Can streamObject be used with useChat?

[martinjo]

Hi!

Is useChat designed to be used together with streamObject? What/how should I return from my api endpoint that calls streamObject for useChat to parse it correctly?

Now my code looks like this

const respJson = await request.json();
		const messages: any[] = respJson.messages;

		 const res = await streamObject({
			model: openai('gpt-4-turbo'),
			schema: z.object({
				formFields: FormFieldsArraySchema,
			}),
			messages: messages,
		});

		const data = new StreamData();
		let fullObj: any = {};
		const encoder = new TextEncoder();
		const stream = new ReadableStream({
			async start(controller) {
				for await (const obj of res.partialObjectStream) {
					fullObj = obj;
					controller.enqueue(encoder.encode(JSON.stringify(fullObj)));
				}
	
				controller.close();
				data.close();
			}
		});
		return new StreamingTextResponse(stream, {}, data);

And I'm trying to use the endpoint like this:

	const { messages, reload, stop, setMessages, isLoading, data } = useChat({
		api: '/api/fill',
		streamMode: 'text'
	});

With streamMode: text nothing is returned. And with 'stream-data' I get a parsing error 🤷‍♂️ 😢
Are there any examples similar to this? Any pointers in the right direction would be super appreciated! 🙏

[lgrammel]

streamObject cannot be used with useChat.

[lgrammel]

not yet but planned

[martinjo]

Thanks! I'll go forward with a custom solution in the meantime. But good to know it's planned!

[lgrammel]

We have a useObject hook now: https://sdk.vercel.ai/docs/reference/ai-sdk-ui/use-object

[martinjo]

This is great! Will there be support to chat when using object gereration? Sometimes the result is a bit off and I’d like to refine it with a new prompt/message but it’s not clear to me how to do it/if this is possible using vercel ai. Any suggestions?

[lgrammel]

how do you envision using something like this? can you provide a hypothetical code snippet?