canvas-lms/app/messages/enrollment_invitation.twitter.erb

<% define_content :link do %>
  http://<%= HostUrl.context_host(asset.course) %>/<%= asset.course.class.to_s.downcase.pluralize %>/<%= asset.course_id %>?invitation=<%= asset.uuid %>
<% end %>
<%= t :body, "Canvas Alert - Invited: course as %{enrollment_type}", :enrollment_type => asset.readable_type %>