Twilio Send a Message and Track Delivery Status

arazzo: 1.0.1
info:
  title: Twilio Send a Message and Track Delivery Status
  summary: Send an SMS/MMS and poll the message resource until it reaches a terminal delivery status.
  description: >-
    The canonical Twilio messaging pattern. The workflow sends an SMS or MMS
    from a Twilio number to a recipient, captures the returned message SID, and
    then re-fetches the message resource to read its current delivery status.
    Because Twilio delivers messages asynchronously, the fetch step is set up to
    be polled until the message reaches a terminal status such as delivered,
    undelivered, 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: messagesApi
  url: ../openapi/twilio-messages-api-openapi.yml
  type: openapi
workflows:
- workflowId: send-message-track-status
  summary: Send a message and confirm its final delivery status.
  description: >-
    Sends a message via the Twilio REST API and then fetches the same message by
    its SID to observe the delivery status, branching to a delivered or failed
    terminal state.
  inputs:
    type: object
    required:
    - accountSid
    - to
    - from
    - body
    properties:
      accountSid:
        type: string
        description: The Twilio account SID (starts with AC) that owns the message.
      to:
        type: string
        description: Recipient phone number in E.164 format.
      from:
        type: string
        description: Twilio phone number, short code, or alphanumeric sender ID.
      body:
        type: string
        description: The text content of the message (up to 1600 characters).
      statusCallback:
        type: string
        description: Optional URL for asynchronous status callbacks.
  steps:
  - stepId: sendMessage
    description: >-
      Send the SMS or MMS message from the Twilio sender to the recipient. The
      message is created and queued for delivery, returning a message SID.
    operationId: createMessage
    parameters:
    - name: AccountSid
      in: path
      value: $inputs.accountSid
    requestBody:
      contentType: application/x-www-form-urlencoded
      payload:
        To: $inputs.to
        From: $inputs.from
        Body: $inputs.body
        StatusCallback: $inputs.statusCallback
    successCriteria:
    - condition: $statusCode == 201
    outputs:
      messageSid: $response.body#/sid
      initialStatus: $response.body#/status
  - stepId: checkStatus
    description: >-
      Fetch the message by its SID to read the current delivery status. Poll
      this step until the status becomes delivered, undelivered, or failed.
    operationId: fetchMessage
    parameters:
    - name: AccountSid
      in: path
      value: $inputs.accountSid
    - name: MessageSid
      in: path
      value: $steps.sendMessage.outputs.messageSid
    successCriteria:
    - condition: $statusCode == 200
    outputs:
      status: $response.body#/status
      errorCode: $response.body#/error_code
    onSuccess:
    - name: delivered
      type: end
      criteria:
      - context: $response.body
        condition: $.status == "delivered"
        type: jsonpath
    - name: failed
      type: end
      criteria:
      - context: $response.body
        condition: $.status == "failed" || $.status == "undelivered"
        type: jsonpath
  outputs:
    messageSid: $steps.sendMessage.outputs.messageSid
    finalStatus: $steps.checkStatus.outputs.status