> ## Documentation Index
> Fetch the complete documentation index at: https://docs.modellix.ai/llms.txt
> Use this file to discover all available pages before exploring further.

# Seedance 2.5 R2V

> [Core Function] Seedance 2.5 R2V is ByteDance Dreamina Seedance 2.5 reference-to-video generation from up to 30 reference images. [Strengths] It supports optional reference audio, fixed or adaptive aspect ratio, 480p/720p/1080p, 4-30 second duration, and mp4 or mov output. [Best For] Highly recommended for: multi-image character consistency and image-led storytelling on Seedance 2.5. [Limitations] Do NOT send first_frame_image, last_frame_image, or video_urls. Do NOT use audio_urls alone. Do NOT use this model when the user requires 4k output. [Routing] Prefer this model when the user provides reference images without a driving video. Use Seedance 2.5 I2V for first-frame or first-and-last-frame animation, Seedance 2.5 T2V for text-only requests, and Seedance 2.5 V2V when reference video is required.



## OpenAPI

````yaml /media-model-api/bytedance/bytedance-i2v.json post /bytedance/seedance-2.5-r2v
openapi: 3.1.0
info:
  description: The image-to-video models API from ByteDance.
  version: 1.0.0
  contact:
    name: Modellix Support
    email: support@modellix.ai
  title: ByteDance Image-to-Video Models API
servers:
  - url: https://api.modellix.ai/api/v1
    description: The image-to-video models API from ByteDance.
security:
  - bearerAuth: []
paths:
  /bytedance/seedance-2.5-r2v:
    post:
      summary: Seedance 2.5 R2V
      description: >-
        [Core Function] Seedance 2.5 R2V is ByteDance Dreamina Seedance 2.5
        reference-to-video generation from up to 30 reference images.
        [Strengths] It supports optional reference audio, fixed or adaptive
        aspect ratio, 480p/720p/1080p, 4-30 second duration, and mp4 or mov
        output. [Best For] Highly recommended for: multi-image character
        consistency and image-led storytelling on Seedance 2.5. [Limitations] Do
        NOT send first_frame_image, last_frame_image, or video_urls. Do NOT use
        audio_urls alone. Do NOT use this model when the user requires 4k
        output. [Routing] Prefer this model when the user provides reference
        images without a driving video. Use Seedance 2.5 I2V for first-frame or
        first-and-last-frame animation, Seedance 2.5 T2V for text-only requests,
        and Seedance 2.5 V2V when reference video is required.
      operationId: seedance25R2vAsync
      requestBody:
        required: true
        content:
          application/json:
            schema:
              $ref: '#/components/schemas/Seedance25R2vRequest'
            examples:
              reference_images:
                summary: Reference-image generation
                description: >-
                  Reference-to-video may use a fixed ratio or adaptive. Duration
                  is 4-30.
                value:
                  prompt: >-
                    Combine @Image1 and @Image2 into one cinematic shot. Follow
                    the rhythm of @Audio1.
                  reference_images:
                    - https://example.com/person.jpg
                    - https://example.com/scene.jpg
                  audio_urls:
                    - https://example.com/voice.mp3
                  ratio: '16:9'
                  duration: 10
                  output_format: mov
      responses:
        '200':
          description: Task submitted successfully
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/AsyncTaskResponse'
components:
  schemas:
    Seedance25R2vRequest:
      type: object
      description: >-
        Seedance 2.5 reference-to-video. `reference_images` is required. Do not
        pass `first_frame_image` or `last_frame_image`.
      required:
        - reference_images
      properties:
        reference_images:
          type: array
          description: >-
            Required. Reference image URLs (1-30). Do not pass first_frame_image
            or last_frame_image.
          minItems: 1
          maxItems: 30
          items:
            type: string
            format: uri
          example:
            - https://example.com/a.jpg
            - https://example.com/b.jpg
        prompt:
          type: string
          description: >-
            Optional. Video description. Maximum 10000 characters. Use @Image1
            and @Audio1 when referencing inputs.
          minLength: 1
          maxLength: 10000
          example: Animate the scene gently with natural motion
        audio_urls:
          type: array
          description: >-
            Optional. Reference audio URLs (1-10). Must accompany
            reference_images; audio-only is not supported.
          minItems: 1
          maxItems: 10
          items:
            type: string
            format: uri
          example:
            - https://example.com/voice.mp3
        ratio:
          type: string
          description: Aspect ratio of the generated video.
          enum:
            - '16:9'
            - '4:3'
            - '1:1'
            - '3:4'
            - '9:16'
            - '21:9'
            - adaptive
          default: adaptive
          example: adaptive
        resolution:
          type: string
          description: >-
            Specifies the resolution tier for the generated video. Seedance 2.5
            supports 480p, 720p, and 1080p
          enum:
            - 480p
            - 720p
            - 1080p
          default: 720p
          example: 720p
        duration:
          type: integer
          description: Video duration in seconds. Allowed values are integers from 4 to 30
          enum:
            - 4
            - 5
            - 6
            - 7
            - 8
            - 9
            - 10
            - 11
            - 12
            - 13
            - 14
            - 15
            - 16
            - 17
            - 18
            - 19
            - 20
            - 21
            - 22
            - 23
            - 24
            - 25
            - 26
            - 27
            - 28
            - 29
            - 30
          default: 5
          example: 5
        seed:
          type: integer
          description: >-
            Random number seed for reproducibility. Use -1 for random. Identical
            seeds cannot guarantee completely identical results
          minimum: -1
          maximum: 4294967295
          default: -1
          example: -1
        camera_fixed:
          type: boolean
          description: Whether to keep the camera fixed during generation
          default: false
          example: false
        generate_audio:
          type: boolean
          description: Whether to generate an audio track with the video
          default: true
          example: true
        output_format:
          type: string
          description: >-
            Output video container. mp4 for general playback; mov for higher
            color precision in editing workflows
          enum:
            - mp4
            - mov
          default: mp4
          example: mp4
        execution_expires_after:
          type: integer
          description: Task expiration time in seconds
          minimum: 3600
          maximum: 259200
          default: 172800
          example: 172800
        return_last_frame:
          type: boolean
          description: Whether to return the last frame of the generated video
          default: false
          example: false
        omni_reference_task_type:
          type: string
          description: >-
            Task type hint for multimodal reference only (requires
            `reference_images`). Do not pass this field for first-frame or
            first-last-frame generation. `auto` infers the type from the prompt
            and inputs. `reference` generates a new video from reference images;
            `ratio` and `duration` have no special constraints.
          enum:
            - auto
            - reference
          default: auto
          example: auto
    AsyncTaskResponse:
      type: object
      required:
        - code
        - message
        - data
      properties:
        code:
          type: integer
          description: Response code, 0 indicates success
          example: 0
        message:
          type: string
          description: Response message
          example: success
        data:
          type: object
          required:
            - status
            - task_id
            - model_id
          properties:
            status:
              type: string
              enum:
                - pending
                - processing
              description: Task status
              example: pending
            task_id:
              type: string
              description: Unique task identifier
              example: task-abc123
            model_id:
              type: string
              description: Model ID
              example: model-123
            get_result:
              type: object
              description: API information to query the task result
              properties:
                method:
                  type: string
                  description: HTTP method
                  example: GET
                url:
                  type: string
                  description: Full URL to query the task result
                  example: https://api.modellix.ai/api/v1/tasks/task-abc123
          description: Detailed data about the submitted asynchronous task.
  securitySchemes:
    bearerAuth:
      type: http
      scheme: bearer
      description: 'API Key authentication. Format: `Bearer YOUR_API_KEY`.'

````

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