Twilio Create a Conversation, Add a Participant, and Send a Message

arazzo: 1.0.1
info:
  title: Twilio Create a Conversation, Add a Participant, and Send a Message
  summary: Stand up a Conversations thread, attach an SMS participant by address, and post the first message.
  description: >-
    The foundational Twilio Conversations flow. The workflow creates a new
    conversation, adds a participant to it by their messaging binding address
    and the Twilio proxy address, and then posts the opening message into the
    conversation. This is the minimum chain needed to start a two-way
    omnichannel thread. 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: conversationsApi
  url: ../openapi/conversations-openapi-original.yml
  type: openapi
workflows:
- workflowId: create-conversation-add-participant-send-message
  summary: Create a conversation, add an SMS participant, and send the first message.
  description: >-
    Creates a conversation, adds a participant addressed by their phone number
    via the Twilio proxy address, and posts an opening message authored by the
    business.
  inputs:
    type: object
    required:
    - participantAddress
    - proxyAddress
    - body
    properties:
      friendlyName:
        type: string
        description: Optional human-readable name for the conversation.
      participantAddress:
        type: string
        description: The participant's address (e.g. their phone number in E.164).
      proxyAddress:
        type: string
        description: The Twilio phone number used as the proxy for the participant.
      author:
        type: string
        description: Optional author identity for the opening message.
      body:
        type: string
        description: The text content of the opening message.
  steps:
  - stepId: createConversation
    description: >-
      Create the conversation thread that will hold the participant and
      messages.
    operationId: CreateConversation
    requestBody:
      contentType: application/x-www-form-urlencoded
      payload:
        FriendlyName: $inputs.friendlyName
    successCriteria:
    - condition: $statusCode == 200
    outputs:
      conversationSid: $response.body#/sid
  - stepId: addParticipant
    description: >-
      Add a participant to the conversation, bound to their messaging address
      and the Twilio proxy address.
    operationId: CreateConversationParticipant
    parameters:
    - name: ConversationSid
      in: path
      value: $steps.createConversation.outputs.conversationSid
    requestBody:
      contentType: application/x-www-form-urlencoded
      payload:
        MessagingBinding.Address: $inputs.participantAddress
        MessagingBinding.ProxyAddress: $inputs.proxyAddress
    successCriteria:
    - condition: $statusCode == 200
    outputs:
      participantSid: $response.body#/sid
  - stepId: sendMessage
    description: >-
      Post the opening message into the conversation.
    operationId: CreateConversationMessage
    parameters:
    - name: ConversationSid
      in: path
      value: $steps.createConversation.outputs.conversationSid
    requestBody:
      contentType: application/x-www-form-urlencoded
      payload:
        Author: $inputs.author
        Body: $inputs.body
    successCriteria:
    - condition: $statusCode == 200
    outputs:
      messageSid: $response.body#/sid
  outputs:
    conversationSid: $steps.createConversation.outputs.conversationSid
    participantSid: $steps.addParticipant.outputs.participantSid
    messageSid: $steps.sendMessage.outputs.messageSid