# Kotoba Speech-to-Text API

> 最大 2 分のクリップに対応し、日本語向けに調整された、単語タイムスタンプとキーワードヒント付き音声認識

`audio_url` の最大 2 分の音声クリップを文字起こしします。`language` は ja、en、ko、zh、es、zh-hk、zh-tw または auto に設定できます。任意の `with_timestamps` で単語ごとの開始・終了時刻を返し、`diarization` で話者を識別し、`keywords` では表記に影響を与える用語を最大 1000 件指定できます。`kana` を指定すると、日本語の名前をカタカナで表記します。出力にはテキスト、検出された言語、音声の長さが含まれます。

- 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/ja/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 |  |  | 2分以内の音声。 |
| `language` |  | enum (string) | yes |  | `ja`, `en`, `ko`, `zh`, `es`, `zh-hk`, `zh-tw`, `auto` | 音声の話者が使用する言語。 |
| `with_timestamps` |  | boolean | no | `false` |  | `words` に出力される単語ごとのタイミング。各単語の開始時刻と終了時刻を含みます。 |
| `diarization` |  | boolean | no | `false` |  | 単語単位の話者属性。話者トークンに対応するモデルでのみ利用できます。各単語に `speaker_id` が付与されますが、`with_timestamps` も有効にしない限り時間はnullのままです。 |
| `keywords` |  | array of string \| null | no |  | ≤ 1000 items | 文字起こしで優先する綴り。名前や製品用語などを指定します。最大1000語までで、各語は64文字以内です。 |
| `kana` |  | boolean | no | `false` |  | 日本語における人名・地名のカタカナ表記。 |

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