Kling 4.0 video edit rewrites a 3 to 30 second clip from a text instruction. It keeps the scene, the subject and the motion and changes what you describe, with up to 10 optional reference images.
Examples use the selected endpoint’s public parameter definitions. Replace the API key and example media, then send the request from your server.
SDKs & integrations
https://api.spicyapi.ai/api/v1/jobs/createTaskKeep the API key in the server environment variable SPICY_API_KEY. Use Bearer authentication and Content-Type: application/json for JSON requests.
Authorization: Bearer $SPICY_API_KEY# Generate the idempotency key once; reuse it when retrying after a lost response.
export SPICY_IDEMPOTENCY_KEY="${SPICY_IDEMPOTENCY_KEY:-$(uuidgen)}"
curl -X POST https://api.spicyapi.ai/api/v1/jobs/createTask \
-H "Authorization: Bearer $SPICY_API_KEY" \
-H "Content-Type: application/json" \
-H "Idempotency-Key: $SPICY_IDEMPOTENCY_KEY" \
-d '{
"model": "kling/4.0/video-edit",
"input": {
"aspect_ratio": "auto",
"duration_seconds": -1,
"prompt": "A slow aerial shot drifting over a misty pine forest at sunrise",
"resolution": "720p",
"video_url": "https://example.com/reference.mp4"
}
}'
# Copy data.taskId from the response into TASK_ID, then poll the status.
TASK_ID="TASK_ID_FROM_RESPONSE"
curl "https://api.spicyapi.ai/api/v1/jobs/recordInfo?taskId=$TASK_ID" \
-H "Authorization: Bearer $SPICY_API_KEY"Generated from this model’s input schema — the same one the API validates every request against.
Place these fields inside the request body’s input object. Names and types match the API. Do not assume a default when none is specified.
video_urlstringRequiredAffects priceThe clip to edit, MP4 or WebM, 3 to 30 seconds. The scene, the subject and the motion are kept.
promptstringRequiredDescribe the edit. Call the source clip @Video1 and the reference images @Image1, @Image2 and so on, in upload order. Say what must stay the same, for example "keep the man, his movements and the camera move as they are".
duration_secondsintegerOptionalAffects priceLength of the result: a whole number from 3 to 30 seconds, or -1 for Match source (default), which follows the source clip rounded up to a whole second. On Match source we hold the 30-second maximum up front and settle on the length delivered. Drives the price.
-13456789101112131415161718192021222324252627282930keep_original_audiobooleanOptionalOn by default, which keeps the source clip's own sound. Turn it off and the model generates new, synchronized audio. When Match source makes the result slightly longer than the source, the source sound ends a moment before the picture. It does not change the price.
resolutionstringOptionalAffects price720p (default) or 1080p. 1080p costs more per second.
"720p""1080p"aspect_ratiostringOptionalauto (default) follows the source clip; 16:9, 9:16, 1:1 or 21:9 set it yourself. It does not change the price.
"auto""16:9""9:16""1:1""21:9"reference_image_urlsarray<string>OptionalOptional, up to 10 images of a person, an object or a style to bring in, 10 MB each. Refer to them as @Image1, @Image2 in upload order. They do not change the price.
{
"additionalProperties": false,
"properties": {
"aspect_ratio": {
"default": "auto",
"description": "Output aspect ratio; auto follows the source clip.",
"enum": [
"auto",
"16:9",
"9:16",
"1:1",
"21:9"
],
"type": "string",
"x-ui": {
"order": 80,
"widget": "select"
}
},
"duration_seconds": {
"default": -1,
"description": "Output length in whole seconds, from 3 to 30, or -1 to match the source clip. Billed per second.",
"enum": [
-1,
3,
4,
5,
6,
7,
8,
9,
10,
11,
12,
13,
14,
15,
16,
17,
18,
19,
20,
21,
22,
23,
24,
25,
26,
27,
28,
29,
30
],
"type": "integer",
"x-ui": {
"affects_price": true,
"enum_labels": {
"-1": "Match source"
},
"order": 60,
"unit": "s",
"widget": "slider"
}
},
"keep_original_audio": {
"default": true,
"description": "Keep the source clip's own sound. Turn it off to generate new synchronized audio instead.",
"type": "boolean",
"x-ui": {
"order": 63,
"widget": "switch"
}
},
"prompt": {
"description": "Describe the edit: change a subject, the setting, the weather or the style. Refer to the video as @Video1 and to reference images as @Image1, @Image2, numbered in upload order.",
"minLength": 1,
"type": "string",
"x-ui": {
"order": 100,
"primary": true,
"reference_tokens": {
"reference_image_urls": "@Image{index}"
},
"widget": "textarea"
}
},
"reference_image_urls": {
"description": "Optional reference images for a subject, object or style to bring into the edit, up to 10. Refer to them as @Image1, @Image2 and so on.",
"items": {
"contentMediaType": [
"image/jpeg",
"image/png",
"image/webp",
"image/gif"
],
"format": "uri",
"type": "string"
},
"maxItems": 10,
"minItems": 1,
"type": "array",
"x-ui": {
"max_size_mb": 10,
"order": 85,
"widget": "multi-upload"
}
},
"resolution": {
"default": "720p",
"description": "Output resolution. 1080p costs more per second.",
"enum": [
"720p",
"1080p"
],
"type": "string",
"x-ui": {
"affects_price": true,
"order": 70,
"widget": "radio"
}
},
"video_url": {
"contentMediaType": [
"video/mp4",
"video/webm",
"video/quicktime"
],
"description": "The clip to edit (MP4 or WebM), 3 to 30 seconds. The edit keeps its scene, subject and motion. Its seconds are billed together with the output seconds.",
"format": "uri",
"minLength": 1,
"type": "string",
"x-ui": {
"accept": [
"video/mp4",
"video/webm"
],
"affects_price": true,
"max_duration_seconds": 30,
"order": 90,
"widget": "upload"
}
}
},
"required": [
"prompt",
"video_url"
],
"type": "object",
"x-pricing": {
"billingMode": "duration_capped",
"variantFields": [
"resolution"
]
}
}HTTP 202 means the task was accepted, not completed. Save the returned taskId and query that task. Do not create another task while waiting for its result.
HTTP/1.1 202 Accepted
Location: /api/v1/jobs/recordInfo?taskId=job_01k3m8x9q2z4v7n5p6r8s0t1w3
{
"code": 200,
"msg": "success",
"request_id": "req_example_create",
"data": {
"taskId": "job_01k3m8x9q2z4v7n5p6r8s0t1w3",
"state": "queued",
"estimatedCost": "0.750000"
}
}The accepted response includes the estimate so your app can show the same amount in task history and billing.
curl --get "https://api.spicyapi.ai/api/v1/jobs/recordInfo" \
--data-urlencode "taskId=$TASK_ID" \
-H "Authorization: Bearer $SPICY_API_KEY"Start polling at about 2 seconds and gradually increase the interval. Stop at a terminal state. After a connection failure, query the original taskId. Retry creation only with the original idempotency key and body.
import { verifyWebhook } from "@spicyapi/sdk";
// express.raw keeps the bytes we signed; express.json never matches.
app.post("/hooks/spicy", express.raw({ type: "application/json" }), (req, res) => {
const { payload } = verifyWebhook({
rawBody: req.body,
timestamp: req.header("X-Webhook-Timestamp"),
signature: req.header("X-Webhook-Signature"),
payloadVersion: Number(req.header("X-Webhook-Payload-Version")),
secret: process.env.SPICY_WEBHOOK_SECRET,
});
res.status(200).end();
void handleFinishedTask(payload);
});Pass callBackUrl when you create the task and the finished record is POSTed to you — no polling loop at all. Every delivery carries X-Webhook-Timestamp, X-Webhook-Signature and X-Webhook-Payload-Version. The signature is a base64 HMAC-SHA256 over taskId.timestamp.sha256(body), so it must be checked against the raw bytes: parsing the JSON and re-serialising it changes them and the check will fail. Failed deliveries are retried, so the same taskId can arrive twice — make the handler idempotent. Answer 2xx first and do the work afterwards; a slow handler is treated as a failed delivery.
Consume output only when state is succeeded. On failure, use errorCode, errorMessage and request_id to investigate. Example costs and states do not represent an actual bill.
{
"code": 200,
"msg": "success",
"request_id": "req_example_record",
"data": {
"taskId": "job_01k3m8x9q2z4v7n5p6r8s0t1w3",
"model": "kling/4.0/video-edit",
"state": "succeeded",
"output": {
"assets": [
{
"key": "tasks/2026/08/28/job_01k3m8x9q2z4v7n5p6r8s0t1w3/3f7a1c9e5b2d48f0a6c1e3d5b7f9a1c3.mp4",
"mime": "video/mp4",
"url": "https://example.r2.cloudflarestorage.com/results/job_01k3m8x9q2z4v7n5p6r8s0t1w3/result.mp4?X-Amz-Signature=SIGNATURE_FROM_RESPONSE",
"expiresAt": "2026-08-28T12:20:08.000Z"
}
]
},
"cost": "0.750000",
"settled": true,
"createdAt": "2026-08-28T12:00:00Z",
"completedAt": "2026-08-28T12:00:30Z"
}
}For each available asset, open or download assets[].url directly without an API Authorization header. The signed URL expires at expiresAt; poll the task again to refresh it while the asset remains within its retention period. A pending or unavailable asset has no URL. Treat signed URLs as private.
Use SpicyAPI in your app, terminal, AI assistant or visual workflow. Choose a setup guide below.
You do not have to write any of the code above. Connect the MCP server once and any agent that speaks MCP — Claude Code, Codex, Cursor, Windsurf, VS Code, Gemini CLI, Cline, LibreChat — can run this model by name, or run it from your shell with a single command.
Use kling/4.0/video-edit to make a five-second shot of a neon-lit rooftop at dusk, slow push-in, and save it to ./out/.
The agent looks the model up in the live catalogue, uploads the local file for you, then shows the exact quote and its maximum charge and waits for your confirmation. Nothing is billed until you say yes.
claude mcp add spicyapi -e SPICY_API_KEY=$SPICY_API_KEY \
-- npx --yes --package=@spicyapi/mcp spicyapi-mcp
npx skills add spicyapi-ai/spicy-skillThe first line gives the agent the tools; the second gives it the Skill — the operating rules for them, so it quotes before it bills, uploads local files instead of pasting bytes, and reads the finished asset URL rather than guessing. Every other client takes the same server through its own config file: see the developer hub.
npx @spicyapi/cli tasks create --model kling/4.0/video-edit \
--input-json '{"aspect_ratio":"auto","duration_seconds":-1,"prompt":"A slow aerial shot drifting over a misty pine forest at sunrise","resolution":"720p","video_url":"https://example.com/reference.mp4"}' \
--waitThe input is this endpoint’s own schema, same as the examples above. --wait polls until the task is finished and prints it; add --yes to skip the confirmation prompt in CI. Set SPICY_API_KEY first — one key works for the API, the CLI and the MCP server.
npx @spicyapi/cli files upload ./poster.png
# -> spicy://uploads/01k3m8x9q2z4v7n5p6r8s0t1w3
npx @spicyapi/cli tasks create --model kling/4.0/video-edit \
--input-json '{"video_url":"spicy://uploads/01k3m8x9q2z4v7n5p6r8s0t1w3"}' \
--waitRequest bodies take URLs, not bytes. Upload the file first and pass the spicy:// URI it prints — the field name above is this endpoint’s own, straight from its schema. An agent on MCP does this step for you, which is why the sentence further up can name ./poster.png directly. Media already reachable over public HTTPS needs no upload.
npx @spicyapi/cli tasks create --model kling/4.0/video-edit \
--input-json '{…}' --retention 1h --wait
npx @spicyapi/cli tasks get $TASK_ID # read back the retention that applied--retention only ever shortens the window — 30m, 1h, 7d, or 0 to delete as soon as the task reaches a terminal state. The value that actually applies is the shortest of your request, your account settings and the platform maximum, so read it back from the task record rather than assuming the number you asked for took effect. Passing a longer window than your account allows does nothing.
Install the SpicyAPI nodes from ComfyUI Manager or with the command below, then search for Kling 4.0 · Video Edit on the canvas. The node has the same options as this page and shows its price before it runs.
cd ComfyUI/custom_nodes
git clone https://github.com/spicyapi-ai/comfyui-spicyapiThe embedded panel reads the same schema as this page, so it cannot drift from the API. If your docs need the content to be searchable, read the JSON under /api/embed/models/ and render it yourself.
<iframe src="https://spicyapi.ai/embed/en/models/kling-4-0/api?model=kling%2F4.0%2Fvideo-edit" width="100%" height="560" loading="lazy" title="Request example" style="border:1px solid rgba(0,0,0,.12)"></iframe>