Changelog

simba-english and simba-multilingual no longer stop working on 2026-11-21. On that date their Simba 1.6 training is switched off and both ids are served by our current models instead:

This replaces the “switched off for every API version” in the 2026-09-21 entry. The retirement itself is unchanged: from API version 2026-09-21 neither id is selectable and naming one returns 400 model_retired, so a workspace pinned before that date is the only place either id still answers.

Nothing breaks, but the audio changes. A voice you tuned on Simba 1.6 is rendered by a different model, and SSML <prosody pitch>, <prosody volume>, <emphasis> and <speechify:style emotion> are not applied by the current models (breaks and <prosody rate> are). The request, the response, the voice IDs and the price stay the same. If you want to choose the model and test your voices before the date, switch the model string yourself: Migrating off Simba 1.6 walks it step by step.

GET /v1/audio/models keeps carrying retired_at: "2026-09-21" and sunset_at: "2026-11-21" for a pinned workspace; sunset_at is now the day the model behind the id changes.