Securing the API

To protect your controllers (usual one or ActionController::API) with OAuth, you just need to setup before_actions specifying the actions you want to protect. For example:

class Api::V1::ProductsController < Api::V1::ApiController
before_action :doorkeeper_authorize! # Requires access token for all actions
# before_action -> { doorkeeper_authorize! :read, :write }
# your actions

You can pass any option before_action accepts, such as if, only, except, and others.

Authenticated resource owner

If you want to return data based on the current resource owner, in other words, the access token owner, you may want to define a method in your controller that returns the resource owner instance:

class Api::V1::CredentialsController < Api::V1::ApiController
before_action :doorkeeper_authorize!
respond_to :json
# GET /me.json
def me
respond_with current_resource_owner
# Find the user that owns the access token
def current_resource_owner
User.find(doorkeeper_token.resource_owner_id) if doorkeeper_token

In this example, we're returning the credentials (me.json) of the access token owner.