@@ -0,0 +1,52 @@
+defmodule Blog.Chat.Presence do
+  @moduledoc """
+  Tracks presence information for connected chat users.
+
+  Uses Phoenix.Presence to maintain a real-time list of connected users
+  and provides functions for tracking and querying user presence.
+  """
+
+  use Phoenix.Presence,
+    otp_app: :blog,
+    pubsub_server: Blog.PubSub
+
+  alias Blog.Chat.Presence
+
+  @presence_topic "allowed_chat:presence"
+
+  @doc """
+  Returns the topic used for presence tracking.
+  """
+  def topic, do: @presence_topic
+
+  @doc """
+  Tracks a user's presence when they connect to the chat.
+  """
+  def track_user(user_id) do
+    Presence.track(
+      self(),
+      @presence_topic,
+      user_id,
+      %{
+        online_at: DateTime.utc_now(),
+        status: "online"
+      }
+    )
+  end
+
+  @doc """
+  Gets the current count of online users.
+  """
+  def list_online_users do
+    Presence.list(@presence_topic)
+  end
+
+  @doc """
+  Returns the count of online users.
+  """
+  def count_online_users do
+    @presence_topic
+    |> Presence.list()
+    |> map_size()
+  end
+end