Implement Lithic Agent Settlement Account (ASA) for real-time spend control and balance management on a virtual card program

Steps

1. Enable ASA on your Lithic program and register your settlement webhook endpoint in the Lithic dashboard
2. When a card authorization fires, Lithic sends a synchronous ASA webhook to your endpoint with the full transaction context (merchant, amount, card token, spend_limit details)
3. Respond with a JSON authorization decision: status=APPROVED or DECLINED within Lithic's required response time; you can also approve a lesser amount for partial authorizations
4. Maintain a real-time balance ledger per card or account in your system; decrement the balance on approval and increment on reversal or decline
5. When the transaction clears and settles, Lithic fires a SETTLEMENT event webhook; reconcile the settled amount against the original hold and adjust your ledger accordingly
6. Use Lithic's spend limit controls (card-level and account-level) as a secondary enforcement layer alongside your ASA logic to provide defense-in-depth