skills/irahardianto/awesome-agv/ruby-idioms"><img src="https://agentmods.dev/badge/skills/irahardianto/awesome-agv/ruby-idioms.svg" alt="Reviewed on agentmods" width="80" height="20"></a>
Per session 0 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 779 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 0 findings. A grade says what 26 rules found in the file — not that it is safe. Third-party audits
  • NVIDIA SkillSpector warn 7 Sept 2026
SkillSpector: 1 finding, up to medium

These are SkillSpector’s own severities. On a checked sample its high-severity flags on skills were ~96% false positives — a documented command, a public API, a “never do X” rule — so we show them as a caution to read, not a verdict. Why →

  • medium Agent Snooping · line 11
    Skill enumerates or reads other installed skills. Access to other skills' SKILL.md files or the skills directory reveals prompt instructions, capabilities, and secrets that should be invisible to peer skills.
    Fix: Remove all code or instructions that list or read other skills' files or directories. Skills should operate independently; cross-skill access is a privilege escalation.
How audits are shown
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 5.1 $0.00000 $0.00779
Opus 5 $0.00000 $0.00390
Sonnet 5 $0.00000 $0.00156
Haiku 4.5 $0.00000 $0.00078

Measured 5d ago against content hash 2815c352a42e, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-08, from the pricing page.

Security

Grade A, and why

ruby-idioms 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.

Origin

Copies of this mod

1 near-identical copy found in the catalogue:

.agents/skills/ruby-idioms/SKILL.md · 100 lines

How it starts

The opening of the file, as written. The whole thing — 100 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Ruby Idioms and Patterns

Ruby rewards expressiveness, convention, and developer happiness. Modern Ruby (3.x) favors pattern matching, Ractor for concurrency, and strict typing via Sorbet/RBS. Idiomatic Ruby = readable, tested, convention-following.

Scope: Ruby coding idioms. Test naming: .agents/rules/testing-strategy.md. Logging: @.agents/skills/logging-implementation/SKILL.md.

Modern Ruby Features (3.x)

  1. Pattern matching:

    case result
    in { status: :success, data: Task => task }
      render json: task
    in { status: :not_found, id: String => id }
      render json: { error: "Task #{id} not found" }, status: :not_found
    end
    
  2. Endless methods for simple accessors:

    def full_name = "#{first_name} #{last_name}"
    
  3. Data class (3.2+) for immutable value objects:

    TaskResult = Data.define(:task, :status)
    result = TaskResult.new(task: task, status: :created)
    

Error Handling

  1. Domain exception hierarchies:

    class DomainError < StandardError; end
    
    class NotFoundError < DomainError
      attr_reader :resource, :resource_id
      def initialize(resource, resource_id)
        @resource = resource
        @resource_id = resource_id
        super("#{resource} '#{resource_id}' not found")
      end
    end
    
  2. rescue specific exceptions — never bare rescue.

  3. Use ensure for cleanup — equivalent to finally.

Naming

  1. snake_case for methods, variables, file names.
  2. PascalCase for classes, modules.
  3. UPPER_SNAKE_CASE for constants.
  4. ? suffix for boolean queries: active?, valid?.
  5. ! suffix for destructive or dangerous methods: save!, delete!.

Testing

  1. RSpec (preferred) or Minitest:
    RSpec.describe TaskService do
      describe '#create' do
        it 'creates a task with valid attributes' do
          task = service.create(title: 'Test', priority: :high)
          expect(task.title).to eq('Test')
        end
    
        it 'raises ValidationError for blank title' do
          expect { service.create(title: '', priority: :high) }
            .to raise_error(ValidationError)
        end
      end
    end
    

Read the full file on GitHub · 100 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.

  1. 5d ago First seen · 100 lines · 0 tokens per session scan A 2815c352a42e

Subscribe to this mod's changes

ruby-idioms is a skill published in the GitHub repository irahardianto/awesome-agv (156 stars, last pushed 18d ago), licensed MIT. It costs nothing until one of its globs matches a file; then it loads 779 tokens. 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 2026-09-03.

Related

Other skills, from other repositories

refactoring-csharp

Rename and refactor C# symbols in a .NET solution or multi-solution monorepo with a one-shot Roslyn CLI. Use when the user asks to rename a symbol, preview impact, update references across a solution, or refactor shared projects across several solutions.

CodeAlive-AI/ai-driven-development · 60 tokens

rust-skills

Comprehensive Rust coding guidelines with 265 rules across 26 categories. Use when writing, reviewing, or refactoring Rust code. Covers ownership, error handling, async patterns, concurrency, unsafe code, API design, memory optimization, performance, numeric safety, conversions, serde, pattern matching, macros…

leonardomso/rust-skills · 84 tokens

rails-dev

Opinionated Rails conventions: rich models, concerns, CRUD-everything, state-as-records, minimal dependencies, Minitest with fixtures. Load this skill BEFORE any code-level thinking, not only before editing a file. It is required the moment a task touches Rails code in ANY way: designing or even just discussing a data…

tech-leads-club/agent-skills · 199 tokens

java-dev

A set of Java development guidelines covering names, error handling, and Spring Boot, a framework commonly used to build Java web services.

doccker/cc-use-exp · 23 tokens

cc-java-dev

Java development guidance covering names, error handling, and common Spring Boot practices.

doccker/cc-use-exp · 24 tokens

cc-frontend-dev

Frontend development guidance covering Vue 3, user-interface style, and TypeScript.

doccker/cc-use-exp · 29 tokens