kling-motion-control

Quick example

curl https://reapi.ai/api/v1/videos/generations \
  -H "Authorization: Bearer YOUR_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{
    "model": "kling-v3-motion-control",
    "prompt": "Keep the subject consistent, follow the reference motion, cinematic lighting",
    "image_url": "https://your-cdn.com/subject.png",
    "video_url": "https://your-cdn.com/motion-8s.mp4",
    "character_orientation": "image",
    "mode": "std",
    "keep_original_sound": "yes"
  }'

import requests

resp = requests.post(
    "https://reapi.ai/api/v1/videos/generations",
    headers={
        "Authorization": "Bearer YOUR_API_KEY",
        "Content-Type": "application/json",
    },
    json={
        "model": "kling-v3-motion-control",
        "prompt": "Follow the reference motion, keep the subject consistent",
        "image_url": "https://your-cdn.com/subject.png",
        "video_url": "https://your-cdn.com/motion-8s.mp4",
        "character_orientation": "image",
        "mode": "std",
    },
    timeout=30,
)
print(resp.json())

const r = await fetch("https://reapi.ai/api/v1/videos/generations", {
  method: "POST",
  headers: {
    Authorization: "Bearer YOUR_API_KEY",
    "Content-Type": "application/json",
  },
  body: JSON.stringify({
    model: "kling-v3-motion-control",
    prompt: "Follow the reference motion, keep the subject consistent",
    image_url: "https://your-cdn.com/subject.png",
    video_url: "https://your-cdn.com/motion-8s.mp4",
    character_orientation: "image",
    mode: "std",
  }),
});
console.log(await r.json());

package main

import (
    "bytes"
    "encoding/json"
    "fmt"
    "io"
    "net/http"
)

func main() {
    body, _ := json.Marshal(map[string]any{
        "model":                 "kling-v3-motion-control",
        "prompt":                "Follow the reference motion, keep the subject consistent",
        "image_url":             "https://your-cdn.com/subject.png",
        "video_url":             "https://your-cdn.com/motion-8s.mp4",
        "character_orientation": "image",
        "mode":                  "std",
    })
    req, _ := http.NewRequest("POST",
        "https://reapi.ai/api/v1/videos/generations", bytes.NewReader(body))
    req.Header.Set("Authorization", "Bearer YOUR_API_KEY")
    req.Header.Set("Content-Type", "application/json")

    resp, _ := http.DefaultClient.Do(req)
    defer resp.Body.Close()
    out, _ := io.ReadAll(resp.Body)
    fmt.Println(string(out))
}

Submit response

{
  "id": "task_018f5a3a1b6e7d9f8c2b4d6e8f0a2c4e",
  "model": "kling-v3-motion-control",
  "status": "processing",
  "created_at": 1735000000
}

Poll GET /api/v1/tasks/{id} (see the Tasks reference) until status === "completed". The completed payload's output.video_urls holds the generated MP4 URLs.

Authentication

Every call needs a Bearer token. Generate keys at reapi.ai/settings/apikeys.

Authorization: Bearer YOUR_API_KEY

Endpoint

POST /api/v1/videos/generations
GET  /api/v1/tasks/{id}

Submission is async. The POST returns immediately with a task_id; the task endpoint returns the same envelope until completion. Polling does not consume credits.

Version tiers

Two model ids share the exact same request shape — pick one by the model string you POST:

Everything else in this page applies identically to both ids. See current per-second rates for each tier on the model page.

Request body

model — required

string. One of "kling-v3-motion-control" or "kling-v2-6-motion-control".

prompt — required

string. Refines the motion, camera, and style. The API rejects requests without a prompt — more specific prompts yield more stable results.

image_url — required

string. Public HTTP(S) URL of the reference image — the subject whose appearance and identity the output keeps.

video_url — required

string. Public HTTP(S) URL of the reference video — the clip whose motion is transferred onto the subject. MP4 / MOV recommended, ≤ 100MB.

The allowed source length depends on character_orientation (see below). The billable second count is the source video's server-probed duration, not a client estimate.

character_orientation — required

string. Controls whose facing the subject follows.

mode — required

string. Quality / cost tier.

keep_original_sound — string, default "yes"

Whether to retain the reference video's original audio track.

watermark_info — object

Watermark control. Default disabled.

{ "watermark_info": { "enabled": false } }

Response envelope

Submit and poll share the same shape — only status and output fill in over time.

{
  "id": "task_018f5a3a1b6e7d9f8c2b4d6e8f0a2c4e",
  "model": "kling-v3-motion-control",
  "status": "completed",
  "created_at": 1735000000,
  "output": {
    "video_urls": ["https://cdn.reapi.ai/media/tasks/018f5a3a1b6e7d9f8c2b4d6e8f0a2c4e/0.mp4"]
  },
  "error": null
}

Pricing

Per-second × mode. The billable second count is the source video's server-probed length — reApi measures the uploaded clip server-side rather than trusting a client value. kling-v3-motion-control and kling-v2-6-motion-control have separate per-second rates, and pro costs more than std.

Bill formula (1 credit = $0.001):

billable_seconds = ceil(server_probed_source_seconds)
bill_usd         = per_second_usd(tier, mode) × billable_seconds
credits          = ceil(bill_usd × 1000)

See current per-second rates for each tier and mode on the model page. Failed jobs refund automatically. A probe failure returns 400 PRICING_UNAVAILABLE (code 30002) with no charge.

Validation errors

All cases below return HTTP 400. Pattern-match on code, not message — message strings carry request-specific context and are not a stable contract.

The full envelope is { "error": { "code", "message", "request_id" } } — see Errors catalog for the wire format and request_id correlation tips.

Recipes

Minimum request (image orientation)

{
  "model": "kling-v3-motion-control",
  "prompt": "Follow the reference motion, keep the subject consistent",
  "image_url": "https://your-cdn.com/subject.png",
  "video_url": "https://your-cdn.com/motion-8s.mp4",
  "character_orientation": "image",
  "mode": "std"
}

Video orientation, pro quality, up to 30s

{
  "model": "kling-v3-motion-control",
  "prompt": "Follow the reference performance and rhythm, keep motion continuous",
  "image_url": "https://your-cdn.com/subject.png",
  "video_url": "https://your-cdn.com/motion-20s.mp4",
  "character_orientation": "video",
  "mode": "pro",
  "keep_original_sound": "no"
}

Budget tier, watermark off

{
  "model": "kling-v2-6-motion-control",
  "image_url": "https://your-cdn.com/subject.png",
  "video_url": "https://your-cdn.com/motion-6s.mp4",
  "character_orientation": "image",
  "mode": "std",
  "watermark_info": { "enabled": false }
}

Tips

• Match the clip to the orientation. character_orientation: "image" caps the reference video at 10s; use "video" when you need up to 30s.
• Cost tracks the source clip. A 5s reference video bills ~5 seconds; trim the input to control spend.
• Prompt the motion, not just the scene. Phrasing the action ("turns and waves, smooth and continuous") sharpens the transfer.
• Start on std, escalate to pro. Validate the motion on the cheaper mode, then re-run on pro for the final take.
• Pick the tier by budget. kling-v2-6-motion-control is the cheaper run; kling-v3-motion-control maximizes fidelity and subject consistency.

Related

• Errors catalog
• Authentication
• Quickstart