unable to sign up with json devise

Here's what we use (check it at http://firststopcosmeticshop.co.uk -- "register" @ top)

 class RegistrationsController < DeviseController  prepend_before_filter :require_no_authentication, :only => [ :new, :create, :cancel ]  prepend_before_filter :authenticate_scope!, :only => [:edit, :update, :destroy]  before_filter :configure_permitted_parameters  prepend_view_path 'app/views/devise'  # GET /resource/sign_up  def new    build_resource({})    respond_with self.resource  end  # POST /resource  def create    build_resource(sign_up_params)    if resource.save      if resource.active_for_authentication?        set_flash_message :notice, :signed_up if is_navigational_format?        sign_up(resource_name, resource)        respond_with resource, :location => after_sign_up_path_for(resource)      else        set_flash_message :notice, :"signed_up_but_#{resource.inactive_message}" if is_navigational_format?        expire_session_data_after_sign_in!        respond_with resource, :location => after_inactive_sign_up_path_for(resource)      end    else      clean_up_passwords resource      respond_to do |format|        format.json { render :json => resource.errors, :status => :unprocessable_entity }        format.html { respond_with resource }      end    end  end  ....

Paths

I think your error is from your devise paths (trying to send a POST request to /sign_up). You can see the method should be create here:

sign_up (Devise::RegistrationsController#create) - Permits authentication keys plus password and password_confirmation

Why don't you try this in your config/routes.rb file:

devise_for :users, controllers: { sessions: "sessions", registrations: "registrations"}, path_names: { sign_in: 'sign_in', password: 'forgot', confirmation: 'confirm', unlock: 'unblock', sign_up: 'sign_up', sign_out: 'logout'}

If we run rake routes we can see that devise sign up (registration) has [new, create, update, ..]

cancel_user_registration GET    /users/cancel(.:format)                 devise/registrations#cancel   new_user_registration GET    /users/sign_up(.:format)                devise/registrations#new  edit_user_registration GET    /users/edit(.:format)                   devise/registrations#edit       user_registration PATCH  /users(.:format)                        devise/registrations#update                         PUT    /users(.:format)                        devise/registrations#update                         DELETE /users(.:format)                        devise/registrations#destroy                         POST   /users(.:format)                        devise/registrations#create

So, the route #new shows only the sign up page and to register new user we use #create and it's correct route: /users.json not /user/sign_up.json

As we can see here:

POST   /users(.:format)                        devise/registrations#create

Here's sign_up page inspect on browser, we can see action = "/users"

routes of devise registration

try these code ,I do it with my rails api

 devise_scope :user do    post 'users' => 'registrations#create', :as => 'user_registration'  end curl: //your-domain:3000/users --data "email=jump@gmail.com&password=123456789&password_confirmation=123456789"