API docsModel reference

Gemini 3.8 Flash TTS API

Google Gemini 3.8 Flash TTS: expressive speech in 30 voices with natural-language style control and inline vocal events like <laugh>.

POST/api/v1/generationsBearer API key

gemini-3.8-flash-ttsAudio · GoogleModel details & pricing

Endpoints for this model

POST/generationsCreate a generation GET/generations/{id}Get the result POST/generations/{id}/cancelCancel a task POST/quoteQuote GET/models/{slug}Get one model

Parameter scope

Select a provider to see its effective parameter limits. Automatic routing chooses a provider that supports your input. Examples include defaults and required inputs; replace example media URLs with accessible files.

Request

cURL

curl 'https://01router.com/api/v1/generations' \
  -H "Authorization: Bearer $API_KEY" \
  -H "Content-Type: application/json" \
  -d '{
  "model": "gemini-3.8-flash-tts",
  "input": {
    "prompt": "A cinematic landscape at sunrise.",
    "voice": "Kore"
  }
}'

Input parameters

JSON body

For /generations and /quote, put these parameters inside input. For /images/generations, put them at the top level. Chat parameters go at the top level of /chat/completions.

model stringRequired: Model slug from the catalog. Project keys may use a project-specific model slug.
Allowed values:"gemini-3.8-flash-tts"
input objectRequired: Model-specific input object. See the selected model reference for required fields, defaults and limits.
provider stringOptional: Optional provider slug. Omit for automatic routing; project settings may pin the provider.
project stringOptional: Optional project ID. Use its published model catalog and routing configuration.
callback_url string<uri>Optional: Public HTTPS URL, up to 1,000 characters. Receives the final generation object. Private network addresses are rejected.
input.prompt stringRequired
input.voice enumOptional: Default:"Kore"
Allowed values:"Kore""Puck""Charon""Fenrir""Leda""Orus""Aoede""Zephyr""Callirrhoe""Autonoe""Enceladus""Iapetus""Umbriel""Algieba""Despina""Erinome""Algenib""Rasalgethi""Laomedeia""Achernar""Alnilam""Schedar""Gacrux""Pulcherrima""Achird""Zubenelgenubi""Vindemiatrix""Sadachbia""Sadaltager""Sulafat"
input.style_instructions stringOptional: e.g. "cheerful and friendly"; billing depends on the provider

Response example

200 · application/json

{
  "id": "gen_example",
  "object": "generation",
  "model": "gemini-3.8-flash-tts",
  "type": "audio",
  "provider": "fal",
  "status": "processing",
  "input": {
    "prompt": "A cinematic landscape at sunrise.",
    "voice": "Kore"
  },
  "outputs": [],
  "error": null,
  "credits": 100,
  "price_usd": 1,
  "created_at": "2026-10-25T08:00:00.000Z",
  "completed_at": null
}

Responses are illustrative. IDs, usage, prices and results depend on the actual request.

Response fields

id string: Generation ID returned by the create request.
object "generation": generation
model string: Model slug from the catalog. Project keys may use a project-specific model slug.
type video | image | audio | chat
provider string: Optional provider slug. Omit for automatic routing; project settings may pin the provider.
status string: queued / processing / succeeded / failed. Stop polling on succeeded or failed.
input object: Model-specific input object. See the selected model reference for required fields, defaults and limits.
outputs string[]: Result file URLs. Empty until available; download promptly because URLs may expire.
error string | null: Error message on failure; null otherwise.
credits number: Credits charged for this generation; zero after a refund.
price_usd number: Price of this generation in USD; zero after a refund.
created_at string: Creation time in ISO 8601 format.
completed_at string | null: Completion time in ISO 8601 format, or null while running.

Usage notes

Poll at intervals of at least 3 seconds. A 504 from the synchronous image endpoint means the task may still be running: poll its error.id instead of submitting it again.

Use with AI

Give your coding assistant the documentation index or the full API reference, including live model parameters.

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