bug: response header wrong for non streamed responses (no chunks)

[Propheticus]

When calling the /chat/completions API endpoint without "stream": true set, the response is indeed a single JSON object of type "chat.completion" and not a streaming of multiple server event lines starting with "data: " followed by objects of type "chat.completion.chunk".

So instead of

data: {"choices":[{"delta":{"content":" Pos"},"finish_reason":null,"index":0}],"created":1711961792,"id":"GEinhvWFJJLg5Qr8KJ6r","model":"_","object":"chat.completion.chunk"}

data: {"choices":[{"delta":{"content":"itive"},"finish_reason":null,"index":0}],"created":1711961792,"id":"h05jZ89hTwi7thCiVrBR","model":"_","object":"chat.completion.chunk"}

data: {"choices":[{"delta":{"content":"."},"finish_reason":null,"index":0}],"created":1711961792,"id":"5XwVZ6y0S8aIdtRSxSe0","model":"_","object":"chat.completion.chunk"}

data: {"choices":[{"delta":{"content":""},"finish_reason":null,"index":0}],"created":1711961792,"id":"6Vi2z9md1sQCWKhSYRJI","model":"_","object":"chat.completion.chunk"}

data: {"choices":[{"delta":{"content":""},"finish_reason":null,"index":0}],"created":1711961792,"id":"dRmZRw35MDeyq23GHAxr","model":"_","object":"chat.completion.chunk"}

data: {"choices":[{"delta":{"content":""},"finish_reason":"stop","index":0}],"created":1711961792,"id":"fpmpyJEnXHidePQM1cnz","model":"_","object":"chat.completion.chunk"}

data: [DONE]

We get

{"choices":[{"finish_reason":null,"index":0,"message":{"content":" Positive.","role":"assistant"}}],"created":1711962125,"id":"7Y3MXJ4ndC5QW1BrTvd4","model":"_","object":"chat.completion","system_fingerprint":"_","usage":{"completion_tokens":3,"prompt_tokens":59,"total_tokens":62}}

However, the response header still says:

HTTP/1.1 200 OK
Content-Type: text/event-stream
Cache-Control: no-cache
Connection: keep-alive
Access-Control-Allow-Origin: *
Date: Mon, 01 Apr 2024 08:55:47 GMT
Transfer-Encoding: chunked

I would expect a content-type of "application/json" and not "text/event-stream". Also the transfer-encoding: chunked is false.

[louis-jan]

Great find! @Propheticus

[Van-QA]

hi @Propheticus, the issue was resolved in our nightlybuild, would you mind retrying it? thank you

[Propheticus]

@Van-QA Will do as soon as I get Avast to stop sandboxing and blocking the installer.

[Propheticus]

That works! Also the JSON is formatted with newlines and indents now.

HTTP/1.1 200 OK
Content-Type: application/json
Cache-Control: no-cache
Connection: keep-alive
Access-Control-Allow-Origin: *
Date: Tue, 09 Apr 2024 07:46:50 GMT
Transfer-Encoding: chunked



{
	"choices":[
		{
			"finish_reason":null,
			"index":0,
			"message":{
				"content":" Positive.",
				"role":"assistant"
			}
		}
	],
	"created":1712648810,
	"id":"pfSUz0sCcSG0jTqmQdlg",
	"model":"_",
	"object":"chat.completion",
	"system_fingerprint":"_",
	"usage":{
		"completion_tokens":3,
		"prompt_tokens":59,
		"total_tokens":62
	}
}

[Propheticus]

2 remarks:

• The finish_reason is shown as null. That is normal for chunks that are not the last chunk. The last chunk, or in this case the only 'chunk' should mention the stop reason, e.g. "finish_reason":"stop" or .."length". Open AI spec.

• The Transfer-Encoding: chunked is still shown in the header while I'd expect a Content-Length: <length> instead. HTTP header doc.