# Kotoba Speech-to-Text API

> Chuyển giọng nói thành văn bản cho clip tối đa 2 phút, tối ưu cho tiếng Nhật, với mốc thời gian từng từ và gợi ý từ khóa

Chuyển biên clip âm thanh tối đa 2 phút từ `audio_url`. Đặt `language` thành ja, en, ko, zh, es, zh-hk, zh-tw hoặc auto. `with_timestamps` tùy chọn trả về thời gian bắt đầu và kết thúc từng từ, `diarization` gắn nhãn người nói, `keywords` nhận tối đa 1000 thuật ngữ để định hướng cách viết, còn `kana` viết tên bằng katakana cho tiếng Nhật. Đầu ra gồm văn bản, ngôn ngữ phát hiện được và thời lượng âm thanh.

- Model id: `kotoba-technologies/kotoba-stt/v1/speech-to-text`
- Made by: Kotoba Technologies
- Category: Speech to Text
- Output: text
- Price per second of your input audio: $0.0000694 / second of input audio (cheapest run $0.001 (1 API credit))
- Run: `POST https://api.doitong.ru/v1/run/kotoba-technologies/kotoba-stt/v1/speech-to-text`
- Quote: `POST https://api.doitong.ru/v1/quote/kotoba-technologies/kotoba-stt/v1/speech-to-text`
- Docs page: https://doitong.com/vi/developers/models/kotoba-technologies/kotoba-stt/v1/speech-to-text

## Pricing

Price: **$0.0000694 / second of input audio**. Price per second of your input audio: the input files are measured before the run (length, resolution, frame rate). The quote measures the same files and is exactly what the run charges.

The full example input below costs $0.001 = 1 API credit (10 s input audio × $0.000069).

Prices are the upstream price in USD, paid from the API balance in API credits (1000 API credits = 1 USD). `POST https://api.doitong.ru/v1/quote/kotoba-technologies/kotoba-stt/v1/speech-to-text` 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

Send either the canonical name or the native field name (not both). Canonical names are the same across models.

| Parameter | Canonical name | Type | Required | Default | Allowed values / range | Description |
|---|---|---|---|---|---|---|
| `audio_url` | `audio` | string (audio URL) | yes |  |  | Thời lượng âm thanh giới hạn ở 2 phút. |
| `language` |  | enum (string) | yes |  | `ja`, `en`, `ko`, `zh`, `es`, `zh-hk`, `zh-tw`, `auto` | Ngôn ngữ được người nói trong âm thanh sử dụng. |
| `with_timestamps` |  | boolean | no | `false` |  | Đầu ra thời gian theo từng từ trong `words`, bao gồm thời điểm bắt đầu và kết thúc của mỗi từ. |
| `diarization` |  | boolean | no | `false` |  | Gán người nói ở cấp từ, chỉ khả dụng với các mô hình hỗ trợ token người nói. Mỗi từ nhận một `speaker_id`, nhưng thời gian vẫn là null trừ khi đồng thời bật `with_timestamps`. |
| `keywords` |  | array of string \| null | no |  | ≤ 1000 items | Các thuật ngữ cần ưu tiên cách viết trong bản chép lời, bao gồm tên hoặc thuật ngữ sản phẩm. Chấp nhận tối đa 1000 thuật ngữ, mỗi thuật ngữ tối đa 64 ký tự. |
| `kana` |  | boolean | no | `false` |  | Cách thể hiện bằng Katakana của tên người và địa danh trong tiếng Nhật. |

File parameters (`audio`) take a public `https://` URL, a `data:` URI up to 10 MB, or the `file_url` of an upload from `POST /files`.

## Example input

Required parameters only:

```json
{
  "audio": "https://content.doitong.com/audio/showcase/v3/tools/dub_es.mp3",
  "language": "ja"
}
```

A fuller example:

```json
{
  "audio_url": "https://content.doitong.com/audio/showcase/v3/tools/dub_es.mp3",
  "language": "ja"
}
```

## 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.ru/v1/run/kotoba-technologies/kotoba-stt/v1/speech-to-text?wait=20" \
  -H "Authorization: Bearer $DOITONG_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{
    "audio_url": "https://content.doitong.com/audio/showcase/v3/tools/dub_es.mp3",
    "language": "ja"
  }'

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

### JavaScript

```javascript
const API = "https://api.doitong.ru/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/kotoba-technologies/kotoba-stt/v1/speech-to-text?wait=20", {
  method: "POST",
  headers,
  body: JSON.stringify({
    "audio_url": "https://content.doitong.com/audio/showcase/v3/tools/dub_es.mp3",
    "language": "ja"
  }),
});
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.ru/v1"
headers = {"Authorization": "Bearer " + os.environ["DOITONG_API_KEY"]}

payload = {
    "audio_url": "https://content.doitong.com/audio/showcase/v3/tools/dub_es.mp3",
    "language": "ja",
}

# Run the model; wait up to 20 s for the finished result in the same call
r = requests.post(API + "/run/kotoba-technologies/kotoba-stt/v1/speech-to-text", 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.ru/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": "kotoba-technologies/kotoba-stt/v1/speech-to-text",
      "input": {
        "audio_url": "https://content.doitong.com/audio/showcase/v3/tools/dub_es.mp3",
        "language": "ja"
      },
      "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": "kotoba-technologies/kotoba-stt/v1/speech-to-text",
  "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": 1,
    "usd": "0.001",
    "charged": 1,
    "refunded": 0
  },
  "input": {
    "audio_url": "https://content.doitong.com/audio/showcase/v3/tools/dub_es.mp3",
    "language": "ja"
  },
  "output": {
    "audio_duration_secs": 1.0,
    "language_code": "string",
    "language_probability": 1.0,
    "text": "string",
    "words": [
      {
        "end": 1.0,
        "speaker_id": "string",
        "start": 1.0,
        "text": "string",
        "type": "word"
      }
    ]
  },
  "outputs": [
    {
      "type": "file",
      "url": "https://content.doitong.com/dev-api/2026/10/20/req_8k2m4q7x1z9c3v5b6n0p2r4t/0-output.jpeg",
      "content_type": "image/jpeg",
      "file_size": 1843200,
      "stored": true
    }
  ],
  "error": null,
  "metrics": {
    "inference_seconds": 6.8
  },
  "urls": {
    "self": "https://api.doitong.ru/v1/requests/req_8k2m4q7x1z9c3v5b6n0p2r4t",
    "cancel": "https://api.doitong.ru/v1/requests/req_8k2m4q7x1z9c3v5b6n0p2r4t/cancel"
  }
}
```

### Output fields (`output`)

| Field | Type | Description |
|---|---|---|
| `audio_duration_secs` | number \| null |  |
| `language_code` | string |  |
| `language_probability` | number |  |
| `text` | string |  |
| `words` | array of object {end, speaker_id, start, text, type} |  |

## Related models

- [Cohere Transcribe](https://doitong.com/developers/models/cohere-transcribe.md) (`cohere-transcribe`): $0.0000694 / second of input audio
- [Elevenlabs - Forced Alignment](https://doitong.com/developers/models/elevenlabs/forced-alignment.md) (`elevenlabs/forced-alignment`): $0.22 / hour of input audio
- [ElevenLabs Speech to Text](https://doitong.com/developers/models/elevenlabs/speech-to-text.md) (`elevenlabs/speech-to-text`): $0.03 / minute of input audio
- [ElevenLabs Speech to Text - Scribe V2](https://doitong.com/developers/models/elevenlabs/speech-to-text/scribe-v2.md) (`elevenlabs/speech-to-text/scribe-v2`): $0.008 / minute of input audio
- [Nemotron 3 Nano Omni · Audio](https://doitong.com/developers/models/nvidia/nemotron-3-nano-omni/audio.md) (`nvidia/nemotron-3-nano-omni/audio`): $0.01 / 1000 tokens
- [Nemotron Asr Multilingual](https://doitong.com/developers/models/nvidia/nemotron-asr-multilingual/asr.md) (`nvidia/nemotron-asr-multilingual/asr`): $0.008 / minute of input audio
- [Pipecat's Smart Turn model](https://doitong.com/developers/models/smart-turn.md) (`smart-turn`): $0.00111 / second of processing time
- [Silero VAD](https://doitong.com/developers/models/silero-vad.md) (`silero-vad`): $0.00001 / second of input audio

## Links

- HTML page: https://doitong.com/developers/models/kotoba-technologies/kotoba-stt/v1/speech-to-text
- 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=kotoba-technologies/kotoba-stt/v1/speech-to-text
- Errors: https://doitong.com/developers/docs/errors
- Model details as JSON: https://api.doitong.ru/v1/models/kotoba-technologies/kotoba-stt/v1/speech-to-text