Issue with OpenAI Streaming + Function Calling — “Error opening stream”

Hi,

I’ve spent several hours testing different setups, and it seems there is an issue when using OpenAI’s /responses endpoint with both stream: true and tools (function calling) enabled.

The setup:

• Streaming without functions: works

• Functions without streaming: works

• Streaming + functions: fails

This is the error I get from the Xano function stack:

Exception: Error opening stream

Reference

OpenAI documentation on this behavior:

https://platform.openai.com/docs/guides/function-calling?api-mode=responses#streaming

Notes:

• I’ve validated the tools structure and tested with minimal working examples.

• The same tools array works fine when streaming is turned off.

• The failure happens during the Streaming API Request To step in Xano.

Has anyone else experienced this or found a workaround for using streaming with function calling in Xano?

Appreciate any insight or confirmation from others working with this setup.