StreamingTextResponse has been removed in AI SDK 4.0. Use streamText.toDataStreamResponse() instead.

Using streamText

import { openai } from '@ai-sdk/openai';
import { streamText } from 'ai';

const { textStream } = streamText({
  model: openai('gpt-4-turbo'),
  prompt: 'Invent a new holiday and describe its traditions.',
});

for await (const textPart of textStream) {
  process.stdout.write(textPart);
}

Reference: https://sdk.vercel.ai/docs/reference/stream-helpers/streaming-text-response