Update

lib/nulla_web/controllers/activitypub/activity_json.ex

@@ -0,0 +1,21 @@
+defmodule NullaWeb.ActivityPub.ActivityJSON do
+  alias Nulla.Activities.Activity
+
+  @doc """
+  Renders a single activity.
+  """
+  def show(activity) do
+    data(activity)
+  end
+
+  defp data(%Activity{} = activity) do
+    Jason.OrderedObject.new(
+      id: activity.ap_id,
+      type: activity.type,
+      actor: activity.actor,
+      object: activity.object,
+      to: activity.to,
+      cc: activity.cc
+    )
+  end
+end