> ## 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 1.5 Pro T2V

> [Core Function] Seedance 1.5 Pro T2V is a joint audio-video text-to-video generation model. [Strengths] It accurately follows complex text instructions to generate high-quality video with synchronized audio. [Best For] Highly recommended for: standard text-to-video generation where strict prompt adherence and audio are required. [Limitations] Do NOT use this model if you need the advanced multi-shot or multimodal reference capabilities of the 2.0 architecture. [Routing] Use this model by default for ByteDance text-to-video tasks.



## OpenAPI

````yaml /media-model-api/bytedance/bytedance-t2v.json post /bytedance/seedance-1.5-pro-t2v
openapi: 3.1.0
info:
  description: The text-to-video models API from ByteDance.
  version: 1.0.0
  contact:
    name: Modellix Support
    email: support@modellix.ai
  title: ByteDance Text-to-Video Models API
servers:
  - url: https://api.modellix.ai/api/v1
    description: The text-to-video models API from ByteDance.
security:
  - bearerAuth: []
paths:
  /bytedance/seedance-1.5-pro-t2v:
    post:
      summary: Seedance 1.5 Pro T2V
      description: >-
        [Core Function] Seedance 1.5 Pro T2V is a joint audio-video
        text-to-video generation model. [Strengths] It accurately follows
        complex text instructions to generate high-quality video with
        synchronized audio. [Best For] Highly recommended for: standard
        text-to-video generation where strict prompt adherence and audio are
        required. [Limitations] Do NOT use this model if you need the advanced
        multi-shot or multimodal reference capabilities of the 2.0 architecture.
        [Routing] Use this model by default for ByteDance text-to-video tasks.
      operationId: seedance15ProT2vAsync
      requestBody:
        required: true
        content:
          application/json:
            schema:
              $ref: '#/components/schemas/Seedance15ProT2vRequest'
            examples:
              basic:
                summary: Basic with auto duration
                value:
                  prompt: A cute puppy playing in the park
              with_audio:
                summary: With audio generation
                value:
                  prompt: '"Hello world!" said the astronaut on the moon'
                  ratio: '16:9'
                  duration: -1
                  generate_audio: true
      responses:
        '200':
          description: Task submitted successfully
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/AsyncTaskResponse'
components:
  schemas:
    Seedance15ProT2vRequest:
      type: object
      required:
        - prompt
      properties:
        prompt:
          type: string
          description: >-
            Video content description. Maximum 10000 characters. Use double
            quotes for dialogue: "Hello world!" Recommended prompt length: under
            1000 words. Lengthy text will lead to scattered information, and the
            model may ignore details and only focus on key points, resulting in
            missing elements in the generated video.
          minLength: 1
          maxLength: 10000
          example: '"Hello world!" said the astronaut on the moon'
        ratio:
          type: string
          enum:
            - '16:9'
            - '4:3'
            - '1:1'
            - '3:4'
            - '9:16'
            - '21:9'
            - adaptive
          default: adaptive
          description: Aspect ratio of the generated video.
        resolution:
          type: string
          enum:
            - 480p
            - 720p
            - 1080p
          default: 720p
          description: Output resolution of the video.
        duration:
          type: integer
          description: Video duration in seconds (4-12 seconds).
          default: 5
          enum:
            - 4
            - 5
            - 6
            - 7
            - 8
            - 9
            - 10
            - 11
            - 12
          example: 5
        seed:
          type: integer
          default: -1
          minimum: -1
          maximum: 2147483647
          description: Random seed for reproducible generation. Use -1 for random.
        camera_fixed:
          type: boolean
          default: false
          description: Whether to keep the camera fixed during generation.
        generate_audio:
          type: boolean
          description: >-
            Whether to generate audio (speech/sound effects/background music).
            1.5 Pro exclusive feature
          default: true
          example: true
        service_tier:
          type: string
          enum:
            - default
            - flex
          default: default
          description: Service tier for generation (e.g., default or flex).
        execution_expires_after:
          type: integer
          default: 172800
          minimum: 3600
          maximum: 259200
          description: Task expiration time in seconds.
        return_last_frame:
          type: boolean
          default: false
          description: Whether to return the last frame of the generated video.
    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`.'

````