gistfile1.rb

# routes.rb
...
 #API Routes
  
  namespace :api, path: '/', constraints: { subdomain: 'api' } do
    resources :venues, only: [ :index, :show ]
  end


# /controllers/api/venues_controller.rb
module API
  class VenuesController < ApplicationController
  
    def show
      venue = Venue.find(params[:id])
      # render json: venue
      respond_to do |format|
        format.json { render :json => venue }
      end
    end
  end
end