SKILL.md
Rails Patterns
Framework patterns for modern Ruby on Rails applications (Rails 7.1+ and 8.x). Rails is opinionated by design; these are the patterns the community has converged on for apps that stay maintainable past the 50-model mark. This skill is the "how." For the "what" and "when" (the decisions about which pattern to reach for), see the Ruby patterns rules — rules/ruby/patterns.md in this repository, installed as rules/ecc/ruby/patterns.md.
When to Activate
- Building a Rails application (full-stack, API-only, or hybrid)
- Reviewing a PR that touches
app/orconfig/ - Generating models, controllers, services, or jobs
- A controller action grows past ~10 lines
- A model file grows past ~200 lines
- ActiveRecord queries start appearing in controllers or views
Core Concepts
The directory contract
Rails apps follow a predictable structure. Add directories deliberately, not casually.