Use Videos Video Extend with Comfy Router

Call kling/videos-video-extend through Comfy Router: endpoint, request shape and the response Router returns.

API Reference for kling/videos-video-extend, served by Comfy Router from Kling.

Quick start

Create a key at platform.comfy.org/profile/api-keys and export it as COMFY_API_KEY. The Python and TypeScript snippets use the Comfy SDKs (pip install comfy-sdk, npm install @comfyorg/sdk); the cURL snippet is the same call over raw HTTP.

Model ID: kling/videos-video-extend

Endpoint: POST https://api.comfy.org/v2/models/kling/videos-video-extend

Python

from comfy_sdk import Comfy

# Reads COMFY_API_KEY from the environment.
# The SDK automatically creates an idempotency key and reuses it for automatic retries.
with Comfy() as client:
    result = client.models.run(
        "kling/videos-video-extend",
        {
            "cfg_scale": 0.5,
            "prompt": "The camera keeps drifting forward down the alley.",
            "video_id": "kling-video-6f5e4d3c2b1a",
        },
    )

print(result)

Schema

Input

callback_url · string (uri)

The callback notification address. Server will notify when the task status changes.

Format: uri

cfg_scale · number · default: "0.5"

Flexibility in video generation. The higher the value, the lower the model’s degree of flexibility, and the stronger the relevance to the user’s prompt.

Range: 0 to 1

Format: float

negative_prompt · string

Negative text prompt for elements to avoid in the extended video

prompt · string

Positive text prompt for guiding the video extension

video_id · string · required

The ID of the video to be extended. Supports videos generated by text-to-video, image-to-video, and previous video extension operations. Cannot exceed 3 minutes total duration after extension.

Generated from the schema Router serves at GET /v2/models/kling/videos-video-extend/openapi.json, the same document it validates a call against before the request reaches the provider.

Output

Router does not publish an output schema for this model.

Examples

Input

{
  "cfg_scale": 0.5,
  "prompt": "The camera keeps drifting forward down the alley.",
  "video_id": "kling-video-6f5e4d3c2b1a"
}

Before you ship

The SDKs create an Idempotency-Key and reuse it for automatic retries. For manual retries, reuse the original key. Router can hold the connection for up to 10 minutes.

When a request fails, Router sends an X-Comfy-Error-Type response header explaining why. A 422 means Router rejected the input before calling the provider. Download generated assets promptly because result URLs can expire.

Headers

Authentication, idempotency, request IDs, error buckets, retry pacing, spend limits.

Using the Router API

Model discovery, validation errors, retries, and billing.

Limitations

What Router does not do today, and what to use instead.