Kling-V3.0-Std - Image To Video - gptproto

Authentication

Sign up for a GPTProto account at https://gptproto.com
Navigate to the API Keys section in your dashboard
Generate a new API key (sk-xxxxx)
Copy and securely store your API key For authentication details, please refer to the Authentication section.

Initiate Request

curl --location 'https://gptproto.com/api/v3/kwaivgi/kling-v3.0-std/image-to-video' \
--header 'Authorization: GPTPROTO_API_KEY' \
--header 'Content-Type: application/json' \
--data '{
  "prompt": "Put a hat on the cat",
  "image": "https://tos.gptproto.com/resource/cat.png",
  "negative_prompt": "",
  "duration": 5
}'

Query Result

If the request that generated your content includes the parameter enable_sync_mode set to true (some models do not support this parameter, but you still need to query the result by id), you must call the Query Result endpoint to retrieve the final output.

curl -X GET "https://gptproto.com/api/v3/predictions/{id}/result" \
  -H "Authorization: GPTPROTO_API_KEY" \
  -H "Content-Type: application/json"

After submitting your prediction request, the response will contain the id you need.
You can find it in either:

data.id – the unique identifier of the prediction
data.urls[0].get – a ready-to-use GET URL that already embeds the id

Response Example

{
    "data": {
        "id": "abc",
        "model": "model_name",
        "outputs": [],
        "urls": {
            "get": "https://gptproto.com/api/v3/predictions/abc/result"
        },
        "status": "completed",
        "error": null,
        "executionTime": 0,
        "timings": {
            "inference": 0
        },
        "has_nsfw_contents": [],
        "created_at": "2026-01-01 00:00:00"
    },
    "message": "success",
    "code": 200
}

Parameters

Parameter	Type	Required	Default	Range	Description
`prompt`	string	✅ Yes	-	-	The positive prompt for the generation. Must not exceed 2,500 characters.
`negative_prompt`	string	❌ No	-	-	The negative prompt for the generation. Must not exceed 2,500 characters.
`image`	string	❌ No	-	-	Source image for image-to-video generation.
`sound`	boolean	❌ No	`true`	`true, false`	Whether to include synchronized sound with the video.
`aspect_ratio`	string	❌ No	`16:9`	`16:9, 1:1, 9:16`	The aspect ratio of the generated video. This parameter is required when the image-to-video or video editing features are not used.
`duration`	integer	❌ No	`5`	`3-15`	The duration of the generated media in seconds.
`guidance_scale`	number	❌ No	-	`0-1`	The guidance scale for the generation. Controls how closely the output follows the prompt.
`multi_prompt`	array	❌ No	-	-	A list of segmented prompts for multi-scene video generation. Each segment specifies its own prompt and duration. Only supported by V3.0 (`kling-v3.0`).
`multi_prompt[].index`	integer	✅ Yes	-	-	The index of the segment, starting from 1.
`multi_prompt[].prompt`	string	✅ Yes	-	-	The prompt for this specific segment.
`multi_prompt[].duration`	string	✅ Yes	-	-	The duration of this segment in seconds. The sum of all segment durations should match the total `duration`.
`voice_list`	array	❌ No	-	-	The list of voices id to use for the generated video, Only V2.6 and subsequent versions of the model supports the current parameters. see Custom Voice to get the voices id.
`voice_list.voice_id`	string	✅ Yes	-	-	The voice id to use for the generated video. A video generation task can reference up to 2 voices at most

Multi-Prompt (V3.0 Only)

{
  "prompt": "A cyberpunk girl walking through neon-lit alleyways, rain falling, close-up of her eyes, camera pans to her silhouette, smoke in the background, futuristic music vibe",
  "negative_prompt": "blur, distort, and low quality",
  "aspect_ratio": "16:9",
  "duration": 5,
  "guidance_scale": 0.5,
  "sound": false,
  "multi_prompt": [
    {
      "index": 1,
      "prompt": "Two friends talking under a streetlight at night. Warm glow, casual poses, no dialogue.",
      "duration": "2"
    },
    {
      "index": 2,
      "prompt": "A runner sprinting through a forest, leaves flying. Low-angle shot, focus on movement.",
      "duration": "3"
    }
  ]
}

Custom Voice (Only V2.6 and subsequent versions)

voice_list is List of tones referenced when generating videos,The value of voice_id parameter is returned through the voice customization interface You can customize your voice by calling the endpoint below; please note:

audio parameter Supports .mp3 / .wav audio file and .mp4 / .mov video file.
The voice needs to be clean and free of noise, with only one type of human voice present, with a duration of no less than 5 seconds and no longer than 30 seconds.

Custom Voice interface

curl --location --request POST 'https://gptproto.com/api/v3/kwaivgi/kling_custom_voice/create_voice' \
--header 'Authorization: GPTPROTO_API_KEY' \
--header 'Content-Type: application/json' \
--data-raw '{
    "audio": "https://oss.gptproto.com/ai/api654ed87e-2e5c-4d2d-979f-fed8b741a8f4.mp3"
}'

Query Custom Voice Result

curl -X GET "https://gptproto.com/api/v3/predictions/{id}/result" \
  -H "Authorization: GPTPROTO_API_KEY" \
  -H "Content-Type: application/json"

After submitting your prediction request, the response will contain the id you need.
You can find it in either:

data.id – the unique identifier of the prediction
data.urls[0].get – a ready-to-use GET URL that already embeds the id

Custom Voice interface response

data.id is the voice id you need.

{
    "data": {
        "id": "123123",
        "model": "kling_custom_voice",
        "outputs": [
            "838227563994169418"
        ],
        "urls": {
            "get": "https://gptproto.com/api/v3/predictions/123123/result"
        },
        "status": "succeed",
        "error": null,
        "executionTime": 0,
        "timings": null,
        "has_nsfw_contents": [],
        "created_at": "2026-01-08T21:05:34"
    },
    "message": "success",
    "code": 200
}

How to use the voice id

Add the voice id to the voice_list parameter when calling the video generation interface.

{
    "prompt": "A man is playing a guitar",
    "aspect_ratio": "16:9",
    "duration": 5,
    "sound": true, // The premise of using voice_list is that the sound parameter must be true
    "voice_list": [
        "838227563994169418"
    ]
}

Error Codes

Common Error Codes

Error Code	Error Name	Description
401	Unauthorized	API key is missing or invalid
403	Forbidden	Your API key doesn’t have permission to access this resource, or insufficient balance for the requested operation
429	Too Many Requests	You’ve exceeded your rate limit
500	Internal server error	An internal server error occurred
503	Content policy violation	Content blocked due to safety concerns (actual status code is 400)

Documentation Index

​Authentication

​Initiate Request

​Query Result

​Parameters

​Multi-Prompt (V3.0 Only)

​Custom Voice (Only V2.6 and subsequent versions)

​Custom Voice interface

​Query Custom Voice Result

​Custom Voice interface response

​How to use the voice id

​Error Codes

​Common Error Codes