From 8b2dcf0d5615cea14f88c80f8974f11783c7d363 Mon Sep 17 00:00:00 2001
From: M1 <m1-pro@M1s-MacBook-Pro.local>
Date: Wed, 18 Mar 2026 23:22:37 +0400
Subject: [PATCH] =?UTF-8?q?fix:=20convert=20zpub=20to=20xpub=20version=20b?=
 =?UTF-8?q?ytes=20=E2=80=94=20bitcore-lib-ltc=20only=20understands=20stand?=
 =?UTF-8?q?ard=20xpub?=
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---
 apps/pay/src/address.ts | 10 +++++-----
 1 file changed, 5 insertions(+), 5 deletions(-)

diff --git a/apps/pay/src/address.ts b/apps/pay/src/address.ts
index bfbb20d..86d86a4 100644
--- a/apps/pay/src/address.ts
+++ b/apps/pay/src/address.ts
@@ -85,11 +85,11 @@ export function deriveAddressSafe(coin: string, index: number): string {
   if (coin === "ltc") {
     // zpub uses BIP84 version bytes — convert to Ltub so bitcore-lib-ltc can parse it
     let key = xpub;
-    if (xpub.startsWith("zpub") || xpub.startsWith("Zpub")) {
-      // Decode base58check, swap version bytes to Ltub (0x019da462), re-encode
-      const decoded = bs58check.decode(xpub);
-      // Replace first 4 bytes with Ltub version: 0x019da462
-      decoded[0] = 0x01; decoded[1] = 0x9d; decoded[2] = 0xa4; decoded[3] = 0x62;
+    if (xpub.startsWith("zpub") || xpub.startsWith("Zpub") || xpub.startsWith("Ltub") || xpub.startsWith("Mtub")) {
+      // bitcore-lib-ltc only understands standard xpub version bytes (0x0488b21e).
+      // Convert zpub/Ltub/Mtub → xpub by swapping the 4-byte version prefix.
+      const decoded = Buffer.from(bs58check.decode(xpub));
+      decoded[0] = 0x04; decoded[1] = 0x88; decoded[2] = 0xb2; decoded[3] = 0x1e;
       key = bs58check.encode(decoded);
     }
     const hd = new bitcoreLtc.HDPublicKey(key);