# Gemini 3.1 Flash Tts API

> Gemini 3.1 Flash texta-í-tal með innbyggðri stílstýringu, 30 röddum og allt að 10 talendum

Breytir `prompt` sem getur verið allt að 50000 stafir í tal. Hægt er að stýra framsögn innbyggt eða með `style_instructions`. Veldu eina af 30 röddum, stilltu `language_code` eða notaðu `speakers` (2 til 10) fyrir hljóð með mörgum talendum. Úttakið er mp3, wav eða ogg_opus, með `temperature` frá 0 til 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/is/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 | Texti fyrir talgervingu í Gemini 3.1 Flash TTS; línur með mörgum hátölurum verða að byrja á samheitum úr speakers-reitnum, eins og í 'Alice: Hello!\nBob: Hi!'. Hægt er að stýra flutningi nákvæmlega með tjáningarríkum hljóðmerkjum á borð við [sigh], [laughing], [whispering], og [short pause], eða með innfelldum leiðbeiningum á náttúrulegu máli um hreim, tilfinningu, hraða og stíl, eins og 'Say cheerfully: Have a wonderful day!'. |
| `style_instructions` |  | string \| null | no |  | ≤ 4000 characters | Valfrjálsar leiðbeiningar á náttúrulegu máli sem eru aðskildar frá töluðu efni og settar fyrir framan kvaðninguna til að móta tjáningu, hreim, hraða, tón og tilfinningu. Dæmi eru 'Speak warmly and slowly', 'Read this as a dramatic newscast', 'Use a British accent with a cheerful tone', og '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 á rödd eins hátalara úr 30 mismunandi forstillingum; þegar speakers er stillt verður þetta val óvirkt. Vinsælar kvenraddir eru Kore, með sterkum og ákveðnum flutningi, Zephyr, með björtum og skýrum flutningi, og Aoede, með hlýjum og melódískum flutningi; vinsælar karlaraddir eru Puck, lífleg og fjörug, og Charon, róleg og fagleg. |
| `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)` | Yfirskrift fyrir tungumál fjöltyngdrar talgervingar: sjálfvirk greining úr textanum gildir nema þú tilgreinir tungumál til að stýra tali líkansins. |
| `speakers` |  | array of object {voice, speaker_id} \| array of any \| null | no |  |  | Raddstilling sem gerir mörgum hátölurum kleift að lesa aðskilda hluta textans. Úthlutaðu hverjum hátalara rödd og speaker_id-samheiti sem passar við samsvarandi forskeyti kvaðningar. |
| `temperature` |  | number | no | `1` | 0 – 2 | Slembistilling tals; áhrifin ná frá einbeittum og fyrirsjáanlegum flutningi við lágar stillingar til skapandi og fjölbreytts flutnings við háar stillingar. |
| `output_format` |  | enum (string) | no | `mp3` | `wav`, `mp3`, `ogg_opus` | Snið úttakshljóðs: mp3 gefur þjappaðar og fyrirferðarlitlar skrár og er mælt með því; wav inniheldur óþjappað PCM í WAV-gámi við 24 kHz með 16-bita mónóhljóði; og ogg_opus notar Opus innan Ogg fyrir gott jafnvægi milli gæða og stærðar. |

## 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} | Hljóðskrá sem verður til við efnisgerð. |

## 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