# Wan 2.7 Video Extend

> Extend an existing video clip into a longer one - up to 15 seconds in total, with matching audio, and optionally steered toward a closing frame you supply.

## Overview

- **Endpoint**: `https://queue.modelrunner.run/wan-video/wan/v2.7/video-extend`
- **Model ID**: `wan-video/wan/v2.7/video-extend`
- **Category**: video-to-video
- **Kind**: inference
- **Tags**: wan, wan-2.7, video-extend, video-extension, video-continuation, video-to-video, video-generation, audio, sound-effects

## Pricing

- **720P**: $0.1 per output second
- **1080P**: $0.15 per output second

## Request Lifecycle

This model runs on the ModelRunner **asynchronous queue API** — a single POST does not return the output. Every call requires an `Authorization: Key $MODEL_RUNNER_KEY` header. Run three steps:

1. **Submit** — `POST https://queue.modelrunner.run/wan-video/wan/v2.7/video-extend` with a JSON body holding the input fields at the top level. The body may also include a reserved top-level `metadata` object — a flat string map (max 16 keys, key ≤64 / value ≤512 chars) stored on the request for your own tagging. It is never sent to the model; filter your request history with `GET https://queue.modelrunner.run/requests?metadata=<url-encoded JSON>` (exact key=value matches, AND-ed). The response carries request handles only (no output yet):

```json
{
  "status": "IN_QUEUE",
  "request_id": "<21-char id>",
  "status_url": "https://queue.modelrunner.run/wan-video/wan/v2.7/video-extend/requests/<request_id>/status",
  "response_url": "https://queue.modelrunner.run/wan-video/wan/v2.7/video-extend/requests/<request_id>",
  "cancel_url": "https://queue.modelrunner.run/wan-video/wan/v2.7/video-extend/requests/<request_id>/cancel"
}
```

2. **Poll status** — `GET <status_url>` until `status` is `COMPLETED`. Possible values are `IN_QUEUE`, `IN_PROGRESS`, `COMPLETED`, `FAILED`, `CANCELLED`. A `FAILED` request responds with HTTP 400 and an `error` field.

3. **Read result** — `GET <response_url>`. Returns the finished request, including the generated `output`:

```json
{ "id": "<request_id>", "status": "COMPLETED", "output": ..., "input": ... }
```

The JavaScript and Python SDKs below perform steps 2–3 for you. In any language without an SDK (Swift, Go, Kotlin, etc.) you must implement the polling loop and the final result fetch yourself — see the cURL example for the full flow.

### Input Schema

- **`seed`** (`integer`, _optional_):
  Random seed for reproducible results. Omit for a random seed each run.
  - Range: `0` to `2147483647`

- **`prompt`** (`string`, _optional_):
  Optional description of how the clip should continue - the motion and camera movement to carry on with. The scene is already fixed by the source clip, so describe what happens next rather than re-describing the picture. Chinese and English are supported.

- **`duration`** (`integer`, _optional_):
  Total length of the video you get back, in seconds (2-15). The source clip is INCLUDED in this number, not added to it: with a 5-second source clip, duration 10 returns a 10-second video - your original 5 seconds followed by 5 newly generated ones - and is billed as 10 seconds. Set it clearly above your source clip's length; at or below that length there is no room for new footage and you still pay for the full duration.
  - Default: `10`
  - Range: `2` to `15`

- **`video_url`** (`string`, _required_):
  The video clip to continue. The delivered video opens with this clip and carries its motion, subject and setting onward. MP4 or MOV; 2 to 10 seconds long; width and height each between 240 and 4096 px; aspect ratio between 1:8 and 8:1; up to 100 MB. The finished video takes its frame shape from this clip.

- **`resolution`** (`ResolutionEnum`, _optional_):
  Output video resolution. 720P bills at $0.10 per second of finished video; 1080P (default) bills at $0.15 per second. This picks the pixel tier only - the frame shape is inherited from your source clip.
  - Default: `"1080P"`
  - Options: `"720P"`, `"1080P"`

- **`end_image_url`** (`string`, _optional_):
  Optional closing frame. Supply it and the continuation is steered to end on this image; it cannot be used on its own, without a source video. JPEG, JPG, PNG (alpha channel not supported), BMP or WEBP; width and height each between 240 and 8000 px, aspect ratio between 1:8 and 8:1, up to 20 MB. It should share the source clip's aspect ratio.

- **`negative_prompt`** (`string`, _optional_):
  Describe content to avoid in the generated continuation.

- **`enable_prompt_expansion`** (`boolean`, _optional_):
  When enabled, an LLM rewrites and enriches your prompt before generation, which suits short prompts but adds some processing time. Disable to follow your exact wording.
  - Default: `true`

### Output Schema

_No `Output` schema properties are available._

## Default Example

**Input**

```json
{
  "prompt": "The camera continues forward along the cliff road as the sun climbs higher, sunlight glittering across the open ocean and the roadside wildflowers swaying in the breeze",
  "duration": 8,
  "video_url": "https://media.modelrunner.ai/biiLLljv7ptZ0QAcTHR6s.mp4",
  "resolution": "720P",
  "enable_prompt_expansion": true
}
```

**Output**

```json
"https://media.modelrunner.ai/IivYkcNJgJ0slNttC3uh5.mp4"
```
## Usage Examples

### cURL

The queue API is asynchronous: submit the request, poll `status_url` until it is `COMPLETED`, then read the result from `response_url`. Requires `jq`.

```bash
# 1. Submit the request (returns request handles, not the output)
SUBMIT=$(curl --silent --request POST \
  --url https://queue.modelrunner.run/wan-video/wan/v2.7/video-extend \
  --header "Authorization: Key $MODEL_RUNNER_KEY" \
  --header "Content-Type: application/json" \
  --data '{
  "prompt": "The camera continues forward along the cliff road as the sun climbs higher, sunlight glittering across the open ocean and the roadside wildflowers swaying in the breeze",
  "duration": 8,
  "video_url": "https://media.modelrunner.ai/biiLLljv7ptZ0QAcTHR6s.mp4",
  "resolution": "720P",
  "enable_prompt_expansion": true
}')

STATUS_URL=$(echo "$SUBMIT" | jq -r '.status_url')
RESPONSE_URL=$(echo "$SUBMIT" | jq -r '.response_url')

# 2. Poll until the request leaves the queue / in-progress state
while true; do
  STATUS=$(curl --silent --url "$STATUS_URL" \
    --header "Authorization: Key $MODEL_RUNNER_KEY" | jq -r '.status')
  echo "Status: $STATUS"
  case "$STATUS" in
    COMPLETED) break ;;
    FAILED|CANCELLED) echo "Request $STATUS"; exit 1 ;;
  esac
  sleep 1
done

# 3. Read the finished request, including the generated output
curl --silent --url "$RESPONSE_URL" \
  --header "Authorization: Key $MODEL_RUNNER_KEY"
```

### JavaScript

```javascript
import { modelrunner } from "@modelrunner/client";

const result = await modelrunner.subscribe("wan-video/wan/v2.7/video-extend", {
  input: {
  "prompt": "The camera continues forward along the cliff road as the sun climbs higher, sunlight glittering across the open ocean and the roadside wildflowers swaying in the breeze",
  "duration": 8,
  "video_url": "https://media.modelrunner.ai/biiLLljv7ptZ0QAcTHR6s.mp4",
  "resolution": "720P",
  "enable_prompt_expansion": true
}
});

console.log(result.data);
```

### Python

```python
import asyncio
import modelrunner_ai

async def main():
    response = await modelrunner_ai.submit_async(
        "wan-video/wan/v2.7/video-extend",
        arguments={
  "prompt": "The camera continues forward along the cliff road as the sun climbs higher, sunlight glittering across the open ocean and the roadside wildflowers swaying in the breeze",
  "duration": 8,
  "video_url": "https://media.modelrunner.ai/biiLLljv7ptZ0QAcTHR6s.mp4",
  "resolution": "720P",
  "enable_prompt_expansion": true
}
    )
    result = await response.get()
    print(result["output"])

asyncio.run(main())
```

## Additional Resources

- [Playground](https://modelrunner.ai/models/wan-video/wan/v2.7/video-extend)
- [OpenAPI Schema](https://modelrunner.ai/models/wan-video/wan/v2.7/video-extend/openapi.json)
- [LLM Instructions](https://modelrunner.ai/models/wan-video/wan/v2.7/video-extend/llms.txt)