ruby on rails - Params not defined -

i'm doing api application, have post route:

{     "user_id":"1" } 

this route calls method of controller:

def shouts   puts(params)   @user = user.find_by_id(params[:user_id])   render json: {status: 0, message: "sucess", data: @user.yells} end 

what happens when test postman on machine runs smoothly. , possible accompany puts terminal:

started post "/api/shouts" 10.0.2.2 @ 2016-01-27 16:11:16 +0000 cannot render console 10.0.2.2! allowed networks: 127.0.0.1, ::1, 127.0.0.0/127.255.255.255 processing api::yellscontroller#shouts */*   parameters: {"user_id"=>"1", "yell"=>{"user_id"=>"1"}} {"user_id"=>"1", "controller"=>"api/yells", "action"=>"shouts", "yell"=>{"user_id"=>"1"}}   user load (0.3ms)  select  "users".* "users" "users"."id" = $1 limit 1  [["id", 1]]   yell load (0.5ms)  select "yells".* "yells" "yells"."user_id" = $1  [["user_id", 1]]   category load (0.4ms)  select "categories".* "categories" inner join "categories_yells" on "categories"."id" = "categories_yells"."category_id" "categories_yells"."yell_id" = $1  [["yell_id", 1]] completed 200 ok  

however when testo on machine within same network, stop comes nothing, or coming:

started post "/api/shouts" 10.0.2.2 @ 2016-01-27 16:09:04 +0000 cannot render console 10.0.2.2! allowed networks: 127.0.0.1, ::1, 127.0.0.0/127.255.255.255 processing api::yellscontroller#shouts */* {"controller"=>"api/yells", "action"=>"shouts"}   user load (0.3ms)  select  "users".* "users" "users"."id" null limit 1 completed 500 

anyone know can happening? how fix? it's have set in vagrant machine? or on server? or ruby on rails?

update

i discovered wrong in call on postman forgetting put on content-type header = aplicatio / json.

is there way of pre configure in ruby on rails? put calls have same header.

you can add in application controller:

before_filter :set_format  def set_format   request.format = 'json' # or whatever want end 

or in routes.rb

resources :shouts, defaults: { format: 'json' }