# Veo 3.1 Fast API

> Das schnellere, kostengünstigere Veo 3.1 für 4 bis 8 Sekunden lange Clips mit Ton.

Veo 3.1 Fast bewahrt Veos Realismus sowie die Generierung von Dialog und Ton, rendert jedoch schneller und zu einem deutlich niedrigeren Preis, wodurch es sich gut für Iterationen eignet. 4, 6 oder 8 Sekunden, 16:9 oder 9:16, mit 720p, 1080p oder 4K; Audio kann deaktiviert werden.

- Model id: `veo3.1/fast`
- Made by: Google
- Category: Text to Video
- Output: video
- Price: from $0.10 / second (8 s ≈ $0.80) (cheapest run $0.80 (800 API credits))
- Run: `POST https://api.doitong.ru/v1/run/veo3.1/fast`
- Quote: `POST https://api.doitong.ru/v1/quote/veo3.1/fast`
- Docs page: https://doitong.com/de/developers/models/veo3.1/fast

## Pricing

Price: **from $0.10 / second (8 s ≈ $0.80)** (the lowest tier; the quote prices your exact input). Billed per second of output (`duration`, default 8).

Price rules (the first rule that matches the input wins; a parameter you leave out counts as its default):

- When `resolution` = 4k and `generate_audio` = true: $0.35 (350 API credits) / second
- When `resolution` = 4k: $0.30 (300 API credits) / second
- When `generate_audio` = true: $0.15 (150 API credits) / second

The full example input below costs $0.90 = 900 API credits (6 s × 150 API credits).

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/veo3.1/fast` 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 |  | ≤ 20000 characters | Textbeschreibung des gewünschten zu generierenden Videos. |
| `aspect_ratio` |  | enum (string) | no | `16:9` | `16:9`, `9:16` | Verhältnis von Breite zu Höhe des generierten Videos. |
| `duration` |  | enum (string) | no | `8s` | `4s`, `6s`, `8s` | Länge des Ausgabevideos. |
| `negative_prompt` |  | string \| null | no |  |  | Negativer Prompt zur Steuerung der Videogenerierung. |
| `resolution` |  | enum (string) | no | `720p` | `720p`, `1080p`, `4k` | Für das Ausgabevideo verwendete Auflösung. |
| `generate_audio` |  | boolean | no | `true` |  | Steuert, ob das Video generiertes Audio enthält. |
| `seed` |  | integer \| null | no |  |  | Seed-Wert zur Initialisierung der Zufallszahlengenerierung. |
| `auto_fix` |  | boolean | no | `true` |  | Automatische Überarbeitung von Prompts, um Fehler bei Inhaltsrichtlinienprüfungen oder anderen Validierungen zu beheben. |
| `safety_tolerance` |  | enum (string) | no | `4` | `1`, `2`, `3`, `4`, `5`, `6` | Stelle die Toleranz der Inhaltsmoderation zwischen der am wenigsten restriktiven Stufe 6 und der strengsten Stufe 1 ein, die den Großteil der Inhalte blockiert. |

## Example input

Required parameters only:

```json
{
  "prompt": "A golden retriever runs along a beach at sunset, waves splashing, slow motion, warm backlight"
}
```

A fuller example:

```json
{
  "prompt": "A golden retriever runs along a beach at sunset, waves splashing, slow motion, warm backlight",
  "duration": 6,
  "resolution": "720p"
}
```

## 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/veo3.1/fast?wait=20" \
  -H "Authorization: Bearer $DOITONG_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{
    "prompt": "A golden retriever runs along a beach at sunset, waves splashing, slow motion, warm backlight",
    "duration": 6,
    "resolution": "720p"
  }'

# 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/veo3.1/fast?wait=20", {
  method: "POST",
  headers,
  body: JSON.stringify({
    "prompt": "A golden retriever runs along a beach at sunset, waves splashing, slow motion, warm backlight",
    "duration": 6,
    "resolution": "720p"
  }),
});
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 = {
    "prompt": "A golden retriever runs along a beach at sunset, waves splashing, slow motion, warm backlight",
    "duration": 6,
    "resolution": "720p",
}

# Run the model; wait up to 20 s for the finished result in the same call
r = requests.post(API + "/run/veo3.1/fast", 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": "veo3.1/fast",
      "input": {
        "prompt": "A golden retriever runs along a beach at sunset, waves splashing, slow motion, warm backlight",
        "duration": 6,
        "resolution": "720p"
      },
      "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": "veo3.1/fast",
  "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": 900,
    "usd": "0.90",
    "charged": 900,
    "refunded": 0
  },
  "input": {
    "prompt": "A golden retriever runs along a beach at sunset, waves splashing, slow motion, warm backlight",
    "duration": 6,
    "resolution": "720p"
  },
  "output": {
    "video": {
      "url": "https://content.doitong.com/dev-api/2026/10/20/req_8k2m4q7x1z9c3v5b6n0p2r4t/0-output.mp4",
      "content_type": "video/mp4",
      "file_name": "0-output.mp4",
      "file_size": 1843200
    }
  },
  "outputs": [
    {
      "type": "video",
      "url": "https://content.doitong.com/dev-api/2026/10/20/req_8k2m4q7x1z9c3v5b6n0p2r4t/0-output.mp4",
      "content_type": "video/mp4",
      "file_size": 1843200,
      "width": 1280,
      "height": 720,
      "duration": 5,
      "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 |
|---|---|---|
| `video` | object {url, content_type, file_name, file_size} | Vom Modell erzeugtes Video. |

## Related models

- [Veo 3.1](https://doitong.com/developers/models/veo3.1.md) (`veo3.1`): from $0.20 / second
- [Veo 3.1 Fast Image to Video](https://doitong.com/developers/models/veo3.1/fast/image-to-video.md) (`veo3.1/fast/image-to-video`): from $0.10 / second
- [Veo 3.1 Image to Video](https://doitong.com/developers/models/veo3.1/image-to-video.md) (`veo3.1/image-to-video`): from $0.20 / second
- [Veo3.1 Fast First Last Frame to Video](https://doitong.com/developers/models/veo3.1/fast/first-last-frame-to-video.md) (`veo3.1/fast/first-last-frame-to-video`): from $0.10 / second
- [Veo3.1 First Last Frame to Video](https://doitong.com/developers/models/veo3.1/first-last-frame-to-video.md) (`veo3.1/first-last-frame-to-video`): from $0.20 / second
- [Veo3.1 Reference to Video](https://doitong.com/developers/models/veo3.1/reference-to-video.md) (`veo3.1/reference-to-video`): from $0.20 / second
- [FLUX 3 Max Text to Video](https://doitong.com/developers/models/blackforestlabs/flux-3-max/text-to-video.md) (`blackforestlabs/flux-3-max/text-to-video`): from $0.0425 / second of output video
- [Grok Imagine Video 1.5 Text to Video](https://doitong.com/developers/models/xai/grok-imagine-video/v1.5/text-to-video.md) (`xai/grok-imagine-video/v1.5/text-to-video`): from $0.08 / second

## Links

- HTML page: https://doitong.com/developers/models/veo3.1/fast
- 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=veo3.1/fast
- Errors: https://doitong.com/developers/docs/errors
- Model details as JSON: https://api.doitong.ru/v1/models/veo3.1/fast