As a newbie to rails I can't find how to solve my issue ^^ I want to create a VideoPost from a form with a text field containing a video url (like youtube) I'm getting information on the video thanks to the gem https://github.com/thibaudgg/video_info And I want to save thoses information using a model of mine (VideoInformation). But I don't know how the create process should work. Thanks for any help ! I'm trying to create a VideoPost in VideoPostsController like this : def create video_info = VideoInfo.new(params[:video_url]) video_information = VideoInformation.create(video_info) #undefined method `stringify_keys' for #<Youtube:0x00000006a24120> if video_information.save @video_post = current_user.video_posts.build(video_information) end end My VideoPost model : # Table name: video_posts # # id :integer not null, primary key # user_id :integer # video_information_id :integer # created_at :datetime not null # updated_at :datetime not null My VideoInformation model (which got same attributes name than VideoInfo gem) : # Table name: video_informations # # id :integer not null, primary key # title :string(255) # description :text # keywords :text # duration :integer # video_url :string(255) # thumbnail_small :string(255) # thumbnail_large :string(255) # created_at :datetime not null # updated_at :datetime not null