AI Video Extension Callbacks

When you submit a task to Extend AI Video with the callBackUrl parameter, the system pushes the result to that URL when the task finishes.

Callback Mechanism Overview

Callbacks remove the need to poll for task status. The system pushes the final result to your server.

HTTP Method: POST

Content Type: application/json

Sent when: the AI video extension task succeeds or fails

Callback Request Format

The callback uses the same format as all Market models. The video URL is inside data.resultJson, a JSON string: JSON.parse(data.resultJson).resultUrls[0].

Success Callback

Failure Callback

{
  "code": 200,
  "msg": "Playground task completed successfully.",
  "data": {
    "taskId": "d6cf9fc7968af5ccd85688083f565757",
    "model": "runway/extend-ai-video",
    "state": "success",
    "param": "{\"input\":\"{\\\"task_id\\\":\\\"94bbfeaa1383c296cd61ba5dfcbfe30e\\\",\\\"prompt\\\":\\\"The cartoon fox steps back and admires the finished rainbow\\\",\\\"quality\\\":\\\"720p\\\"}\",\"callBackUrl\":\"https://your-domain.com/api/callback\",\"model\":\"runway/extend-ai-video\"}",
    "resultJson": "{\"resultUrls\":[\"https://tempfile.aiquickdraw.com/p/d6cf9fc7968af5ccd85688083f565757_1_1791218886_3642.mp4\"]}",
    "costTime": 85,
    "creditsConsumed": 12,
    "createTime": 1791218802000,
    "completeTime": 1791218887652,
    "updateTime": 1791218887652
  }
}

Parameter Description

Parameter	Type	Description
`code`	integer	`200` = success, `501` = failed
`msg`	string	Status message
`data.taskId`	string	Task ID returned when you submitted the task
`data.model`	string	Model used for the task (`runway/extend-ai-video`)
`data.state`	string	`success` or `fail`
`data.param`	string	Parameters submitted when creating the task, as a JSON string
`data.resultJson`	string	Result as a JSON string, e.g. `{"resultUrls":["https://...mp4"]}`. Present on success
`data.failCode`	string	Failure code. Present on failure
`data.failMsg`	string	Failure reason. Present on failure
`data.costTime`	integer	Task duration in seconds
`data.creditsConsumed`	number	Credits consumed by the task
`data.createTime` / `data.completeTime` / `data.updateTime`	integer	Unix timestamps in milliseconds

Callback Reception Examples

Node.js

Python

PHP

Best Practices

Callback URL Configuration Recommendations

Use HTTPS for your callback URL.

Verify the source of callback requests.

Process idempotently: the same taskId may be delivered more than once.

Respond quickly with HTTP 200, and run heavy work asynchronously.

Download promptly: save the video to your own storage as soon as you receive it.

Important Reminders

The callback URL must be publicly accessible.

The server must respond within 15 seconds, otherwise the request is treated as timed out.

After 3 consecutive failed retries, the system stops sending the callback.

Troubleshooting

Callback not received

Cannot read the video URL

Alternative Solution

If you cannot use callbacks, poll the task status instead:

Get Task Details

Query the task with its taskId. The result is in resultJson.resultUrls, the same as in the callback.

AI Video Extension Callbacks

Callback Mechanism Overview#

Callback Request Format#

Parameter Description#

Callback Reception Examples#

Best Practices#

Troubleshooting#

Alternative Solution#

Callback Mechanism Overview

Callback Request Format

Parameter Description

Callback Reception Examples

Best Practices

Troubleshooting

Alternative Solution