Format javascript variable to be used by Rails -

i sending post request rails server.

the server executing code :

list.create!(params[:list])

here javascript (coffeescript) call :

createlist: (list) ->   $$.post 'http://localhost:3000/lists.json', data, null, 'json'

i trying pass data formatted in way rails able read it. tried creating var params = { "list":list }, error

nomethoderror (undefined method `stringify_keys' "[object object]":string)

how can correctly format data passed rails?

createlist: (list) ->   $$.post 'http://localhost:3000/lists.json', json.stringify(data), null, 'json'

Live