diff --git a/app/models/activity_pub.rb b/app/models/activity_pub.rb
new file mode 100644
index 00000000..c0474b89
--- /dev/null
+++ b/app/models/activity_pub.rb
@@ -0,0 +1,33 @@
+# frozen_string_literal: true
+
+# = ActivityPub =
+#
+# El registro de actividades recibidas y su estado.  Cuando recibimos
+# una actividad, puede estar destinada a varies actores dentro de Sutty,
+# con lo que generamos una cola para cada une.
+#
+# @see {https://www.w3.org/TR/activitypub/#client-to-server-interactions}
+class ActivityPub < ApplicationRecord
+  include AASM
+
+  belongs_to :site
+  belongs_to :object, polymorphic: true
+  has_many :activities
+
+  validates :site_id, presence: true
+  validates :object_id, presence: true
+  validates :aasm_state, presence: true, inclusion: { in: %w[paused approved rejected reported deleted] }
+
+  aasm do
+    # Todavía no hay una decisión sobre el objeto
+    state :paused, initial: true
+    # Le usuarie aprobó el objeto
+    state :approved
+    # Le usuarie rechazó el objeto
+    state :rejected
+    # Le usuarie reportó el objeto
+    state :reported
+    # Le actore eliminó el objeto
+    state :deleted
+  end
+end
diff --git a/app/models/activity_pub/activity.rb b/app/models/activity_pub/activity.rb
new file mode 100644
index 00000000..4a88c1f3
--- /dev/null
+++ b/app/models/activity_pub/activity.rb
@@ -0,0 +1,24 @@
+# frozen_string_literal: true
+
+# = Activity =
+#
+# Lleva un registro de las actividades que nos piden hacer remotamente.
+#
+# Las actividades pueden tener distintos destinataries (sitios/actores).
+#
+# @todo Obtener el contenido del objeto dinámicamente si no existe
+# localmente, por ejemplo cuando la actividad crea un objeto pero lo
+# envía como referencia en lugar de anidarlo.
+#
+# @see {https://www.w3.org/TR/activitypub/#client-to-server-interactions}
+class ActivityPub::Activity < ApplicationRecord
+  include ActivityPub::Concerns::JsonLdConcern
+
+  belongs_to :activity_pub
+  has_one :object, through: :activity_pub
+
+  validates :activity_pub_id, presence: true
+
+  # Siempre en orden descendiente para saber el último estado
+  default_scope -> { order(created_at: :desc) }
+end
diff --git a/app/models/activity_pub/activity/create.rb b/app/models/activity_pub/activity/create.rb
new file mode 100644
index 00000000..3dcba5c2
--- /dev/null
+++ b/app/models/activity_pub/activity/create.rb
@@ -0,0 +1,3 @@
+# frozen_string_literal: true
+
+class ActivityPub::Activity::Create < ActivityPub::Activity; end
diff --git a/app/models/activity_pub/activity/delete.rb b/app/models/activity_pub/activity/delete.rb
new file mode 100644
index 00000000..f3684a0f
--- /dev/null
+++ b/app/models/activity_pub/activity/delete.rb
@@ -0,0 +1,3 @@
+# frozen_string_literal: true
+
+class ActivityPub::Activity::Delete < ActivityPub::Activity; end
diff --git a/app/models/activity_pub/activity/flag.rb b/app/models/activity_pub/activity/flag.rb
new file mode 100644
index 00000000..2911911e
--- /dev/null
+++ b/app/models/activity_pub/activity/flag.rb
@@ -0,0 +1,3 @@
+# frozen_string_literal: true
+
+class ActivityPub::Activity::Flag < ActivityPub::Activity; end
diff --git a/app/models/activity_pub/activity/follow.rb b/app/models/activity_pub/activity/follow.rb
new file mode 100644
index 00000000..c22dfd51
--- /dev/null
+++ b/app/models/activity_pub/activity/follow.rb
@@ -0,0 +1,7 @@
+# frozen_string_literal: true
+
+# = Follow =
+#
+# Una actividad de seguimiento se refiere siempre a une actore (el
+# sitio) y proviene de otre actore.
+class ActivityPub::Activity::Follow < ActivityPub::Activity; end
diff --git a/app/models/activity_pub/activity/generic.rb b/app/models/activity_pub/activity/generic.rb
new file mode 100644
index 00000000..8bf76471
--- /dev/null
+++ b/app/models/activity_pub/activity/generic.rb
@@ -0,0 +1,3 @@
+# frozen_string_literal: true
+
+class ActivityPub::Activity::Generic < ActivityPub::Activity; end
diff --git a/app/models/activity_pub/activity/undo.rb b/app/models/activity_pub/activity/undo.rb
new file mode 100644
index 00000000..a4915394
--- /dev/null
+++ b/app/models/activity_pub/activity/undo.rb
@@ -0,0 +1,8 @@
+# frozen_string_literal: true
+
+# = Undo =
+#
+# Deshace una actividad, dependiendo de la actividad a la que se
+# refiere.
+class ActivityPub::Activity::Undo < ActivityPub::Activity
+end
diff --git a/app/models/activity_pub/activity/update.rb b/app/models/activity_pub/activity/update.rb
new file mode 100644
index 00000000..8089cdcf
--- /dev/null
+++ b/app/models/activity_pub/activity/update.rb
@@ -0,0 +1,3 @@
+# frozen_string_literal: true
+
+class ActivityPub::Activity::Update < ActivityPub::Activity; end
diff --git a/app/models/activity_pub/actor.rb b/app/models/activity_pub/actor.rb
new file mode 100644
index 00000000..f29c382a
--- /dev/null
+++ b/app/models/activity_pub/actor.rb
@@ -0,0 +1,14 @@
+# frozen_string_literal: true
+
+# = Actor =
+#
+# Actor es la entidad que realiza acciones en ActivityPub
+#
+# @todo Obtener el perfil dinámicamente
+class ActivityPub::Actor < ApplicationRecord
+  include ActivityPub::Concerns::JsonLdConcern
+
+  belongs_to :instance
+  has_many :activity_pubs, as: :object
+  has_many :objects
+end
diff --git a/app/models/activity_pub/concerns/json_ld_concern.rb b/app/models/activity_pub/concerns/json_ld_concern.rb
new file mode 100644
index 00000000..b0899606
--- /dev/null
+++ b/app/models/activity_pub/concerns/json_ld_concern.rb
@@ -0,0 +1,32 @@
+# frozen_string_literal: true
+
+class ActivityPub
+  module Concerns
+    module JsonLdConcern
+      extend ActiveSupport::Concern
+
+      included do
+        validates :uri, presence: true, uniqueness: true
+
+        # Cuando asignamos contenido, obtener la URI si no lo hicimos ya
+        before_save :uri_from_content!, unless: :uri?
+
+        # Obtiene un tipo de actividad a partir del tipo informado
+        #
+        # @param object [Hash]
+        # @return [Activity]
+        def self.type_from(object)
+          "#{self.class.name}::#{object[:type].presence || 'Generic'}".constantize
+        rescue NameError
+          self.class::Generic
+        end
+
+        private
+
+        def uri_from_content!
+          self.uri = content[:id]
+        end
+      end
+    end
+  end
+end
diff --git a/app/models/activity_pub/instance.rb b/app/models/activity_pub/instance.rb
new file mode 100644
index 00000000..fe4a777b
--- /dev/null
+++ b/app/models/activity_pub/instance.rb
@@ -0,0 +1,21 @@
+# frozen_string_literal: true
+
+# = Instance =
+#
+# Representa cada instancia del fediverso que interactúa con la Social
+# Inbox.
+class ActivityPub::Instance < ApplicationRecord
+  include AASM
+
+  validates :aasm_state, presence: true, inclusion: { in: %w[paused allowed blocked] }
+  validates :hostname, uniqueness: true, hostname: true
+
+  has_many :activity_pubs
+  has_many :actors
+
+  aasm do
+    state :paused, initial: true
+    state :allowed
+    state :blocked
+  end
+end
diff --git a/app/models/activity_pub/object.rb b/app/models/activity_pub/object.rb
new file mode 100644
index 00000000..519749ef
--- /dev/null
+++ b/app/models/activity_pub/object.rb
@@ -0,0 +1,11 @@
+# frozen_string_literal: true
+
+# Almacena objetos de ActivityPub, como Note, Article, etc.
+class ActivityPub::Object < ApplicationRecord
+  include ActivityPub::Concerns::JsonLdConcern
+
+  belongs_to :actor
+  has_many :activity_pubs, as: :object
+
+  validates :actor_id, presence: true
+end
diff --git a/app/models/activity_pub/object/application.rb b/app/models/activity_pub/object/application.rb
new file mode 100644
index 00000000..e8a6f97c
--- /dev/null
+++ b/app/models/activity_pub/object/application.rb
@@ -0,0 +1,6 @@
+# frozen_string_literal: true
+
+# = Application =
+#
+# Una aplicación o instancia
+class ActivityPub::Object::Application < ActivityPub::Object; end
diff --git a/app/models/activity_pub/object/article.rb b/app/models/activity_pub/object/article.rb
new file mode 100644
index 00000000..ad1a6131
--- /dev/null
+++ b/app/models/activity_pub/object/article.rb
@@ -0,0 +1,6 @@
+# frozen_string_literal: true
+
+# = Article =
+#
+# Representa artículos
+class ActivityPub::Object::Article < ActivityPub::Object; end
diff --git a/app/models/activity_pub/object/generic.rb b/app/models/activity_pub/object/generic.rb
new file mode 100644
index 00000000..f345e7a9
--- /dev/null
+++ b/app/models/activity_pub/object/generic.rb
@@ -0,0 +1,4 @@
+# frozen_string_literal: true
+
+# = Generic =
+class ActivityPub::Object::Generic < ActivityPub::Object; end
diff --git a/app/models/activity_pub/object/note.rb b/app/models/activity_pub/object/note.rb
new file mode 100644
index 00000000..0f84c747
--- /dev/null
+++ b/app/models/activity_pub/object/note.rb
@@ -0,0 +1,6 @@
+# frozen_string_literal: true
+
+# = Note =
+#
+# Representa notas, el tipo más común de objeto del Fediverso.
+class ActivityPub::Object::Note < ActivityPub::Object; end
diff --git a/app/models/activity_pub/object/organization.rb b/app/models/activity_pub/object/organization.rb
new file mode 100644
index 00000000..a5327d10
--- /dev/null
+++ b/app/models/activity_pub/object/organization.rb
@@ -0,0 +1,6 @@
+# frozen_string_literal: true
+
+# = Organization =
+#
+# Una organización
+class ActivityPub::Object::Organization < ActivityPub::Object; end
diff --git a/app/models/activity_pub/object/person.rb b/app/models/activity_pub/object/person.rb
new file mode 100644
index 00000000..98a1568d
--- /dev/null
+++ b/app/models/activity_pub/object/person.rb
@@ -0,0 +1,6 @@
+# frozen_string_literal: true
+
+# = Person =
+#
+# Una persona, el perfil de une actore
+class ActivityPub::Object::Person < ActivityPub::Object; end
diff --git a/db/migrate/20240219153919_create_activity_pub_activities.rb b/db/migrate/20240219153919_create_activity_pub_activities.rb
new file mode 100644
index 00000000..555656ad
--- /dev/null
+++ b/db/migrate/20240219153919_create_activity_pub_activities.rb
@@ -0,0 +1,16 @@
+# frozen_string_literal: true
+
+# Actividades.  Se asocian a un objeto y a una cola de moderación
+class CreateActivityPubActivities < ActiveRecord::Migration[6.1]
+  def change
+    create_table :activity_pub_activities, id: :uuid do |t|
+      t.timestamps
+
+      t.uuid :activity_pub_id, index: true, null: false
+
+      t.string :type, null: false
+      t.string :uri, null: false
+      t.jsonb :content, default: {}
+    end
+  end
+end
diff --git a/db/migrate/20240219175839_create_activity_pub_actors.rb b/db/migrate/20240219175839_create_activity_pub_actors.rb
new file mode 100644
index 00000000..656b3f63
--- /dev/null
+++ b/db/migrate/20240219175839_create_activity_pub_actors.rb
@@ -0,0 +1,12 @@
+# frozen_string_literal: true
+
+# Almacena actores de ActivityPub y los relaciona con actividades
+class CreateActivityPubActors < ActiveRecord::Migration[6.1]
+  def change
+    create_table :activity_pub_actors, id: :uuid do |t|
+      t.timestamps
+      t.uuid :instance_id, index: true, null: false
+      t.string :uri, index: true, unique: true, null: false
+    end
+  end
+end
diff --git a/db/migrate/20240219204011_create_activity_pubs.rb b/db/migrate/20240219204011_create_activity_pubs.rb
new file mode 100644
index 00000000..cf797fc8
--- /dev/null
+++ b/db/migrate/20240219204011_create_activity_pubs.rb
@@ -0,0 +1,18 @@
+# frozen_string_literal: true
+
+# Registro de actividades.
+class CreateActivityPubs < ActiveRecord::Migration[6.1]
+  def change
+    create_table :activity_pubs, id: :uuid do |t|
+      t.timestamps
+
+      t.bigint :site_id, null: false
+      t.uuid :object_id, null: false
+      t.string :object_type, null: false
+
+      t.string :aasm_state, null: false
+
+      t.index %i[site_id object_id object_type], unique: true
+    end
+  end
+end
diff --git a/db/migrate/20240219204224_create_activity_pub_objects.rb b/db/migrate/20240219204224_create_activity_pub_objects.rb
new file mode 100644
index 00000000..865589ab
--- /dev/null
+++ b/db/migrate/20240219204224_create_activity_pub_objects.rb
@@ -0,0 +1,17 @@
+# frozen_string_literal: true
+
+# Almacena objetos de ActivityPub.  Los objetos pueden estar compartidos
+# por toda la instancia.
+class CreateActivityPubObjects < ActiveRecord::Migration[6.1]
+  def change
+    create_table :activity_pub_objects, id: :uuid do |t|
+      t.timestamps
+
+      t.uuid :actor_id, index: true, null: false
+
+      t.string :type, null: false
+      t.string :uri, null: false, unique: true
+      t.jsonb :content, default: {}
+    end
+  end
+end
diff --git a/db/migrate/20240220161414_create_activity_pub_instances.rb b/db/migrate/20240220161414_create_activity_pub_instances.rb
new file mode 100644
index 00000000..feb9351d
--- /dev/null
+++ b/db/migrate/20240220161414_create_activity_pub_instances.rb
@@ -0,0 +1,13 @@
+# frozen_string_literal: true
+
+# Almacena las instancias
+class CreateActivityPubInstances < ActiveRecord::Migration[6.1]
+  def change
+    create_table :activity_pub_instances, id: :uuid do |t|
+      t.timestamps
+      t.string :hostname, index: true, unique: true, null: false
+      t.string :aasm_state, null: false
+      t.jsonb :content, default: {}
+    end
+  end
+end
diff --git a/db/structure.sql b/db/structure.sql
index dede286d..723c9e99 100644
--- a/db/structure.sql
+++ b/db/structure.sql
@@ -473,6 +473,78 @@ CREATE SEQUENCE public.active_storage_variant_records_id_seq
 ALTER SEQUENCE public.active_storage_variant_records_id_seq OWNED BY public.active_storage_variant_records.id;
 
 
+--
+-- Name: activity_pub_activities; Type: TABLE; Schema: public; Owner: -
+--
+
+CREATE TABLE public.activity_pub_activities (
+    id uuid DEFAULT gen_random_uuid() NOT NULL,
+    created_at timestamp(6) without time zone NOT NULL,
+    updated_at timestamp(6) without time zone NOT NULL,
+    activity_pub_id uuid NOT NULL,
+    type character varying NOT NULL,
+    uri character varying NOT NULL,
+    content jsonb DEFAULT '{}'::jsonb
+);
+
+
+--
+-- Name: activity_pub_actors; Type: TABLE; Schema: public; Owner: -
+--
+
+CREATE TABLE public.activity_pub_actors (
+    id uuid DEFAULT gen_random_uuid() NOT NULL,
+    created_at timestamp(6) without time zone NOT NULL,
+    updated_at timestamp(6) without time zone NOT NULL,
+    instance_id uuid NOT NULL,
+    uri character varying NOT NULL
+);
+
+
+--
+-- Name: activity_pub_instances; Type: TABLE; Schema: public; Owner: -
+--
+
+CREATE TABLE public.activity_pub_instances (
+    id uuid DEFAULT gen_random_uuid() NOT NULL,
+    created_at timestamp(6) without time zone NOT NULL,
+    updated_at timestamp(6) without time zone NOT NULL,
+    hostname character varying NOT NULL,
+    aasm_state character varying NOT NULL,
+    content jsonb DEFAULT '{}'::jsonb
+);
+
+
+--
+-- Name: activity_pub_objects; Type: TABLE; Schema: public; Owner: -
+--
+
+CREATE TABLE public.activity_pub_objects (
+    id uuid DEFAULT gen_random_uuid() NOT NULL,
+    created_at timestamp(6) without time zone NOT NULL,
+    updated_at timestamp(6) without time zone NOT NULL,
+    actor_id uuid NOT NULL,
+    type character varying NOT NULL,
+    uri character varying NOT NULL,
+    content jsonb DEFAULT '{}'::jsonb
+);
+
+
+--
+-- Name: activity_pubs; Type: TABLE; Schema: public; Owner: -
+--
+
+CREATE TABLE public.activity_pubs (
+    id uuid DEFAULT gen_random_uuid() NOT NULL,
+    created_at timestamp(6) without time zone NOT NULL,
+    updated_at timestamp(6) without time zone NOT NULL,
+    site_id bigint NOT NULL,
+    object_id uuid NOT NULL,
+    object_type character varying NOT NULL,
+    aasm_state character varying NOT NULL
+);
+
+
 --
 -- Name: ar_internal_metadata; Type: TABLE; Schema: public; Owner: -
 --
@@ -1565,6 +1637,46 @@ ALTER TABLE ONLY public.active_storage_variant_records
     ADD CONSTRAINT active_storage_variant_records_pkey PRIMARY KEY (id);
 
 
+--
+-- Name: activity_pub_activities activity_pub_activities_pkey; Type: CONSTRAINT; Schema: public; Owner: -
+--
+
+ALTER TABLE ONLY public.activity_pub_activities
+    ADD CONSTRAINT activity_pub_activities_pkey PRIMARY KEY (id);
+
+
+--
+-- Name: activity_pub_actors activity_pub_actors_pkey; Type: CONSTRAINT; Schema: public; Owner: -
+--
+
+ALTER TABLE ONLY public.activity_pub_actors
+    ADD CONSTRAINT activity_pub_actors_pkey PRIMARY KEY (id);
+
+
+--
+-- Name: activity_pub_instances activity_pub_instances_pkey; Type: CONSTRAINT; Schema: public; Owner: -
+--
+
+ALTER TABLE ONLY public.activity_pub_instances
+    ADD CONSTRAINT activity_pub_instances_pkey PRIMARY KEY (id);
+
+
+--
+-- Name: activity_pub_objects activity_pub_objects_pkey; Type: CONSTRAINT; Schema: public; Owner: -
+--
+
+ALTER TABLE ONLY public.activity_pub_objects
+    ADD CONSTRAINT activity_pub_objects_pkey PRIMARY KEY (id);
+
+
+--
+-- Name: activity_pubs activity_pubs_pkey; Type: CONSTRAINT; Schema: public; Owner: -
+--
+
+ALTER TABLE ONLY public.activity_pubs
+    ADD CONSTRAINT activity_pubs_pkey PRIMARY KEY (id);
+
+
 --
 -- Name: blazer_audits blazer_audits_pkey; Type: CONSTRAINT; Schema: public; Owner: -
 --
@@ -1865,6 +1977,48 @@ CREATE UNIQUE INDEX index_active_storage_blobs_on_key_and_service_name ON public
 CREATE UNIQUE INDEX index_active_storage_variant_records_uniqueness ON public.active_storage_variant_records USING btree (blob_id, variation_digest);
 
 
+--
+-- Name: index_activity_pub_activities_on_activity_pub_id; Type: INDEX; Schema: public; Owner: -
+--
+
+CREATE INDEX index_activity_pub_activities_on_activity_pub_id ON public.activity_pub_activities USING btree (activity_pub_id);
+
+
+--
+-- Name: index_activity_pub_actors_on_instance_id; Type: INDEX; Schema: public; Owner: -
+--
+
+CREATE INDEX index_activity_pub_actors_on_instance_id ON public.activity_pub_actors USING btree (instance_id);
+
+
+--
+-- Name: index_activity_pub_actors_on_uri; Type: INDEX; Schema: public; Owner: -
+--
+
+CREATE INDEX index_activity_pub_actors_on_uri ON public.activity_pub_actors USING btree (uri);
+
+
+--
+-- Name: index_activity_pub_instances_on_hostname; Type: INDEX; Schema: public; Owner: -
+--
+
+CREATE INDEX index_activity_pub_instances_on_hostname ON public.activity_pub_instances USING btree (hostname);
+
+
+--
+-- Name: index_activity_pub_objects_on_actor_id; Type: INDEX; Schema: public; Owner: -
+--
+
+CREATE INDEX index_activity_pub_objects_on_actor_id ON public.activity_pub_objects USING btree (actor_id);
+
+
+--
+-- Name: index_activity_pubs_on_site_id_and_object_id_and_object_type; Type: INDEX; Schema: public; Owner: -
+--
+
+CREATE UNIQUE INDEX index_activity_pubs_on_site_id_and_object_id_and_object_type ON public.activity_pubs USING btree (site_id, object_id, object_type);
+
+
 --
 -- Name: index_blazer_audits_on_query_id; Type: INDEX; Schema: public; Owner: -
 --
@@ -2320,6 +2474,11 @@ INSERT INTO "schema_migrations" (version) VALUES
 ('20230829204127'),
 ('20230921155401'),
 ('20230927153926'),
-('20240216170202');
+('20240216170202'),
+('20240219153919'),
+('20240219175839'),
+('20240219204011'),
+('20240219204224'),
+('20240220161414');