Cellulant Express Checkout and Poll Status

arazzo: 1.0.1
info:
  title: Cellulant Express Checkout and Poll Status
  summary: Authenticate, raise a Tingg Express Checkout, then poll the request status until the payment settles.
  description: >-
    The canonical Tingg hosted-checkout flow. The workflow exchanges client
    credentials for a bearer access token, creates an Express Checkout request
    that returns short_url and long_url for the customer to complete payment,
    and then polls the query-status endpoint by merchant_transaction_id until
    the request reaches a terminal state. Every step spells out its request
    inline — the bearer token from the auth step and the merchant apikey header
    — so the flow can be read and executed without opening the underlying
    OpenAPI description.
  version: 1.0.0
sourceDescriptions:
- name: checkoutApi
  url: ../openapi/cellulant-checkout-api-openapi.yml
  type: openapi
workflows:
- workflowId: express-checkout-and-poll-status
  summary: Create an Express Checkout session and poll until payment status is resolved.
  description: >-
    Issues an access token, creates a hosted Express Checkout returning the
    customer payment URLs, and repeatedly queries the request status until a
    payment is reported.
  inputs:
    type: object
    required:
    - clientId
    - clientSecret
    - apiKey
    - merchantTransactionId
    - serviceCode
    - countryCode
    - currencyCode
    - requestAmount
    - callbackUrl
    properties:
      clientId:
        type: string
        description: OAuth client id issued in the Tingg dashboard.
      clientSecret:
        type: string
        description: OAuth client secret issued in the Tingg dashboard.
      apiKey:
        type: string
        description: Merchant apikey header value issued in the Tingg dashboard.
      merchantTransactionId:
        type: string
        description: Unique merchant transaction id for this checkout.
      serviceCode:
        type: string
        description: Tingg service code identifying the merchant product line.
      countryCode:
        type: string
        description: ISO 3166-1 alpha-2 country code (KE, UG, TZ, NG, GH, ...).
      currencyCode:
        type: string
        description: ISO 4217 currency code.
      requestAmount:
        type: number
        description: Amount to charge the customer.
      requestDescription:
        type: string
        description: Human-readable description shown on the checkout.
      msisdn:
        type: string
        description: Customer phone in E.164 format.
      customerEmail:
        type: string
        description: Customer email address.
      callbackUrl:
        type: string
        description: IPN callback URL Tingg posts the payment result to.
  steps:
  - stepId: authenticate
    description: >-
      Exchange the client credentials for a bearer access token used to
      authorize the checkout calls.
    operationId: requestAccessToken
    requestBody:
      contentType: application/json
      payload:
        grant_type: client_credentials
        client_id: $inputs.clientId
        client_secret: $inputs.clientSecret
    successCriteria:
    - condition: $statusCode == 200
    outputs:
      accessToken: $response.body#/access_token
  - stepId: createCheckout
    description: >-
      Create a hosted Express Checkout session and return the short and long
      URLs the customer uses to pay.
    operationId: createExpressCheckout
    parameters:
    - name: apikey
      in: header
      value: $inputs.apiKey
    - name: Authorization
      in: header
      value: "Bearer $steps.authenticate.outputs.accessToken"
    requestBody:
      contentType: application/json
      payload:
        merchant_transaction_id: $inputs.merchantTransactionId
        service_code: $inputs.serviceCode
        country_code: $inputs.countryCode
        currency_code: $inputs.currencyCode
        request_amount: $inputs.requestAmount
        request_description: $inputs.requestDescription
        msisdn: $inputs.msisdn
        customer_email: $inputs.customerEmail
        callback_url: $inputs.callbackUrl
    successCriteria:
    - condition: $statusCode == 200
    outputs:
      checkoutRequestId: $response.body#/checkout_request_id
      shortUrl: $response.body#/short_url
      longUrl: $response.body#/long_url
  - stepId: pollStatus
    description: >-
      Query the status of the checkout request by merchant_transaction_id.
      Repeat this step while the request remains in flight; branch to the end
      once a payment is reported.
    operationId: queryRequestStatus
    parameters:
    - name: apikey
      in: header
      value: $inputs.apiKey
    - name: Authorization
      in: header
      value: "Bearer $steps.authenticate.outputs.accessToken"
    - name: merchant_transaction_id
      in: query
      value: $inputs.merchantTransactionId
    - name: service_code
      in: query
      value: $inputs.serviceCode
    successCriteria:
    - condition: $statusCode == 200
    outputs:
      requestStatusCode: $response.body#/request_status_code
      requestStatusDescription: $response.body#/request_status_description
      payments: $response.body#/payments
    onSuccess:
    - name: paymentSettled
      type: end
      criteria:
      - context: $response.body
        condition: $.payments.length > 0
        type: jsonpath
    - name: stillPending
      type: goto
      stepId: pollStatus
      criteria:
      - context: $response.body
        condition: $.payments.length == 0
        type: jsonpath
  outputs:
    checkoutRequestId: $steps.createCheckout.outputs.checkoutRequestId
    shortUrl: $steps.createCheckout.outputs.shortUrl
    requestStatusCode: $steps.pollStatus.outputs.requestStatusCode
    payments: $steps.pollStatus.outputs.payments