From 84504fa8c52c1a6f0235ecaf89ed10501d1f125b Mon Sep 17 00:00:00 2001
From: ziggie <ziggie1984@protonmail.com>
Date: Sun, 16 Nov 2025 09:28:12 +0100
Subject: [PATCH] lnwire: implement SerializedSize for onion messages

---
 lnwire/onion_message.go | 9 +++++++++
 1 file changed, 9 insertions(+)

diff --git a/lnwire/onion_message.go b/lnwire/onion_message.go
index cabbc2141..5d568085b 100644
--- a/lnwire/onion_message.go
+++ b/lnwire/onion_message.go
@@ -36,6 +36,8 @@ func NewOnionMessage(pathKey *btcec.PublicKey,
 // A compile-time check to ensure OnionMessage implements the Message interface.
 var _ Message = (*OnionMessage)(nil)
 
+var _ SizeableMessage = (*OnionMessage)(nil)
+
 // Decode reads the bytes stream and converts it to the object.
 func (o *OnionMessage) Decode(r io.Reader, _ uint32) error {
 	if err := ReadElement(r, &o.PathKey); err != nil {
@@ -79,3 +81,10 @@ func (o *OnionMessage) Encode(w *bytes.Buffer, _ uint32) error {
 func (o *OnionMessage) MsgType() MessageType {
 	return MsgOnionMessage
 }
+
+// SerializedSize returns the serialized size of the message in bytes.
+//
+// This is part of the lnwire.SizeableMessage interface.
+func (o *OnionMessage) SerializedSize() (uint32, error) {
+	return MessageSerializedSize(o)
+}