onFinish doesn't return message role

[DonaldNgai]

I am using the streamText api call on the server side. However, the role is not passed with the onFinish. I am appending system messages but it is triggering and I can't save the messages properly without knowing the role onFinish.

[lgrammel]

onFinish has response.messages that you can append: https://sdk.vercel.ai/docs/reference/ai-sdk-core/stream-text#on-finish