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

# Gen 4

> Generate videos using Gen 4 via PixelByte API

Generate videos from images with Runway's Gen 4 model. Supports image-to-video generation with multiple aspect ratios and duration options.

| Property            | Value                                   |
| ------------------- | --------------------------------------- |
| **Provider**        | Runway                                  |
| **Slug**            | `runway/gen-4`                          |
| **Capabilities**    | Image to Video                          |
| **Base Cost**       | 100,000 micro-cents/second (\$0.10/sec) |
| **Processing Time** | \~120 seconds                           |

***

## Image to Video

Generate videos from a source image and text prompt.

**Slug:** `runway/gen-4/image-to-video`

### Request Body

<ParamField body="model" type="string" required placeholder="runway/gen-4/image-to-video">
  Model slug. Use `runway/gen-4/image-to-video` for image-to-video generation.
</ParamField>

<ParamField body="input" type="object" required>
  Input parameters for image-to-video generation.

  <Expandable title="properties" defaultOpen>
    <ParamField body="prompt" type="string" required>
      Text description to guide video generation (max 1000 characters).
    </ParamField>

    <ParamField body="image_url" type="string" required>
      URL of the source image to animate.
    </ParamField>

    <ParamField body="aspect_ratio" type="string">
      Video aspect ratio. Default: `16:9`. Options: `16:9`, `9:16`, `1:1`, `4:3`, `3:4`, `21:9`.
    </ParamField>

    <ParamField body="duration" type="string">
      Video duration in seconds. Default: `5`. Options: `5`, `10`.
    </ParamField>
  </Expandable>
</ParamField>

<ParamField body="webhookUrl" type="string">
  HTTPS URL to receive a webhook notification when the job completes or fails.
</ParamField>

### Code Examples

<CodeGroup>
  ```bash cURL theme={null}
  curl -X POST https://api.muvi.video/v1/jobs/submit \
    -H "Authorization: Bearer $PIXELBYTE_API_KEY" \
    -H "Content-Type: application/json" \
    -d '{
      "model": "runway/gen-4/image-to-video",
      "input": {
        "prompt": "The camera slowly zooms in as the subject turns to face the viewer",
        "image_url": "https://example.com/portrait.jpg",
        "aspect_ratio": "16:9",
        "duration": "5"
      }
    }'
  ```

  ```python Python theme={null}
  import requests

  response = requests.post(
      "https://api.muvi.video/v1/jobs/submit",
      headers={
          "Authorization": "Bearer YOUR_API_KEY",
          "Content-Type": "application/json"
      },
      json={
          "model": "runway/gen-4/image-to-video",
          "input": {
              "prompt": "The camera slowly zooms in as the subject turns to face the viewer",
              "image_url": "https://example.com/portrait.jpg",
              "aspect_ratio": "16:9",
              "duration": "5"
          }
      }
  )

  data = response.json()
  print(data)
  ```

  ```javascript JavaScript theme={null}
  const response = await fetch("https://api.muvi.video/v1/jobs/submit", {
    method: "POST",
    headers: {
      "Authorization": "Bearer YOUR_API_KEY",
      "Content-Type": "application/json"
    },
    body: JSON.stringify({
      model: "runway/gen-4/image-to-video",
      input: {
        prompt: "The camera slowly zooms in as the subject turns to face the viewer",
        image_url: "https://example.com/portrait.jpg",
        aspect_ratio: "16:9",
        duration: "5"
      }
    })
  });

  const data = await response.json();
  console.log(data);
  ```
</CodeGroup>

***

## Pricing

**Base cost:** 100,000 micro-cents per second (\$0.10/sec)

```
finalCost = baseCost × duration
```

| Factor       | Option | Multiplier |
| ------------ | ------ | ---------- |
| **Duration** | `5`    | 5x         |
|              | `10`   | 10x        |

<Tip>
  **Default cost:** 5 seconds = 100,000 × 5 = **500,000 micro-cents (\$0.50)**
</Tip>

## Response

<ResponseField name="jobId" type="string">
  Unique identifier for the submitted job.
</ResponseField>

<ResponseField name="status" type="string">
  Initial job status. Always `"pending"` on successful submission.
</ResponseField>

<ResponseField name="estimatedCompletionTime" type="string">
  ISO 8601 timestamp of the estimated completion time.
</ResponseField>

<ResponseField name="costMicroCents" type="number">
  The cost of the job in micro-cents.
</ResponseField>