The Real World Rails repository is a collection of 200+ production Rails application source code. The directory contains the full source of each app — models, migrations, schema, controllers, views, concerns, gems. The directory contains Rails engines.

Notable apps in the collection include Discourse, Mastodon, GitLab, Chatwoot, Gumroad, Spree, Solidus, Redmine, Canvas LMS, Loomio, Fat Free CRM, Locomotive CMS, Camaleon CMS, and many others. Recent additions include 37signals apps: Upright (monitoring), Fizzy (kanban), and Campfire (chat).

Look for a directory called with an subdirectory. Check the current working directory first, then . If not found, ask the user where it lives.

The user gives you a topic. Spin up parallel agents to search the apps for how real codebases implement that pattern. Read actual code — models, schemas, migrations, associations, validations, query patterns — not just file names. Synthesize what you find into a clear analysis.

If the user's wording suggests they want help choosing a pattern for their current project (words like "compare for us", "which fits best", "adversarial", "debate", "evaluate for our project"), also spin up adversarial agents that each argue for a different pattern in the context of the current project's architecture and goals.