Add sound to Kling video

August 8, 2025

Table of contents

  1. Request Headers
  2. Request Body
  3. Responses
  4. Model
  5. Examples
  6. Try It

This endpoint generates sound for an existing video using Kling’s AI audio generation capabilities.

Video can’t be shorter than 3 seconds or longer than 20 seconds.

https://api.useapi.net/v1/kling/videos/add-sound

Request Headers 
Authorization: Bearer {API token}
Content-Type: application/json
# Alternatively you can use multipart/form-data
# Content-Type: multipart/form-data
Request Body 
{
  "video": "https://s21-kling.klingai.com/....mp4",
  "replyUrl": "https://my.domain.com/webhook-endpoint-kling",
  "replyRef": "my-id-1234"
}

  • email is optional when only one account configured.
    However, if you have multiple accounts configured, this parameter becomes required.

  • video is required, the URL of the video to add sound to.
    Video can be uploaded using POST /assets and the returned URL can be used here.
    Video can’t be shorter than 3 seconds or longer than 20 seconds.

  • cropVideoOriginalSound is optional, whether to preserve the original video’s sound.
    Default false (original sound will be replaced).

  • maxJobs is optional, the maximum number of concurrent Kling jobs.

  • replyUrl is optional, a URL to receive webhooks when the video is completed.
    See useapi.net Webhooks.

  • replyRef is optional, include a custom reference to identify the job.
    Passed as-is to the replyUrl webhook.

Responses

  • 200 OK

    {
  "task": {
    "id": 1234567890,
    "userId": 12345,
    "type": "kwave_video2audio",
    "scene": "NORMAL_CREATION",
    "status": 5,
    "taskInfo": {
      "type": "kwave_video2audio",
      "inputs": [
        {
          "name": "video",
          "inputType": "URL",
          "token": null,
          "blobStorage": null,
          "url": "https://v15-kling.klingai.com/…",
          "cover": null,
          "fromWorkId": null,
          "fromUploadId": null
        }
      ],
      "arguments": [
        {
          "name": "biz",
          "value": "klingai"
        },
        {
          "name": "imageCount",
          "value": "1"
        },
        {
          "name": "duration",
          "value": "20"
        }
      ],
      "extraArgs": {},
      "callbackPayloads": [
        {
          "name": "video2audio_payloads",
          "resources": [
            {
              "name": "originalVideoUrl",
              "type": "VIDEO",
              "url": "https://v15-kling.klingai.com/…"
            }
          ],
          "arguments": [
            {
              "name": "cropVideoOriginalSound",
              "value": "false"
            }
          ]
        }
      ],
      "scene": "NORMAL_CREATION"
    },
    "favored": false,
    "deleted": false,
    "viewed": false,
    "createTime": 1754630611379,
    "updateTime": 1754630611379,
    "viewTime": 0,
    "status_name": "submitted",
    "status_final": false
  },
  "works": [],
  "status": 5,
  "message": "",
  "limitation": null,
  "userPoints": {
    "points": [
      {
        "orderId": "1234567890",
        "type": "reward",
        "amount": 26600,
        "balance": 3150,
        "startTime": 1754406534079,
        "endTime": 1757084934079
      }
    ],
    "total": 113390
  },
  "userTickets": {
    "ticket": [
      {
        "orderId": "1234456789",
        "type": "priority",
        "packageType": "reward",
        "amount": 1,
        "balance": 1,
        "startTime": 1754406534079,
        "endTime": 1757084934079
      }
    ]
  },
  "editProject": null,
  "status_name": "submitted",
  "status_final": false
}

  • 400 Bad Request

    {
  "error": "Invalid video URL format"
}

  • 401 Unauthorized

    {
  "error": "Unauthorized",
  "code": 401
}

  • 404 Not Found

    Kling was unable to locate one of the referenced assets. Make sure to use POST /assets to upload assets.

    {
    "error": "Sorry, the requested resource was not found (VALID.ResourceNotFound)",
    "message": "Not Found"
}

When successful, the response includes a task ID which can be used to check the status using GET /tasks/task_id.

Model 
{ // TypeScript, all fields are optional
    task: {
        id: number              // Unique task identifier
        userId: number          // User ID
        type: string            // Task type: "kwave_video2audio"
        scene: string           // Scene type: "NORMAL_CREATION"
        status: number          // Task status 
        taskInfo: {
            type: string        // Task type
            inputs: {
                name: string    // Input name: "video"
                inputType: string // Input type: "URL"
                token: string | null
                blobStorage: string | null
                url: string     // Video URL
                cover: string | null
                fromWorkId: number | null
                fromUploadId: number | null
            }[]
            arguments: {
                name: string    // Argument name
                value: string   // Argument value
            }[]
            extraArgs: Record<string, any>
            callbackPayloads: {
                name: string    // "video2audio_payloads"
                resources: {
                    name: string    // "originalVideoUrl"
                    type: string    // "VIDEO"
                    url: string     // Original video URL
                    marginTop?: number
                    countInRow?: number
                    mode?: string
                }[]
                arguments: {
                    name: string    // Parameter name
                    value: string   // Parameter value
                }[]
            }[]
            scene: string       // Scene type
        }
        favored: boolean
        deleted: boolean
        viewed: boolean
        createTime: number      // Creation timestamp
        updateTime: number      // Update timestamp
        viewTime: number        // View timestamp
        status_name: string     // Status name: "submitted"
        status_final: boolean   // Whether status is final
    }
    works: any[]                // Work items (empty initially)
    status: number              // Overall status
    message: string             // Status message
    limitation: any | null      // Rate limiting info
    userPoints: {
        points: {
            orderId: string     // Order ID
            type: string        // Point type
            amount: number      // Point amount
            balance: number     // Remaining balance
            startTime: number   // Start timestamp
            endTime: number     // End timestamp
        }[]
        total: number           // Total points
    }
    userTickets: {
        ticket: {
            orderId: string     // Order ID
            type: string        // Ticket type
            packageType: string // Package type
            amount: number      // Ticket amount
            balance: number     // Remaining balance
            startTime: number   // Start timestamp
            endTime: number     // End timestamp
        }[]
    }
    editProject: any | null     // Edit project info
    status_name: string         // Status name
    status_final: boolean       // Whether status is final
}
Examples 
  • curl "https://api.useapi.net/v1/kling/videos/add-sound" \
  -H "Accept: application/json" \
  -H "Content-Type: application/json" \
  -H "Authorization: Bearer …" \
  -d '{
    "email": "[email protected]",
    "video": "https://s21-kling.klingai.com/....mp4",
    "replyUrl": "https://my.domain.com/webhook-endpoint-kling"
  }'

  • const token = "API token";
const email = "Previously configured account email";
const requestData = {
  email,
  video: "https://s21-kling.klingai.com/....mp4",
  replyUrl: "https://my.domain.com/webhook-endpoint-kling"
};
const response = await fetch("https://api.useapi.net/v1/kling/videos/add-sound", {
  method: "POST",
  headers: {
    "Content-Type": "application/json", 
    "Authorization": `Bearer ${token}`,
  },
  body: JSON.stringify(requestData)
});
const result = await response.json();
console.log("response", {response, result});

  • import requests
token = "API token"
email = "Previously configured account email"
request_data = {
    "email": email,
    "video": "https://s21-kling.klingai.com/....mp4",
    "replyUrl": "https://my.domain.com/webhook-endpoint-kling"
}
headers = {
    "Content-Type": "application/json",
    "Authorization": f"Bearer {token}"
}
response = requests.post("https://api.useapi.net/v1/kling/videos/add-sound", 
                        headers=headers, 
                        json=request_data)
print(response, response.json())
Try It