Twilio Validate a Number then Start a Verification

arazzo: 1.0.1
info:
  title: Twilio Validate a Number then Start a Verification
  summary: Look up a phone number, and only when it is a valid mobile number start a Verify verification.
  description: >-
    A fraud-resistant onboarding pattern that pairs Lookup with Verify. The
    workflow first looks up the phone number with the validation and line type
    intelligence packages, branches on whether the number is valid, and only
    when it is valid does it start a verification on the Verify service. Invalid
    numbers short-circuit the flow before any verification is sent. 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: phoneNumbersApi
  url: ../openapi/twilio-phone-numbers-api-openapi.yml
  type: openapi
- name: verificationsApi
  url: ../openapi/twilio-verifications-api-openapi.yml
  type: openapi
workflows:
- workflowId: lookup-then-start-verification
  summary: Validate a number with Lookup, then conditionally start a verification.
  description: >-
    Fetches phone number intelligence and branches on the valid flag, starting a
    Verify verification only for valid numbers.
  inputs:
    type: object
    required:
    - phoneNumber
    - serviceSid
    - channel
    properties:
      phoneNumber:
        type: string
        description: The phone number to validate and verify, in E.164 format.
      serviceSid:
        type: string
        description: The Verify service SID (starts with VA).
      channel:
        type: string
        description: Delivery channel - one of sms, call, email, whatsapp, or sna.
  steps:
  - stepId: lookupNumber
    description: >-
      Query the Lookup API for validation and line type intelligence on the
      supplied number.
    operationId: fetchPhoneNumber
    parameters:
    - name: PhoneNumber
      in: path
      value: $inputs.phoneNumber
    - name: Fields
      in: query
      value: validation,line_type_intelligence
    successCriteria:
    - condition: $statusCode == 200
    outputs:
      valid: $response.body#/valid
    onSuccess:
    - name: numberValid
      type: goto
      stepId: startVerification
      criteria:
      - context: $response.body
        condition: $.valid == true
        type: jsonpath
    - name: numberInvalid
      type: end
      criteria:
      - context: $response.body
        condition: $.valid == false
        type: jsonpath
  - stepId: startVerification
    description: >-
      Start a verification on the Verify service for the validated number.
    operationId: createVerification
    parameters:
    - name: ServiceSid
      in: path
      value: $inputs.serviceSid
    requestBody:
      contentType: application/x-www-form-urlencoded
      payload:
        To: $inputs.phoneNumber
        Channel: $inputs.channel
    successCriteria:
    - condition: $statusCode == 201
    outputs:
      verificationSid: $response.body#/sid
      status: $response.body#/status
  outputs:
    valid: $steps.lookupNumber.outputs.valid
    verificationSid: $steps.startVerification.outputs.verificationSid