In this gem you will find an OmniAuth eBay strategy that is compliant with the Open eBay Apps API. You can read all about it here: Open eBay Apps Developers Zone

Note: The examples are for a Rails 3 app.

• Add our gem to your Gemfile:

gem 'omniauth-ebay'

• Add to your omniauth initializer (config/initializers/omniauth.rb) the ebay strategy like so:

    Rails.application.config.middleware.use OmniAuth::Builder do
       provider :ebay, "runame", "devid", "appid", "certid", "siteid", "environment", "auth_type"
    end

Insert your app credentials in the given order. You can find out these details by going into your developer's account at eBay DevZone

environment - Defaults to :production and other valid option is :sandbox

auth_type - An optional argument when initializing the strategy, by default it's configured to SSO(SingleSignOn), and should be changed to AuthType::Simple (SignIn), as it's the standard option.

• To use the strategy, you will need to access it's omniauth provider path: /auth/ebay. The callback phase path is the default one: /auth/ebay/callback. You will need to define the callback path in your relevant app RUname, so don't forget to set the accept/reject paths in the devzone to the callback path.

• Set a route to the callback path of your sessions controller, and handle the session creation there. You will be able to access the omniauth session data by accessing request.env['omniauth.auth']

Ruby 1.8.7+, Rails 3.0+, OmniAuth 1.0+.

The ebay strategy module uses the standard omniauth strategy module, and it also uses a small module designed just for the eBay API calls.

• API call to eBay, requesting a session id.
• Redirecting to eBay login with the session id.

• API call to eBay, requesting an ebay auth token, with the secret id and username retrieved from the request.
• API call to eBay, requesting the user's info by using the ebay auth token from the last call.
• The strategy's UID is the eBay EIAS Token. Also these fields will also be exposed by accessing request.env['omniauth.auth'].info:

ebay_id - The user's eBay username.

ebay_token - The current session's auth token, to be used for API calls.

email - The user's email address.

full_name - The user's registered full name.

country - The user's registered country.

• Extra data - We're also passing an optional parameter, return_to, which allows you to specify a URL you want the redirect the user to when the authentication process is completed.