rails

name	rails
description	Ruby on Rails with service-oriented architecture, Dry-validation, Sidekiq/Solid Queue, Hotwire. Use for Rails API, Rails services, Rails forms, RSpec, ActiveRecord, Rails migrations. Not for standalone Ruby gems (use ruby skill), and not for judging whether a migration is safe to run in production (that is the database-reviewer agent).
compatibility	Requires Bundler and Rails. Optional: lefthook, RSpec.
allowed-tools	["mcp__acp__Read","mcp__acp__Edit","mcp__acp__Write","mcp__acp__Bash"]

ABOUTME: Rails service-oriented architecture, validation contracts, background jobs, Hotwire

ABOUTME: API development with thin controllers, services, forms, filters

Ruby on Rails

Quick Reference

bundle exec lefthook run all    # Quality checks
bundle exec rspec               # Tests
rails s / bin/dev               # Server (bin/dev for Hotwire)
bin/jobs                        # Solid Queue workers

See also: _AST_GREP.md (sg patterns), _PATTERNS.md, source-control

Architecture calls:

MyService.new(user:, params:).call    # Service
MyForm.new(params, user).save         # Form
MyFilter.result(params, scope)        # Filter
MyJob.perform_async(id)               # Sidekiq
MyJob.perform_later(id)               # Solid Queue

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Version (determine, don't assume)

See ../_LANG_COMMON.md. Fetch the truth:

bundle exec rails -v                                                      # project Rails version
ruby -v && cat .ruby-version 2>/dev/null                                  # project Ruby version
curl -s https://rubygems.org/api/v1/gems/rails.json | jq -r .version      # latest upstream Rails

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Pre-Commit Verification (MANDATORY)

make check && make test-e2e must pass (enforced by the pre-commit-gate hook; see ../_LANG_COMMON.md). What make check expands to for Rails:

bundle exec lefthook run all    # Rubocop, Brakeman, tests, etc.
bundle exec rspec               # Full RSpec suite
bundle exec brakeman --no-pager # Security scan
bundle audit check --update     # Dependency CVEs

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Sacred Rules (NON-NEGOTIABLE)

1. NO LOGIC IN CONTROLLERS: HTTP layer only
2. ALL LOGIC IN SERVICES/FORMS/FILTERS
3. NO ACTIVERECORD VALIDATIONS: Dry-validation contracts only
4. MINIMUM MODEL LOGIC: Data structures + associations
5. NO MODEL CALLBACKS: Exception: attachment destruction

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Pattern Summary

Service: Complex business logic, multi-step operations, transactions

MyService.new(user:, params:).call  # Returns OpenStruct(success, record)

Form: User input validation + persistence

MyForm.new(params, user).save  # Returns true/false

Contract: Validation rules (Dry-validation)

CreateContract.new.call(params)  # Returns Result(success?, errors)

Controller: HTTP layer only, no business logic

def create
  form = CreateForm.new(params, current_user)
  form.save ? render(json: form.model, status: :created) : render(json: { errors: form.errors }, status: :unprocessable_entity)
end

Model: Associations, enums, simple scopes. NO validations, NO callbacks, NO business logic.

belongs_to :user
has_many :tags, dependent: :destroy
enum :status, { draft: 0, published: 1 }
scope :recent, -> { order(created_at: :desc) }

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Background Jobs

Component	Use When
Solid Queue	<100 jobs/sec, no Redis needed
Solid Cache	DB-backed caching
Solid Cable	WebSockets, no Redis infra
Sidekiq	Latency <100ms, 10k+ jobs/min

Jobs MUST be idempotent.

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Quality Checklist

• NO controller logic
• Validation in contracts only
• Business logic in services
• Jobs idempotent
• Tests pass

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Resources

• https://guides.rubyonrails.org/
• https://dry-rb.org/gems/dry-validation/
• https://github.com/rails/solid_queue
• https://turbo.hotwired.dev/

Key gems: Dry-validation, Sidekiq/Solid Queue, Scenic, Pundit, Devise/Rodauth, ViewComponent/Phlex

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For detailed patterns and examples, see references/rails-patterns.md