> ## Documentation Index > Fetch the complete documentation index at: https://docs.vidgo.ai/llms.txt > Use this file to discover all available pages before exploring further. # Kling 1.6 Pro Image to Video > Kling 1.6 Pro Image to Video parameters and billing factors. # Kling 1.6 Pro Image to Video Public model ID: `kwaivgi/kling-video/v1.6/pro/image-to-video`. Submit with `VIDGO_API_KEY`, then use [Query Task Status](/api-manual/task-management/status) with the returned `task_id`. Optional root-level `callback_url` enables [webhook notifications](/api-manual/task-management/webhooks). ## Input workflow Provide **either** `start_image_url` for first-frame animation **or** `image_urls` for Elements. The endpoint does not accept text-only requests. * Elements accepts 1–4 reference images and cannot be combined with `start_image_url`, `end_image_url`, or `cfg_scale`. * Pro supports an optional `end_image_url` when `start_image_url` is present; aspect ratio is supported in both workflows. The image fields select the workflow. ## Parameters Place generation parameters inside `input`. Keep `model` and optional `callback_url` at the request root. Unsupported input fields are rejected before credits are deducted. | Parameter | Requirement | Description | | ----------------- | ----------- | ------------------------------------------------------------------------------------------------------------------- | | `prompt` | Required | Required nonblank string, at most 2,500 Unicode characters after trimming. | | `duration` | Required | Required integer: 5 or 10 seconds. No API default. | | `aspect_ratio` | Optional | Optional: 1:1, 16:9 or 9:16. No API default. | | `negative_prompt` | Optional | Optional string, at most 2,500 Unicode characters. | | `cfg_scale` | Optional | Optional finite number from 0 to 1. Not supported with image\_urls. No API default. | | `start_image_url` | Conditional | First-frame HTTP(S) URL. Required for the first-frame workflow; mutually exclusive with image\_urls. | | `end_image_url` | Optional | Optional Pro last-frame HTTP(S) URL. Requires start\_image\_url; not supported with image\_urls. | | `image_urls` | Conditional | Elements: 1 to 4 HTTP(S) reference URLs. Mutually exclusive with start\_image\_url, end\_image\_url and cfg\_scale. | Image URLs must be public HTTP(S) URLs with a hostname, without embedded credentials or whitespace. Local files can be uploaded in the playground before submitting their URL. Optional parameters have no documented API defaults. ## Billing Factors Billing depends on the selected model tier (Standard or Pro) and video duration (`duration`). Usage is charged per generated second. Within a tier, text-to-video, first-frame animation, and Elements use the same rate. Credits are deducted on submission and refunded if the task fails. ## OpenAPI ````yaml api-manual/video-series/kwaivgi-kling-video-v1-6-pro-image-to-video.json POST /api/generate/submit openapi: 3.0.0 info: title: Vidgo API - Kling 1.6 Pro Image to Video description: >- Animate reference images with Kling 1.6 Pro, using text direction and negative prompts to shape the scene and motion. version: 1.0.0 servers: - url: https://api.vidgo.ai security: - BearerAuth: [] paths: /api/generate/submit: post: tags: - Video Series summary: Kling 1.6 Pro Image to Video description: >- Send only the fields shown for this workflow. Parameters from other workflows are rejected before credits are deducted. When supplied, prompt must not be blank. Input URL fields require HTTP(S) URLs with a hostname and no embedded credentials. operationId: submit_kwaivgi_kling_video_v1_6_pro_image_to_video requestBody: required: true content: application/json: schema: type: object required: - model - input additionalProperties: true properties: model: type: string example: kwaivgi/kling-video/v1.6/pro/image-to-video input: type: object required: - prompt - duration description: >- Input parameters for generation. PoYo selects the generation workflow from the provided image fields. additionalProperties: false properties: prompt: type: string description: >- Required nonblank string, at most 2,500 Unicode characters after trimming. maxLength: 2500 example: A cinematic video scene minLength: 1 duration: type: integer description: 'Required integer: 5 or 10 seconds. No API default.' enum: - 5 - 10 example: 5 aspect_ratio: type: string description: 'Optional: 1:1, 16:9 or 9:16. No API default.' enum: - '1:1' - '16:9' - '9:16' example: '16:9' negative_prompt: type: string description: Optional string, at most 2,500 Unicode characters. maxLength: 2500 example: blur, low quality, artifacts cfg_scale: type: number description: >- Optional finite number from 0 to 1. Not supported with image_urls. No API default. minimum: 0 maximum: 1 example: 0.5 start_image_url: type: string format: uri description: >- First-frame HTTP(S) URL. Required for the first-frame workflow; mutually exclusive with image_urls. example: https://example.com/start-frame.png end_image_url: type: string format: uri description: >- Optional Pro last-frame HTTP(S) URL. Requires start_image_url; not supported with image_urls. example: https://example.com/end-frame.png image_urls: type: array items: type: string format: uri description: >- Elements: 1 to 4 HTTP(S) reference URLs. Mutually exclusive with start_image_url, end_image_url and cfg_scale. minItems: 1 maxItems: 4 example: - https://example.com/reference-1.png oneOf: - required: - start_image_url not: required: - image_urls - required: - image_urls not: anyOf: - required: - start_image_url - required: - end_image_url - required: - cfg_scale callback_url: type: string nullable: true description: >- Optional public HTTP(S) endpoint for task completion notifications. HTTPS is recommended. Omit, use null, or use an empty string to disable callbacks. description: >- Keep model and callback_url at the root. Unknown root fields are ignored; unsupported input fields are rejected. examples: basic: summary: First-frame image to video value: model: kwaivgi/kling-video/v1.6/pro/image-to-video input: prompt: A quiet forest in morning light, with a slow camera pan. duration: 5 start_image_url: https://example.com/start-frame.png callback: summary: Receive a completion callback value: model: kwaivgi/kling-video/v1.6/pro/image-to-video input: prompt: A quiet forest in morning light, with a slow camera pan. duration: 5 start_image_url: https://example.com/start-frame.png callback_url: https://your-domain.com/callback elements: summary: Elements reference images value: model: kwaivgi/kling-video/v1.6/pro/image-to-video input: prompt: A quiet forest in morning light, with a slow camera pan. duration: 5 aspect_ratio: '16:9' image_urls: - https://example.com/reference-1.png first-last-frame: summary: Pro first and last frames value: model: kwaivgi/kling-video/v1.6/pro/image-to-video input: prompt: A quiet forest in morning light, with a slow camera pan. duration: 5 start_image_url: https://example.com/start-frame.png end_image_url: https://example.com/end-frame.png cfg_scale: 0.5 aspect_ratio: '16:9' responses: '200': description: Task submitted content: application/json: schema: type: object required: - code - data properties: code: type: integer enum: - 200 data: type: object required: - task_id - status - created_time properties: task_id: type: string status: type: string enum: - not_started - running - finished - failed created_time: type: string format: date-time example: code: 200 data: task_id: task-unified-example status: running created_time: '2026-09-10T08:00:00' '400': description: >- Invalid input, unsupported tier, inaccessible media, or insufficient credits content: application/json: schema: type: object required: - detail properties: detail: oneOf: - type: string - type: object additionalProperties: true - type: array items: {} '401': description: Invalid credentials content: application/json: schema: type: object required: - detail properties: detail: oneOf: - type: string - type: object additionalProperties: true - type: array items: {} '403': description: Access denied content: application/json: schema: type: object required: - detail properties: detail: oneOf: - type: string - type: object additionalProperties: true - type: array items: {} '404': description: Unknown or disabled model content: application/json: schema: type: object required: - detail properties: detail: oneOf: - type: string - type: object additionalProperties: true - type: array items: {} '408': description: Request timed out content: text/plain: schema: type: string example: Request timeout '422': description: Invalid JSON or non-object request body content: application/json: schema: type: object required: - detail properties: detail: oneOf: - type: string - type: object additionalProperties: true - type: array items: {} '429': description: Rate or API key credit limit exceeded content: application/json: schema: type: object required: - detail properties: detail: oneOf: - type: string - type: object additionalProperties: true - type: array items: {} '500': description: Internal error content: application/json: schema: type: object required: - detail properties: detail: oneOf: - type: string - type: object additionalProperties: true - type: array items: {} '502': description: Unable to create the upstream generation task content: application/json: schema: type: object required: - detail properties: detail: oneOf: - type: string - type: object additionalProperties: true - type: array items: {} '503': description: Model configuration or capability is not approved content: application/json: schema: type: object required: - detail properties: detail: oneOf: - type: string - type: object additionalProperties: true - type: array items: {} components: securitySchemes: BearerAuth: type: http scheme: bearer description: Use VIDGO_API_KEY. ````