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

# Music Extension

> Extend the generated audio, **Note: This endpoint can only be used after the previous task completes successfully**



## OpenAPI

````yaml openapi/en/flowmuisc.json POST /flowmusic/v1/extend
openapi: 3.1.0
info:
  title: Flowmusic API DOCS
  version: 1.0.0
  description: >-
    TTAPI Flowmusic API endpoint service, currently integrating the most
    advanced music large models on the market.
servers:
  - url: https://api.ttapi.io
security: []
paths:
  /flowmusic/v1/extend:
    post:
      description: >-
        Extend the generated audio, **Note: This endpoint can only be used after
        the previous task completes successfully**
      requestBody:
        required: true
        content:
          application/json:
            schema:
              $ref: '#/components/schemas/ExtendRequest'
      responses:
        '200':
          $ref: '#/components/responses/SuccessResponse'
        '400':
          $ref: '#/components/responses/400Response'
        '401':
          $ref: '#/components/responses/401Response'
      security:
        - CustomApiKey: []
components:
  schemas:
    ExtendRequest:
      type: object
      properties:
        clip_id:
          type: string
          description: Source music clip_id
        model:
          type: string
          description: Music model name, defaults to Lyria 3 Pro when empty
          default: Lyria 3 Pro
        extend_from_s:
          type: number
          description: >-
            From which time point to extend the source clip, in seconds; cannot
            exceed source clip duration.
        extend_s:
          type: number
          description: Extension duration in seconds; maximum 164 seconds.
          maximum: 164
        instruction:
          type: string
          description: Edit instruction for extending music.
        title:
          type: string
          description: Title after extension.
        seed:
          type: string
          description: Random seed; used to reproduce or control generation results.
        hook_url:
          type: string
          description: >-
            Business callback URL after task completion; no callback push when
            empty
      required:
        - clip_id
        - extend_from_s
        - extend_s
        - instruction
  responses:
    SuccessResponse:
      description: Request successful
      content:
        application/json:
          schema:
            type: object
            properties:
              status:
                type: string
                example: SUCCESS
              message:
                type: string
                example: success
              data:
                type: object
                example:
                  jobId: jobId
            required:
              - status
              - message
              - data
    400Response:
      description: Parameter error
      content:
        application/json:
          schema:
            type: object
            properties:
              status:
                type: string
                example: FAILED
              message:
                type: string
                example: '"prompt" cannot be empty.'
              data:
                type: object
            required:
              - status
              - message
    401Response:
      description: Authorization failed
      content:
        application/json:
          schema:
            type: object
            properties:
              status:
                type: string
                example: FAILED
              message:
                type: string
                example: Wrong TT-API-KEY or email is not activated.
            required:
              - status
              - message
  securitySchemes:
    CustomApiKey:
      type: apiKey
      in: header
      name: TT-API-KEY
      description: >-
        Please visit <a href='https://dashboard.ttapi.io' target='_blank'>TTAPI
        Dashboard</a> to obtain your API key.

````