gistfile1.rb

# app/models/activity.rb

class Activity < ActiveRecord::Base
  serialize :details

end

# app/controllers/deploys_controller.rb

def create
  payload = JSON.pare(params[:payload])
  Activity.create!.tap do |activity|
    activity.action  = "change deployed"
    activity.details = { :identifier => payload['identifier'], :name => payload['name'] }
    activity.user    = User.first
  end

  render :status => :created, :text => "success"
rescue ActiveRecord::RecordInvalid => e
  render :status => :unprocessible_entity, :text => "an error has occured"
end