`onFinish` is never called in `useChat` args

[rob-gordon]

Description

Currently running a bit of code in the onFinish handler of useChat. It's never called. The streaming works just fine but the handler isn't called.

Here you can see the specific line where we would get a console log if it were running: https://github.com/Frostwork-Media/back-of-the-envelope/blob/19a3e1fdf3d24b36206b01fcc1c1c9088c88b4db/src/app/_components/Chat.tsx#L30-L31

You can test it for yourself at https://backoftheenvelope.app/ or pull the code and try locally.

Code example

const {
    messages,
    input,
    handleInputChange,
    handleSubmit,
    isLoading,
    setMessages,
    reload,
  } = useChat({
    onFinish() {
      console.log("onFinish() ran.");
    },
});

Additional context

Running Next 14, App Router, Served on vercel, running with bun Repository: https://github.com/Frostwork-Media/back-of-the-envelope Public URL: https://backoftheenvelope.app/

[chanmathew]

I'm having the same issue on 3.0.22, Sveltekit. onFinish and onResponse is not firing at all.

Downgraded to 3.0.19 and that seems to work.

[hu-qi]

I'm having the same issue on 3.0.22, Sveltekit. onFinish and onResponse is not firing at all.

Downgraded to 3.0.19 and that seems to work.

In my case, the same issue on 3.0.22, and 3.0.19 is work.
Ask for help: are there any incompatible changes?

[lgrammel]

This is potentially a duplicate of https://github.com/vercel/ai/issues/1316

You can check out https://github.com/vercel/ai/issues/1316#issuecomment-2048346351 for upgrade instructions.

[myudak]

me too the onFinish in nextjs 14 doesnt work