issue a virtual card with Lithic and respond to auth-stream (ASA) decisions

Steps

1. Create a card via POST /cards with type=VIRTUAL and an optional spend_limit and spend_limit_duration; the response immediately returns the card number, CVV, and expiry for a virtual card.
2. Configure your Auth Stream Enrollment (ASA) webhook URL in the Lithic dashboard; this endpoint will receive real-time authorization requests for all cards in your account.
3. Implement the ASA endpoint — Lithic sends a POST request with a JSON payload describing the transaction (amount, merchant, card token, etc.); your server must respond within 2 seconds.
4. In your ASA handler, apply your business logic (balance check, fraud rules, merchant category controls) and return a JSON response with decision=APPROVE or decision=DECLINE.
5. Handle the case where your ASA endpoint is unreachable or times out — Lithic falls back to the card's configured default_authorization_code (typically DECLINE); set this appropriately for your risk tolerance.
6. Reconcile settled transactions by consuming Lithic's transaction webhooks or by polling GET /transactions, noting that settled amounts may differ from authorized amounts.