> ## 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.

# Seedance 2.0 Fast Reference to Video

> Seedance 2.0 Fast reference to video model with multimodal generation and optional audio

<Tip>
  1. Submit the request with `VIDGO_API_KEY`. After submission, a `task_id` is returned. If `callback_url` is provided, Vidgo sends the result after the task finishes or fails.
  2. You can always retrieve the result through the unified [Query Task Status](/api-manual/task-management/status) endpoint.
</Tip>

## Available Models

* **seedance-2.0-fast/reference-to-video** - Seedance 2.0 Fast reference to video generation

## Key Features

* **Reference To Video**: Guide generation with reference images, videos, and optional audio.
* **Optional Audio**: Request generated audio together with the video.

## Variant Notes

* This public model ID uses the `seedance-2-fast` provider variant.
* Supported resolutions are `480p` and `720p`.

## Important Notes

* `prompt` is required and accepts up to 20,000 characters.
* `duration` supports integer values from `4` to `15`.
* Reference input supports up to 9 images, 3 videos, and 3 audio files, with at most 12 files in total. Reference audio requires at least one reference image or reference video.
* `aspect_ratio` accepts `auto`, `21:9`, `16:9`, `4:3`, `1:1`, `3:4`, or `9:16`.
* Provide at least one reference image or reference video. Reference audio cannot be used alone.
* All remote URLs must be publicly accessible and directly downloadable.

## Credits Reference

* Usage is calculated from selected resolution and billed duration. Each reference-video duration, rounded down separately, is added to output duration.
* Check the Vidgo dashboard for the current model rate before submitting production traffic.


## OpenAPI

````yaml api-manual/video-series/seedance-2-0-fast-reference-to-video.json POST /api/generate/submit
openapi: 3.0.0
info:
  title: Vidgo API - Seedance 2.0 Fast Reference to Video
  description: >-
    Seedance 2.0 Fast Reference to Video through the Vidgo unified generation
    API.
  version: 1.0.0
servers:
  - url: https://api.vidgo.ai
    description: Production server
security:
  - BearerAuth: []
paths:
  /api/generate/submit:
    post:
      tags:
        - Seedance 2.0 Fast Reference to Video
      summary: Submit Seedance 2.0 Fast Reference to Video Task
      operationId: submitSeedance20FastReferenceToVideoTask
      requestBody:
        required: true
        content:
          application/json:
            schema:
              $ref: '#/components/schemas/SubmitRequest'
            examples:
              default:
                summary: Seedance 2.0 Fast Reference to Video
                value:
                  model: seedance-2.0-fast/reference-to-video
                  callback_url: https://your-domain.com/callback
                  input:
                    prompt: >-
                      A cinematic scene with natural lighting and coherent
                      motion
                    duration: 5
                    resolution: 480p
                    reference_image_urls:
                      - https://cdn.vidgo.ai/examples/reference-1.jpg
      responses:
        '200':
          description: Task submitted successfully
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/SubmitResponse'
        '400':
          description: Invalid request parameters
        '401':
          description: Unauthorized
components:
  schemas:
    SubmitRequest:
      type: object
      required:
        - model
        - input
      additionalProperties: false
      properties:
        model:
          type: string
          description: Vidgo public model identifier.
          enum:
            - seedance-2.0-fast/reference-to-video
          example: seedance-2.0-fast/reference-to-video
        callback_url:
          type: string
          format: uri
          description: Optional webhook callback URL.
        input:
          type: object
          required:
            - prompt
            - duration
            - resolution
          additionalProperties: false
          anyOf:
            - required:
                - reference_image_urls
            - required:
                - reference_video_urls
          properties:
            prompt:
              type: string
              description: Prompt describing the target video.
              minLength: 1
              maxLength: 20000
            duration:
              type: integer
              description: Output duration in seconds.
              minimum: 4
              maximum: 15
            resolution:
              type: string
              description: Output resolution.
              enum:
                - 480p
                - 720p
            aspect_ratio:
              type: string
              description: >-
                Output aspect ratio. Image-to-video accepts only auto when
                provided.
              enum:
                - auto
                - '21:9'
                - '16:9'
                - '4:3'
                - '1:1'
                - '3:4'
                - '9:16'
            generate_audio:
              type: boolean
              description: Whether to generate an audio track.
            reference_image_urls:
              type: array
              description: Reference images.
              minItems: 1
              maxItems: 9
              items:
                type: string
                format: uri
            reference_video_urls:
              type: array
              description: >-
                Reference videos. Their whole-second durations are included in
                billing.
              minItems: 1
              maxItems: 3
              items:
                type: string
                format: uri
            reference_audio_urls:
              type: array
              description: Reference audio. Requires a reference image or video.
              maxItems: 3
              items:
                type: string
                format: uri
            return_last_frame:
              type: boolean
              description: Whether to return the final generated frame.
            web_search:
              type: boolean
              description: Whether to enable web-assisted generation when supported.
            seed:
              type: integer
              description: Optional deterministic seed.
    SubmitResponse:
      type: object
      required:
        - code
        - data
      properties:
        code:
          type: integer
          example: 200
        data:
          type: object
          required:
            - task_id
            - status
            - created_time
          properties:
            task_id:
              type: string
            status:
              type: string
              enum:
                - not_started
                - running
                - failed
            created_time:
              type: string
              format: date-time
  securitySchemes:
    BearerAuth:
      type: http
      scheme: bearer
      bearerFormat: API Key
      description: 'Use `Authorization: Bearer VIDGO_API_KEY`.'

````