Rails Principles and Boundaries

Use this skill when writing or reviewing Rails application code where design principles and per-area rules matter more than stack-specific UI choices (see rails-stack-conventions for Hotwire + Tailwind).

Style source of truth: Style and formatting follow whatever linter(s) the project configures (see Linter — initial analysis below). This skill adds non-style behavior and architecture guidance only.

Linter — initial analysis

Before recommending style fixes or contradicting formatting rules:

1. Detect which linter(s) the repo uses — e.g. RuboCop (.rubocop.yml, rubocop in Gemfile), Standard Ruby (standardrb, standard gem), frontend linters (eslint.config.*, .eslintrc*, biome.json, etc.), or scripts in package.json / bin/ (lint, rubocop, standardrb).
2. Run the command the project documents or that matches the config (e.g. bundle exec rubocop, bundle exec standardrb, npm run lint). Do not assume RuboCop if the project uses Standard or another stack.

Quick Reference