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).
license: MIT
---

# ABOUTME: Rails service-oriented architecture, validation contracts, background jobs, Hotwire
# ABOUTME: API development with thin controllers, services, forms, filters

# Ruby on Rails

## Quick Reference

```bash
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:**
```ruby
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
```

---

## Version (determine, don't assume)

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

```bash
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
```

---

## 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:

```bash
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
```

---

## 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

---

## Pattern Summary

**Service:** Complex business logic, multi-step operations, transactions
```ruby
MyService.new(user:, params:).call  # Returns OpenStruct(success, record)
```

**Form:** User input validation + persistence
```ruby
MyForm.new(params, user).save  # Returns true/false
```

**Contract:** Validation rules (Dry-validation)
```ruby
CreateContract.new.call(params)  # Returns Result(success?, errors)
```

**Controller:** HTTP layer only, no business logic
```ruby
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.
```ruby
belongs_to :user
has_many :tags, dependent: :destroy
enum :status, { draft: 0, published: 1 }
scope :recent, -> { order(created_at: :desc) }
```

---

## 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.

---

## Quality Checklist

- [ ] NO controller logic
- [ ] Validation in contracts only
- [ ] Business logic in services
- [ ] Jobs idempotent
- [ ] Tests pass

---

## 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

---

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