Sift Login Step-Up Verification

arazzo: 1.0.1
info:
  title: Sift Login Step-Up Verification
  summary: Score a login for account takeover and require verification when risk is high.
  description: >-
    Adaptive authentication driven by the Sift Score. A $login event is scored
    synchronously for account takeover, and when the score crosses the configured
    threshold the workflow steps up: it sends a verification challenge to the user
    and then validates the code the user enters. Low-risk logins skip the friction
    entirely. Every request is inlined so the flow reads and runs on its own.
  version: 1.0.0
sourceDescriptions:
- name: eventsApi
  url: ../openapi/sift-events-api-openapi.yml
  type: openapi
- name: verificationApi
  url: ../openapi/sift-verification-api-openapi.yml
  type: openapi
workflows:
- workflowId: login-step-up-verification
  summary: Submit a login event, branch on the ATO score, and run a verification challenge.
  description: >-
    Records a $login event with synchronous scoring, and when the account
    takeover score is high enough it dispatches a verification challenge and
    checks the user-supplied code.
  inputs:
    type: object
    required:
    - apiKey
    - userId
    - sendTo
    - verificationCode
    properties:
      apiKey:
        type: string
        description: Sift account API key sent in the event body as $api_key.
      userId:
        type: string
        description: The user's unique identifier ($user_id).
      sessionId:
        type: string
        description: Optional session identifier for the login.
      ip:
        type: string
        description: Optional originating IP address for the login.
      sendTo:
        type: string
        description: Phone number or email to send the verification challenge to.
      verificationType:
        type: string
        description: Verification channel to use ($sms, $email, $phone, $face, $fingerprint, $push, $security_key).
        default: $sms
      brandName:
        type: string
        description: Optional brand name shown in the verification message.
      verificationCode:
        type: integer
        description: The code the user entered, submitted for validation.
      abuseTypes:
        type: string
        description: Comma-separated abuse types to score the login on.
        default: account_takeover
      scoreThreshold:
        type: number
        description: ATO score (0-100) at or above which step-up verification is required.
        default: 70
  steps:
  - stepId: sendLogin
    description: >-
      Submit a $login event with return_score=true so Sift scores the login for
      account takeover synchronously.
    operationId: sendEvent
    parameters:
    - name: return_score
      in: query
      value: true
    - name: abuse_types
      in: query
      value: $inputs.abuseTypes
    requestBody:
      contentType: application/json
      payload:
        $type: $login
        $api_key: $inputs.apiKey
        $user_id: $inputs.userId
        $session_id: $inputs.sessionId
        $ip: $inputs.ip
    successCriteria:
    - condition: $statusCode == 200
    outputs:
      eventStatus: $response.body#/status
      scoreResponse: $response.body#/score_response
    onSuccess:
    - name: highRiskLogin
      type: goto
      stepId: sendChallenge
      criteria:
      - context: $response.body
        condition: $.score_response.scores.account_takeover.score >= $inputs.scoreThreshold
        type: jsonpath
    - name: lowRiskLogin
      type: end
  - stepId: sendChallenge
    description: >-
      Dispatch a verification challenge to the user through the requested
      channel, tying it to the parent $login event.
    operationId: sendVerification
    requestBody:
      contentType: application/json
      payload:
        $user_id: $inputs.userId
        $send_to: $inputs.sendTo
        $verification_type: $inputs.verificationType
        $verified_event: $login
        $brand_name: $inputs.brandName
    successCriteria:
    - condition: $statusCode == 200
    outputs:
      sendStatus: $response.body#/status
      sentAt: $response.body#/sent_at
  - stepId: checkChallenge
    description: >-
      Validate the code the user entered against the active verification
      challenge.
    operationId: checkVerification
    requestBody:
      contentType: application/json
      payload:
        $user_id: $inputs.userId
        $code: $inputs.verificationCode
    successCriteria:
    - condition: $statusCode == 200
    outputs:
      checkStatus: $response.body#/status
      checkedAt: $response.body#/checked_at
  outputs:
    loginEventStatus: $steps.sendLogin.outputs.eventStatus
    verificationCheckStatus: $steps.checkChallenge.outputs.checkStatus