Heyo, I work on the realtime api, this is a very cool app!

With transcription I would recommend trying out "gpt-4o-transcribe" or "gpt-4o-mini-transcribe" models, which will be more accurate than "whisper-1". On any model you can set the language parameter, see docs here: https://platform.openai.com/docs/api-reference/realtime-clie.... This doesn't guarantee ordering relative to the rest of the response, but the idea is to optimize for conversational-feeling latency. Hope this is helpful.