# Gemini 3.1 Flash Tts API

> Gemini 3.1 Flash text-till-tal med inline-styrning av stil, 30 röster och upp till 10 talare

Omvandlar en `prompt` på upp till 50000 tecken till tal. Framförandet kan styras inline eller via `style_instructions`. Välj en av 30 röster, ange en `language_code` eller använd `speakers` (2 till 10) för ljud med flera talare. Utdata är mp3, wav eller ogg_opus, med `temperature` från 0 till 2.

- Model id: `gemini-3.1-flash-tts`
- Made by: Google
- Category: Text to Speech
- Output: audio
- Price: $0.05 / 1000 characters (cheapest run $0.05 (50 API credits))
- Run: `POST https://api.doitong.com/v1/run/gemini-3.1-flash-tts`
- Quote: `POST https://api.doitong.com/v1/quote/gemini-3.1-flash-tts`
- Docs page: https://doitong.com/sv/developers/models/gemini-3.1-flash-tts

## Pricing

Price: **$0.05 / 1000 characters**. Billed per character of `prompt` (the price is per 1000 characters).

The full example input below costs $0.003 = 3 API credits (50 characters × 50 API credits / 1000 characters).

Prices are the upstream price in USD, paid from the API balance in API credits (1000 API credits = 1 USD). `POST https://api.doitong.com/v1/quote/gemini-3.1-flash-tts` with the same JSON body returns the exact price for that input; the quote is exactly what a run charges. Invalid input is never charged and failed or canceled requests are refunded automatically.

## Input parameters

| Parameter | Canonical name | Type | Required | Default | Allowed values / range | Description |
|---|---|---|---|---|---|---|
| `prompt` |  | string | yes |  | 1 – 50000 characters | Talsyntestext för Gemini 3.1 Flash TTS; rader med flera talare måste börja med alias från speakers-fältet, som i 'Alice: Hello!\nBob: Hi!'. Leveransen kan styras detaljerat med uttrycksfulla ljudtaggar som [sigh], [laughing], [whispering] och [short pause], eller med infogade instruktioner på naturligt språk för accent, känsla, tempo och stil, som 'Say cheerfully: Have a wonderful day!'. |
| `style_instructions` |  | string \| null | no |  | ≤ 4000 characters | Valfria instruktioner på naturligt språk som hålls separerade från det talade innehållet och infogas före prompten för att forma uttrycksfullhet, accent, tempo, ton och känsla. Exempel är 'Speak warmly and slowly', 'Read this as a dramatic newscast', 'Use a British accent with a cheerful tone' och 'Whisper mysteriously'. |
| `voice` |  | enum (string) | no | `Kore` | `Achernar`, `Achird`, `Algenib`, `Algieba`, `Alnilam`, `Aoede`, `Autonoe`, `Callirrhoe`, `Charon`, `Despina`, `Enceladus`, `Erinome`, `Fenrir`, `Gacrux`, `Iapetus`, `Kore`, `Laomedeia`, `Leda`, `Orus`, `Pulcherrima`, `Puck`, `Rasalgethi`, `Sadachbia`, `Sadaltager`, `Schedar`, `Sulafat`, `Umbriel`, `Vindemiatrix`, `Zephyr`, `Zubenelgenubi` | Val av röst för en enda talare bland 30 olika förinställningar; om speakers anges blir detta val inaktivt. Populära kvinnliga alternativ är Kore, med ett kraftfullt och bestämt framförande, Zephyr, med ett ljust och tydligt framförande, och Aoede, med ett varmt och melodiskt framförande; populära manliga alternativ är Puck, pigg och livlig, och Charon, lugn och professionell. |
| `language_code` |  | enum (string) \| null | no |  | `Arabic (Egypt)`, `Bangla (Bangladesh)`, `Dutch (Netherlands)`, `English (India)`, `English (US)`, `French (France)`, `German (Germany)`, `Hindi (India)`, `Indonesian (Indonesia)`, `Italian (Italy)`, `Japanese (Japan)`, `Korean (South Korea)`, `Marathi (India)`, `Polish (Poland)`, `Portuguese (Brazil)`, `Romanian (Romania)`, `Russian (Russia)`, `Spanish (Spain)`, `Tamil (India)`, `Telugu (India)`, `Thai (Thailand)`, `Turkish (Turkey)`, `Ukrainian (Ukraine)`, `Vietnamese (Vietnam)`, `Afrikaans (South Africa)`, `Albanian (Albania)`, `Amharic (Ethiopia)`, `Arabic (World)`, `Armenian (Armenia)`, `Azerbaijani (Azerbaijan)`, `Basque (Spain)`, `Belarusian (Belarus)`, `Bulgarian (Bulgaria)`, `Burmese (Myanmar)`, `Catalan (Spain)`, `Cebuano (Philippines)`, `Chinese Mandarin (China)`, `Chinese Mandarin (Taiwan)`, `Croatian (Croatia)`, `Czech (Czech Republic)`, `Danish (Denmark)`, `English (Australia)`, `English (UK)`, `Estonian (Estonia)`, `Filipino (Philippines)`, `Finnish (Finland)`, `French (Canada)`, `Galician (Spain)`, `Georgian (Georgia)`, `Greek (Greece)`, `Gujarati (India)`, `Haitian Creole (Haiti)`, `Hebrew (Israel)`, `Hungarian (Hungary)`, `Icelandic (Iceland)`, `Javanese (Java)`, `Kannada (India)`, `Konkani (India)`, `Lao (Laos)`, `Latin (Vatican City)`, `Latvian (Latvia)`, `Lithuanian (Lithuania)`, `Luxembourgish (Luxembourg)`, `Macedonian (North Macedonia)`, `Maithili (India)`, `Malagasy (Madagascar)`, `Malay (Malaysia)`, `Malayalam (India)`, `Mongolian (Mongolia)`, `Nepali (Nepal)`, `Norwegian Bokmal (Norway)`, `Norwegian Nynorsk (Norway)`, `Odia (India)`, `Pashto (Afghanistan)`, `Persian (Iran)`, `Portuguese (Portugal)`, `Punjabi (India)`, `Serbian (Serbia)`, `Sindhi (India)`, `Sinhala (Sri Lanka)`, `Slovak (Slovakia)`, `Slovenian (Slovenia)`, `Spanish (Latin America)`, `Spanish (Mexico)`, `Swahili (Kenya)`, `Swedish (Sweden)`, `Urdu (Pakistan)` | Åsidosättning av språk för flerspråkig syntes: automatisk identifiering från texten används om du inte anger ett språk för att styra modellens tal. |
| `speakers` |  | array of object {voice, speaker_id} \| array of any \| null | no |  |  | Röstkonfiguration som gör att flera talare kan läsa separata delar av texten. Tilldela varje talare en röst samt ett speaker_id-alias som matchar motsvarande promptprefix. |
| `temperature` |  | number | no | `1` | 0 – 2 | Inställning för talets slumpmässighet, från fokuserat och förutsägbart framförande vid lägre värden till kreativt och varierat framförande vid högre värden. |
| `output_format` |  | enum (string) | no | `mp3` | `wav`, `mp3`, `ogg_opus` | Format för utdata-ljudet: mp3 ger komprimerade, kompakta filer och rekommenderas; wav innehåller okomprimerad PCM i en WAV-behållare vid 24 kHz med 16-bitars monoljud; ogg_opus använder Opus i Ogg för en bra balans mellan kvalitet och storlek. |

## Example input

Required parameters only:

```json
{
  "prompt": "Hello from Doitong. This is a short test sentence."
}
```

A fuller example:

```json
{
  "prompt": "Hello from Doitong. This is a short test sentence."
}
```

## Run it

Set `DOITONG_API_KEY` to a key from https://doitong.com/developers/dashboard#keys. `?wait=20` returns the finished request in the same call when it is ready within 20 seconds; otherwise poll `GET /requests/{id}` (it also accepts `?wait=`), or pass `webhook_url`.

### curl

```bash
# Run the model; wait up to 20 s for the finished result in the same call
curl -X POST "https://api.doitong.com/v1/run/gemini-3.1-flash-tts?wait=20" \
  -H "Authorization: Bearer $DOITONG_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{
    "prompt": "Hello from Doitong. This is a short test sentence."
  }'

# Still "queued" or "running"? Poll with the id from the response:
curl "https://api.doitong.com/v1/requests/REQUEST_ID?wait=20" \
  -H "Authorization: Bearer $DOITONG_API_KEY"
```

### JavaScript

```javascript
const API = "https://api.doitong.com/v1";
const headers = {
  "Authorization": "Bearer " + process.env.DOITONG_API_KEY,
  "Content-Type": "application/json",
};

// Run the model; wait up to 20 s for the finished result in the same call
let res = await fetch(API + "/run/gemini-3.1-flash-tts?wait=20", {
  method: "POST",
  headers,
  body: JSON.stringify({
    "prompt": "Hello from Doitong. This is a short test sentence."
  }),
});
let request = await res.json();
if (!res.ok) throw new Error(request.error.code + ": " + request.error.message);

// Not finished yet: long-poll until it is
while (request.status === "queued" || request.status === "running") {
  res = await fetch(API + "/requests/" + request.id + "?wait=20", { headers });
  request = await res.json();
}
if (request.status !== "succeeded") throw new Error(JSON.stringify(request.error));
console.log(request.outputs.map((o) => o.url), request.cost.credits + " API credits ($" + request.cost.usd + ")");
```

### Python

```python
import os
import requests

API = "https://api.doitong.com/v1"
headers = {"Authorization": "Bearer " + os.environ["DOITONG_API_KEY"]}

payload = {
    "prompt": "Hello from Doitong. This is a short test sentence.",
}

# Run the model; wait up to 20 s for the finished result in the same call
r = requests.post(API + "/run/gemini-3.1-flash-tts", params={"wait": 20}, json=payload, headers=headers)
request = r.json()
if not r.ok:
    raise RuntimeError(request["error"]["code"] + ": " + request["error"]["message"])

# Not finished yet: long-poll until it is
while request["status"] in ("queued", "running"):
    request = requests.get(API + "/requests/" + request["id"], params={"wait": 20}, headers=headers).json()
if request["status"] != "succeeded":
    raise RuntimeError(request["error"])
print([o["url"] for o in request["outputs"]], request["cost"]["credits"], "API credits", "$" + request["cost"]["usd"])
```

### MCP

The MCP server at `https://api.doitong.com/v1/mcp` exposes the tools `search_models`, `get_model`, `quote`, `run`, `get_request`, `cancel_request`, `list_requests`, `create_upload` and `get_account`. A `run` call for this model:

```json
{
  "jsonrpc": "2.0",
  "id": 1,
  "method": "tools/call",
  "params": {
    "name": "run",
    "arguments": {
      "model_id": "gemini-3.1-flash-tts",
      "input": {
        "prompt": "Hello from Doitong. This is a short test sentence."
      },
      "wait_seconds": 20
    }
  }
}
```

## Response

Every call returns a request object. `status` is one of `queued`, `running`, `succeeded`, `failed`, `canceled`. `outputs` lists the generated files with URLs on our storage (kept forever, or 7 days with `?storage=temporary`; `storage` says which); `output` is the model's own result object with the same URLs.

```json
{
  "id": "req_8k2m4q7x1z9c3v5b6n0p2r4t",
  "object": "request",
  "model": "gemini-3.1-flash-tts",
  "status": "succeeded",
  "created_at": "2026-10-20T12:00:00Z",
  "started_at": "2026-10-20T12:00:02Z",
  "completed_at": "2026-10-20T12:00:09Z",
  "queue_position": null,
  "cost": {
    "credits": 3,
    "usd": "0.003",
    "charged": 3,
    "refunded": 0
  },
  "input": {
    "prompt": "Hello from Doitong. This is a short test sentence."
  },
  "output": {
    "audio": {
      "url": "https://content.doitong.com/dev-api/2026/10/20/req_8k2m4q7x1z9c3v5b6n0p2r4t/0-output.mp3",
      "content_type": "audio/mpeg",
      "file_name": "0-output.mp3",
      "file_size": 1843200
    }
  },
  "outputs": [
    {
      "type": "audio",
      "url": "https://content.doitong.com/dev-api/2026/10/20/req_8k2m4q7x1z9c3v5b6n0p2r4t/0-output.mp3",
      "content_type": "audio/mpeg",
      "file_size": 1843200,
      "duration": 12,
      "stored": true
    }
  ],
  "error": null,
  "metrics": {
    "inference_seconds": 6.8
  },
  "urls": {
    "self": "https://api.doitong.com/v1/requests/req_8k2m4q7x1z9c3v5b6n0p2r4t",
    "cancel": "https://api.doitong.com/v1/requests/req_8k2m4q7x1z9c3v5b6n0p2r4t/cancel"
  }
}
```

### Output fields (`output`)

| Field | Type | Description |
|---|---|---|
| `audio` | object {url, content_type, file_name, file_size} | Ljudfil som skapats genom generering. |

## Related models

- [Eleven v4 Text to Speech](https://doitong.com/developers/models/elevenlabs/tts/eleven-v4.md) (`elevenlabs/tts/eleven-v4`): $0.08 / 1000 characters
- [MiniMax Speech 2.8 HD](https://doitong.com/developers/models/minimax/speech-2.8-hd.md) (`minimax/speech-2.8-hd`): $0.10 / 1000 characters
- [Gemini 3.8 Flash Lite TTS](https://doitong.com/developers/models/google/gemini-3.8-flash-lite-tts.md) (`google/gemini-3.8-flash-lite-tts`): $0.111 / run
- [Gemini 3.8 Flash TTS](https://doitong.com/developers/models/google/gemini-3.8-flash-tts.md) (`google/gemini-3.8-flash-tts`): $0.045 / run
- [Gemini TTS](https://doitong.com/developers/models/gemini-tts.md) (`gemini-tts`): $0.03 / run
- [Async Text to Speech Pro V1.0](https://doitong.com/developers/models/async/tts-pro/v1.0.md) (`async/tts-pro/v1.0`): $0.01 / 1000 characters
- [Bytedance Seed Speech Text to Speech](https://doitong.com/developers/models/bytedance/seed-speech/tts/v2.md) (`bytedance/seed-speech/tts/v2`): $0.03 / 1000 characters
- [Chatterbox · Speech to Speech](https://doitong.com/developers/models/chatterbox/speech-to-speech.md) (`chatterbox/speech-to-speech`): $0.015 / minute of input audio

## Links

- HTML page: https://doitong.com/developers/models/gemini-3.1-flash-tts
- All models and guides for AI agents: https://doitong.com/developers/llms.txt
- OpenAPI 3.1 with this model's typed request body: https://doitong.com/developers/openapi.json?model=gemini-3.1-flash-tts
- Errors: https://doitong.com/developers/docs/errors
- Model details as JSON: https://api.doitong.com/v1/models/gemini-3.1-flash-tts
