11 files changed, 719 insertions, 230 deletions

diff --git a/lib/pleroma/web/activity_pub/activity_pub.ex b/lib/pleroma/web/activity_pub/activity_pub.ex
index cb14f6a57..76c15cf21 100644
--- a/lib/pleroma/web/activity_pub/activity_pub.ex
+++ b/lib/pleroma/web/activity_pub/activity_pub.ex
@@ -10,16 +10,39 @@ defmodule Pleroma.Web.ActivityPub.ActivityPub do
 
   @httpoison Application.get_env(:pleroma, :httpoison)
 
-  @instance Application.get_env(:pleroma, :instance)
+  # For Announce activities, we filter the recipients based on following status for any actors
+  # that match actual users.  See issue #164 for more information about why this is necessary.
+  defp get_recipients(%{"type" => "Announce"} = data) do
+    to = data["to"] || []
+    cc = data["cc"] || []
+    recipients = to ++ cc
+    actor = User.get_cached_by_ap_id(data["actor"])
+
+    recipients
+    |> Enum.filter(fn recipient ->
+      case User.get_cached_by_ap_id(recipient) do
+        nil ->
+          true
+
+        user ->
+          User.following?(user, actor)
+      end
+    end)
+
+    {recipients, to, cc}
+  end
 
-  def get_recipients(data) do
-    (data["to"] || []) ++ (data["cc"] || [])
+  defp get_recipients(data) do
+    to = data["to"] || []
+    cc = data["cc"] || []
+    recipients = to ++ cc
+    {recipients, to, cc}
   end
 
   defp check_actor_is_active(actor) do
     if not is_nil(actor) do
       with user <- User.get_cached_by_ap_id(actor),
-           nil <- user.info["deactivated"] do
+           false <- !!user.info["deactivated"] do
         :ok
       else
         _e -> :reject
@@ -35,12 +58,14 @@ defmodule Pleroma.Web.ActivityPub.ActivityPub do
          :ok <- check_actor_is_active(map["actor"]),
          {:ok, map} <- MRF.filter(map),
          :ok <- insert_full_object(map) do
+      {recipients, _, _} = get_recipients(map)
+
       {:ok, activity} =
         Repo.insert(%Activity{
           data: map,
           local: local,
           actor: map["actor"],
-          recipients: get_recipients(map)
+          recipients: recipients
         })
 
       Notification.create_notifications(activity)
@@ -66,6 +91,11 @@ defmodule Pleroma.Web.ActivityPub.ActivityPub do
           Pleroma.Web.Streamer.stream("public:local", activity)
         end
 
+        activity.data["object"]
+        |> Map.get("tag", [])
+        |> Enum.filter(fn tag -> is_bitstring(tag) end)
+        |> Enum.map(fn tag -> Pleroma.Web.Streamer.stream("hashtag:" <> tag, activity) end)
+
         if activity.data["object"]["attachment"] != [] do
           Pleroma.Web.Streamer.stream("public:media", activity)
 
@@ -241,8 +271,7 @@ defmodule Pleroma.Web.ActivityPub.ActivityPub do
       "to" => [user.follower_address, "https://www.w3.org/ns/activitystreams#Public"]
     }
 
-    with Repo.delete(object),
-         Repo.delete_all(Activity.all_non_create_by_object_ap_id_q(id)),
+    with {:ok, _} <- Object.delete(object),
          {:ok, activity} <- insert(data, local),
          :ok <- maybe_federate(activity),
          {:ok, _actor} <- User.decrease_note_count(user) do
@@ -381,6 +410,20 @@ defmodule Pleroma.Web.ActivityPub.ActivityPub do
 
   defp restrict_tag(query, _), do: query
 
+  defp restrict_to_cc(query, recipients_to, recipients_cc) do
+    from(
+      activity in query,
+      where:
+        fragment(
+          "(?->'to' \\?| ?) or (?->'cc' \\?| ?)",
+          activity.data,
+          ^recipients_to,
+          activity.data,
+          ^recipients_cc
+        )
+    )
+  end
+
   defp restrict_recipients(query, [], _user), do: query
 
   defp restrict_recipients(query, recipients, nil) do
@@ -522,9 +565,17 @@ defmodule Pleroma.Web.ActivityPub.ActivityPub do
     |> Enum.reverse()
   end
 
-  def upload(file) do
-    data = Upload.store(file, Application.get_env(:pleroma, :instance)[:dedupe_media])
-    Repo.insert(%Object{data: data})
+  def fetch_activities_bounded(recipients_to, recipients_cc, opts \\ %{}) do
+    fetch_activities_query([], opts)
+    |> restrict_to_cc(recipients_to, recipients_cc)
+    |> Repo.all()
+    |> Enum.reverse()
+  end
+
+  def upload(file, opts \\ []) do
+    with {:ok, data} <- Upload.store(file, opts) do
+      Repo.insert(%Object{data: data})
+    end
   end
 
   def user_data_from_user_object(data) do
@@ -554,19 +605,28 @@ defmodule Pleroma.Web.ActivityPub.ActivityPub do
         "locked" => locked
       },
       avatar: avatar,
-      nickname: "#{data["preferredUsername"]}@#{URI.parse(data["id"]).host}",
       name: data["name"],
       follower_address: data["followers"],
       bio: data["summary"]
     }
 
+    # nickname can be nil because of virtual actors
+    user_data =
+      if data["preferredUsername"] do
+        Map.put(
+          user_data,
+          :nickname,
+          "#{data["preferredUsername"]}@#{URI.parse(data["id"]).host}"
+        )
+      else
+        Map.put(user_data, :nickname, nil)
+      end
+
     {:ok, user_data}
   end
 
   def fetch_and_prepare_user_from_ap_id(ap_id) do
-    with {:ok, %{status_code: 200, body: body}} <-
-           @httpoison.get(ap_id, [Accept: "application/activity+json"], follow_redirect: true),
-         {:ok, data} <- Jason.decode(body) do
+    with {:ok, data} <- fetch_and_contain_remote_object_from_id(ap_id) do
       user_data_from_user_object(data)
     else
       e -> Logger.error("Could not decode user at fetch #{ap_id}, #{inspect(e)}")
@@ -593,14 +653,12 @@ defmodule Pleroma.Web.ActivityPub.ActivityPub do
     end
   end
 
-  @quarantined_instances Keyword.get(@instance, :quarantined_instances, [])
-
   def should_federate?(inbox, public) do
     if public do
       true
     else
       inbox_info = URI.parse(inbox)
-      inbox_info.host not in @quarantined_instances
+      !Enum.member?(Pleroma.Config.get([:instance, :quarantined_instances], []), inbox_info.host)
     end
   end
 
@@ -619,7 +677,7 @@ defmodule Pleroma.Web.ActivityPub.ActivityPub do
       (Pleroma.Web.Salmon.remote_users(activity) ++ followers)
       |> Enum.filter(fn user -> User.ap_enabled?(user) end)
       |> Enum.map(fn %{info: %{"source_data" => data}} ->
-        (data["endpoints"] && data["endpoints"]["sharedInbox"]) || data["inbox"]
+        (is_map(data["endpoints"]) && Map.get(data["endpoints"], "sharedInbox")) || data["inbox"]
       end)
       |> Enum.uniq()
       |> Enum.filter(fn inbox -> should_federate?(inbox, public) end)
@@ -670,27 +728,22 @@ defmodule Pleroma.Web.ActivityPub.ActivityPub do
     else
       Logger.info("Fetching #{id} via AP")
 
-      with true <- String.starts_with?(id, "http"),
-           {:ok, %{body: body, status_code: code}} when code in 200..299 <-
-             @httpoison.get(
-               id,
-               [Accept: "application/activity+json"],
-               follow_redirect: true,
-               timeout: 10000,
-               recv_timeout: 20000
-             ),
-           {:ok, data} <- Jason.decode(body),
+      with {:ok, data} <- fetch_and_contain_remote_object_from_id(id),
            nil <- Object.normalize(data),
            params <- %{
              "type" => "Create",
              "to" => data["to"],
              "cc" => data["cc"],
-             "actor" => data["attributedTo"],
+             "actor" => data["actor"] || data["attributedTo"],
              "object" => data
            },
+           :ok <- Transmogrifier.contain_origin(id, params),
            {:ok, activity} <- Transmogrifier.handle_incoming(params) do
         {:ok, Object.normalize(activity.data["object"])}
       else
+        {:error, {:reject, nil}} ->
+          {:reject, nil}
+
         object = %Object{} ->
           {:ok, object}
 
@@ -705,6 +758,27 @@ defmodule Pleroma.Web.ActivityPub.ActivityPub do
     end
   end
 
+  def fetch_and_contain_remote_object_from_id(id) do
+    Logger.info("Fetching #{id} via AP")
+
+    with true <- String.starts_with?(id, "http"),
+         {:ok, %{body: body, status_code: code}} when code in 200..299 <-
+           @httpoison.get(
+             id,
+             [Accept: "application/activity+json"],
+             follow_redirect: true,
+             timeout: 10000,
+             recv_timeout: 20000
+           ),
+         {:ok, data} <- Jason.decode(body),
+         :ok <- Transmogrifier.contain_origin_from_id(id, data) do
+      {:ok, data}
+    else
+      e ->
+        {:error, e}
+    end
+  end
+
   def is_public?(activity) do
     "https://www.w3.org/ns/activitystreams#Public" in (activity.data["to"] ++
                                                          (activity.data["cc"] || []))
@@ -719,4 +793,38 @@ defmodule Pleroma.Web.ActivityPub.ActivityPub do
     y = activity.data["to"] ++ (activity.data["cc"] || [])
     visible_for_user?(activity, nil) || Enum.any?(x, &(&1 in y))
   end
+
+  # guard
+  def entire_thread_visible_for_user?(nil, user), do: false
+
+  # child
+  def entire_thread_visible_for_user?(
+        %Activity{data: %{"object" => %{"inReplyTo" => parent_id}}} = tail,
+        user
+      )
+      when is_binary(parent_id) do
+    parent = Activity.get_in_reply_to_activity(tail)
+    visible_for_user?(tail, user) && entire_thread_visible_for_user?(parent, user)
+  end
+
+  # root
+  def entire_thread_visible_for_user?(tail, user), do: visible_for_user?(tail, user)
+
+  # filter out broken threads
+  def contain_broken_threads(%Activity{} = activity, %User{} = user) do
+    entire_thread_visible_for_user?(activity, user)
+  end
+
+  # do post-processing on a specific activity
+  def contain_activity(%Activity{} = activity, %User{} = user) do
+    contain_broken_threads(activity, user)
+  end
+
+  # do post-processing on a timeline
+  def contain_timeline(timeline, user) do
+    timeline
+    |> Enum.filter(fn activity ->
+      contain_activity(activity, user)
+    end)
+  end
 end
diff --git a/lib/pleroma/web/activity_pub/activity_pub_controller.ex b/lib/pleroma/web/activity_pub/activity_pub_controller.ex
index d337532d0..3570a75cb 100644
--- a/lib/pleroma/web/activity_pub/activity_pub_controller.ex
+++ b/lib/pleroma/web/activity_pub/activity_pub_controller.ex
@@ -3,12 +3,28 @@ defmodule Pleroma.Web.ActivityPub.ActivityPubController do
   alias Pleroma.{User, Object}
   alias Pleroma.Web.ActivityPub.{ObjectView, UserView}
   alias Pleroma.Web.ActivityPub.ActivityPub
+  alias Pleroma.Web.ActivityPub.Relay
+  alias Pleroma.Web.ActivityPub.Utils
   alias Pleroma.Web.Federator
 
   require Logger
 
   action_fallback(:errors)
 
+  plug(Pleroma.Web.FederatingPlug when action in [:inbox, :relay])
+  plug(:relay_active? when action in [:relay])
+
+  def relay_active?(conn, _) do
+    if Keyword.get(Application.get_env(:pleroma, :instance), :allow_relay) do
+      conn
+    else
+      conn
+      |> put_status(404)
+      |> json(%{error: "not found"})
+      |> halt
+    end
+  end
+
   def user(conn, %{"nickname" => nickname}) do
     with %User{} = user <- User.get_cached_by_nickname(nickname),
          {:ok, user} <- Pleroma.Web.WebFinger.ensure_keys_present(user) do
@@ -86,25 +102,54 @@ defmodule Pleroma.Web.ActivityPub.ActivityPubController do
     outbox(conn, %{"nickname" => nickname, "max_id" => nil})
   end
 
-  # TODO: Ensure that this inbox is a recipient of the message
+  def inbox(%{assigns: %{valid_signature: true}} = conn, %{"nickname" => nickname} = params) do
+    with %User{} = user <- User.get_cached_by_nickname(nickname),
+         true <- Utils.recipient_in_message(user.ap_id, params),
+         params <- Utils.maybe_splice_recipient(user.ap_id, params) do
+      Federator.enqueue(:incoming_ap_doc, params)
+      json(conn, "ok")
+    end
+  end
+
   def inbox(%{assigns: %{valid_signature: true}} = conn, params) do
     Federator.enqueue(:incoming_ap_doc, params)
     json(conn, "ok")
   end
 
+  # only accept relayed Creates
+  def inbox(conn, %{"type" => "Create"} = params) do
+    Logger.info(
+      "Signature missing or not from author, relayed Create message, fetching object from source"
+    )
+
+    ActivityPub.fetch_object_from_id(params["object"]["id"])
+
+    json(conn, "ok")
+  end
+
   def inbox(conn, params) do
     headers = Enum.into(conn.req_headers, %{})
 
-    if !String.contains?(headers["signature"] || "", params["actor"]) do
-      Logger.info("Signature not from author, relayed message, fetching from source")
-      ActivityPub.fetch_object_from_id(params["object"]["id"])
-    else
-      Logger.info("Signature error - make sure you are forwarding the HTTP Host header!")
-      Logger.info("Could not validate #{params["actor"]}")
+    if String.contains?(headers["signature"], params["actor"]) do
+      Logger.info(
+        "Signature validation error for: #{params["actor"]}, make sure you are forwarding the HTTP Host header!"
+      )
+
       Logger.info(inspect(conn.req_headers))
     end
 
-    json(conn, "ok")
+    json(conn, "error")
+  end
+
+  def relay(conn, params) do
+    with %User{} = user <- Relay.get_actor(),
+         {:ok, user} <- Pleroma.Web.WebFinger.ensure_keys_present(user) do
+      conn
+      |> put_resp_header("content-type", "application/activity+json")
+      |> json(UserView.render("user.json", %{user: user}))
+    else
+      nil -> {:error, :not_found}
+    end
   end
 
   def errors(conn, {:error, :not_found}) do
diff --git a/lib/pleroma/web/activity_pub/mrf/normalize_markup.ex b/lib/pleroma/web/activity_pub/mrf/normalize_markup.ex
new file mode 100644
index 000000000..c53cb1ad2
--- /dev/null
+++ b/lib/pleroma/web/activity_pub/mrf/normalize_markup.ex
@@ -0,0 +1,23 @@
+defmodule Pleroma.Web.ActivityPub.MRF.NormalizeMarkup do
+  alias Pleroma.HTML
+
+  @behaviour Pleroma.Web.ActivityPub.MRF
+
+  def filter(%{"type" => activity_type} = object) when activity_type == "Create" do
+    scrub_policy = Pleroma.Config.get([:mrf_normalize_markup, :scrub_policy])
+
+    child = object["object"]
+
+    content =
+      child["content"]
+      |> HTML.filter_tags(scrub_policy)
+
+    child = Map.put(child, "content", content)
+
+    object = Map.put(object, "object", child)
+
+    {:ok, object}
+  end
+
+  def filter(object), do: {:ok, object}
+end
diff --git a/lib/pleroma/web/activity_pub/mrf/reject_non_public.ex b/lib/pleroma/web/activity_pub/mrf/reject_non_public.ex
index b6936fe90..627284083 100644
--- a/lib/pleroma/web/activity_pub/mrf/reject_non_public.ex
+++ b/lib/pleroma/web/activity_pub/mrf/reject_non_public.ex
@@ -2,48 +2,45 @@ defmodule Pleroma.Web.ActivityPub.MRF.RejectNonPublic do
   alias Pleroma.User
   @behaviour Pleroma.Web.ActivityPub.MRF
 
-  @mrf_rejectnonpublic Application.get_env(:pleroma, :mrf_rejectnonpublic)
-  @allow_followersonly Keyword.get(@mrf_rejectnonpublic, :allow_followersonly)
-  @allow_direct Keyword.get(@mrf_rejectnonpublic, :allow_direct)
-
   @impl true
-  def filter(object) do
-    if object["type"] == "Create" do
-      user = User.get_cached_by_ap_id(object["actor"])
-      public = "https://www.w3.org/ns/activitystreams#Public"
-
-      # Determine visibility
-      visibility =
-        cond do
-          public in object["to"] -> "public"
-          public in object["cc"] -> "unlisted"
-          user.follower_address in object["to"] -> "followers"
-          true -> "direct"
-        end
+  def filter(%{"type" => "Create"} = object) do
+    user = User.get_cached_by_ap_id(object["actor"])
+    public = "https://www.w3.org/ns/activitystreams#Public"
 
-      case visibility do
-        "public" ->
-          {:ok, object}
+    # Determine visibility
+    visibility =
+      cond do
+        public in object["to"] -> "public"
+        public in object["cc"] -> "unlisted"
+        user.follower_address in object["to"] -> "followers"
+        true -> "direct"
+      end
+
+    policy = Pleroma.Config.get(:mrf_rejectnonpublic)
+
+    case visibility do
+      "public" ->
+        {:ok, object}
+
+      "unlisted" ->
+        {:ok, object}
 
-        "unlisted" ->
+      "followers" ->
+        with true <- Keyword.get(policy, :allow_followersonly) do
           {:ok, object}
+        else
+          _e -> {:reject, nil}
+        end
 
-        "followers" ->
-          with true <- @allow_followersonly do
-            {:ok, object}
-          else
-            _e -> {:reject, nil}
-          end
-
-        "direct" ->
-          with true <- @allow_direct do
-            {:ok, object}
-          else
-            _e -> {:reject, nil}
-          end
-      end
-    else
-      {:ok, object}
+      "direct" ->
+        with true <- Keyword.get(policy, :allow_direct) do
+          {:ok, object}
+        else
+          _e -> {:reject, nil}
+        end
     end
   end
+
+  @impl true
+  def filter(object), do: {:ok, object}
 end
diff --git a/lib/pleroma/web/activity_pub/mrf/simple_policy.ex b/lib/pleroma/web/activity_pub/mrf/simple_policy.ex
index 7fecb8a4f..86dcf5080 100644
--- a/lib/pleroma/web/activity_pub/mrf/simple_policy.ex
+++ b/lib/pleroma/web/activity_pub/mrf/simple_policy.ex
@@ -2,81 +2,92 @@ defmodule Pleroma.Web.ActivityPub.MRF.SimplePolicy do
   alias Pleroma.User
   @behaviour Pleroma.Web.ActivityPub.MRF
 
-  @mrf_policy Application.get_env(:pleroma, :mrf_simple)
+  defp check_accept(%{host: actor_host} = _actor_info, object) do
+    accepts = Pleroma.Config.get([:mrf_simple, :accept])
 
-  @accept Keyword.get(@mrf_policy, :accept)
-  defp check_accept(actor_info, object) do
-    if length(@accept) > 0 and not (actor_info.host in @accept) do
-      {:reject, nil}
-    else
-      {:ok, object}
+    cond do
+      accepts == [] -> {:ok, object}
+      actor_host == Pleroma.Config.get([Pleroma.Web.Endpoint, :url, :host]) -> {:ok, object}
+      Enum.member?(accepts, actor_host) -> {:ok, object}
+      true -> {:reject, nil}
     end
   end
 
-  @reject Keyword.get(@mrf_policy, :reject)
-  defp check_reject(actor_info, object) do
-    if actor_info.host in @reject do
+  defp check_reject(%{host: actor_host} = _actor_info, object) do
+    if Enum.member?(Pleroma.Config.get([:mrf_simple, :reject]), actor_host) do
       {:reject, nil}
     else
       {:ok, object}
     end
   end
 
-  @media_removal Keyword.get(@mrf_policy, :media_removal)
-  defp check_media_removal(actor_info, object) do
-    if actor_info.host in @media_removal do
-      child_object = Map.delete(object["object"], "attachment")
-      object = Map.put(object, "object", child_object)
-      {:ok, object}
-    else
-      {:ok, object}
-    end
+  defp check_media_removal(
+         %{host: actor_host} = _actor_info,
+         %{"type" => "Create", "object" => %{"attachement" => child_attachment}} = object
+       )
+       when length(child_attachment) > 0 do
+    object =
+      if Enum.member?(Pleroma.Config.get([:mrf_simple, :media_removal]), actor_host) do
+        child_object = Map.delete(object["object"], "attachment")
+        Map.put(object, "object", child_object)
+      else
+        object
+      end
+
+    {:ok, object}
   end
 
-  @media_nsfw Keyword.get(@mrf_policy, :media_nsfw)
-  defp check_media_nsfw(actor_info, object) do
-    child_object = object["object"]
+  defp check_media_removal(_actor_info, object), do: {:ok, object}
 
-    if actor_info.host in @media_nsfw and child_object["attachment"] != nil and
-         length(child_object["attachment"]) > 0 do
-      tags = (child_object["tag"] || []) ++ ["nsfw"]
-      child_object = Map.put(child_object, "tags", tags)
-      child_object = Map.put(child_object, "sensitive", true)
-      object = Map.put(object, "object", child_object)
-      {:ok, object}
-    else
-      {:ok, object}
-    end
+  defp check_media_nsfw(
+         %{host: actor_host} = _actor_info,
+         %{
+           "type" => "Create",
+           "object" => %{"attachment" => child_attachment} = child_object
+         } = object
+       )
+       when length(child_attachment) > 0 do
+    object =
+      if Enum.member?(Pleroma.Config.get([:mrf_simple, :media_nsfw]), actor_host) do
+        tags = (child_object["tag"] || []) ++ ["nsfw"]
+        child_object = Map.put(child_object, "tags", tags)
+        child_object = Map.put(child_object, "sensitive", true)
+        Map.put(object, "object", child_object)
+      else
+        object
+      end
+
+    {:ok, object}
   end
 
-  @ftl_removal Keyword.get(@mrf_policy, :federated_timeline_removal)
-  defp check_ftl_removal(actor_info, object) do
-    if actor_info.host in @ftl_removal do
-      user = User.get_by_ap_id(object["actor"])
+  defp check_media_nsfw(_actor_info, object), do: {:ok, object}
 
-      # flip to/cc relationship to make the post unlisted
-      object =
-        if "https://www.w3.org/ns/activitystreams#Public" in object["to"] and
-             user.follower_address in object["cc"] do
-          to =
-            List.delete(object["to"], "https://www.w3.org/ns/activitystreams#Public") ++
-              [user.follower_address]
+  defp check_ftl_removal(%{host: actor_host} = _actor_info, object) do
+    object =
+      with true <-
+             Enum.member?(
+               Pleroma.Config.get([:mrf_simple, :federated_timeline_removal]),
+               actor_host
+             ),
+           user <- User.get_cached_by_ap_id(object["actor"]),
+           true <- "https://www.w3.org/ns/activitystreams#Public" in object["to"],
+           true <- user.follower_address in object["cc"] do
+        to =
+          List.delete(object["to"], "https://www.w3.org/ns/activitystreams#Public") ++
+            [user.follower_address]
 
-          cc =
-            List.delete(object["cc"], user.follower_address) ++
-              ["https://www.w3.org/ns/activitystreams#Public"]
+        cc =
+          List.delete(object["cc"], user.follower_address) ++
+            ["https://www.w3.org/ns/activitystreams#Public"]
 
-          object
-          |> Map.put("to", to)
-          |> Map.put("cc", cc)
-        else
-          object
-        end
+        object
+        |> Map.put("to", to)
+        |> Map.put("cc", cc)
+      else
+        _ -> object
+      end
 
-      {:ok, object}
-    else
-      {:ok, object}
-    end
+    {:ok, object}
   end
 
   @impl true
diff --git a/lib/pleroma/web/activity_pub/mrf/user_allowlist.ex b/lib/pleroma/web/activity_pub/mrf/user_allowlist.ex
new file mode 100644
index 000000000..3503d8692
--- /dev/null
+++ b/lib/pleroma/web/activity_pub/mrf/user_allowlist.ex
@@ -0,0 +1,23 @@
+defmodule Pleroma.Web.ActivityPub.MRF.UserAllowListPolicy do
+  alias Pleroma.Config
+
+  @behaviour Pleroma.Web.ActivityPub.MRF
+
+  defp filter_by_list(object, []), do: {:ok, object}
+
+  defp filter_by_list(%{"actor" => actor} = object, allow_list) do
+    if actor in allow_list do
+      {:ok, object}
+    else
+      {:reject, nil}
+    end
+  end
+
+  @impl true
+  def filter(object) do
+    actor_info = URI.parse(object["actor"])
+    allow_list = Config.get([:mrf_user_allowlist, String.to_atom(actor_info.host)], [])
+
+    filter_by_list(object, allow_list)
+  end
+end
diff --git a/lib/pleroma/web/activity_pub/relay.ex b/lib/pleroma/web/activity_pub/relay.ex
new file mode 100644
index 000000000..fcdc6b1c0
--- /dev/null
+++ b/lib/pleroma/web/activity_pub/relay.ex
@@ -0,0 +1,46 @@
+defmodule Pleroma.Web.ActivityPub.Relay do
+  alias Pleroma.{User, Object, Activity}
+  alias Pleroma.Web.ActivityPub.ActivityPub
+  require Logger
+
+  def get_actor do
+    User.get_or_create_instance_user()
+  end
+
+  def follow(target_instance) do
+    with %User{} = local_user <- get_actor(),
+         %User{} = target_user <- User.get_or_fetch_by_ap_id(target_instance),
+         {:ok, activity} <- ActivityPub.follow(local_user, target_user) do
+      Logger.info("relay: followed instance: #{target_instance}; id=#{activity.data["id"]}")
+      {:ok, activity}
+    else
+      e ->
+        Logger.error("error: #{inspect(e)}")
+        {:error, e}
+    end
+  end
+
+  def unfollow(target_instance) do
+    with %User{} = local_user <- get_actor(),
+         %User{} = target_user <- User.get_or_fetch_by_ap_id(target_instance),
+         {:ok, activity} <- ActivityPub.unfollow(local_user, target_user) do
+      Logger.info("relay: unfollowed instance: #{target_instance}: id=#{activity.data["id"]}")
+      {:ok, activity}
+    else
+      e ->
+        Logger.error("error: #{inspect(e)}")
+        {:error, e}
+    end
+  end
+
+  def publish(%Activity{data: %{"type" => "Create"}} = activity) do
+    with %User{} = user <- get_actor(),
+         %Object{} = object <- Object.normalize(activity.data["object"]["id"]) do
+      ActivityPub.announce(user, object)
+    else
+      e -> Logger.error("error: #{inspect(e)}")
+    end
+  end
+
+  def publish(_), do: nil
+end
diff --git a/lib/pleroma/web/activity_pub/transmogrifier.ex b/lib/pleroma/web/activity_pub/transmogrifier.ex
index 1367bc7e3..5864855b0 100644
--- a/lib/pleroma/web/activity_pub/transmogrifier.ex
+++ b/lib/pleroma/web/activity_pub/transmogrifier.ex
@@ -21,13 +21,46 @@ defmodule Pleroma.Web.ActivityPub.Transmogrifier do
     if is_binary(Enum.at(actor, 0)) do
       Enum.at(actor, 0)
     else
-      Enum.find(actor, fn %{"type" => type} -> type == "Person" end)
+      Enum.find(actor, fn %{"type" => type} -> type in ["Person", "Service", "Application"] end)
       |> Map.get("id")
     end
   end
 
-  def get_actor(%{"actor" => actor}) when is_map(actor) do
-    actor["id"]
+  def get_actor(%{"actor" => %{"id" => id}}) when is_bitstring(id) do
+    id
+  end
+
+  def get_actor(%{"actor" => nil, "attributedTo" => actor}) when not is_nil(actor) do
+    get_actor(%{"actor" => actor})
+  end
+
+  @doc """
+  Checks that an imported AP object's actor matches the domain it came from.
+  """
+  def contain_origin(id, %{"actor" => nil}), do: :error
+
+  def contain_origin(id, %{"actor" => actor} = params) do
+    id_uri = URI.parse(id)
+    actor_uri = URI.parse(get_actor(params))
+
+    if id_uri.host == actor_uri.host do
+      :ok
+    else
+      :error
+    end
+  end
+
+  def contain_origin_from_id(id, %{"id" => nil}), do: :error
+
+  def contain_origin_from_id(id, %{"id" => other_id} = params) do
+    id_uri = URI.parse(id)
+    other_uri = URI.parse(other_id)
+
+    if id_uri.host == other_uri.host do
+      :ok
+    else
+      :error
+    end
   end
 
   @doc """
@@ -37,6 +70,7 @@ defmodule Pleroma.Web.ActivityPub.Transmogrifier do
     object
     |> fix_actor
     |> fix_attachments
+    |> fix_url
     |> fix_context
     |> fix_in_reply_to
     |> fix_emoji
@@ -82,9 +116,25 @@ defmodule Pleroma.Web.ActivityPub.Transmogrifier do
     object
   end
 
-  def fix_in_reply_to(%{"inReplyTo" => in_reply_to_id} = object)
-      when not is_nil(in_reply_to_id) do
-    case ActivityPub.fetch_object_from_id(in_reply_to_id) do
+  def fix_in_reply_to(%{"inReplyTo" => in_reply_to} = object)
+      when not is_nil(in_reply_to) do
+    in_reply_to_id =
+      cond do
+        is_bitstring(in_reply_to) ->
+          in_reply_to
+
+        is_map(in_reply_to) && is_bitstring(in_reply_to["id"]) ->
+          in_reply_to["id"]
+
+        is_list(in_reply_to) && is_bitstring(Enum.at(in_reply_to, 0)) ->
+          Enum.at(in_reply_to, 0)
+
+        # Maybe I should output an error too?
+        true ->
+          ""
+      end
+
+    case fetch_obj_helper(in_reply_to_id) do
       {:ok, replied_object} ->
         with %Activity{} = activity <-
                Activity.get_create_activity_by_object_ap_id(replied_object.data["id"]) do
@@ -96,12 +146,12 @@ defmodule Pleroma.Web.ActivityPub.Transmogrifier do
           |> Map.put("context", replied_object.data["context"] || object["conversation"])
         else
           e ->
-            Logger.error("Couldn't fetch #{object["inReplyTo"]} #{inspect(e)}")
+            Logger.error("Couldn't fetch \"#{inspect(in_reply_to_id)}\", error: #{inspect(e)}")
             object
         end
 
       e ->
-        Logger.error("Couldn't fetch #{object["inReplyTo"]} #{inspect(e)}")
+        Logger.error("Couldn't fetch \"#{inspect(in_reply_to_id)}\", error: #{inspect(e)}")
         object
     end
   end
@@ -116,9 +166,9 @@ defmodule Pleroma.Web.ActivityPub.Transmogrifier do
     |> Map.put("conversation", context)
   end
 
-  def fix_attachments(object) do
+  def fix_attachments(%{"attachment" => attachment} = object) when is_list(attachment) do
     attachments =
-      (object["attachment"] || [])
+      attachment
       |> Enum.map(fn data ->
         url = [%{"type" => "Link", "mediaType" => data["mediaType"], "href" => data["url"]}]
         Map.put(data, "url", url)
@@ -128,21 +178,41 @@ defmodule Pleroma.Web.ActivityPub.Transmogrifier do
     |> Map.put("attachment", attachments)
   end
 
-  def fix_emoji(object) do
-    tags = object["tag"] || []
+  def fix_attachments(%{"attachment" => attachment} = object) when is_map(attachment) do
+    Map.put(object, "attachment", [attachment])
+    |> fix_attachments()
+  end
+
+  def fix_attachments(object), do: object
+
+  def fix_url(%{"url" => url} = object) when is_map(url) do
+    object
+    |> Map.put("url", url["href"])
+  end
+
+  def fix_url(%{"url" => url} = object) when is_list(url) do
+    first_element = Enum.at(url, 0)
+
+    url_string =
+      cond do
+        is_bitstring(first_element) -> first_element
+        is_map(first_element) -> first_element["href"] || ""
+        true -> ""
+      end
+
+    object
+    |> Map.put("url", url_string)
+  end
+
+  def fix_url(object), do: object
+
+  def fix_emoji(%{"tag" => tags} = object) when is_list(tags) do
     emoji = tags |> Enum.filter(fn data -> data["type"] == "Emoji" and data["icon"] end)
 
     emoji =
       emoji
       |> Enum.reduce(%{}, fn data, mapping ->
-        name = data["name"]
-
-        name =
-          if String.starts_with?(name, ":") do
-            name |> String.slice(1..-2)
-          else
-            name
-          end
+        name = String.trim(data["name"], ":")
 
         mapping |> Map.put(name, data["icon"]["url"])
       end)
@@ -154,18 +224,37 @@ defmodule Pleroma.Web.ActivityPub.Transmogrifier do
     |> Map.put("emoji", emoji)
   end
 
-  def fix_tag(object) do
+  def fix_emoji(%{"tag" => %{"type" => "Emoji"} = tag} = object) do
+    name = String.trim(tag["name"], ":")
+    emoji = %{name => tag["icon"]["url"]}
+
+    object
+    |> Map.put("emoji", emoji)
+  end
+
+  def fix_emoji(object), do: object
+
+  def fix_tag(%{"tag" => tag} = object) when is_list(tag) do
     tags =
-      (object["tag"] || [])
+      tag
       |> Enum.filter(fn data -> data["type"] == "Hashtag" and data["name"] end)
       |> Enum.map(fn data -> String.slice(data["name"], 1..-1) end)
 
-    combined = (object["tag"] || []) ++ tags
+    combined = tag ++ tags
 
     object
     |> Map.put("tag", combined)
   end
 
+  def fix_tag(%{"tag" => %{"type" => "Hashtag", "name" => hashtag} = tag} = object) do
+    combined = [tag, String.slice(hashtag, 1..-1)]
+
+    object
+    |> Map.put("tag", combined)
+  end
+
+  def fix_tag(object), do: object
+
   # content map usually only has one language so this will do for now.
   def fix_content_map(%{"contentMap" => content_map} = object) do
     content_groups = Map.to_list(content_map)
@@ -187,7 +276,7 @@ defmodule Pleroma.Web.ActivityPub.Transmogrifier do
   # - tags
   # - emoji
   def handle_incoming(%{"type" => "Create", "object" => %{"type" => objtype} = object} = data)
-      when objtype in ["Article", "Note", "Video"] do
+      when objtype in ["Article", "Note", "Video", "Page"] do
     actor = get_actor(data)
 
     data =
@@ -271,8 +360,10 @@ defmodule Pleroma.Web.ActivityPub.Transmogrifier do
   def handle_incoming(
         %{"type" => "Accept", "object" => follow_object, "actor" => actor, "id" => id} = data
       ) do
-    with %User{} = followed <- User.get_or_fetch_by_ap_id(actor),
+    with actor <- get_actor(data),
+         %User{} = followed <- User.get_or_fetch_by_ap_id(actor),
          {:ok, follow_activity} <- get_follow_activity(follow_object, followed),
+         {:ok, follow_activity} <- Utils.update_follow_state(follow_activity, "accept"),
          %User{local: true} = follower <- User.get_cached_by_ap_id(follow_activity.data["actor"]),
          {:ok, activity} <-
            ActivityPub.accept(%{
@@ -295,8 +386,10 @@ defmodule Pleroma.Web.ActivityPub.Transmogrifier do
   def handle_incoming(
         %{"type" => "Reject", "object" => follow_object, "actor" => actor, "id" => id} = data
       ) do
-    with %User{} = followed <- User.get_or_fetch_by_ap_id(actor),
+    with actor <- get_actor(data),
+         %User{} = followed <- User.get_or_fetch_by_ap_id(actor),
          {:ok, follow_activity} <- get_follow_activity(follow_object, followed),
+         {:ok, follow_activity} <- Utils.update_follow_state(follow_activity, "reject"),
          %User{local: true} = follower <- User.get_cached_by_ap_id(follow_activity.data["actor"]),
          {:ok, activity} <-
            ActivityPub.accept(%{
@@ -315,11 +408,11 @@ defmodule Pleroma.Web.ActivityPub.Transmogrifier do
   end
 
   def handle_incoming(
-        %{"type" => "Like", "object" => object_id, "actor" => actor, "id" => id} = _data
+        %{"type" => "Like", "object" => object_id, "actor" => actor, "id" => id} = data
       ) do
-    with %User{} = actor <- User.get_or_fetch_by_ap_id(actor),
-         {:ok, object} <-
-           get_obj_helper(object_id) || ActivityPub.fetch_object_from_id(object_id),
+    with actor <- get_actor(data),
+         %User{} = actor <- User.get_or_fetch_by_ap_id(actor),
+         {:ok, object} <- get_obj_helper(object_id) || fetch_obj_helper(object_id),
          {:ok, activity, _object} <- ActivityPub.like(actor, object, id, false) do
       {:ok, activity}
     else
@@ -328,11 +421,11 @@ defmodule Pleroma.Web.ActivityPub.Transmogrifier do
   end
 
   def handle_incoming(
-        %{"type" => "Announce", "object" => object_id, "actor" => actor, "id" => id} = _data
+        %{"type" => "Announce", "object" => object_id, "actor" => actor, "id" => id} = data
       ) do
-    with %User{} = actor <- User.get_or_fetch_by_ap_id(actor),
-         {:ok, object} <-
-           get_obj_helper(object_id) || ActivityPub.fetch_object_from_id(object_id),
+    with actor <- get_actor(data),
+         %User{} = actor <- User.get_or_fetch_by_ap_id(actor),
+         {:ok, object} <- get_obj_helper(object_id) || fetch_obj_helper(object_id),
          {:ok, activity, _object} <- ActivityPub.announce(actor, object, id, false) do
       {:ok, activity}
     else
@@ -341,9 +434,10 @@ defmodule Pleroma.Web.ActivityPub.Transmogrifier do
   end
 
   def handle_incoming(
-        %{"type" => "Update", "object" => %{"type" => "Person"} = object, "actor" => actor_id} =
+        %{"type" => "Update", "object" => %{"type" => object_type} = object, "actor" => actor_id} =
           data
-      ) do
+      )
+      when object_type in ["Person", "Application", "Service", "Organization"] do
     with %User{ap_id: ^actor_id} = actor <- User.get_by_ap_id(object["id"]) do
       {:ok, new_user_data} = ActivityPub.user_data_from_user_object(object)
 
@@ -373,15 +467,20 @@ defmodule Pleroma.Web.ActivityPub.Transmogrifier do
     end
   end
 
-  # TODO: Make secure.
+  # TODO: We presently assume that any actor on the same origin domain as the object being
+  # deleted has the rights to delete that object.  A better way to validate whether or not
+  # the object should be deleted is to refetch the object URI, which should return either
+  # an error or a tombstone.  This would allow us to verify that a deletion actually took
+  # place.
   def handle_incoming(
-        %{"type" => "Delete", "object" => object_id, "actor" => actor, "id" => _id} = _data
+        %{"type" => "Delete", "object" => object_id, "actor" => _actor, "id" => _id} = data
       ) do
     object_id = Utils.get_ap_id(object_id)
 
-    with %User{} = _actor <- User.get_or_fetch_by_ap_id(actor),
-         {:ok, object} <-
-           get_obj_helper(object_id) || ActivityPub.fetch_object_from_id(object_id),
+    with actor <- get_actor(data),
+         %User{} = actor <- User.get_or_fetch_by_ap_id(actor),
+         {:ok, object} <- get_obj_helper(object_id) || fetch_obj_helper(object_id),
+         :ok <- contain_origin(actor.ap_id, object.data),
          {:ok, activity} <- ActivityPub.delete(object, false) do
       {:ok, activity}
     else
@@ -395,11 +494,11 @@ defmodule Pleroma.Web.ActivityPub.Transmogrifier do
           "object" => %{"type" => "Announce", "object" => object_id},
           "actor" => actor,
           "id" => id
-        } = _data
+        } = data
       ) do
-    with %User{} = actor <- User.get_or_fetch_by_ap_id(actor),
-         {:ok, object} <-
-           get_obj_helper(object_id) || ActivityPub.fetch_object_from_id(object_id),
+    with actor <- get_actor(data),
+         %User{} = actor <- User.get_or_fetch_by_ap_id(actor),
+         {:ok, object} <- get_obj_helper(object_id) || fetch_obj_helper(object_id),
          {:ok, activity, _} <- ActivityPub.unannounce(actor, object, id, false) do
       {:ok, activity}
     else
@@ -425,9 +524,6 @@ defmodule Pleroma.Web.ActivityPub.Transmogrifier do
     end
   end
 
-  @ap_config Application.get_env(:pleroma, :activitypub)
-  @accept_blocks Keyword.get(@ap_config, :accept_blocks)
-
   def handle_incoming(
         %{
           "type" => "Undo",
@@ -436,7 +532,7 @@ defmodule Pleroma.Web.ActivityPub.Transmogrifier do
           "id" => id
         } = _data
       ) do
-    with true <- @accept_blocks,
+    with true <- Pleroma.Config.get([:activitypub, :accept_blocks]),
          %User{local: true} = blocked <- User.get_cached_by_ap_id(blocked),
          %User{} = blocker <- User.get_or_fetch_by_ap_id(blocker),
          {:ok, activity} <- ActivityPub.unblock(blocker, blocked, id, false) do
@@ -450,7 +546,7 @@ defmodule Pleroma.Web.ActivityPub.Transmogrifier do
   def handle_incoming(
         %{"type" => "Block", "object" => blocked, "actor" => blocker, "id" => id} = data
       ) do
-    with true <- @accept_blocks,
+    with true <- Pleroma.Config.get([:activitypub, :accept_blocks]),
          %User{local: true} = blocked = User.get_cached_by_ap_id(blocked),
          %User{} = blocker = User.get_or_fetch_by_ap_id(blocker),
          {:ok, activity} <- ActivityPub.block(blocker, blocked, id, false) do
@@ -468,11 +564,11 @@ defmodule Pleroma.Web.ActivityPub.Transmogrifier do
           "object" => %{"type" => "Like", "object" => object_id},
           "actor" => actor,
           "id" => id
-        } = _data
+        } = data
       ) do
-    with %User{} = actor <- User.get_or_fetch_by_ap_id(actor),
-         {:ok, object} <-
-           get_obj_helper(object_id) || ActivityPub.fetch_object_from_id(object_id),
+    with actor <- get_actor(data),
+         %User{} = actor <- User.get_or_fetch_by_ap_id(actor),
+         {:ok, object} <- get_obj_helper(object_id) || fetch_obj_helper(object_id),
          {:ok, activity, _, _} <- ActivityPub.unlike(actor, object, id, false) do
       {:ok, activity}
     else
@@ -482,6 +578,9 @@ defmodule Pleroma.Web.ActivityPub.Transmogrifier do
 
   def handle_incoming(_), do: :error
 
+  def fetch_obj_helper(id) when is_bitstring(id), do: ActivityPub.fetch_object_from_id(id)
+  def fetch_obj_helper(obj) when is_map(obj), do: ActivityPub.fetch_object_from_id(obj["id"])
+
   def get_obj_helper(id) do
     if object = Object.normalize(id), do: {:ok, object}, else: nil
   end
@@ -508,6 +607,8 @@ defmodule Pleroma.Web.ActivityPub.Transmogrifier do
     |> prepare_attachments
     |> set_conversation
     |> set_reply_to_uri
+    |> strip_internal_fields
+    |> strip_internal_tags
   end
 
   #  @doc
@@ -523,7 +624,7 @@ defmodule Pleroma.Web.ActivityPub.Transmogrifier do
     data =
       data
       |> Map.put("object", object)
-      |> Map.put("@context", "https://www.w3.org/ns/activitystreams")
+      |> Map.merge(Utils.make_json_ld_header())
 
     {:ok, data}
   end
@@ -542,7 +643,7 @@ defmodule Pleroma.Web.ActivityPub.Transmogrifier do
       data =
         data
         |> Map.put("object", object)
-        |> Map.put("@context", "https://www.w3.org/ns/activitystreams")
+        |> Map.merge(Utils.make_json_ld_header())
 
       {:ok, data}
     end
@@ -560,7 +661,7 @@ defmodule Pleroma.Web.ActivityPub.Transmogrifier do
       data =
         data
         |> Map.put("object", object)
-        |> Map.put("@context", "https://www.w3.org/ns/activitystreams")
+        |> Map.merge(Utils.make_json_ld_header())
 
       {:ok, data}
     end
@@ -570,14 +671,14 @@ defmodule Pleroma.Web.ActivityPub.Transmogrifier do
     data =
       data
       |> maybe_fix_object_url
-      |> Map.put("@context", "https://www.w3.org/ns/activitystreams")
+      |> Map.merge(Utils.make_json_ld_header())
 
     {:ok, data}
   end
 
   def maybe_fix_object_url(data) do
     if is_binary(data["object"]) and not String.starts_with?(data["object"], "http") do
-      case ActivityPub.fetch_object_from_id(data["object"]) do
+      case fetch_obj_helper(data["object"]) do
         {:ok, relative_object} ->
           if relative_object.data["external_url"] do
             _data =
@@ -612,12 +713,9 @@ defmodule Pleroma.Web.ActivityPub.Transmogrifier do
   end
 
   def add_mention_tags(object) do
-    recipients = object["to"] ++ (object["cc"] || [])
-
     mentions =
-      recipients
-      |> Enum.map(fn ap_id -> User.get_cached_by_ap_id(ap_id) end)
-      |> Enum.filter(& &1)
+      object
+      |> Utils.get_notified_from_object()
       |> Enum.map(fn user ->
         %{"type" => "Mention", "href" => user.ap_id, "name" => "@#{user.nickname}"}
       end)
@@ -677,6 +775,29 @@ defmodule Pleroma.Web.ActivityPub.Transmogrifier do
     |> Map.put("attachment", attachments)
   end
 
+  defp strip_internal_fields(object) do
+    object
+    |> Map.drop([
+      "likes",
+      "like_count",
+      "announcements",
+      "announcement_count",
+      "emoji",
+      "context_id"
+    ])
+  end
+
+  defp strip_internal_tags(%{"tag" => tags} = object) do
+    tags =
+      tags
+      |> Enum.filter(fn x -> is_map(x) end)
+
+    object
+    |> Map.put("tag", tags)
+  end
+
+  defp strip_internal_tags(object), do: object
+
   defp user_upgrade_task(user) do
     old_follower_address = User.ap_followers(user)
 
diff --git a/lib/pleroma/web/activity_pub/utils.ex b/lib/pleroma/web/activity_pub/utils.ex
index 7cdc1656b..549148989 100644
--- a/lib/pleroma/web/activity_pub/utils.ex
+++ b/lib/pleroma/web/activity_pub/utils.ex
@@ -1,11 +1,13 @@
 defmodule Pleroma.Web.ActivityPub.Utils do
-  alias Pleroma.{Repo, Web, Object, Activity, User}
+  alias Pleroma.{Repo, Web, Object, Activity, User, Notification}
   alias Pleroma.Web.Router.Helpers
   alias Pleroma.Web.Endpoint
   alias Ecto.{Changeset, UUID}
   import Ecto.Query
   require Logger
 
+  @supported_object_types ["Article", "Note", "Video", "Page"]
+
   # Some implementations send the actor URI as the actor field, others send the entire actor object,
   # so figure out what the actor's URI is based on what we have.
   def get_ap_id(object) do
@@ -19,22 +21,58 @@ defmodule Pleroma.Web.ActivityPub.Utils do
     Map.put(params, "actor", get_ap_id(params["actor"]))
   end
 
+  defp recipient_in_collection(ap_id, coll) when is_binary(coll), do: ap_id == coll
+  defp recipient_in_collection(ap_id, coll) when is_list(coll), do: ap_id in coll
+  defp recipient_in_collection(_, _), do: false
+
+  def recipient_in_message(ap_id, params) do
+    cond do
+      recipient_in_collection(ap_id, params["to"]) ->
+        true
+
+      recipient_in_collection(ap_id, params["cc"]) ->
+        true
+
+      recipient_in_collection(ap_id, params["bto"]) ->
+        true
+
+      recipient_in_collection(ap_id, params["bcc"]) ->
+        true
+
+      # if the message is unaddressed at all, then assume it is directly addressed
+      # to the recipient
+      !params["to"] && !params["cc"] && !params["bto"] && !params["bcc"] ->
+        true
+
+      true ->
+        false
+    end
+  end
+
+  defp extract_list(target) when is_binary(target), do: [target]
+  defp extract_list(lst) when is_list(lst), do: lst
+  defp extract_list(_), do: []
+
+  def maybe_splice_recipient(ap_id, params) do
+    need_splice =
+      !recipient_in_collection(ap_id, params["to"]) &&
+        !recipient_in_collection(ap_id, params["cc"])
+
+    cc_list = extract_list(params["cc"])
+
+    if need_splice do
+      params
+      |> Map.put("cc", [ap_id | cc_list])
+    else
+      params
+    end
+  end
+
   def make_json_ld_header do
     %{
       "@context" => [
         "https://www.w3.org/ns/activitystreams",
-        "https://w3id.org/security/v1",
-        %{
-          "manuallyApprovesFollowers" => "as:manuallyApprovesFollowers",
-          "sensitive" => "as:sensitive",
-          "Hashtag" => "as:Hashtag",
-          "ostatus" => "http://ostatus.org#",
-          "atomUri" => "ostatus:atomUri",
-          "inReplyToAtomUri" => "ostatus:inReplyToAtomUri",
-          "conversation" => "ostatus:conversation",
-          "toot" => "http://joinmastodon.org/ns#",
-          "Emoji" => "toot:Emoji"
-        }
+        "#{Web.base_url()}/schemas/litepub-0.1.jsonld"
       ]
     }
   end
@@ -59,6 +97,21 @@ defmodule Pleroma.Web.ActivityPub.Utils do
     "#{Web.base_url()}/#{type}/#{UUID.generate()}"
   end
 
+  def get_notified_from_object(%{"type" => type} = object) when type in @supported_object_types do
+    fake_create_activity = %{
+      "to" => object["to"],
+      "cc" => object["cc"],
+      "type" => "Create",
+      "object" => object
+    }
+
+    Notification.get_notified_from_activity(%Activity{data: fake_create_activity}, false)
+  end
+
+  def get_notified_from_object(object) do
+    Notification.get_notified_from_activity(%Activity{data: object}, false)
+  end
+
   def create_context(context) do
     context = context || generate_id("contexts")
     changeset = Object.context_mapping(context)
@@ -128,7 +181,7 @@ defmodule Pleroma.Web.ActivityPub.Utils do
   Inserts a full object if it is contained in an activity.
   """
   def insert_full_object(%{"object" => %{"type" => type} = object_data})
-      when is_map(object_data) and type in ["Article", "Note", "Video"] do
+      when is_map(object_data) and type in @supported_object_types do
     with {:ok, _} <- Object.create(object_data) do
       :ok
     end
@@ -247,11 +300,11 @@ defmodule Pleroma.Web.ActivityPub.Utils do
       "actor" => follower_id,
       "to" => [followed_id],
       "cc" => ["https://www.w3.org/ns/activitystreams#Public"],
-      "object" => followed_id
+      "object" => followed_id,
+      "state" => "pending"
     }
 
     data = if activity_id, do: Map.put(data, "id", activity_id), else: data
-    data = if User.locked?(followed), do: Map.put(data, "state", "pending"), else: data
 
     data
   end
@@ -306,6 +359,24 @@ defmodule Pleroma.Web.ActivityPub.Utils do
   @doc """
   Make announce activity data for the given actor and object
   """
+  # for relayed messages, we only want to send to subscribers
+  def make_announce_data(
+        %User{ap_id: ap_id, nickname: nil} = user,
+        %Object{data: %{"id" => id}} = object,
+        activity_id
+      ) do
+    data = %{
+      "type" => "Announce",
+      "actor" => ap_id,
+      "object" => id,
+      "to" => [user.follower_address],
+      "cc" => [],
+      "context" => object.data["context"]
+    }
+
+    if activity_id, do: Map.put(data, "id", activity_id), else: data
+  end
+
   def make_announce_data(
         %User{ap_id: ap_id} = user,
         %Object{data: %{"id" => id}} = object,
@@ -360,7 +431,12 @@ defmodule Pleroma.Web.ActivityPub.Utils do
     if activity_id, do: Map.put(data, "id", activity_id), else: data
   end
 
-  def add_announce_to_object(%Activity{data: %{"actor" => actor}}, object) do
+  def add_announce_to_object(
+        %Activity{
+          data: %{"actor" => actor, "cc" => ["https://www.w3.org/ns/activitystreams#Public"]}
+        },
+        object
+      ) do
     announcements =
       if is_list(object.data["announcements"]), do: object.data["announcements"], else: []
 
@@ -369,6 +445,8 @@ defmodule Pleroma.Web.ActivityPub.Utils do
     end
   end
 
+  def add_announce_to_object(_, object), do: {:ok, object}
+
   def remove_announce_from_object(%Activity{data: %{"actor" => actor}}, object) do
     announcements =
       if is_list(object.data["announcements"]), do: object.data["announcements"], else: []
diff --git a/lib/pleroma/web/activity_pub/views/object_view.ex b/lib/pleroma/web/activity_pub/views/object_view.ex
index cc0b0556b..ff664636c 100644
--- a/lib/pleroma/web/activity_pub/views/object_view.ex
+++ b/lib/pleroma/web/activity_pub/views/object_view.ex
@@ -1,27 +1,34 @@
 defmodule Pleroma.Web.ActivityPub.ObjectView do
   use Pleroma.Web, :view
+  alias Pleroma.{Object, Activity}
   alias Pleroma.Web.ActivityPub.Transmogrifier
 
-  def render("object.json", %{object: object}) do
-    base = %{
-      "@context" => [
-        "https://www.w3.org/ns/activitystreams",
-        "https://w3id.org/security/v1",
-        %{
-          "manuallyApprovesFollowers" => "as:manuallyApprovesFollowers",
-          "sensitive" => "as:sensitive",
-          "Hashtag" => "as:Hashtag",
-          "ostatus" => "http://ostatus.org#",
-          "atomUri" => "ostatus:atomUri",
-          "inReplyToAtomUri" => "ostatus:inReplyToAtomUri",
-          "conversation" => "ostatus:conversation",
-          "toot" => "http://joinmastodon.org/ns#",
-          "Emoji" => "toot:Emoji"
-        }
-      ]
-    }
+  def render("object.json", %{object: %Object{} = object}) do
+    base = Pleroma.Web.ActivityPub.Utils.make_json_ld_header()
 
     additional = Transmogrifier.prepare_object(object.data)
     Map.merge(base, additional)
   end
+
+  def render("object.json", %{object: %Activity{data: %{"type" => "Create"}} = activity}) do
+    base = Pleroma.Web.ActivityPub.Utils.make_json_ld_header()
+    object = Object.normalize(activity.data["object"])
+
+    additional =
+      Transmogrifier.prepare_object(activity.data)
+      |> Map.put("object", Transmogrifier.prepare_object(object.data))
+
+    Map.merge(base, additional)
+  end
+
+  def render("object.json", %{object: %Activity{} = activity}) do
+    base = Pleroma.Web.ActivityPub.Utils.make_json_ld_header()
+    object = Object.normalize(activity.data["object"])
+
+    additional =
+      Transmogrifier.prepare_object(activity.data)
+      |> Map.put("object", object.data["id"])
+
+    Map.merge(base, additional)
+  end
 end
diff --git a/lib/pleroma/web/activity_pub/views/user_view.ex b/lib/pleroma/web/activity_pub/views/user_view.ex
index 0b1d5a9fa..eb335813d 100644
--- a/lib/pleroma/web/activity_pub/views/user_view.ex
+++ b/lib/pleroma/web/activity_pub/views/user_view.ex
@@ -9,6 +9,35 @@ defmodule Pleroma.Web.ActivityPub.UserView do
   alias Pleroma.Web.ActivityPub.Utils
   import Ecto.Query
 
+  # the instance itself is not a Person, but instead an Application
+  def render("user.json", %{user: %{nickname: nil} = user}) do
+    {:ok, user} = WebFinger.ensure_keys_present(user)
+    {:ok, _, public_key} = Salmon.keys_from_pem(user.info["keys"])
+    public_key = :public_key.pem_entry_encode(:SubjectPublicKeyInfo, public_key)
+    public_key = :public_key.pem_encode([public_key])
+
+    %{
+      "id" => user.ap_id,
+      "type" => "Application",
+      "following" => "#{user.ap_id}/following",
+      "followers" => "#{user.ap_id}/followers",
+      "inbox" => "#{user.ap_id}/inbox",
+      "name" => "Pleroma",
+      "summary" => "Virtual actor for Pleroma relay",
+      "url" => user.ap_id,
+      "manuallyApprovesFollowers" => false,
+      "publicKey" => %{
+        "id" => "#{user.ap_id}#main-key",
+        "owner" => user.ap_id,
+        "publicKeyPem" => public_key
+      },
+      "endpoints" => %{
+        "sharedInbox" => "#{Pleroma.Web.Endpoint.url()}/inbox"
+      }
+    }
+    |> Map.merge(Utils.make_json_ld_header())
+  end
+
   def render("user.json", %{user: user}) do
     {:ok, user} = WebFinger.ensure_keys_present(user)
     {:ok, _, public_key} = Salmon.keys_from_pem(user.info["keys"])
@@ -42,7 +71,8 @@ defmodule Pleroma.Web.ActivityPub.UserView do
       "image" => %{
         "type" => "Image",
         "url" => User.banner_url(user)
-      }
+      },
+      "tag" => user.info["source_data"]["tag"] || []
     }
     |> Map.merge(Utils.make_json_ld_header())
   end