> ## 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 Text to Video > Kling 1.6 Pro Text to Video parameters and billing factors. # Kling 1.6 Pro Text to Video Public model ID: `kwaivgi/kling-video/v1.6/pro/text-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 This endpoint generates videos from text prompts. ## 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. No API default. | 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-text-to-video.json POST /api/generate/submit openapi: 3.0.0 info: title: Vidgo API - Kling 1.6 Pro Text to Video description: >- Create short video scenes with Kling 1.6 Pro, using text direction and negative prompts to shape the action and appearance. 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 Text 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. operationId: submit_kwaivgi_kling_video_v1_6_pro_text_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/text-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. No API default. minimum: 0 maximum: 1 example: 0.5 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: Text to video value: model: kwaivgi/kling-video/v1.6/pro/text-to-video input: prompt: A quiet forest in morning light, with a slow camera pan. duration: 5 callback: summary: Receive a completion callback value: model: kwaivgi/kling-video/v1.6/pro/text-to-video input: prompt: A quiet forest in morning light, with a slow camera pan. duration: 5 callback_url: https://your-domain.com/callback 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. ````