Handle OpenAI api streaming error messages

lib/open_ai/api.ex

@@ -33,7 +33,7 @@ defmodule OpenAI.API do
                                                                                     any())) ::
           :ok | {:error, String.t()}
   def chat_stream(messages, instructions, model, temperature, config, cb) do
-    case config
+    config
     |> new_request()
     |> Req.merge(
       url: "/v1/responses",
@@ -52,18 +52,42 @@ defmodule OpenAI.API do
         {events, buffer} = ServerSentEvents.parse(buffer <> data)
         req = Req.Request.put_private(req, :sse_buffer, buffer)
 
-             for %{data: json} <- events do
-               decode_responses_event(json, cb)
-             end
-
-             {:cont, {req, resp}}
+        decode_events(events, cb, req, resp)
       end
     )
-         |> Req.post() do
-      {:ok, %{status: status}} when status in 200..299 -> :ok
-      {:ok, %{body: body}} -> {:error, "OpenAI API error: #{inspect(body)}"}
-      {:error, exception} -> {:error, "Connection error: #{Exception.message(exception)}"}
+    |> do_chat_stream()
   end
+
+  defp decode_events([], _cb, req, resp), do: {:cont, {req, resp}}
+
+  defp decode_events([%{data: json} | rest], cb, req, resp) do
+    case decode_responses_event(json, cb) do
+      {:error, message} ->
+        Logger.error(message)
+        {:halt, {req, Req.Response.put_private(resp, :error, message)}}
+
+      _ ->
+        decode_events(rest, cb, req, resp)
+    end
+  end
+
+  defp do_chat_stream(req) do
+    case Req.post(req) do
+      {:ok, %{status: status} = resp} when status in 200..299 ->
+        if message = Req.Response.get_private(resp, :error) do
+          {:error, message}
+        else
+          :ok
+        end
+
+      {:ok, %{body: body}} ->
+        {:error, "OpenAI API error: #{inspect(body)}"}
+
+      {:error, exception} ->
+        {:error, "Connection error: #{Exception.message(exception)}"}
+    end
+  catch
+    {:stream_error, message} -> {:error, message}
   end
 
   @spec get_embeddings(String.t(), OpenAI.Config.t()) :: {:ok, [float()]} | {:error, term()}
@@ -101,8 +125,22 @@ defmodule OpenAI.API do
 
   defp decode_responses_event(json, cb) do
     case JSON.decode!(json) do
-      %{"type" => "response.output_text.delta", "delta" => delta} -> cb.(delta)
-      _other -> :ok
+      %{"type" => "response.output_text.delta", "delta" => delta} ->
+        cb.(delta)
+
+      %{"type" => "error", "error" => %{"message" => message}} ->
+        {:error, message}
+
+      %{"type" => "response.failed", "response" => %{"error" => %{"message" => message}}} ->
+        {:error, message}
+
+      %{"type" => "response." <> _} ->
+        :ok
+
+      other ->
+        Logger.warning(fn ->
+          "Unexpected response: #{inspect(other)}"
+        end)
     end
   end