This gem contains the Yelp strategy for OmniAuth.
Yelp uses the OAuth2 flow, you can read about it here: http://www.yelp.com/developers/documentation/v2/authentication
So let's say you're using Rails, you need to add the strategy to your Gemfile:
gem 'omniauth-yelp'
Once these are in, you need to add the following to your config/initializers/omniauth.rb:
Rails.application.config.middleware.use OmniAuth::Builder do
provider :yelp, "consumer_key", "consumer_secret"
end
You will obviously have to put in your key and secret, which you get when you register your app with Foursquare (they call them API Key and Secret Key).
Now just follow the README at: https://github.com/intridea/omniauth
OmniAuth Yelp is tested under 1.9