Gpt-4 createChatCompletion stream response format and model switch

ChatGPT
1

I’m using the Node SDK version 3.2.1 running createChatCompletion with gpt-4

Here my settings:

{
          temperature: 0.5,
          max_tokens: 200,
          top_p: 1,
          frequency_penalty: 0,
          presence_penalty: 0,
          user: uid,
          model: "gpt-4",
          stream: true,
          messages: [
            {
              role: "system",
              content: systemMessage,
            },
            { role: "user", content: userMessage},
          ],
        }

The API responds but:

  1. Replaces gpt-4 with gpt-4-0314
  2. Delivers a different response format than is documented. Specifically instead of choices[0]message.content it responds with choices[0].delta.content.

Response of one stream/message:

{
          id: "chatcmpl-6wjCfqoSnIjjqUjmdvwKB7VH6Rmp5",
          object: "chat.completion.chunk",
          created: 1679454805,
          model: "gpt-4-0314",
          choices: [{ delta: { content: " for" }, index: 0, finish_reason: null }],
}

I’m unclear if this is a bug or the standard response format to a when stream: true. As per docu, when stream is set to true it responds with server-sent events, but I’m unclear about the differences in the choices array.

Appreciate any pointers or guidance on this.Thanks!