diff --git a/Gemfile b/Gemfile
index 51a4b183..c698f747 100644
--- a/Gemfile
+++ b/Gemfile
@@ -25,7 +25,7 @@ gem 'turbolinks', '~> 5'
 # Build JSON APIs with ease. Read more: https://github.com/rails/jbuilder
 gem 'jbuilder', '~> 2.5'
 # Use ActiveModel has_secure_password
-# gem 'bcrypt', '~> 3.1.7'
+gem 'bcrypt', '~> 3.1.7'
 
 # Use Capistrano for deployment
 # gem 'capistrano-rails', group: :development
diff --git a/Gemfile.lock b/Gemfile.lock
index b2bf8f7f..0c7f3e3d 100644
--- a/Gemfile.lock
+++ b/Gemfile.lock
@@ -45,6 +45,7 @@ GEM
     arel (8.0.0)
     autoprefixer-rails (9.1.4)
       execjs
+    bcrypt (3.1.12)
     bcrypt_pbkdf (1.0.0)
     bindex (0.5.0)
     bootstrap (4.0.0)
@@ -302,6 +303,7 @@ PLATFORMS
   ruby
 
 DEPENDENCIES
+  bcrypt (~> 3.1.7)
   bcrypt_pbkdf
   bootstrap (~> 4.0.0)
   capistrano
diff --git a/app/controllers/invitadxs_controller.rb b/app/controllers/invitadxs_controller.rb
new file mode 100644
index 00000000..3906c70d
--- /dev/null
+++ b/app/controllers/invitadxs_controller.rb
@@ -0,0 +1,53 @@
+class InvitadxsController < ApplicationController
+  include Pundit
+
+  def index
+    authenticate!
+
+    @site = find_site
+    @invitadxs = @site.invitadxs
+  end
+
+  def new
+    @site = Site.find(params[:site_id])
+    @has_cover = true
+    @invitadx = Invitadx.new
+  end
+
+  def create
+    @site = Site.find(params[:invitadx][:site])
+    @invitadx = Invitadx.new(invitadx_params)
+    @invitadx.confirmation_token = SecureRandom.hex(16)
+    @invitadx.sites << @site
+
+    if @invitadx.save
+      InvitadxMailer.with(site: @site, invitadx: @invitadx).confirmation_required.deliver
+      redirect_to invitadx_path(@invitadx)
+    else
+      render 'new'
+    end
+  end
+
+  def show
+    @has_cover = true
+    @invitadx = Invitadx.find(params[:id])
+  end
+
+  def confirmation
+    @invitadx = Invitadx.find(params[:invitadx_id])
+    @site = @invitadx.sites.find do |site|
+      site.id == params[:site_id]
+    end
+
+    if @invitadx.confirmation_token = params[:confirmation_token]
+      @invitadx.update_attribute :confirmed, true
+      redirect_to site_
+    end
+  end
+
+  private
+
+  def invitadx_params
+    params.require(:invitadx).permit(:email, :password, :password_confirmation)
+  end
+end
diff --git a/app/mailers/invitadx_mailer.rb b/app/mailers/invitadx_mailer.rb
new file mode 100644
index 00000000..45adb104
--- /dev/null
+++ b/app/mailers/invitadx_mailer.rb
@@ -0,0 +1,7 @@
+class InvitadxMailer < ApplicationMailer
+  def confirmation_required
+    @invitadx = params[:invitadx]
+    @site = params[:site]
+    mail to: @invitadx.email, subject: t('.subject')
+  end
+end
diff --git a/app/models/invitadx.rb b/app/models/invitadx.rb
new file mode 100644
index 00000000..714df737
--- /dev/null
+++ b/app/models/invitadx.rb
@@ -0,0 +1,76 @@
+class Invitadx < ApplicationRecord
+  has_secure_password
+  validates_uniqueness_of :email
+
+  after_create :create_invitadx_directory!
+  after_save :add_sites!
+
+  # Para facilitar la serialización de Warden
+  def username
+    email
+  end
+
+  def path
+    File.join(Rails.root, '_invitadxs', email)
+  end
+
+  # TODO convertir el Pathname en un helper
+  def site_dirs
+    return [] unless Dir.exists? path
+    Pathname.new(path).children.map(&:expand_path).map(&:to_s)
+  end
+
+  def sites
+    @sites ||= site_dirs.map do |site|
+      Site.find(File.basename(site))
+    end.compact
+  end
+
+  private
+
+  # Crea el directorio en _sites
+  def create_invitadx_directory!
+    FileUtils.mkdir_p(path)
+  end
+
+  # Agrega el sitio a las invitadxs y viceversa
+  def add_sites!
+    sites.each do |site|
+      dir  = File.join(path, site.name)
+      file = site.invitadxs_file
+
+      unless File.exists? dir
+        FileUtils.ln_s File.join('..', '..', '_sites', site.name), dir
+      end
+
+      if File.exists? file
+        invitadxs = File.read(file).split("\n")
+        invitadxs_orig = invitadxs.dup
+        invitadxs << email unless invitadxs.include? email
+      else
+        invitadxs_orig = []
+        invitadxs = [email]
+      end
+
+      # Solo escribir los cambios si hubo cambios en la lista
+      return if invitadxs_orig == invitadxs
+
+      r = File.open(file, File::RDWR | File::CREAT, 0o640) do |f|
+        # Bloquear el archivo para que no sea accedido por otro
+        # proceso u otra editora
+        f.flock(File::LOCK_EX)
+
+        # Empezar por el principio
+        f.rewind
+
+        # Escribir la fecha de creación
+        f.write(invitadxs.join("\n"))
+
+        # Eliminar el resto
+        f.flush
+        f.truncate(f.pos)
+      end
+
+    end
+  end
+end
diff --git a/app/models/site.rb b/app/models/site.rb
index 70abc621..ce0a7c43 100644
--- a/app/models/site.rb
+++ b/app/models/site.rb
@@ -11,6 +11,15 @@ class Site
     @collections = {}
   end
 
+  # Este sitio acepta invitadxs?
+  def invitadxs?
+    jekyll.config.fetch('invitadxs', false)
+  end
+
+  def cover
+    "/covers/#{name}.png"
+  end
+
   # Determina si el sitio está en varios idiomas
   def i18n?
     !translations.empty?
@@ -173,6 +182,16 @@ class Site
     end
   end
 
+  def invitadxs_file
+    File.join(path, '.invitadxs')
+  end
+
+  def invitadxs
+    @invitadxs ||= File.read(invitadxs_file).split("\n").map do |i|
+      Invitadx.find_by_email(i)
+    end
+  end
+
   def failed_file
     File.join(path, '.failed')
   end
diff --git a/app/views/invitadx_mailer/confirmation_required.html.haml b/app/views/invitadx_mailer/confirmation_required.html.haml
new file mode 100644
index 00000000..78764d85
--- /dev/null
+++ b/app/views/invitadx_mailer/confirmation_required.html.haml
@@ -0,0 +1,5 @@
+%h1= t('.hi')
+
+%p= t('.body')
+
+%code= site_invitadx_confirmation_url(@site, @invitadx, confirmation_token: @invitadx.confirmation_token)
diff --git a/app/views/invitadx_mailer/confirmation_required.txt.haml b/app/views/invitadx_mailer/confirmation_required.txt.haml
new file mode 100644
index 00000000..c082b77a
--- /dev/null
+++ b/app/views/invitadx_mailer/confirmation_required.txt.haml
@@ -0,0 +1,5 @@
+= t('.hi')
+
+= t('.body')
+
+= site_invitadx_confirmation_url(@site, @invitadx, confirmation_token: @invitadx.confirmation_token)
diff --git a/app/views/invitadxs/index.haml b/app/views/invitadxs/index.haml
new file mode 100644
index 00000000..3fc782cc
--- /dev/null
+++ b/app/views/invitadxs/index.haml
@@ -0,0 +1,13 @@
+.row
+  .col
+    = render 'layouts/breadcrumb', crumbs: [ t('sites.index'), t('.title') ]
+.row
+  .col
+    %h1= t('.title')
+
+    %table.table.table-striped.table-condensed
+      %tbody
+        - @invitadxs.each do |invitadx|
+          %tr
+            %td= invitadx.email
+            %td= invitadx.created_at
diff --git a/app/views/invitadxs/new.haml b/app/views/invitadxs/new.haml
new file mode 100644
index 00000000..4399f059
--- /dev/null
+++ b/app/views/invitadxs/new.haml
@@ -0,0 +1,31 @@
+.row.align-items-center.justify-content-center.full-height
+  .col-md-6.align-self-center
+    - if @invitadx.errors.full_messages.empty?
+      .alert.alert-dismissible.alert-info.fade.show{role: 'alert'}
+        = @site.config.dig('welcome', 'message') || t('.welcome')
+        %button.close{type: 'button',
+          data: { dismiss: 'alert' },
+          'aria-label': t('help.close') }
+          %span{'aria-hidden': true} &times;
+    - else
+      .alert.alert-dismissible.alert-info.fade.show{role: 'alert'}
+        %ul
+          - @invitadx.errors.full_messages.each do |message|
+            %li= message
+        %button.close{type: 'button',
+          data: { dismiss: 'alert' },
+          'aria-label': t('help.close') }
+          %span{'aria-hidden': true} &times;
+
+    = form_for @invitadx do |f|
+      = f.hidden_field :site, value: @site.id
+      .form-group
+        = f.email_field :email, class: 'form-control', placeholder: t('.email')
+      .form-group
+        = f.password_field :password, class: 'form-control', placeholder: t('.password')
+      .form-group
+        = f.password_field :password_confirmation, class: 'form-control', placeholder: t('.password_confirmation')
+
+      .form-group
+        - button = @site.config.dig('welcome', 'button')
+        = f.submit t('.submit'), class: 'btn btn-lg btn-primary btn-block', style: (button) ? "background-color: #{button};" : ''
diff --git a/app/views/invitadxs/show.haml b/app/views/invitadxs/show.haml
new file mode 100644
index 00000000..7a01aac8
--- /dev/null
+++ b/app/views/invitadxs/show.haml
@@ -0,0 +1,3 @@
+.row.align-items-center.justify-content-center.full-height
+  .col-md-6.align-self-center
+    = t('.confirmation_sent')
diff --git a/app/views/layouts/application.html.haml b/app/views/layouts/application.html.haml
index 36982cf4..9d730b6a 100644
--- a/app/views/layouts/application.html.haml
+++ b/app/views/layouts/application.html.haml
@@ -6,7 +6,7 @@
     = csrf_meta_tags
     = stylesheet_link_tag 'application', media: 'all', 'data-turbolinks-track': 'reload'
     = javascript_include_tag 'application', 'data-turbolinks-track': 'reload'
-  %body{class: @has_cover ? 'background-cover' : ''}
+  %body{class: @has_cover ? 'background-cover' : '', style: @has_cover ? "background-image: url(#{@site.try(:cover)})": ''}
     .container-fluid
       = yield
     %footer.footer
diff --git a/app/views/layouts/mailer.html.haml b/app/views/layouts/mailer.html.haml
new file mode 100644
index 00000000..5ef091a7
--- /dev/null
+++ b/app/views/layouts/mailer.html.haml
@@ -0,0 +1,3 @@
+%html
+  %body
+    = yield
diff --git a/app/views/layouts/mailer.text.haml b/app/views/layouts/mailer.text.haml
new file mode 100644
index 00000000..0a90f092
--- /dev/null
+++ b/app/views/layouts/mailer.text.haml
@@ -0,0 +1 @@
+= yield
diff --git a/config/initializers/inflections.rb b/config/initializers/inflections.rb
index ac033bf9..d5cf5d86 100644
--- a/config/initializers/inflections.rb
+++ b/config/initializers/inflections.rb
@@ -1,16 +1,9 @@
-# Be sure to restart your server when you modify this file.
+ActiveSupport::Inflector.inflections(:en) do |inflect|
+  inflect.plural 'invitadx', 'invitadxs'
+  inflect.singular 'invitadxs', 'invitadx'
+end
 
-# Add new inflection rules using the following format. Inflections
-# are locale specific, and you may define rules for as many different
-# locales as you wish. All of these examples are active by default:
-# ActiveSupport::Inflector.inflections(:en) do |inflect|
-#   inflect.plural /^(ox)$/i, '\1en'
-#   inflect.singular /^(ox)en/i, '\1'
-#   inflect.irregular 'person', 'people'
-#   inflect.uncountable %w( fish sheep )
-# end
-
-# These inflection rules are supported but not enabled by default:
-# ActiveSupport::Inflector.inflections(:en) do |inflect|
-#   inflect.acronym 'RESTful'
-# end
+ActiveSupport::Inflector.inflections(:es) do |inflect|
+  inflect.plural 'invitadx', 'invitadxs'
+  inflect.singular 'invitadxs', 'invitadx'
+end
diff --git a/config/initializers/warden.rb b/config/initializers/warden.rb
index c750b089..aec9a8b0 100644
--- a/config/initializers/warden.rb
+++ b/config/initializers/warden.rb
@@ -1,7 +1,8 @@
 require 'warden/imap'
+require 'warden/email_and_password'
 
 Rails.configuration.middleware.use RailsWarden::Manager do |manager|
-  manager.default_strategies :imap
+  manager.default_strategies :email, :imap
   manager.failure_app = -> (env) { LoginController.action(:new).call(env) }
 end
 
@@ -11,8 +12,9 @@ class Warden::SessionSerializer
   end
 
   def deserialize(keys)
-    Usuaria.find(keys.first)
+    Invitadx.find_by_email(keys.first) || Usuaria.find(keys.first)
   end
 end
 
 Warden::Strategies.add(:imap, Warden::IMAP::Strategy)
+Warden::Strategies.add(:email, Warden::EmailAndPassword::Strategy)
diff --git a/config/locales/en.yml b/config/locales/en.yml
index 9eb0d3f5..9bcfec0c 100644
--- a/config/locales/en.yml
+++ b/config/locales/en.yml
@@ -1,4 +1,13 @@
 en:
+  activerecord:
+    errors:
+      models:
+        invitadx:
+          attributes:
+            email:
+              taken: 'This e-mail address is already taken, please choose another'
+            password_confirmation:
+              confirmation: The passwords don't match
   errors:
     argument_error: 'Argument `%{argument}` must be an instance of %{class}'
     unknown_locale: 'Unknown %{locale} locale'
@@ -6,6 +15,14 @@ en:
       reorder: "We're sorry, we couldn't reorder the articles"
       disordered: "The posts are disordered, this will prevent you from reordering them!"
       disordered_button: 'Reorder!'
+  invitadxs:
+    index:
+      title: Guests
+    new:
+      email: E-Mail
+      password: Password
+      password_confirmation: Repeat password
+      submit: Register
   info:
     posts:
       reorder: "The articles have been reordered!"
diff --git a/config/locales/es.yml b/config/locales/es.yml
index a31f0084..aba594a2 100644
--- a/config/locales/es.yml
+++ b/config/locales/es.yml
@@ -1,4 +1,13 @@
 es:
+  activerecord:
+    errors:
+      models:
+        invitadx:
+          attributes:
+            email:
+              taken: 'Esa cuenta ya está tomada, por favor elige otra.'
+            password_confirmation:
+              confirmation: Las contraseñas no coinciden
   errors:
     argument_error: 'El argumento `%{argument}` debe ser una instancia de %{class}'
     unknown_locale: 'El idioma %{locale} es desconocido'
@@ -6,6 +15,14 @@ es:
       reorder: "Lo sentimos, no pudimos reordenar los artículos."
       disordered: 'Los artículos no tienen número de orden, esto impedirá que los puedas reordenar'
       disordered_button: '¡Reordenar!'
+  invitadxs:
+    index:
+      title: Invitadxs
+    new:
+      email: Correo electrónico
+      password: Contraseña
+      password_confirmation: Repite la contraseña
+      submit: Registrarme
   info:
     posts:
       reorder: "¡Los artículos fueron reordenados!"
diff --git a/config/routes.rb b/config/routes.rb
index 3792d851..af6d6e64 100644
--- a/config/routes.rb
+++ b/config/routes.rb
@@ -9,9 +9,15 @@ Rails.application.routes.draw do
 
   get '/sites/:site_id/public/:type/:basename', to: 'sites#send_public_file'
 
+  resources :invitadxs, only: [:create, :show] do
+  end
+
   resources :sites, only: [:index, :show], constraints: { site_id: /[^\/]+/, id: /[^\/]+/ } do
     resources :posts
     resources :templates
+    resources :invitadxs, only: [:index, :new] do
+      get :confirmation, to: 'invitadxs#confirmation'
+    end
 
     get 'i18n', to: 'i18n#index'
     get 'i18n/edit', to: 'i18n#edit'
diff --git a/db/migrate/20180925183241_create_invitadxs.rb b/db/migrate/20180925183241_create_invitadxs.rb
new file mode 100644
index 00000000..7fafd54b
--- /dev/null
+++ b/db/migrate/20180925183241_create_invitadxs.rb
@@ -0,0 +1,11 @@
+class CreateInvitadxs < ActiveRecord::Migration[5.1]
+  def change
+    create_table :invitadxs do |t|
+      t.timestamps
+      t.string :password_digest
+      t.string :email, unique: true, index: true
+      t.string :confirmation_token
+      t.boolean :confirmed
+    end
+  end
+end
diff --git a/doc/invitadxs.md b/doc/invitadxs.md
new file mode 100644
index 00000000..11032a53
--- /dev/null
+++ b/doc/invitadxs.md
@@ -0,0 +1,53 @@
+# Gestión de usuarixs invitadxs
+
+Lxs usuarixs invitadxs solo tienen cuenta en Sutty, no comparten cuenta
+con el resto del sistema (Sutty está integrada a otras cuentas vía
+IMAP).
+
+Pueden cambiar su contraseña y recuperarla.
+
+Cuando se loguean, solo pueden ver sus artículos y editarlos.  También
+pueden crear nuevos.
+
+Cuando crean un artículo o cuando lo editan, los artículos pasan a
+estado borrador.  Solo las usuarias de Sutty pueden revisar el artículo
+y publicarlo.
+
+Cada invitadx está asociadx a uno o más sitios.
+
+
+## Idea
+
+Que cada sitio gestione sus propias cuentas usando un archivo en formato
+`/etc/passwd` (ver `man 5 passwd`).
+
+Con esto habría portabilidad de cuentas junto con los sitios, pero sería
+un problema para poder gestionar varios sitios con cuentas compartidas.
+
+## Temporal
+
+Usar `devise` con una base de datos SQLite.  La idea es descartarla más
+adelante y tener un `passwd` + `shadow` de Sutty.  Sino vamos a empezar
+a poner cosas en una base de datos y no es la idea...
+
+**No se puede usar devise porque toma el control de toda la gestión de
+usuarias.**
+
+## Implementación
+
+Para poder separar la autenticación de usuarias de invitadxs, cada
+controlador tiene su propio `namespace`, de forma que no se crucen
+funcionalidades.
+
+Lxs invitadxs se almacenan con email y contraseña en una base de datos
+SQLite3.
+
+La pertenencia a un sitio se almacena en el archivo `.invitadxs` de cada
+sitio (como `.usuarias`).
+
+Además, se vincula el sitio al directorio de invitadx para poder tener
+acceso a varios sitios.
+
+El directorio de lx invitadx es `_invitadxs/direccion@mail`.
+
+El registro de cuentas se hace en base al sitio.
diff --git a/lib/warden/email_and_password.rb b/lib/warden/email_and_password.rb
new file mode 100644
index 00000000..8f05f00a
--- /dev/null
+++ b/lib/warden/email_and_password.rb
@@ -0,0 +1,32 @@
+require 'email_address'
+module Warden
+  module EmailAndPassword
+
+    class Strategy < Warden::Strategies::Base
+      def valid?
+        return false unless params.include? 'username'
+        return false unless params.include? 'password'
+        username = params['username']
+        @email = EmailAddress.new(username, host_validation: :a)
+
+        Rails.logger.error [username, @email.error].join(': ') unless @email.valid?
+
+        @email.valid?
+      end
+
+      # Autentica a una posible invitadx, no fallamos para que haya
+      # fallback con IMAP
+      def authenticate!
+        u = Invitadx.find_by_email(params['username'])
+
+        if u.try(:authenticate, params['password'])
+          if u.confirmed?
+            success! u
+          else
+            fail! 'unconfirmed'
+          end
+        end
+      end
+    end
+  end
+end
diff --git a/public/covers/.keep b/public/covers/.keep
new file mode 100644
index 00000000..e69de29b