> ## Documentation Index
> Fetch the complete documentation index at: https://docs.hoox.video/llms.txt
> Use this file to discover all available pages before exploring further.

# Veo 3.1 Fast

> Google · `veo-3.1-fast` · video

## Identifier

Use the model identifier `veo-3.1-fast` in the `model` field when calling [`/asset/start`](/api-reference/assets/start).

## Capabilities

| Property            | Value                                  |
| ------------------- | -------------------------------------- |
| Reference inputs    | 0–3                                    |
| Aspect ratios       | `16:9`, `9:16` (default `9:16`)        |
| Resolutions         | `720p`, `1080p`, `4K` (default `720p`) |
| Durations (seconds) | `4`, `6`, `8` (default `8`)            |
| Audio               | yes                                    |

## Inputs

Pass reference media in the `references` array (0–3 items). Optional. Each item accepts exactly one of:

* `url` — a direct, publicly accessible file URL
* `asset_id` — the ID of an existing asset in your Hoox space (e.g. a previous generation)
* `avatar_id` — the ID of an avatar defined in your Hoox space

## Custom settings

These keys go inside the `model_settings` object of the request body.

| Key             | Type    | Default | Affects cost |
| --------------- | ------- | ------- | ------------ |
| `generateAudio` | boolean | `true`  | yes          |

## Pricing

Default parameters (8s at `720p`): **\~12 credits / generation**.

For exact pricing with your own parameters, call [`/asset/pricing`](/api-reference/assets/pricing) with the `model` and any parameters that affect cost.

## Example request

```json theme={null}
{
  "type": "video",
  "model": "veo-3.1-fast",
  "prompt": "Describe what you want to generate",
  "aspect_ratio": "9:16",
  "resolution": "720p",
  "duration": 8
}
```

See [`/asset/start`](/api-reference/assets/start) for the full request/response reference, error codes, and code samples in cURL / Python / JavaScript.