diff --git a/app/controllers/application_controller.rb b/app/controllers/application_controller.rb
index 117be995..0fc2440f 100644
--- a/app/controllers/application_controller.rb
+++ b/app/controllers/application_controller.rb
@@ -2,7 +2,7 @@
 
 # Forma de ingreso a Sutty
 class ApplicationController < ActionController::Base
-  include ExceptionHandler
+  include ExceptionHandler if Rails.env.production?
   include Pundit::Authorization
 
   protect_from_forgery with: :null_session, prepend: true
@@ -117,4 +117,9 @@ class ApplicationController < ActionController::Base
 
     session[:usuarie_return_to] = request.fullpath
   end
+
+  # Detecta si una petición fue hecha por HTMX
+  def htmx?
+    request.headers.key? 'HX-Request'
+  end
 end
diff --git a/app/controllers/posts_controller.rb b/app/controllers/posts_controller.rb
index f241dfb1..ff3ecb8e 100644
--- a/app/controllers/posts_controller.rb
+++ b/app/controllers/posts_controller.rb
@@ -32,6 +32,33 @@ class PostsController < ApplicationController
     render layout: false
   end
 
+  def new_related_post
+    @uuid = params.require(:value).strip
+
+    @indexed_post = site.indexed_posts.find_by!(post_id: @uuid)
+
+    render layout: false
+  end
+
+  # El formulario de un Post, si pasamos el uuid, estamos editando, sino
+  # estamos creando.
+  def form
+    uuid = params.permit(:uuid).try(:[], :uuid)
+    locale
+
+    @post =
+      if uuid.present?
+        site.indexed_posts.find_by!(post_id: uuid).post
+      else
+        # @todo Usar la base de datos
+        site.posts(lang: locale).build(layout: params.require(:layout))
+      end
+
+    swap_modals
+
+    render layout: false
+  end
+
   def index
     authorize Post
 
@@ -87,7 +114,23 @@ class PostsController < ApplicationController
     if @post.persisted?
       site.touch
       forget_content
+    end
 
+    # @todo Enviar la creación a otro endpoint para evitar tantas
+    # condiciones.
+    if htmx?
+      if @post.persisted?
+        swap_modals
+
+        @value = @post.title.value
+        @uuid = @post.uuid.value
+        @name = params.require(:name)
+
+        render 'posts/new_has_many_value', layout: false
+      else
+        # @todo Mostrar errores
+      end
+    elsif @post.persisted?
       redirect_to site_post_path(@site, @post)
     else
       render 'posts/new'
@@ -185,4 +228,13 @@ class PostsController < ApplicationController
   def service_for_direct_upload
     session[:service_name] = site.name.to_sym
   end
+
+  # @param triggers [Hash] Otros disparadores
+  def swap_modals(triggers = {})
+    params.permit(:show, :hide).each_pair do |key, value|
+      triggers["modal:#{key}"] = { id: value }
+    end
+
+    headers['HX-Trigger'] = triggers.to_json if triggers.present?
+  end
 end
diff --git a/app/javascript/controllers/modal_controller.js b/app/javascript/controllers/modal_controller.js
index 3a614b80..20154f79 100644
--- a/app/javascript/controllers/modal_controller.js
+++ b/app/javascript/controllers/modal_controller.js
@@ -3,8 +3,30 @@ import { Controller } from "stimulus";
 export default class extends Controller {
   static targets = ["modal", "backdrop"];
 
+  // TODO: Stimulus >1
+  connect() {
+    this.showEvent = this.show.bind(this);
+    this.hideEvent = this.hide.bind(this);
+
+    window.addEventListener("modal:show", this.showEvent);
+    window.addEventListener("modal:hide", this.hideEvent);
+  }
+
+  // TODO: Stimulus >1
+  disconnect() {
+    window.removeEventListener("modal:show", this.showEvent);
+    window.removeEventListener("modal:hide", this.hideEvent);
+  }
+
+  /*
+   * Podemos enviar la orden de apertura como un click o como un
+   * CustomEvent incluyendo el id del modal como detail.
+   */
   show(event = undefined) {
     event?.preventDefault();
+    const modalId = event?.detail?.id;
+
+    if (modalId && this.element.id !== modalId) return;
 
     this.modalTarget.style.display = "block";
     this.backdropTarget.style.display = "block";
@@ -22,6 +44,9 @@ export default class extends Controller {
 
   hide(event = undefined) {
     event?.preventDefault();
+    const modalId = event?.detail?.id;
+
+    if (modalId && this.element.id !== modalId) return;
 
     this.backdropTarget.classList.remove("show");
     this.modalTarget.classList.remove("show");
diff --git a/app/models/metadata_new_has_many.rb b/app/models/metadata_new_has_many.rb
new file mode 100644
index 00000000..3bf37d45
--- /dev/null
+++ b/app/models/metadata_new_has_many.rb
@@ -0,0 +1,4 @@
+# frozen_string_literal: true
+
+# Interfaz nueva para uno a muchos
+class MetadataNewHasMany < MetadataHasMany; end
diff --git a/app/models/metadata_related_posts.rb b/app/models/metadata_related_posts.rb
index 42d1381b..2728020e 100644
--- a/app/models/metadata_related_posts.rb
+++ b/app/models/metadata_related_posts.rb
@@ -26,6 +26,13 @@ class MetadataRelatedPosts < MetadataArray
     posts.where(uuid: value).map(&:title).map(&:value)
   end
 
+  # Encuentra el filtro
+  #
+  # @return [Hash]
+  def filter
+    layout.metadata.dig(name, 'filter')&.to_h&.symbolize_keys || {}
+  end
+
   private
 
   # Obtiene todos los posts y opcionalmente los filtra
@@ -37,11 +44,6 @@ class MetadataRelatedPosts < MetadataArray
     "#{post&.title&.value || post&.slug&.value} #{post&.date&.value.strftime('%F')} (#{post.layout.humanized_name})"
   end
 
-  # Encuentra el filtro
-  def filter
-    layout.metadata.dig(name, 'filter')&.to_h&.symbolize_keys || {}
-  end
-
   def sanitize(uuid)
     super(uuid.map do |u|
       u.to_s.gsub(/[^a-f0-9\-]/i, '')
diff --git a/app/services/post_service.rb b/app/services/post_service.rb
index 9aa3becf..1de50f1b 100644
--- a/app/services/post_service.rb
+++ b/app/services/post_service.rb
@@ -15,7 +15,7 @@ PostService = Struct.new(:site, :usuarie, :post, :params, keyword_init: true) do
     post.draft.value = true if site.invitade? usuarie
     post.assign_attributes(post_params)
 
-    params.require(:post).permit(:slug).tap do |p|
+    params.require(base).permit(:slug).tap do |p|
       post.slug.value = p[:slug] if p[:slug].present?
     end
 
@@ -87,7 +87,7 @@ PostService = Struct.new(:site, :usuarie, :post, :params, keyword_init: true) do
   #
   # { uuid => 2, uuid => 1, uuid => 0 }
   def reorder
-    reorder = params.require(:post).permit(reorder: {})&.dig(:reorder)&.transform_values(&:to_i)
+    reorder = params.require(base).permit(reorder: {})&.dig(:reorder)&.transform_values(&:to_i)
     posts = site.posts(lang: locale).where(uuid: reorder.keys)
 
     files = posts.map do |post|
@@ -110,6 +110,13 @@ PostService = Struct.new(:site, :usuarie, :post, :params, keyword_init: true) do
 
   private
 
+  # La base donde buscar los parámetros
+  #
+  # @return [Symbol]
+  def base
+    @base ||= params.permit(:base).try(:[], :base).try(:to_sym) || :post
+  end
+
   # Una lista de archivos a modificar
   #
   # @return [Set]
@@ -131,7 +138,7 @@ PostService = Struct.new(:site, :usuarie, :post, :params, keyword_init: true) do
 
   # Solo permitir cambiar estos atributos de cada articulo
   def post_params
-    @post_params ||= params.require(:post).permit(post.params).to_h
+    @post_params ||= params.require(base).permit(post.params).to_h
   end
 
   # Eliminar metadatos internos
diff --git a/app/views/posts/_htmx_form.haml b/app/views/posts/_htmx_form.haml
new file mode 100644
index 00000000..25c45aad
--- /dev/null
+++ b/app/views/posts/_htmx_form.haml
@@ -0,0 +1,41 @@
+-#
+  El formulario del artículo, con HTMX activado.
+
+  @param :site [Site]
+  @param :post [Post]
+  @param :locale [Symbol, String]
+  @param :dir [Symbol, String]
+:ruby
+  options = {
+    multipart: true,
+    class: 'form post ',
+    'hx-swap': params.require(:swap),
+    'hx-target': "##{params.require(:target)}"
+  }
+
+  if post.new?
+    url = options[:'hx-post'] = site_posts_path(site, locale: locale)
+    options[:class] += 'new'
+  else
+    url = options[:'hx-patch'] = site_post_path(site, post.id, locale: locale)
+    options[:method] = :patch
+    options[:class] += 'edit'
+  end
+
+= form_tag url, **options do
+  -# Parámetros para HTMX
+  %input{ type: 'hidden', name: 'hide', value: params.require(:show) }
+  %input{ type: 'hidden', name: 'show', value: params.require(:hide) }
+  %input{ type: 'hidden', name: 'name', value: params.require(:name) }
+  %input{ type: 'hidden', name: 'base', value: params.require(:base) }
+
+  -# Botones de guardado
+  = render 'posts/submit', site: site, post: post
+
+  = hidden_field_tag "#{base}[layout]", post.layout.name
+
+  -# Dibuja cada atributo
+  = render 'posts/attributes', site: site, post: post, dir: dir, base: base, locale: locale
+
+  -# Botones de guardado
+  = render 'posts/submit', site: site, post: post
diff --git a/app/views/posts/_new_related_post.haml b/app/views/posts/_new_related_post.haml
new file mode 100644
index 00000000..f3cc2a94
--- /dev/null
+++ b/app/views/posts/_new_related_post.haml
@@ -0,0 +1,2 @@
+.col
+  %p= link_to post.title, post.path
diff --git a/app/views/posts/attribute_ro/_new_has_many.haml b/app/views/posts/attribute_ro/_new_has_many.haml
new file mode 100644
index 00000000..d6b51a7a
--- /dev/null
+++ b/app/views/posts/attribute_ro/_new_has_many.haml
@@ -0,0 +1,6 @@
+%tr{ id: attribute }
+  %th= post_label_t(attribute, post: post)
+  %td
+    %ul{ dir: dir, lang: locale }
+      - metadata.has_many.each do |p|
+        %li= link_to p.title.value, site_post_path(site, p.id)
diff --git a/app/views/posts/attributes/_new_has_many.haml b/app/views/posts/attributes/_new_has_many.haml
new file mode 100644
index 00000000..16d68322
--- /dev/null
+++ b/app/views/posts/attributes/_new_has_many.haml
@@ -0,0 +1,92 @@
+-#
+  Genera un listado de checkboxes entre los que se puede elegir para
+  guardar.  Podemos elegir entre los artículos ya cargados o agregar uno
+  nuevo.
+
+  Al agregar uno nuevo, se abre un segundo modal que carga el formulario
+  correspondiente vía HTMX. El formulario tiene que cargarse por fuera
+  del formulario principal porque no se pueden anidar.
+
+:ruby
+  id = "#{base}_#{attribute}"
+  name = "#{base}[#{attribute}][]"
+  form_id = "form-#{Nanoid.generate}"
+  modal_id = "modal-#{Nanoid.generate}"
+  post_id = "post-#{Nanoid.generate}"
+  post_form_id = "post-form-#{Nanoid.generate}"
+  post_modal_id = "post-modal-#{Nanoid.generate}"
+  post_form_loaded_id = "post-loaded-#{Nanoid.generate}"
+  value_list_id = "#{id}_body"
+
+%div{ id: modal_id, data: { controller: 'modal array', 'array-original-value': metadata.value.to_json, 'array-new-array-value': site_posts_new_related_post_path(site) } }
+  .form-group
+    = hidden_field_tag name, ''
+    = label_tag id, post_label_t(attribute, post: post)
+    -# Mostramos la lista de valores actuales.
+
+      Al aceptar el modal, se vacía el listado y se completa en base a
+      renderizaciones con HTMX. Para poder hacer eso, tenemos que poder
+      acceder a todos los items dentro del modal (como array.item) y
+      enviar el valor al endpoint que devuelve uno por uno. Esto lo
+      tenemos disponible en Stimulus, pero queremos usar HTMX o técnica
+      similar para poder renderizar del lado del servidor.
+
+      Para poder cancelar, mantenemos el estado original y desactivamos
+      o activamos los ítemes según estén incluidos en esa lista o no.
+    .row.row-cols-1.row-cols-md-2{ data: { target: 'array.current' } }
+      - metadata.values.slice(*metadata.value).each do |value|
+        = render 'posts/new_array_value', value: value
+
+    = render 'bootstrap/btn', content: t('.edit'), action: 'modal#show'
+
+  = render 'bootstrap/modal', id: id, modal_content_attributes: { class: 'h-100' }, hide_actions: ['array#cancel'] do
+    - content_for :"#{id}_header" do
+      .form-group.flex-grow-1.mb-0
+        = label_tag id, post_label_t(attribute, post: post)
+        %input.form-control{ data: { target: 'array.search', action: 'input->array#search' }, type: 'search', placeholder: t('.filter') }
+
+    - content_for :"#{id}_body" do
+      .form-group.mb-0{ id: value_list_id }
+        - metadata.values.each_pair do |value, uuid|
+          .mb-2{ data: { target: 'array.item', 'searchable-value': value.remove_diacritics.downcase, value: uuid } }
+            = render 'bootstrap/custom_checkbox', name: name, id: "value-#{Nanoid.generate}", value: uuid, checked: metadata.value.include?(uuid), content: value
+
+    -#
+      Según la definición del campo, si hay un filtro, tenemos que poder
+      elegir qué tipo de esquema queremos o si hay uno solo, siempre
+      vamos a enviar ese. Si no hay ninguno, tendríamos que poder elegir
+      entre todos los esquemas.
+
+    - content_for :"#{id}_footer" do
+      - layout = metadata.filter[:layout]
+      - if layout.is_a?(String)
+        %input{ type: 'hidden', name: 'layout', value: layout, form: post_form_id }
+        = render 'bootstrap/btn', content: t('.add', layout: site.layouts[layout].humanized_name), form: post_form_id, type: 'submit', class: 'm-0 mr-1'
+      - else
+        - layouts   = layout&.map { |x| site.layouts[x] }
+        - layouts ||= site.layouts.values
+        .input-group.w-auto.flex-grow-1.my-0
+          %select.form-control{ form: post_form_id, name: 'layout' }
+            - layouts.each do |layout|
+              %option{ value: layout.name }= layout.humanized_name
+          .input-group-append
+            = render 'bootstrap/btn', content: t('.add', layout: ''), form: post_form_id, type: 'submit', class: 'mb-0 mr-0'
+      = render 'bootstrap/btn', content: t('.accept'), action: 'array#accept modal#hide', class: 'm-0 mr-1'
+      = render 'bootstrap/btn', content: t('.cancel'), action: 'array#cancel modal#hide', class: 'm-0'
+
+-#
+  Este segundo modal es el que carga los formularios de
+  creación/modificación de artículos relacionados. Se envía a post_form
+  para que sea externo al formulario actual.
+- content_for :post_form do
+  %form{ id: post_form_id, 'hx-get': site_posts_form_path(site), 'hx-target': "##{post_form_loaded_id}" }
+    %input{ type: 'hidden', name: 'show', value: post_modal_id }
+    %input{ type: 'hidden', name: 'hide', value: modal_id }
+    %input{ type: 'hidden', name: 'target', value: value_list_id }
+    %input{ type: 'hidden', name: 'swap', value: 'beforeend' }
+    %input{ type: 'hidden', name: 'base', value: id }
+    %input{ type: 'hidden', name: 'name', value: name }
+  %div{ id: post_modal_id, data: { controller: 'modal' } }
+    = render 'bootstrap/modal', id: post_id, modal_content_attributes: { class: 'h-100' } do
+      - content_for :"#{post_id}_body" do
+        %div{ id: post_form_loaded_id }
diff --git a/app/views/posts/form.haml b/app/views/posts/form.haml
new file mode 100644
index 00000000..df4369e1
--- /dev/null
+++ b/app/views/posts/form.haml
@@ -0,0 +1,7 @@
+-#
+  El formulario sin ninguna decoración, para incluir dentro de otros
+  elementos.
+
+  @param :site [Site]
+  @param :post [Post]
+= render 'posts/htmx_form', site: @site, post: @post, locale: @locale, dir: t("locales.#{@locale}.dir"), base: params.require(:base)
diff --git a/app/views/posts/new_has_many_value.haml b/app/views/posts/new_has_many_value.haml
new file mode 100644
index 00000000..b26acc89
--- /dev/null
+++ b/app/views/posts/new_has_many_value.haml
@@ -0,0 +1,2 @@
+.mb-2{ data: { target: 'array.item', 'searchable-value': @value.remove_diacritics.downcase, value: @uuid } }
+  = render 'bootstrap/custom_checkbox', name: @name, id: "value-#{Nanoid.generate}", value: @uuid, checked: true, content: @value
diff --git a/app/views/sites/index.haml b/app/views/sites/index.haml
index 6419a138..3bc1477f 100644
--- a/app/views/sites/index.haml
+++ b/app/views/sites/index.haml
@@ -4,7 +4,7 @@
     %p.lead= t('.help')
     - if policy(Site).new?
       = link_to t('sites.new.title'), new_site_path,
-        class: 'btn btn-secondary'
+                class: 'btn btn-secondary'
 
   %section.col
     - if @sites.empty?
@@ -15,11 +15,14 @@
       %tbody
         - @sites.each do |site|
           - next unless site.jekyll?
+
           %tr
             %td
               %h2
                 - if policy(site).show?
-                  = link_to site.title, site_posts_path(site, locale: site.default_locale)
+                  = link_to site.title,
+                            site_posts_path(site,
+                                            locale: site.default_locale)
                 - else
                   = site.title
               %p.lead= site.description
@@ -28,27 +31,27 @@
                 = link_to t('.visit'), site.url, class: 'btn btn-secondary'
                 - if current_usuarie.rol_for_site(site).temporal?
                   = render 'components/btn_base',
-                    text: t('sites.invitations.accept'),
-                    path: site_usuaries_accept_invitation_path(site),
-                    title: t('help.sites.invitations.accept'),
-                    class: 'btn-secondary'
+                           text: t('sites.invitations.accept'),
+                           path: site_usuaries_accept_invitation_path(site),
+                           title: t('help.sites.invitations.accept'),
+                           class: 'btn-secondary'
                   = render 'components/btn_base',
-                    text: t('sites.invitations.reject'),
-                    path: site_usuaries_reject_invitation_path(site),
-                    title: t('help.sites.invitations.reject'),
-                    class: 'btn-secondary'
+                           text: t('sites.invitations.reject'),
+                           path: site_usuaries_reject_invitation_path(site),
+                           title: t('help.sites.invitations.reject'),
+                           class: 'btn-secondary'
                 - else
                   - if policy(site).show?
                     = render 'layouts/btn_with_tooltip',
-                      tooltip: t('help.sites.edit_posts'),
-                      type: 'success',
-                      link: site_path(site),
-                      text: t('sites.posts')
+                             tooltip: t('help.sites.edit_posts'),
+                             type: 'success',
+                             link: site_path(site),
+                             text: t('sites.posts')
                   = render 'sites/build', site: site
                   = render 'sites/moderation_queue', site: site
                   - if policy(SiteUsuarie.new(site, current_usuarie)).index?
                     = render 'layouts/btn_with_tooltip',
-                      tooltip: t('usuaries.index.help.self'),
-                      text: t('usuaries.index.title'),
-                      type: 'info',
-                      link: site_usuaries_path(site)
+                             tooltip: t('usuaries.index.help.self'),
+                             text: t('usuaries.index.title'),
+                             type: 'info',
+                             link: site_usuaries_path(site)
diff --git a/config/locales/en.yml b/config/locales/en.yml
index 3f12482f..56fe8919 100644
--- a/config/locales/en.yml
+++ b/config/locales/en.yml
@@ -720,6 +720,12 @@ en:
     new_array:
       remove: "Remove"
     attributes:
+      new_has_many:
+        edit: "Edit"
+        filter: "Start typing to filter..."
+        accept: "Accept"
+        cancel: "Cancel"
+        add: "Add %{layout}"
       new_predefined_array:
         edit: "Edit"
         filter: "Start typing to filter..."
@@ -756,6 +762,12 @@ en:
       image:
         label: Image
         destroy: Remove image
+      audio:
+        label: Audio file
+      logo:
+        label: Logo
+      download:
+        label: Archivo
       belongs_to:
         empty: "(Empty)"
       predefined_value:
diff --git a/config/locales/es.yml b/config/locales/es.yml
index 3b3085bd..13b2e89d 100644
--- a/config/locales/es.yml
+++ b/config/locales/es.yml
@@ -728,6 +728,12 @@ es:
     new_array:
       remove: "Eliminar"
     attributes:
+      new_has_many:
+        edit: "Editar"
+        filter: "Empezá a escribir para filtrar..."
+        accept: "Aceptar"
+        cancel: "Cancelar"
+        add: "Agregar %{layout}"
       new_predefined_array:
         edit: "Editar"
         filter: "Empezá a escribir para filtrar..."
@@ -764,6 +770,12 @@ es:
       image:
         label: Imagen
         destroy: 'Eliminar imagen'
+      logo:
+        label: Logo
+      audio:
+        label: Audio
+      download:
+        label: Archivo
       belongs_to:
         empty: "(Vacío)"
       predefined_value:
diff --git a/config/routes.rb b/config/routes.rb
index eb20edce..45410782 100644
--- a/config/routes.rb
+++ b/config/routes.rb
@@ -102,6 +102,8 @@ Rails.application.routes.draw do
 
         get :'posts/new_array', to: 'posts#new_array'
         get :'posts/new_array_value', to: 'posts#new_array_value'
+        get :'posts/new_related_post', to: 'posts#new_related_post'
+        get :'posts/form', to: 'posts#form'
 
         resources :posts do
           get 'p/:page', action: :index, on: :collection
diff --git a/public/assets/.sprockets-manifest-a1cbb907961024fc033716a7d30668dd.json b/public/assets/.sprockets-manifest-a1cbb907961024fc033716a7d30668dd.json
index 06149e3b..c7d72d80 100644
--- a/public/assets/.sprockets-manifest-a1cbb907961024fc033716a7d30668dd.json
+++ b/public/assets/.sprockets-manifest-a1cbb907961024fc033716a7d30668dd.json
@@ -1,3 +1,3 @@
 version https://git-lfs.github.com/spec/v1
-oid sha256:d777657714c83b2e791148484ccc6e5b65e6a78a3b5cc171ab4c741b6ffbdbe5
+oid sha256:0455a9d1c1863feac7b6eb0521e0d598df4cc2a29deebacb20df338833d29e7e
 size 10553