Assistant Hook: Add client side function handling and other events

[johannbuscail]

Feature Description

Add events on the useAssistant hook, just like the useChat hook.

https://sdk.vercel.ai/docs/api-reference/use-chat
onResponse
onError
onFinish

But most importantly, making the assistant hook actually useful is the onFunctionCall event.
This is a MAJOR and really really important event as it allows the assistant to interact with the client side.

https://sdk.vercel.ai/docs/guides/providers/openai-functions#handling-function-calls-on-the-client

[nico-herrera]

bumping this, need it badly. If anyone has found a solution or workaround please let me know!

[hgrias]

bump

[vladdg-dev]

A isLoading boolean response from useAssistant would also be nice.

[shaurya157]

bump, my use cases needs the onFinish hook. Currently, the frontend has no way of knowing that assistant responses are done... This wouldn't be a problem usually but the dependency i'm using relies on an onFinish hook

[rostgoat]

bump.

here is my workaround for now:

  // Track the previous status to detect when the assistant finishes processing
  const previousStatus = useRef<string>("awaiting_message");
  console.log("previousStatus :>> ", previousStatus);

  useEffect(() => {
    if (
      previousStatus.current === "in_progress" &&
      assistantStatus === "awaiting_message"
    ) {
      console.log("Assistant has finished responding.");
      // Custom onFinish logic here
    }
    previousStatus.current = assistantStatus; // Update the ref with the current status
  }, [assistantStatus, assistantMessages]);