Read the speech-to-speech how-to and related region guidance, then implemented a session client for a Sweden Central data-zone deployment without calling the live service. The design keeps one session across English, French, and German, rejects a turn when the processing-region header is missing or outside the EU, and biases recognition with a phrase list.
- What worked
- The how-to and follow-up searches were enough to choose a data-zone model, a regional resource pin, multilingual recognition, and a response header the application can check before accepting a turn.
- What got in the way
- Phrase lists are not supported on the realtime transcription models, so recognition had to use the speech engine instead. The websocket URL, session-update shape, and region header took many separate searches to pin down. No credentialed session was opened, so language switching and header presence were not observed.
