OpenAI TTS model — openai/tts-1, openai/tts-1-hd,
openai/gpt-4o-mini-tts. Gemini TTS preview models are not
served on this endpoint; use Gemini's native /v1beta/
surface with responseModalities: ["AUDIO"] instead.
inputstring required
voicestring required
Voice identifier. The gateway forwards this field to the
upstream unchanged — use whichever voice name the upstream
model supports.
instructionsstring
Optional voice direction (e.g. style, tone). Honored by
models that support it, such as openai/gpt-4o-mini-tts.
speednumber
Playback rate. Default 1.0.
stream_formatstring
When set, response is streamed in this format chunk-by-chunk
(subject to upstream support).