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OpenRouterText to speechComing soon

google/gemini-3.1-flash-tts-preview

google/gemini-3.1-flash-tts-preview is a text to speech tool from OpenRouter that runs in the background and returns audio. Coming soon: listed with its price, not yet open to runs.

This tool is listed but not yet available to run.

Price pending

Pricing

Price pending.

Limits

Runs
In the background
Returns
audio
Longest queue wait
3600s
Run deadline
1800s
Largest inline input
1024 KB
Largest input file
500 MB
Largest output
4768 MB
Outputs per run
16

Input

FieldKindDefaultDescription
input requiredJSON—Text to synthesize, or a list of turns for multi-speaker input. Each turn has its own text, voice, and instructions. Multi-speaker input is supported by Gemini TTS models and by Fish Audio models other than S1.
voice requiredone of
Zephyr, Puck, Charon, Kore, Fenrir, Leda, Orus, Aoede, Callirrhoe, Autonoe, Enceladus, Iapetus, Umbriel, Algieba, Despina, Erinome, Algenib, Rasalgethi, Laomedeia, Achernar, Alnilam, Schedar, Gacrux, Pulcherrima, Achird, Zubenelgenubi, Vindemiatrix, Sadachbia, Sadaltager, Sulafat
—Voice identifier (provider-specific).
response_formatone of
mp3, pcm
pcmAudio output format

Same request in code

curl https://api.spiral.ai/v1/runs \
  -H "Authorization: Bearer $SPIRAL_API_KEY" \
  -H "Content-Type: application/json" \
  -H "Idempotency-Key: $(uuidgen)" \
  -d '{
    "provider": "openrouter",
    "model": "google/gemini-3.1-flash-tts-preview",
    "input": {
      "input": {},
      "voice": "Zephyr"
    }
  }'