# Gen-4.5

> State-of-the-art video motion quality, prompt adherence and visual fidelity

- **Provider**: replicate
- **Model ID**: runwayml/gen-4.5
- **Category**: video_generation
- **Credits**: 1400 per request
- **Pricing Type**: input_based

## API Endpoint

Base URL: https://api.core.today/v1

### Create Prediction
POST /predictions

### Get Status
GET /predictions/{job_id}

### Cancel
DELETE /predictions/{job_id}

## Authentication

Header: `X-API-Key: YOUR_API_KEY`

## Input Parameters

- `image` (string, optional): Optional initial image for video generation (first frame). If not provided, video will be generated from text only.
- `aspect_ratio` (string, optional): Video aspect ratio (Default: `16:9`; Options: `16:9`, `9:16`, `4:3`, `3:4`, `1:1`, `21:9`)
- `prompt` (string, **required**): Text prompt for video generation
- `duration` (integer, optional): Duration of the output video in seconds (Default: `5`; Options: `5`, `10`)
- `seed` (integer, optional): Random seed. Set for reproducible generation

## Example Request

```json
{
  "model": "runwayml/gen-4.5",
  "input": {
    "duration": 10,
    "prompt": "A dense, verdant jungle world made up of small lego-like pieces. We see a rainbow chameleon running through the 3D world, the camera in and out of focus.",
    "aspect_ratio": "16:9"
  }
}
```

## Response Format

```json
{
  "job_id": "abc123",
  "status": "pending",
  "provider": "replicate",
  "model": "black-forest-labs/flux-schnell",
  "created_at": "2026-01-01T00:00:00Z",
  "result": null,
  "error": null
}
```

Status values: `pending`, `processing`, `completed`, `failed`, `cancelled`

## Usage Flow

1. POST /predictions with model and input → receive job_id
2. Poll GET /predictions/{job_id} until status is `completed` or `failed`
3. Result contains output URL(s) or data

## Output Type

url

## Tags

runwayml, gen-4, video-generation, text-to-video, image-to-video, cinematic

## Documentation

https://replicate.com/runwayml/gen-4.5