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🆕 Update: See more extensive repo here: https://github.com/marckohlbrugge/unofficial-37signals-coding-style-guide

The Unofficial 37signals/DHH Rails Style Guide

About This Document

This style guide was generated by Claude Code through deep analysis of the Fizzy codebase - 37signals' open-source project management tool.

Why Fizzy matters: While 37signals has long advocated for "vanilla Rails" and opinionated software design, their production codebases (Basecamp, HEY, etc.) have historically been closed source. Fizzy changes that. For the first time, developers can study a real 37signals/DHH-style Rails application - not just blog posts and conference talks, but actual production code with all its patterns, trade-offs, and deliberate omissions.

@peterc
peterc / CONVENTIONS.md
Last active January 17, 2026 13:46
CONVENTIONS.md file for AI Rails 8 development
  • You MUST NOT try and generate a Rails app from scratch on your own by generating each file. For a NEW app you MUST use rails new first to generate all of the boilerplate files necessary.
  • Create an app in the current directory with rails new .
  • Use Tailwind CSS for styling. Use --css tailwind as an option on the rails new call to do this automatically.
  • Use Ruby 3.2+ and Rails 8.0+ practices.
  • Use the default Minitest approach for testing, do not use RSpec.
  • Default to using SQLite in development. rails new will do this automatically but take care if you write any custom SQL that it is SQLite compatible.
  • An app can be built with a devcontainer such as rails new myapp --devcontainer but only do this if requested directly.
  • Rails apps have a lot of directories to consider, such as app, config, db, etc.
  • Adhere to MVC conventions: singular model names (e.g., Product) map to plural tables (products); controllers are plural.
  • Guard against incapable browsers accessing controllers with `allo
@codeSTACKr
codeSTACKr / mongodb_cheat_sheet_2022.md
Created January 10, 2022 22:54
MongoDB Cheat Sheet 2022