Assistant forwardStream should be more extensible

[samuelint]

Hi

It would be great to have AssistantResponse, forwardStream more extensible & to handle more event types.

It would be useful to

• Visualize tool progress
• Handle annotations (for answer citations)

Currently forwardStream only support a few OpenAI assistant events.

• thread.message.created
• thread.message.delta
• thread.run.completed
• thread.run.requires_action

ai/packages/core/streams/assistant-response.ts

Lines 85 to 126 in 03eb9e3

	const forwardStream = async (stream: AssistantStream) => {
	let result: Run | undefined = undefined;
	for await (const value of stream) {
	switch (value.event) {
	case 'thread.message.created': {
	controller.enqueue(
	textEncoder.encode(
	formatStreamPart('assistant_message', {
	id: value.data.id,
	role: 'assistant',
	content: [{ type: 'text', text: { value: '' } }],
	}),
	),
	);
	break;
	}
	case 'thread.message.delta': {
	const content = value.data.delta.content?.[0];
	if (content?.type === 'text' && content.text?.value != null) {
	controller.enqueue(
	textEncoder.encode(
	formatStreamPart('text', content.text.value),
	),
	);
	}
	break;
	}
	case 'thread.run.completed':
	case 'thread.run.requires_action': {
	result = value.data;
	break;
	}
	}
	}
	return result;
	};

Is there a workaround for tool visualization & annotation handling? Or I have to re-write a custom AssistantResponse?

---

Implementation suggestion:

const onStepCreated = () => { ... }
const onStepCompleted = () => { ... }
let runResult = await forwardStream(runStream, { onStepCreated, onStepCompleted });

or even more extensible

const onEventReceived = ({ event, data } ) => { 
  switch(event)
    case 'thread.run.step.created':
      ...
}

let runResult = await forwardStream(runStream, { onEventReceived });