Devise is my preferred gem for introducing user authentication into a Rails project. In Rails 3, it’s easy to install but if you attempt to run the devise:install generator, you may receive this message:

Could not find generator devise:install

Edit: Stib left a comment about the change to the generator. The original content for this post is below.

Rails doesn’t recognize that the gem is needed so it doesn’t load it.¬†Simply add the following line to your Gemfile (assuming 1.3.4 is your working version):

gem 'devise', '1.3.4'

You can check out more information on GitHub or