Generate a Lacuna track and collect the audio

arazzo: 1.0.1
info:
  title: Generate a Lacuna track and collect the audio
  version: 1.0.0
  description: >-
    Submits a music generation task to the Lacuna Music API, polls it to a terminal state, and returns
    the hosted audio URL of the first rendered track. Both operationIds are verified against the
    provider's published OpenAPI.
sourceDescriptions:
  - name: lacunaMusic
    url: ../openapi/lacuna-music-openapi-original.json
    type: openapi
workflows:
  - workflowId: generate-and-collect
    summary: Submit a generation, poll until ready, return the audio URL.
    description: >-
      Credits are deducted synchronously on the submit step and there is no idempotency key, so this
      workflow must not be re-run blindly on a transport failure.
    inputs:
      type: object
      required: [style, title]
      properties:
        style:
          type: string
          description: Style description, up to 1000 characters.
          default: lofi hip hop, mellow piano, 70 bpm
        title:
          type: string
          description: Track title, up to 200 characters.
          default: Late Night Study
        lyrics:
          type: string
          description: Required unless instrumental is true.
        instrumental:
          type: boolean
          default: true
        model:
          type: string
          description: aether (default) or echo. Do not use nocturne for new integrations.
          default: aether
    steps:
      - stepId: submit
        description: Create the generation task. Returns 202 with a pending GenerationTask.
        operationId: $sourceDescriptions.lacunaMusic.createGeneration
        requestBody:
          contentType: application/json
          payload:
            style: $inputs.style
            title: $inputs.title
            instrumental: $inputs.instrumental
            model: $inputs.model
        successCriteria:
          - condition: $statusCode == 202
        outputs:
          taskId: $response.body#/id
          status: $response.body#/status
          creditsUsed: $response.body#/credits_used
      - stepId: poll
        description: >-
          Poll the task until it is terminal. Intended to be repeated on a 5 second interval; typical
          completion is 60-120 seconds.
        operationId: $sourceDescriptions.lacunaMusic.getGeneration
        parameters:
          - name: id
            in: path
            value: $steps.submit.outputs.taskId
        successCriteria:
          - condition: $statusCode == 200
          - context: $response.body
            condition: $.status == 'ready'
            type: jsonpath
        onFailure:
          - name: retryPoll
            type: retry
            retryAfter: 5
            retryLimit: 120
            criteria:
              - context: $response.body
                condition: $.status == 'pending'
                type: jsonpath
          - name: stopOnFailed
            type: end
            criteria:
              - context: $response.body
                condition: $.status == 'failed'
                type: jsonpath
        outputs:
          status: $response.body#/status
          audioUrl: $response.body#/tracks/0/audio_url
          trackTitle: $response.body#/tracks/0/title
          duration: $response.body#/tracks/0/duration
          creditsRefunded: $response.body#/credits_refunded
    outputs:
      taskId: $steps.submit.outputs.taskId
      status: $steps.poll.outputs.status
      audioUrl: $steps.poll.outputs.audioUrl
      duration: $steps.poll.outputs.duration