# Gemini 3.1 Flash Tts API

> Gemini 3.1 Flash tekst-til-tale med inline-styring af stil, 30 stemmer og op til 10 talere

Konverterer en `prompt` på op til 50000 tegn til tale. Leveringen kan styres inline eller via `style_instructions`. Vælg en af 30 stemmer, angiv en `language_code`, eller brug `speakers` (2 til 10) til lyd med flere talere. Outputtet er mp3, wav eller ogg_opus, med `temperature` fra 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/da/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 | Tekst til talesyntese for Gemini 3.1 Flash TTS; linjer med flere talere skal begynde med aliaser fra speakers-feltet, som i 'Alice: Hello!\nBob: Hi!'. Leveringen kan styres detaljeret med udtryksfulde lydtags som [sigh], [laughing], [whispering] og [short pause] eller med inline-instruktioner på naturligt sprog om accent, følelse, tempo og stil, som 'Say cheerfully: Have a wonderful day!'. |
| `style_instructions` |  | string \| null | no |  | ≤ 4000 characters | Valgfrie instruktioner på naturligt sprog, holdt adskilt fra det talte indhold og indsat før prompten for at forme udtryksfuldhed, accent, tempo, tone og følelse. Eksempler omfatter '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` | Valg af stemme til én taler blandt 30 forskellige forudindstillinger; hvis speakers angives, bliver dette valg inaktivt. Populære kvindestemmer er Kore med en stærk og fast levering, Zephyr med en lys og klar levering og Aoede med en varm og melodisk levering; populære mandestemmer er Puck, energisk og livlig, og Charon, rolig og professionel. |
| `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)` | Tilsidesættelse af sprog til flersproget syntese: automatisk registrering fra teksten anvendes, medmindre du angiver et sprog til at styre modellens tale. |
| `speakers` |  | array of object {voice, speaker_id} \| array of any \| null | no |  |  | Stemmekonfiguration, der gør det muligt for flere talere at læse separate dele af teksten. Tildel hver taler en stemme samt et speaker_id-alias, der matcher de tilsvarende promptpræfikser. |
| `temperature` |  | number | no | `1` | 0 – 2 | Indstilling for talens tilfældighed, fra fokuseret og forudsigelig levering ved lave værdier til kreativ og varieret levering ved høje værdier. |
| `output_format` |  | enum (string) | no | `mp3` | `wav`, `mp3`, `ogg_opus` | Format for outputlyden: mp3 giver komprimerede, kompakte filer og anbefales; wav indeholder ukomprimeret PCM i en WAV-container ved 24 kHz med 16-bit mono-lyd; ogg_opus bruger Opus i Ogg for en god saldo mellem kvalitet og størrelse. |

## 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} | Lydfil produceret ved 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