To create a gem, minimally, you only need a .gemspec specification file. However, most gems are a combination of libraries, tests, documentation, and more. To quickly create a scaffold that includes those, we recommend using Bundler’s generator:

bundle gem GEM_NAME

This will create a directory GEM_NAME with the initial gem structure including the GEM_NAME.gemspec specification. Take a look inside – it’s just a Ruby file.

Before you can build this gem, you will need to fill out the specification fields marked with TODO.

Once it’s ready, build it with the gem command:

cd GEM_NAME
gem build GEM_NAME.gemspec

Now you have a gem that you can install locally or upload into your Gemfury account.