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.

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Testing in sandbox

In sandbox, users can self-enroll and disenroll in ASA. In production, onboarding requires manual approval and setup.

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Pre-ASA auth request checks

For ASA-enabled users, 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 or spending limits. 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,
  "cardholder_authentication": CardholderAuthentication,
  "cash_amount": Integer,
  "conversion_rate": Integer,
  "created": String,
  "events": [
      Event
  ],
  "funding": [
      {
          "amount": Integer,
          "token": String,
          "type": String
      }
  ],
  "merchant_amount": Integer,
  "merchant_currency": String,
  "merchant": Merchant,
  "network": String,
  "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,
  "token_info": {
    "wallet_type": Enum{}
  }
}

User Response

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

Response Guidelines

Response Time

If no response is received, the transaction will timeout resulting in a decline for the cardholder. The ASA request timeout is configurable, with a default of 5 seconds. Response before the timeout does not guarantee that the authorization will succeed. Even in the case that the timeout is changed, we recommend responding in less than 5 seconds to ensure that all merchants will process the transaction.

AVS Matching

Address verification (AVS) checks two pieces of information, the postal code and the billing street address. Responding with AVS 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

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

Cardholder Status

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

ASA Response Result

AVS Response Result

Wallet Type