Extract OpenAI.Completion struct

lib/music_library/records.ex

@@ -191,15 +191,17 @@ defmodule MusicLibrary.Records do
       |> Enum.map(fn a -> a.name end)
       |> Enum.join(",")
 
-    prompt = """
-    Provide a list of music genres applicable to the album "#{record.title}" by #{artists}.
+    completion = %OpenAI.Completion{
+      content: """
+      Provide a list of music genres applicable to the album "#{record.title}" by #{artists}.
 
-    Limit the list to 5 genres, ordered by decreasing specificity, all lowercase.
+      Limit the list to 5 genres, ordered by decreasing specificity, all lowercase.
 
-    Return a valid JSON list.
-    """
+      Return a valid JSON list.
+      """
+    }
 
-    {:ok, response} = OpenAI.gpt(prompt)
+    {:ok, response} = OpenAI.gpt(completion)
 
     record
     |> Record.add_genres(response["genres"])

lib/open_ai.ex

@@ -1,8 +1,8 @@
 defmodule OpenAI do
-  def gpt(prompt) do
+  def gpt(completion) do
     {:ok, collector} = Agent.start_link(fn -> "" end)
 
-    gpt_stream(prompt, fn data ->
+    gpt_stream(completion, fn data ->
       case get_in(data, ["choices", Access.at(0), "delta", "content"]) do
         nil -> :ok
         data -> Agent.update(collector, fn current -> current <> data end)
@@ -15,7 +15,7 @@ defmodule OpenAI do
   end
 
   # Lifted from https://fly.io/phoenix-files/streaming-openai-responses/
-  defp gpt_stream(prompt, cb) do
+  defp gpt_stream(completion, cb) do
     fun = fn request, finch_request, finch_name, finch_options ->
       fun = fn
         {:status, status}, response ->
@@ -49,10 +49,10 @@ defmodule OpenAI do
     Req.post!("https://api.openai.com/v1/chat/completions",
       json: %{
         model: "gpt-4o-mini",
-        messages: [%{role: "user", content: prompt}],
+        messages: [Map.take(completion, [:content, :role])],
         response_format: %{type: "json_object"},
         stream: true,
-        temperature: 0.2
+        temperature: completion.temperature
       },
       auth: {:bearer, api_key()},
       finch_request: fun

lib/open_ai/prompt.ex

@@ -0,0 +1,5 @@
+defmodule OpenAI.Completion do
+  defstruct content: "",
+            temperature: 0.2,
+            role: "user"
+end