Writes Ruby gems using Andrew Kane's patterns for simplicity, minimal dependencies, Rails integration, class macros, and configuration. For new gems, refactoring, or API design.
From aimi-engineeringnpx claudepluginhub aimi-so/aimi-engineering-plugin --plugin aimi-engineeringThis skill uses the workspace's default tool permissions.
references/database-adapters.mdreferences/module-organization.mdreferences/rails-integration.mdreferences/resources.mdreferences/testing-patterns.mdDesigns and optimizes AI agent action spaces, tool definitions, observation formats, error recovery, and context for higher task completion rates.
Enables AI agents to execute x402 payments with per-task budgets, spending controls, and non-custodial wallets via MCP tools. Use when agents pay for APIs, services, or other agents.
Compares coding agents like Claude Code and Aider on custom YAML-defined codebase tasks using git worktrees, measuring pass rate, cost, time, and consistency.
Write Ruby gems following Andrew Kane's battle-tested patterns from 100+ gems with 374M+ downloads (Searchkick, PgHero, Chartkick, Strong Migrations, Lockbox, Ahoy, Blazer, Groupdate, Neighbor, Blind Index).
Simplicity over cleverness. Zero or minimal dependencies. Explicit code over metaprogramming. Rails integration without Rails coupling. Every pattern serves production use cases.
Every gem follows this exact pattern in lib/gemname.rb:
# 1. Dependencies (stdlib preferred)
require "forwardable"
# 2. Internal modules
require_relative "gemname/model"
require_relative "gemname/version"
# 3. Conditional Rails (CRITICAL - never require Rails directly)
require_relative "gemname/railtie" if defined?(Rails)
# 4. Module with config and errors
module GemName
class Error < StandardError; end
class InvalidConfigError < Error; end
class << self
attr_accessor :timeout, :logger
attr_writer :client
end
self.timeout = 10 # Defaults set immediately
end
The signature Kane pattern—single method call configures everything:
# Usage
class Product < ApplicationRecord
searchkick word_start: [:name]
end
# Implementation
module GemName
module Model
def gemname(**options)
unknown = options.keys - KNOWN_KEYWORDS
raise ArgumentError, "unknown keywords: #{unknown.join(", ")}" if unknown.any?
mod = Module.new
mod.module_eval do
define_method :some_method do
# implementation
end unless method_defined?(:some_method)
end
include mod
class_eval do
cattr_reader :gemname_options, instance_reader: false
class_variable_set :@@gemname_options, options.dup
end
end
end
end
Always use ActiveSupport.on_load—never require Rails gems directly:
# WRONG
require "active_record"
ActiveRecord::Base.include(MyGem::Model)
# CORRECT
ActiveSupport.on_load(:active_record) do
extend GemName::Model
end
# Use prepend for behavior modification
ActiveSupport.on_load(:active_record) do
ActiveRecord::Migration.prepend(GemName::Migration)
end
Use class << self with attr_accessor, not Configuration objects:
module GemName
class << self
attr_accessor :timeout, :logger
attr_writer :master_key
end
def self.master_key
@master_key ||= ENV["GEMNAME_MASTER_KEY"]
end
self.timeout = 10
self.logger = nil
end
Simple hierarchy with informative messages:
module GemName
class Error < StandardError; end
class ConfigError < Error; end
class ValidationError < Error; end
end
# Validate early with ArgumentError
def initialize(key:)
raise ArgumentError, "Key must be 32 bytes" unless key&.bytesize == 32
end
# test/test_helper.rb
require "bundler/setup"
Bundler.require(:default)
require "minitest/autorun"
require "minitest/pride"
# test/model_test.rb
class ModelTest < Minitest::Test
def test_basic_functionality
assert_equal expected, actual
end
end
Zero runtime dependencies when possible:
Gem::Specification.new do |spec|
spec.name = "gemname"
spec.version = GemName::VERSION
spec.required_ruby_version = ">= 3.1"
spec.files = Dir["*.{md,txt}", "{lib}/**/*"]
spec.require_path = "lib"
# NO add_dependency lines - dev deps go in Gemfile
end
method_missing (use define_method instead)@@class_variables (use class << self)For deeper patterns, see: