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

# Omni Flash Ext

> Google's extended Gemini video model. Per-second pricing with resolution multipliers — supports text-to-video, image-to-video, and 3-image reference fusion at up to 4K.

## Model Description

Google's extended Gemini video model (`omni-flash-ext`) supports three generation modes — text-to-video, single-image animation, and 3-reference-image fusion — with per-second billing so you only pay for the duration you choose.

**Maximum Resolution:** 4K
**Durations:** 4, 6, 8, or 10 seconds

### Key Capabilities

* **Per-Second Billing:** Pay only for the duration you generate — a 4s clip costs significantly less than a 10s clip.
* **Three Generation Modes:** Text-to-video (0 images), image-to-video (1 image), or reference fusion (exactly 3 images).
* **Up to 4K Resolution:** Choose 720p (base), 1080p (1.5× multiplier), or 4K (3× multiplier).
* **Extended Durations:** Supports 4, 6, 8, and 10 second clips — more flexibility than most Veo tiers.
* **Reference Fusion:** Combine scene, character, and object reference images into a single generated video.
* **Aspect Ratio Control:** 16:9 landscape or 9:16 portrait.

### Image Input Rules

| Images | Mode                                          |
| ------ | --------------------------------------------- |
| 0      | Text-to-video                                 |
| 1      | Image-to-video (single reference)             |
| 3      | Reference fusion (scene + character + object) |
| 2      | ❌ Not supported — will error                  |

***

## Quick Start

### 1. Text-to-Video (No Images)

```bash theme={null}
curl --request POST \
  --url https://api.veogen.studio/api/v1/generations \
  --header 'Authorization: Bearer <API_KEY>' \
  --header 'Content-Type: application/json' \
  --data '{
    "model": "omni-flash-ext",
    "prompt": "A golden retriever running through a field of wildflowers at sunrise, cinematic slow motion, 4K.",
    "duration": 6,
    "resolution": "1080p",
    "aspect_ratio": "16:9"
  }'
```

### 2. Image-to-Video (Single Reference Image)

```bash theme={null}
curl --request POST \
  --url https://api.veogen.studio/api/v1/generations \
  --header 'Authorization: Bearer <API_KEY>' \
  --header 'Content-Type: application/json' \
  --data '{
    "model": "omni-flash-ext",
    "prompt": "The character walks forward confidently into the sunlight.",
    "duration": 4,
    "resolution": "720p",
    "image_urls": ["https://example.com/character.jpg"]
  }'
```

### 3. Reference Fusion (3 Images)

```bash theme={null}
curl --request POST \
  --url https://api.veogen.studio/api/v1/generations \
  --header 'Authorization: Bearer <API_KEY>' \
  --header 'Content-Type: application/json' \
  --data '{
    "model": "omni-flash-ext",
    "prompt": "The character explores the scene with the object in hand.",
    "duration": 8,
    "resolution": "720p",
    "image_urls": [
      "https://example.com/scene.jpg",
      "https://example.com/character.jpg",
      "https://example.com/object.jpg"
    ]
  }'
```

<ResponseExample>
  ```json theme={null}
  {
    "data": {
      "id": "gen_def456uvw",
      "model": "omni-flash-ext",
      "status": "pending",
      "created_at": "2026-05-21T09:00:00Z"
    }
  }
  ```
</ResponseExample>

***

## Parameters

| Parameter      | Type    | Required | Description                                                                   |
| -------------- | ------- | -------- | ----------------------------------------------------------------------------- |
| `model`        | string  | ✅        | Must be `"omni-flash-ext"`                                                    |
| `prompt`       | string  | ✅        | Text description of the video to generate                                     |
| `duration`     | integer | —        | `4`, `6`, `8`, or `10` (seconds). Only these exact values are valid.          |
| `resolution`   | string  | —        | `"720p"` (default), `"1080p"`, or `"4k"`                                      |
| `aspect_ratio` | string  | —        | `"16:9"` (default) or `"9:16"`                                                |
| `image_urls`   | array   | —        | 0, 1, or exactly 3 publicly accessible image URLs. 2 images is not supported. |

***

## FAQ

<AccordionGroup>
  <Accordion title="Why can't I use exactly 2 images?">
    The underlying Omni-Flash-Ext API explicitly does not support 2-image
    input. Use 0 images (text-to-video), 1 image (animation), or exactly 3
    images (reference fusion).
  </Accordion>

  <Accordion title="What durations are supported?">
    Only fixed values: 4, 6, 8, or 10 seconds. Values like 5 or 7 will
    return a validation error.
  </Accordion>

  <Accordion title="How does reference fusion work with 3 images?">
    When you provide exactly 3 images, the model treats them as scene,
    character, and object references respectively and fuses them into a
    single coherent video. The order matters — first image is scene, second
    is character, third is object.
  </Accordion>

  <Accordion title="Does Omni Flash Ext generate audio?">
    No. Omni Flash Ext produces silent video output. For AI-generated audio,
    use Veo 3.1 Fast.
  </Accordion>
</AccordionGroup>