Dinh Ngoc Hien hiendinhngoc

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.

How this was created: Claude Code analyzed the entire codebase - routes, controllers, models, concerns, views, JavaScript, CSS, tests, and configuration. The goal was to extract not just what patterns are used, but why - inferring philosophy from implementation choices.

Claude Linux System Configuration Assistant

System Context

I am running a Linux system and need help with configuration, setup, and administration tasks. Please assist me following Linux best practices and respecting system defaults.

Current System Information

Distribution: Omarchy Linux (Arch-based)
Window Manager: Hyprland
Home Directory: /home/jorge
Working Directory: Check with pwd before making assumptions

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

JWT Auth + Refresh Tokens in Rails

This is just some code I recently used in my development application in order to add token-based authentication for my api-only rails app. The api-client was to be consumed by a mobile application, so I needed an authentication solution that would keep the user logged in indefinetly and the only way to do this was either using refresh tokens or sliding sessions.

I also needed a way to both blacklist and whitelist tokens based on a unique identifier (jti)

Before trying it out DIY, I considered using:

1. Clone your fork:

git clone [email protected]:YOUR-USERNAME/YOUR-FORKED-REPO.git

2. Add remote from original repository in your forked repository:

cd into/cloned/fork-repo
git remote add upstream git://github.com/ORIGINAL-DEV-USERNAME/REPO-YOU-FORKED-FROM.git
git fetch upstream

	#!/bin/bash
	# Script to update a firewall rule in a Hetzner Firewall with your current IP address.
	# Good if you would like to restrict SSH access only for your current IP address (secure).

	#################
	# WARNING: This script will overwrite all rules in the firewall rules, so make sure you
	# added all the required rules.
	# I use a separate firewall rule just for SSH access.
	#################

	#!/bin/bash

	# Production Docker Host Hardening Script v2
	# For Ubuntu Server 24.04 LTS (Noble)
	# Suitable for both Kamal deployment and builder hosts

	set -euo pipefail
	IFS=$'\n\t'

	# --- Constants ---