Kling 2.1 API reference

Call Kling 2.1 from your own code with one PopNow API key. Below are the exact model IDs to send, every input field the model accepts, what each request costs in credits, and a request you can paste into a terminal.

At a glance

Made by: Kuaishou
Output: Video
From: 5.25 credits per second of output ($0.0525)
Model IDs: kling/2.1/image-to-video

1 credit = $0.01. A task holds the highest possible charge when it is accepted and settles the real amount when it finishes, rounded up to whole credits; failed tasks are not charged. Ask POST /api/v1/jobs/quote for the exact figure before you run.

Image to Video

kling/2.1/image-to-video

Price

Option	Credits (per second of output)	US dollars
`720p`	5.25	$0.0525
`1080p`	10.2	$0.102

Parameters

Field	Type	Default	Allowed	What it does
`prompt`Required	`string`	—	up to 5,000 characters	Describe what happens after the opening frame: the action, the camera.
`image_url`Required	`string (uri)`	—	—	Opening frame. The clip starts from this image. JPEG or PNG only.
`last_image_url`Optional	`string (uri)`	—	—	Optional closing frame the clip should end on. JPEG or PNG only.
`resolution`Optional	`string`	`720p`	720p, 1080p	Output resolution. Higher tiers cost more per second.
`duration_seconds`Optional	`integer`	`5`	5, 10	Output length: 5 or 10 seconds. Billed per second.
`negative_prompt`Optional	`string`	—	up to 500 characters	Things the clip should avoid, written as a short list.
`guidance_scale`Optional	`number`	`0.5`	0 to 1	How strictly the clip follows the prompt, from 0 to 1. Higher is more literal, lower gives the model more freedom.

Example request

This request runs as it is; any field you leave out uses its default. Put your key in POPNOW_API_KEY first.

The example uses PopNow sample files in image_url. Replace them with your own public HTTPS links, uploads or saved assets.

POST /api/v1/jobs/createTask

curl -X POST "https://api.popnow.ai/api/v1/jobs/createTask" \
  -H "Authorization: Bearer $POPNOW_API_KEY" \
  -H "Content-Type: application/json" \
  -H "Idempotency-Key: $(uuidgen)" \
  -d '{
  "model": "kling/2.1/image-to-video",
  "input": {
    "prompt": "He lands softly on the rooftop, laughs and turns toward the camera while the balloons sway in the evening breeze; slow push-in",
    "image_url": "https://media.popnow.ai/influencer/examples/marco.webp",
    "duration_seconds": 5,
    "resolution": "720p"
  }
}'

The response carries a taskId straight away. Read the result with GET /api/v1/jobs/recordInfo, or add callBackUrl to be notified.

GET /api/v1/jobs/recordInfo

curl "https://api.popnow.ai/api/v1/jobs/recordInfo?taskId=TASK_ID_FROM_CREATE_TASK" \
  -H "Authorization: Bearer $POPNOW_API_KEY"