Handle card issuer webhook events for authorization and clearing to maintain a real-time ledger

Steps

1. Subscribe to authorization and clearing webhook event types in your card issuing platform; for authorization events, parse the state (PENDING, CLEARED, DECLINED), the network_metadata, and the transaction token as the idempotency key
2. On receiving an authorization.created event, place a hold on the account for the authorized amount; do not permanently debit the account as the authorization may expire or be reversed
3. On receiving a clearing/settlement event (transaction.cleared or equivalent), apply the final debit using the cleared amount, which may differ from the authorized amount due to tip adjustment, currency conversion, or partial capture
4. Handle authorization reversal events: release the full hold immediately on reversal; for partial reversals, adjust the hold to the remaining authorized amount
5. Reconcile end-of-day: match each cleared transaction to its originating authorization by transaction token; any cleared transactions without a matching authorization indicate a silent authorization (force-post) and must be handled as a balance debit without a prior hold