how to scope the /auth/:provider/callback , using OmniAuth for users and members

I have two separate groups of people authenticated w Devise , but in this case I cannot used the Devise embedded OmniAuth support. So i am using directly the OmniAuth gem.

Initialized w : Rails.configuration.middleware.use OmniAuth::Builder do ..provider :twitter, .. end

It's running fine , but I have an issue with the callback route mapping :

I tried     match '/users/auth/:provider/callback', to: 'users/ omniauth_callbacks#create'     match '/members/auth/:provider/callback', to: 'members/ omniauth_callbacks#create' but the provider ( fb , twitter, google) claimebd about the callback uri : "/auth/:provider/callback" .. as the path_prefix (:path_prefix => "/auth" ) is set in the initializer , I have no mean to modify it dynamically...

any clue ? or feedback from previous experiences...

thanks

[SOLVED] maybe not the best way, but it runs .. using only one callback url, I can test the request.env["omniauth.origin"] which can be tested :

"http://lvh.me:3000/en/users/sign_in" or "http://acme.lvh.me:3000/en/members/sign_in" ( in this cas I can even test for current_subdomain.nil?