Twilio Make a Call and Track Its Status

arazzo: 1.0.1
info:
  title: Twilio Make a Call and Track Its Status
  summary: Place an outbound call with a TwiML URL, then fetch the call resource to follow its progress.
  description: >-
    The canonical Twilio voice pattern. The workflow initiates an outbound call
    from a Twilio number to a destination, handing the call a TwiML URL to drive
    the in-call experience, and captures the returned call SID. It then fetches
    the same call resource to read its current status, which can be polled until
    the call reaches a terminal state such as completed, busy, no-answer, or
    failed. Every step spells out its request inline so the flow can be read and
    executed without opening the underlying OpenAPI description.
  version: 1.0.0
sourceDescriptions:
- name: voiceApi
  url: ../openapi/twilio-voice-openapi.yml
  type: openapi
workflows:
- workflowId: make-call-track-status
  summary: Initiate an outbound call and observe its final status.
  description: >-
    Creates a call via the Twilio REST API and then fetches the call by SID,
    branching to completed or failed terminal states.
  inputs:
    type: object
    required:
    - accountSid
    - to
    - from
    - url
    properties:
      accountSid:
        type: string
        description: The Twilio account SID (starts with AC) placing the call.
      to:
        type: string
        description: Destination phone number, SIP URI, or client identifier.
      from:
        type: string
        description: Twilio phone number or verified caller ID.
      url:
        type: string
        description: TwiML URL that returns instructions for the call.
      statusCallback:
        type: string
        description: Optional URL for call status webhooks.
  steps:
  - stepId: makeCall
    description: >-
      Initiate the outbound call from the Twilio caller ID to the destination,
      using the supplied TwiML URL to control the call flow.
    operationId: createCall
    parameters:
    - name: AccountSid
      in: path
      value: $inputs.accountSid
    requestBody:
      contentType: application/x-www-form-urlencoded
      payload:
        To: $inputs.to
        From: $inputs.from
        Url: $inputs.url
        StatusCallback: $inputs.statusCallback
    successCriteria:
    - condition: $statusCode == 201
    outputs:
      callSid: $response.body#/sid
      initialStatus: $response.body#/status
  - stepId: checkCall
    description: >-
      Fetch the call by SID to read its current status. Poll this step until the
      call reaches a terminal status.
    operationId: fetchCall
    parameters:
    - name: AccountSid
      in: path
      value: $inputs.accountSid
    - name: CallSid
      in: path
      value: $steps.makeCall.outputs.callSid
    successCriteria:
    - condition: $statusCode == 200
    outputs:
      status: $response.body#/status
      duration: $response.body#/duration
    onSuccess:
    - name: completed
      type: end
      criteria:
      - context: $response.body
        condition: $.status == "completed"
        type: jsonpath
    - name: notConnected
      type: end
      criteria:
      - context: $response.body
        condition: $.status == "busy" || $.status == "no-answer" || $.status == "failed" || $.status == "canceled"
        type: jsonpath
  outputs:
    callSid: $steps.makeCall.outputs.callSid
    finalStatus: $steps.checkCall.outputs.status