I'm using Devise on my application and would like to create a global API key that can access JSON data of anyone's account without having to log-in.

For example, say my API Key is 1234 and I have two users who have created two different restaurants.

• User 1 - Restaurant 1 (/restaurants/1)
• User 2 - Restaurant 2 (/restaurants/2)

And I open a brand new browser and haven't logged into anything and I pass into my URL .../restaurants/2.json?api_key=1234, I should be able to access the JSON data of that restaurant without having to log-in as User 2

Whats the best way to do this?

I've followed the Railscast #352 Securing an API so I'm able to access JSON stuff by passing in the API key but I have to log-in to see anything.

Edit 1: Using CanCan

I should mention that I'm also using CanCan for roles but not sure if that'll play any role (pun not intended) in this situation.

Edit 2: Implimenting with API Versioning

I followed the Railscast #350 and #352 which teach you how to create REST API Versioning and how to secure it with an API Key.

Here's what my controllers/api/v1/restaurants/restaurants_controller.rb looks like:

module Api
  module V1
    class RestaurantsController < ApplicationController
      before_filter :restrict_access

      respond_to :json

      def index
        respond_with Restaurant.all
      end

      def show
        respond_with Restaurant.find(params[:id])
      end

    private

      def restrict_access
        api_key = ApiKey.find_by_access_token(params[:api_key])
        head :unauthorized unless api_key        
      end
    end
  end
end

And my application_controller.rb still has the before_filter :authenticate_user! code in it.

Solution

I first followed the Railscast #350 on REST API Versioning and moved all my JSON API calls to /apps/api/v1/...

Then, following Steve Jorgensen's solution below, made sure my API module inherited from ActionController::Base instead of ApplicationController so that it bypassed Devise's before_filter :authenticate_user! code within the ApplicationController.

So, my Edit 2 code when from looking like this:

module Api
  module V1
    class RestaurantsController < ApplicationController
    ...

to

module Api
  module V1
    #Replace 'ApplicationController' with 'ActionController::Base'
    class RestaurantsController < ActionController::Base
    ...