Interswitch Hosted Fields Checkout

arazzo: 1.0.1
info:
  title: Interswitch Hosted Fields Checkout
  summary: Open a hosted-fields session to collect card data out of PCI scope, then confirm the resulting payment.
  description: >-
    PCI-minimizing checkout flow on the Payment Gateway. The workflow creates a
    hosted-fields session so the browser collects raw card data and posts it
    directly to Interswitch, keeping the merchant out of PCI scope, then reads
    back the payment by id to confirm its authoritative status once the
    browser-side authorization completes. The paymentId is supplied as an input
    since it is produced by the browser-side hosted-fields submission. Requests
    are Bearer-authenticated.
  version: 1.0.0
sourceDescriptions:
- name: paymentGatewayApi
  url: ../openapi/interswitch-payment-gateway-api-openapi.yml
  type: openapi
workflows:
- workflowId: hosted-fields-checkout
  summary: Create a hosted-fields session, then confirm the resulting payment.
  description: >-
    Creates a hosted-fields session for browser-side card capture, then reads the
    resulting payment to confirm its final status.
  inputs:
    type: object
    required:
    - accessToken
    - transactionRef
    - amount
    - currency
    - redirectUrl
    - paymentId
    properties:
      accessToken:
        type: string
        description: Bearer access token from the Passport OAuth token endpoint.
      transactionRef:
        type: string
        description: Unique merchant transaction reference.
      amount:
        type: integer
        description: Amount in minor currency units.
      currency:
        type: string
        description: ISO currency code.
      redirectUrl:
        type: string
        description: URL the hosted-fields page redirects to after capture.
      paymentId:
        type: string
        description: Payment id produced by the browser-side hosted-fields submission.
  steps:
  - stepId: createSession
    description: >-
      Create a hosted-fields session so the browser can collect raw card data and
      POST it directly to Interswitch, keeping the merchant out of PCI scope.
    operationId: createHostedFieldsSession
    parameters:
    - name: Authorization
      in: header
      value: Bearer $inputs.accessToken
    requestBody:
      contentType: application/json
      payload:
        transactionRef: $inputs.transactionRef
        amount: $inputs.amount
        currency: $inputs.currency
        redirectUrl: $inputs.redirectUrl
    successCriteria:
    - condition: $statusCode == 200
    outputs:
      sessionId: $response.body#/sessionId
      hostedFieldsUrl: $response.body#/hostedFieldsUrl
      expiresAt: $response.body#/expiresAt
  - stepId: confirmPayment
    description: >-
      Read the payment produced by the hosted-fields submission to confirm its
      authoritative final status.
    operationId: getPayment
    parameters:
    - name: Authorization
      in: header
      value: Bearer $inputs.accessToken
    - name: paymentId
      in: path
      value: $inputs.paymentId
    successCriteria:
    - condition: $statusCode == 200
    outputs:
      status: $response.body#/status
      responseCode: $response.body#/responseCode
      authCode: $response.body#/authCode
      amount: $response.body#/amount
  outputs:
    sessionId: $steps.createSession.outputs.sessionId
    hostedFieldsUrl: $steps.createSession.outputs.hostedFieldsUrl
    paymentStatus: $steps.confirmPayment.outputs.status