Gemini-2.5-flash-native-audio-preview-09-2025 Text -> Text Only Not Working

Hello! I’m currently using gemini-live-2.5-flash-preview to power my website Homeway. I’m using dotnet, so I wrote my own WebSocket impl because I couldn’t find one in the official SDK. I’m going text → text chat completions, with tools, search grounding, etc. It’s all working well**,** and I have been very impressed with the latency.

I got an email saying that gemini-live-2.5-flash-preview was being replaced by "`gemini-2.5-flash-native-audio-preview-09-2025` But when I swap the model strings, I my websocket is closed after I send the config object with the error:

Cannot extract voices from a non-audio request

My config object is set up with the output to only be TEXT, and I don’t create any of the voice-related generation config subobjects.

The website says the audio-preview model supports text as input and output, so it seems like it should work. Do you have any idea what I need to do to fix this? Do I need to set up AUDIO as a possible output but never use it?

Thanks!

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Hello,

You should still be able to use gemini-live-2.5-flash-preview model, could you please try this and see it works for you?

Hey! Yes, I can still use the model right now. But I got this email on the 10/14/25 saying:

What you need to know

The following two Gemini API models will be discontinued on December 9, 2025:

  • Gemini 2.0 Flash Live (gemini-2.0-live-001)

  • Gemini 2.5 Flash Live (gemini-live-2.5-flash-preview)

We have recently launched a new, updated preview version to replace the previuos ones: Gemini 2.5 Flash Native Audio Preview (September 2025 version) (gemini-2.5-flash-native-audio-preview-09-2025)

This new model provides significant improvements in function calling and speech quality.

What you need to do

To avoid service disruption, please upgrade to the new model, Gemini 2.5 Flash Native Audio Preview (gemini-2.5-flash-native-audio-preview-09-2025) before December 9, 2025.

That’s why I was looking to update the model.

Same issue here. And also got a similar email.
Staying with gemini-live-2.5-flash-preview for now - but December 9 is not too far…

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Yeah, it seems like an API problem. The model should be able to accept text in and text out as a valid config, but the API isn’t allowing it right now. But if they asked us to use the model and are deprecating the old one, it should be 100% supported.

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I’m having similar issues. Looks like there are issues across the board for the new model.

Also, I’m getting terrible results from the new gemini-2.5-flash-native-audio-preview-09-2025 in general: breaks up mid-sentence, gets stuck, speaks nonsense and so on. I’m worried that they’re considering this generally available.

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@Lalit_Kumar do you have any guidance for us?

Hello,

Apologies for the delay in response. Could you please share your minimum reproducible code? We would like to run and analyze it on our end so we can assist you better.

@Lalit_Kumar Sorry for the delay. Here’s a quick PY single-file demo I made that reproduces the issue.

https://homeway.io/gemini-bug-demo.py

All you need to do is add an API key in the main() function and then toggle between the working model I’m currently using, but is now deprecated, and the new model that is suggested to use, but it doesn’t work.