Authorization Stream Access (ASA) provides the ability to make custom transaction approval decisions through an HTTP interface to the ISO 8583 message stream.

ASA requests are delivered as an HTTP POST during authorization. The ASA request body adheres to the Lithic transaction schema, with some additional fields added for use in decisioning. A response should be sent with HTTP response code 200 and the approval decision in the response body. This response is converted by Lithic back into ISO-8583 format and forwarded to the network.

📘

In sandbox, users can self-enroll and disenroll in ASA; API reference: Auth Stream Access (ASA). In production, onboarding requires manual approval and setup.

🚧

For ASA-enabled customers, Lithic will only perform very basic pre-authorization checks before sending the request out (decrypt EMV cryptogram, validate PAN, validate CVV/PIN if present). For example, we won't check auth rules such as MERCHANT_LOCKED. You must supply your own auth rules.

Lithic will not send ASA requests to your endpoint if the message fails basic pre-authorization checks. For a list of all pre-authorization checks, please reference Transaction.result.

Set up an ASA responder in under 10 minutes!

Full details on responding to ASA requests follow, but to get you up and running quickly we’ve also provided sample application for creating an auth stream access webhook with AWS API Gateway and Lambda, managed via AWS Serverless Application Model (SAM).

1. NodeJS example: https://github.com/lithic-com/asa-demo-node
2. Python example: https://github.com/lithic-com/asa-demo-python

Schema

Lithic Request

Similar to Transaction object in Transaction Webhooks with additional properties.

{
  "amount": Integer,
  "acquirer_fee": Integer,
  "authorization_amount": Integer,
  "avs": {
      "address": String,
      "zipcode": String
  },
  "card": Card,
  "created": String,
  "events": [
      Event
  ],
  "funding": [
      {
          "amount": Integer,
          "token": String,
          "type": String
      }
  ],
  "merchant": Merchant,
  "pos": {
      "terminal": {
          "attended": Boolean,
          "operator": String,
          "on_premise": Boolean,
          "card_retention_capable": Boolean,
          "pin_capability": String,
          "type": String,
          "partial_approval_capable": Boolean
      },
      "entry_mode": {
          "pan": String,
          "pin_entered": Boolean,
          "cardholder": String,
          "card": String
      }
  },
  "settled_amount": Integer,
  "status": String,
  "token": String
}

Client Response

{
  "result": String,
  "token": String,
  "avs_result": String,
  "balance": {
      "amount": Integer,
      "available": Integer
  }
}

Response Guidelines

Response Time

The request timeout is configurable per request, with a default of 5 seconds. Response before the timeout does not guarantee that the authorization will succeed.

AVS Matching

AVS response is optional. If AVS is present and a response is not received, Lithic will return AVS validated.
If AVS attributes aren’t included in the authorization, any AVS response result will be ignored.

Returned Balances

BALANCE_INQUIRY ASA messages require a settled and available amount to be returned.

• amount represents the balance held on the card.
• available represents the balance available for the cardholder to spend. This is calculated as the settled amount minus any pending authorizations on the card.

If no balance is returned, Lithic will return $0 for both attributes.

Enumerations

Point of Sale

📘

Partial approval is currently not supported.

POS Type

• ATM
• AUTHORIZATION
• COUPON_MACHINE
• DIAL_TERMINAL
• ECOMMERCE
• ECR
• FUEL_MACHINE
• HOME_TERMINAL
• MICR
• OFF_PREMISE
• PAYMENT
• PDA
• PHONE
• POINT
• POS_TERMINAL
• SELF_SERVICE
• TELEVISION
• TELLER
• TRAVELERS_CHECK_MACHINE
• VENDING
• VOICE

Method of Entry

• AUTO_ENTRY
• BAR_CODE
• CONTACTLESS
• ECOMMERCE
• ERROR_KEYED
• ERROR_MAGNETIC_STRIPE
• ICC
• KEY_ENTERED
• MAGNETIC_STRIPE
• MANUAL
• OCR
• SECURE_CARDLESS
• UNSPECIFIED

Cardholder Status

• DEFERRED_BILLING
• INSTALLMENT
• MAIL_ORDER
• NOT_PRESENT
• PREAUTHORIZED
• PRESENT
• REOCCURRING
• TELEPHONE_ORDER

ASA Response Result

AVS Response Result