LDS I/O uses OAuth3, so it doesn't require an LDS I/O specific module.
See LDS I/O ruby sinatra example and ruby-oauth3.
Ruby / Sinatra OAuth2 authentication strategy for connecting to lds.org thru LDS Connect
gem install ldsconnect
require "ldsconnect"
client_id = '55c7-test-bd03'
client_secret = '6b2fc4f5-test-8126-64e0-b9aa0ce9a50d'
strategy = LdsConnect.new(client_id, client_secret, options={})Apache2