37signals-skills

Why we included this project

Rails developers who use AI coding assistants and are tired of getting generic, gem-heavy suggestions will find a practical fix here. The repo packages the conventions 37signals actually follows, rich domain models over service objects, state as records, fixtures over factories, and vanilla Rails over gems, into SKILL.md files you can drop into Claude Code or Cursor. A core skill runs automatically on every request, while focused skills for Hotwire, background jobs, migrations, security, testing, and webhooks load only when you invoke them, so they don't weigh down each prompt. There's also a reference guide built from 100+ of DHH's code reviews and the Fizzy and Campfire codebases, worth reading even if you never install the skills. Just keep in mind this is an unofficial community project, not affiliated with 37signals, so treat the guidance as opinionated defaults to verify rather than gospel.