WIP: Add callback-based payment receiving for instant confirmation

packages/core/src/handlers/webhooks.ts

@@ -12,31 +12,32 @@ const webhookSchema = z.object({
 async function handleIncomingPayment() {
   const node = createMoneyDevKitNode();
   const client = createMoneyDevKitClient();
-  const payments = node.receivePayments();
 
-  if (payments.length === 0) {
-    return;
-  }
-
-  payments.forEach((payment) => {
+  // Use callback-based receive to process payments IMMEDIATELY as they arrive
+  // This allows instant customer confirmation while node continues running
+  node.receivePaymentsWithCallback((payment) => {
+    // Mark payment received in local state IMMEDIATELY
     markPaymentReceived(payment.paymentHash);
-  });
 
-  try {
-    await client.checkouts.paymentReceived({
-      payments: payments.map((payment) => ({
-        paymentHash: payment.paymentHash,
-        // amount comes in msat from the node, convert to sats
-        amountSats: payment.amount / 1000,
-        sandbox: false,
-      })),
-    });
-  } catch (error) {
-    warn(
-      "Failed to notify MoneyDevKit checkout about received payments. Will rely on local state and retry on next webhook.",
-      error,
-    );
-  }
+    // Notify backend asynchronously (fire and forget for speed)
+    // Note: payment.amount is in msat, convert to sats
+    client.checkouts
+      .paymentReceived({
+        payments: [
+          {
+            paymentHash: payment.paymentHash,
+            amountSats: payment.amount / 1000,
+            sandbox: false,
+          },
+        ],
+      })
+      .catch((error) => {
+        warn(
+          "Failed to notify MoneyDevKit checkout about received payment. Will rely on local state and retry on next webhook.",
+          error,
+        );
+      });
+  });
 }
 
 export async function handleMdkWebhook(request: Request): Promise<Response> {

packages/core/src/lightning-node.ts

@@ -128,6 +128,29 @@ export class MoneyDevKitNode {
     )
   }
 
+  /**
+   * Receive payments with an immediate callback for each payment received.
+   *
+   * This method behaves like `receivePayments` but fires a callback immediately
+   * when each payment is received, allowing for instant customer confirmation
+   * while the node continues to run for the full timeout period.
+   */
+  receivePaymentsWithCallback(
+    onPaymentReceived: (payment: { paymentHash: string; amount: number }) => void
+  ) {
+    return this.node.receivePaymentWithCallback(
+      RECEIVE_PAYMENTS_MIN_THRESHOLD_MS,
+      RECEIVE_PAYMENTS_QUIET_THRESHOLD_MS,
+      (err: unknown, payment: { paymentHash: string; amount: number }) => {
+        if (err) {
+          console.error('[MoneyDevKitNode] Payment callback error:', err)
+          return
+        }
+        onPaymentReceived(payment)
+      }
+    )
+  }
+
   payBolt12Offer(bolt12: string, amountMsat: number): string {
     return this.node.payBolt12Offer(bolt12, amountMsat, 30)
   }