Use callback_url on Kling async tasks when you want push delivery instead of pure polling.
Where to use it
- Text-to-video and image-to-video tasks
- Avatar and video-effects tasks
- Other Kling async routes that expose an optional
callback_url field
Delivery behavior
- Kling posts to your callback endpoint whenever task status changes
- Common statuses are
submitted, processing, succeed, and failed
- The payload can include
task_result.images or task_result.videos depending on the task type
- Keep manual polling available for reconciliation, retries, or missed webhook handling
Integration checklist
- Use an HTTPS callback endpoint you control
- Accept repeated status updates for the same task id
- Treat webhook delivery as asynchronous and eventually consistent
- Persist the final asset URLs quickly if your workflow needs durable storage
Last modified on June 23, 2026