centralizing pubsub topics

lib/elixir_ai/pubsub_topics.ex

@@ -0,0 +1,6 @@
+defmodule ElixirAi.PubsubTopics do
+
+  def conversation_message_topic(name), do: "conversation_messages:#{name}"
+  def chat_topic(name), do: "ai_chat:#{name}"
+  def providers_topic, do: "providers"
+end