chore: add example for wrapped invoices

examples/nwc/client/hold-invoice.ts

@@ -3,7 +3,7 @@ import "websocket-polyfill"; // required in node.js
 import * as readline from "node:readline/promises";
 import { stdin as input, stdout as output } from "node:process";
 
-import { NWCClient } from "@getalby/sdk/nwc";
+import { Nip47Notification, NWCClient } from "@getalby/sdk/nwc";
 
 const rl = readline.createInterface({ input, output });
 
@@ -21,7 +21,7 @@ const client = new NWCClient({
   nostrWalletConnectUrl: nwcUrl,
 });
 
-const toHexString = (bytes) =>
+const toHexString = (bytes: Uint8Array<ArrayBuffer>) =>
   bytes.reduce((str, byte) => str + byte.toString(16).padStart(2, "0"), "");
 
 const preimageBytes = crypto.getRandomValues(new Uint8Array(32));
@@ -41,7 +41,7 @@ const response = await client.makeHoldInvoice({
 
 console.info(response.invoice);
 
-const onNotification = async (notification) => {
+const onNotification = async (notification: Nip47Notification) => {
   if (notification.notification.payment_hash !== paymentHash) {
     console.info("Skipping unrelated notification", notification);
     return;

examples/nwc/client/wrapped-invoice.ts

@@ -0,0 +1,80 @@
+import "websocket-polyfill"; // required in node.js
+
+import * as readline from "node:readline/promises";
+import { stdin as input, stdout as output } from "node:process";
+
+import { Nip47Notification, NWCClient } from "@getalby/sdk/nwc";
+import { Invoice } from "@getalby/lightning-tools";
+
+console.warn(
+  "Alby Hub WARNING: This currently only works with Alby Hub LND backend or self payments between sub-wallets\n",
+);
+
+const rl = readline.createInterface({ input, output });
+
+const nwcUrl =
+  process.env.NWC_URL ||
+  (await rl.question("Nostr Wallet Connect URL (nostr+walletconnect://...): "));
+
+const upstreamInvoice = await rl.question("Upstream Invoice: ");
+
+const paymentHash = new Invoice({ pr: upstreamInvoice.trim() }).paymentHash;
+console.info("Payment hash:", paymentHash);
+
+const amount =
+  parseInt(
+    (await rl.question("Extra amount in sats (default 1 sat): ")) || "1",
+  ) * 1000;
+
+rl.close();
+
+const client = new NWCClient({
+  nostrWalletConnectUrl: nwcUrl,
+});
+
+const response = await client.makeHoldInvoice({
+  amount, // in millisats
+  description: "NWC HODL invoice example",
+  payment_hash: paymentHash,
+  // or set a 256-bit description hash:
+  //description_hash: "a40f2b27a4414044995b26b73eb5aa66688b5f18d6a8a2513827d9a116ad95f1",
+});
+
+console.info(response.invoice);
+
+const onNotification = async (notification: Nip47Notification) => {
+  if (notification.notification.payment_hash !== paymentHash) {
+    console.info("Skipping unrelated notification", notification);
+    return;
+  }
+  console.info(
+    "HOLD invoice accepted! It can be settled or canceled before block " +
+      notification.notification.settle_deadline,
+  );
+
+  console.info("Paying upstream invoice", upstreamInvoice);
+
+  const { preimage } = await client.payInvoice({
+    invoice: upstreamInvoice,
+  });
+
+  console.info("Paid upstream invoice", preimage);
+
+  await client.settleHoldInvoice({ preimage });
+
+  process.exit();
+};
+
+const unsub = await client.subscribeNotifications(onNotification, [
+  "hold_invoice_accepted",
+]);
+
+console.info("Waiting for payment to be made...");
+process.on("SIGINT", function () {
+  console.info("Caught interrupt signal");
+
+  unsub();
+  client.close();
+
+  process.exit();
+});