Errors and callback handling

Kling tasks are asynchronous. Create a task, persist its public GENGEN id, and poll the retrieve endpoint until the normalized status is terminal.

Error compatibility

GENGEN keeps its standard error envelope even when Kling rejects the upstream request:

{
  "error_code": "provider.request_failed",
  "error": "Provider request failed",
  "error_params": {
    "provider": "kling",
    "status": 429,
    "upstreamCode": 1302
  }
}

Use the HTTP status and GENGEN error_code for application logic. upstreamCode is diagnostic and can be used to distinguish the following Kling categories.

Kling code range	HTTP status	Meaning	Client action
`1000`–`1004`	`401`	Upstream credential validation failed	Do not retry; contact GENGEN support if persistent
`1100`–`1102`	`429`	Upstream account or resource package unavailable	Retry later only when instructed
`1103`	`403`	Model or resource is not authorized	Do not retry unchanged
`1200`–`1201`	`400`	Invalid request parameter	Correct the request
`1202`–`1203`	`404`	Method, resource, or model not found	Check model and endpoint documentation
`1300`–`1301`	`400`	Policy or content-safety rejection	Change the input
`1302`–`1304`	`429`	Rate, concurrency, or network-policy limit	Retry with backoff when appropriate
`5000`–`5002`	`500`–`504`	Upstream internal error, unavailable service, or timeout	Retry with exponential backoff

Never branch on provider message text. It can change independently of the GENGEN API.

Callback protocol

GENGEN registers its own callback URL with Kling and verifies every event before updating a task or settling its wallet hold. Callback verification covers the exact raw body and the webhook-id, webhook-timestamp, and webhook-signature headers. Events outside a five-minute timestamp window are rejected, and multiple v1 signatures are accepted during secret rotation. This provider callback is an internal GENGEN integration surface; it is not a customer webhook. Applications should continue polling the public task endpoint. Callback processing and polling share the same idempotent task ID, so either path can safely observe the terminal result first.

Kling output URLs are retained by the provider for a limited period. Copy successful videos to storage you control when you need durable access.

Unsupported task deletion

The current Kling 3.0 task API does not expose cancellation or deletion. Calling the shared DELETE /contents/generations/tasks/{id} route for a Kling task returns provider.operation_not_supported; it does not release an active hold or pretend the remote task was cancelled.

Reference

BytePlus

OpenAI

Kling

Higgsfield

MiniMax

Happy Horse

Google

WonderClip

Flash VSR

Wan

Qwen

Errors and callback handling

Error compatibility

Callback protocol

Unsupported task deletion

​Error compatibility

​Callback protocol

​Unsupported task deletion

Error compatibility

Callback protocol

Unsupported task deletion