The first step is to install Ruby. I use rvm and take advantage of gemsets also.

% rvm install ruby-3.0.2
% rvm list
=> ruby-3.0.2 [ x86_64 ]

# => - current
# =* - current && default
#  * - default

Then create a gemset for Rails 7.

% rvm gemset create rails7

Install Postgres 14 using Homebrew.

% brew install postgresql

Install the latest Ruby on Rails.

% gem install rails
Fetching concurrent-ruby-1.1.10.gem
Fetching activesupport-7.0.3.gem
...
Successfully installed rails-7.0.3
...
15 gems installed

Create a new application. Make sure to do this in the folder above where we cloned our GitHub repository. Also specify that TailwindCSS and Postgres are being used.

% cd ..
% rails new catalogue_cleanser --css tailwind --database=postgresql

Install all of the required gems that come with an initial Rails application.

% cd catalogue_cleanser
% rvm gemset use rails7
% bundle install

We can now commit this to git and push it to our repository as the initial state.

% git add .
% git commit -am "Rails 7 with Tailwind and Postgres Initial"
% git push origin main

Useful links:

Installing Homebrew

Installing rvm

Installing Postgresql

Rails Getting Started

Creating a Rails 7 App with Tailwind