## Passing Arbitrary Options to A Serializer Let's say you have a basic Post Controller: ``` class PostController < ApplicationController def dashboard render json: @posts end end ``` Odds are, your serializer will look something like this: ``` class PostSerializer < ActiveModel::Serializer attributes :id, :title, :body end ``` This works all fine and well, but maybe you passing in some "artibrary" options into the serializer. Here's what you would do: ### posts_controller.rb ``` ... def dashboard render json: @posts, user_id: 12 end ... ``` ### posts_serializer.rb ``` ... def comments_by_me Comments.where(user_id: instance_options[:user_id], post_id: object.id) end ... ``` These options can be anything that isn't already reserved for use by AMS. For example, you won't be able to pass in a `meta` or `root` option like the example above. Those parameters are reserved for specific behavior within the app.