diff --git a/app/models/metadata_has_one_nested.rb b/app/models/metadata_has_one_nested.rb
new file mode 100644
index 00000000..ed509013
--- /dev/null
+++ b/app/models/metadata_has_one_nested.rb
@@ -0,0 +1,11 @@
+# frozen_string_literal: true
+
+class MetadataHasOneNested < MetadataHasOne
+  def nested
+    @nested ||= layout.metadata.dig(name, 'nested')
+  end
+
+  def nested?
+    true
+  end
+end
diff --git a/app/models/metadata_template.rb b/app/models/metadata_template.rb
index a9765918..886b5f5d 100644
--- a/app/models/metadata_template.rb
+++ b/app/models/metadata_template.rb
@@ -12,6 +12,10 @@ MetadataTemplate = Struct.new(:site, :document, :name, :label, :type,
     false
   end
 
+  def nested?
+    false
+  end
+
   def inspect
     "#<#{self.class} site=#{site.name.inspect} post=#{post.id.inspect} value=#{value.inspect}>"
   end
@@ -38,18 +42,10 @@ MetadataTemplate = Struct.new(:site, :document, :name, :label, :type,
     "#{cache_key}-#{cache_version}"
   end
 
-  # XXX: Deberíamos sanitizar durante la asignación?
-  def value=(new_value)
-    @value_was = value
-    self[:value] = new_value
-  end
-
   # Siempre obtener el valor actual y solo obtenerlo del documento una
   # vez.
   def value_was
-    return @value_was if instance_variable_defined? '@value_was'
-
-    @value_was = document_value
+    @value_was ||= document_value.nil? ? default_value : document_value
   end
 
   def changed?
@@ -169,7 +165,7 @@ MetadataTemplate = Struct.new(:site, :document, :name, :label, :type,
   # once => el campo solo se puede modificar si estaba vacío
   def writable?
     case layout.metadata.dig(name, 'writable')
-    when 'once' then value.blank?
+    when 'once' then value_was.blank?
     else true
     end
   end
diff --git a/app/models/post.rb b/app/models/post.rb
index 591821eb..053c995f 100644
--- a/app/models/post.rb
+++ b/app/models/post.rb
@@ -15,6 +15,9 @@ class Post
   PUBLIC_ATTRIBUTES = %i[lang date uuid created_at].freeze
   ATTR_SUFFIXES = %w[? =].freeze
 
+  class PostError < StandardError; end
+  class UnknownAttributeError < PostError; end
+
   attr_reader :attributes, :errors, :layout, :site, :document
 
   # TODO: Modificar el historial de Git con callbacks en lugar de
@@ -54,12 +57,33 @@ class Post
     @errors = {}
     @metadata = {}
 
-    # Inicializar valores
+    # Leer el documento si existe
+    # @todo Asignar todos los valores a self[:value] luego de leer
+    document&.read! unless new?
+
+    # Inicializar valores o modificar los que vengan del documento
+    assignable_attributes = args.slice(*attributes)
+    assign_attributes(assignable_attributes) if assignable_attributes.present?
+  end
+
+  # Asignar atributos, ignorando atributos que no se pueden modificar
+  # o inexistentes
+  #
+  # @param attrs [Hash]
+  def assign_attributes(attrs)
+    attrs = attrs.transform_keys(&:to_sym)
+
     attributes.each do |attr|
-      public_send(attr)&.value = args[attr] if args.key?(attr)
+      self[attr].value = attrs[attr] if attrs.key?(attr) && self[attr].writable?
     end
 
-    document.read! unless new?
+    unknown_attrs = attrs.keys.map(&:to_sym) - attributes
+
+    if unknown_attrs.present?
+      raise UnknownAttributeError, "Unknown attribute(s) #{unknown_attrs.map(&:to_s).join(', ')} for Post"
+    end
+
+    nil
   end
 
   def inspect
@@ -169,8 +193,7 @@ class Post
     # Limpiar el nombre del atributo, para que todos los ayudantes
     # reciban el método en limpio
     unless attribute? name
-      raise NoMethodError, I18n.t('exceptions.post.no_method',
-                                  method: name)
+      raise UnknownAttributeError, I18n.t('exceptions.post.no_method', method: name)
     end
 
     define_singleton_method(name) do
@@ -390,11 +413,7 @@ class Post
   end
 
   def update_attributes(hashable)
-    hashable.to_hash.each do |attr, value|
-      next unless self[attr].writable?
-
-      self[attr].value = value
-    end
+    assign_attributes(hashable)
 
     save
   end
@@ -408,6 +427,13 @@ class Post
     @usuaries ||= document_usuaries.empty? ? [] : Usuarie.where(id: document_usuaries).to_a
   end
 
+  # Todos los atributos anidados
+  #
+  # @return [Array<Symbol>]
+  def nested_attributes
+    @nested_attributes ||= attributes.map { |a| self[a] }.select(&:nested?).map(&:name)
+  end
+
   private
 
   # Levanta un error si al construir el artículo no pasamos un atributo.
diff --git a/app/services/post_service.rb b/app/services/post_service.rb
index 4631a9a4..08a46ae7 100644
--- a/app/services/post_service.rb
+++ b/app/services/post_service.rb
@@ -10,13 +10,18 @@ PostService = Struct.new(:site, :usuarie, :post, :params, keyword_init: true) do
     self.post = site.posts(lang: locale)
                     .build(layout: layout)
     post.usuaries << usuarie
-    params[:post][:draft] = true if site.invitade? usuarie
+    post.draft.value = true if site.invitade? usuarie
+    post.assign_attributes(post_params)
 
     params.require(:post).permit(:slug).tap do |p|
       post.slug.value = p[:slug] if p[:slug].present?
     end
 
-    commit(action: :created, add: update_related_posts) if post.update(post_params)
+    # Crea los posts anidados
+    create_nested_posts! post, params[:post]
+    update_related_posts
+
+    commit(action: :created, add: files) if post.save
 
     update_site_license!
 
@@ -34,7 +39,7 @@ PostService = Struct.new(:site, :usuarie, :post, :params, keyword_init: true) do
     # Los artículos anónimos siempre son borradores
     params[:draft] = true
 
-    commit(action: :created, add: [post.path.absolute]) if post.update(anon_post_params)
+    commit(action: :created, add: files) if post.update(anon_post_params)
     post
   end
 
@@ -47,9 +52,11 @@ PostService = Struct.new(:site, :usuarie, :post, :params, keyword_init: true) do
       rm = []
       rm << post.path.value_was if post.path.changed?
 
+      update_related_posts
+
       # Es importante que el artículo se guarde primero y luego los
       # relacionados.
-      commit(action: :updated, add: update_related_posts, rm: rm)
+      commit(action: :updated, add: files, rm: rm)
 
       update_site_license!
     end
@@ -96,6 +103,15 @@ PostService = Struct.new(:site, :usuarie, :post, :params, keyword_init: true) do
 
   private
 
+  # Una lista de archivos a modificar
+  #
+  # @return [Set]
+  def files
+    @files ||= Set.new.tap do |f|
+      f << post.path.absolute
+    end
+  end
+
   def commit(action:, add: [], rm: [])
     site.repository.commit(add: add,
                            rm: rm,
@@ -108,7 +124,7 @@ PostService = Struct.new(:site, :usuarie, :post, :params, keyword_init: true) do
 
   # Solo permitir cambiar estos atributos de cada articulo
   def post_params
-    params.require(:post).permit(post.params)
+    @post_params ||= params.require(:post).permit(post.params).to_h
   end
 
   # Eliminar metadatos internos
@@ -146,8 +162,10 @@ PostService = Struct.new(:site, :usuarie, :post, :params, keyword_init: true) do
     end
 
     posts.map do |p|
-      p.path.absolute if p.save(validate: false)
-    end.compact << post.path.absolute
+      next unless p.save(validate: false)
+
+      files << p.path.absolute
+    end
   end
 
   # Si les usuaries modifican o crean una licencia, considerarla
@@ -157,4 +175,20 @@ PostService = Struct.new(:site, :usuarie, :post, :params, keyword_init: true) do
       site.update licencia: Licencia.find_by_icons('custom')
     end
   end
+
+  # Encuentra todos los posts anidados y los crea o modifica
+  def create_nested_posts!(post, params)
+    post.nested_attributes.each do |nested_attribute|
+     nested_metadata = post[nested_attribute]
+     # @todo find_or_initialize
+     nested_post = site.posts(lang: post.lang.value).build(layout: nested_metadata.nested)
+     nested_params = params.require(nested_attribute).permit(nested_post.params).to_hash
+
+     # Completa la relación 1:1
+     nested_params[nested_metadata.inverse.to_s] = post.uuid.value
+     post[nested_attribute].value = nested_post.uuid.value
+
+     files << nested_post.path.absolute if nested_post.update(nested_params)
+    end
+  end
 end
diff --git a/app/views/posts/_attributes.haml b/app/views/posts/_attributes.haml
new file mode 100644
index 00000000..ed958d08
--- /dev/null
+++ b/app/views/posts/_attributes.haml
@@ -0,0 +1,16 @@
+-#
+  @param base [String]
+  @param locale [String]
+  @param post [Post]
+  @param site [Site]
+  @param dir [String]
+- post.attributes.each do |attribute|
+  - metadata = post[attribute]
+  - type = metadata.type
+
+  - cache [metadata, I18n.locale] do
+    = render("posts/attributes/#{type}",
+            base: base, post: post, attribute: attribute,
+            metadata: metadata, site: site,
+            dir: dir, locale: locale,
+            autofocus: (post.attributes.first == attribute))
diff --git a/app/views/posts/_attributes_nested.haml b/app/views/posts/_attributes_nested.haml
new file mode 100644
index 00000000..33996aa3
--- /dev/null
+++ b/app/views/posts/_attributes_nested.haml
@@ -0,0 +1,19 @@
+-#
+  @param inverse [Symbol]
+  @param base [String]
+  @param locale [String]
+  @param post [Post]
+  @param site [Site]
+  @param dir [String]
+- post.attributes.each do |attribute|
+  - next if attribute == :date
+  - next if attribute == :draft
+  - next if attribute == inverse
+  - metadata = post[attribute]
+  - type = metadata.type
+
+  - cache [metadata, I18n.locale] do
+    = render "posts/attributes/#{type}",
+      base: base, post: post, attribute: attribute,
+      metadata: metadata, site: site,
+      dir: dir, locale: locale, autofocus: false
diff --git a/app/views/posts/_form.haml b/app/views/posts/_form.haml
index 7de0ea79..92bee939 100644
--- a/app/views/posts/_form.haml
+++ b/app/views/posts/_form.haml
@@ -41,16 +41,7 @@
   = hidden_field_tag 'post[layout]', post.layout.name
 
   -# Dibuja cada atributo
-  - post.attributes.each do |attribute|
-    - metadata = post[attribute]
-    - type = metadata.type
-
-    - cache [metadata, I18n.locale] do
-      = render("posts/attributes/#{type}",
-              base: 'post', post: post, attribute: attribute,
-              metadata: metadata, site: site,
-              dir: dir, locale: @locale,
-              autofocus: (post.attributes.first == attribute))
+  = render 'posts/attributes', site: site, post: post, dir: dir, base: 'post', locale: @locale
 
   -# Botones de guardado
   = render 'posts/submit', site: site, post: post
diff --git a/app/views/posts/attribute_ro/_has_one_nested.haml b/app/views/posts/attribute_ro/_has_one_nested.haml
new file mode 100644
index 00000000..425e659e
--- /dev/null
+++ b/app/views/posts/attribute_ro/_has_one_nested.haml
@@ -0,0 +1,6 @@
+%tr{ id: attribute }
+  %th= post_label_t(attribute, post: post)
+  %td{ dir: dir, lang: locale }
+    - p = metadata.has_one
+    - if p
+      = link_to p.title.value, site_post_path(site, p.id)
diff --git a/app/views/posts/attributes/_has_one_nested.haml b/app/views/posts/attributes/_has_one_nested.haml
new file mode 100644
index 00000000..e98bff47
--- /dev/null
+++ b/app/views/posts/attributes/_has_one_nested.haml
@@ -0,0 +1,6 @@
+- new_post = site.posts(lang: locale).build(layout: metadata.nested)
+- base = "#{base}[#{metadata.name}]"
+
+.form-group
+  = render 'layouts/details', id: metadata.nested, summary: site.layouts[metadata.nested].humanized_name do
+    = render 'posts/attributes_nested', site: site, post: new_post, dir: dir, base: base, locale: locale, inverse: metadata.inverse