## TL;DR

Fix: Reporter jambudipa, after investigation with the maintainers: 'No changes to Haystack required, I was passing the stream handler in the wrong place.' The fix is to pass model_kwargs={'stream': True, 'stream_handler': custom_handler} on the PromptNode while constructing the PromptModel with the handler too - i.e. create the streaming PromptModel via create_streaming_*_prompt_model(custom_handler) rather than attaching the handler only at the PromptNode level.

## The error

```text
Issue deepset-ai/haystack#5896 (closed, 12 comments): **Describe the bug** The `model_kwargs={"stream": True, "stream_handler": custom_handler}` on `PromptNode` has no effect when using a `PromptModel` based on an Azure OpenAI model. **Expected behavior** The answer output should stream as it does when using other prompt models. **Additional context** The following code works fine: ``` prompt_node = PromptNode( "gpt-3.5-turbo-16k", default_prompt_template=lfqa_prompt, api_key [your value], max_length= 3072, model_kwargs={"stream": True} ) ``` This streams as expected. **To Reproduce** Changing the prompt model like this: ``` # new prompt_azure_
```

## Fix

1. Reporter jambudipa, after investigation with the maintainers: 'No changes to Haystack required, I was passing the stream handler in the wrong place.' The fix is to pass model_kwargs={'stream': True, 'stream_handler': custom_handler} on the PromptNode while constructing the PromptModel with the handler too - i.e. create the streaming PromptModel via create_streaming_*_prompt_model(custom_handler) rather than attaching the handler only at the PromptNode level.

Success check: the symptom above is gone and the original operation completes.

## When to use

- You hit this exact symptom in haystack.
- You want the verified fix without digging through the thread.

## When not to use

- A different error in haystack, even a similar-looking one.
- General haystack setup or credential questions.

## Compatibility

- Haystack (deepset-ai/haystack)

## Variant phrasings

- How to fix "streaming not working on Azure OpenAI" in haystack
- haystack: streaming not working on Azure OpenAI

## Source

- https://github.com/deepset-ai/haystack/issues/5896