Make counterparty_node_id non-optional on ChannelReady and ChannelClosed event

We no longer need to maintain backwards compatibility with LDK Node
v0.1.0, so we can make this a required field and avoid propagating
the Option through the API.

Author: f3r10

CHANGELOG.md

@@ -1,3 +1,10 @@
+# Pending
+
+## Serialization Compatibility
+- The `counterparty_node_id` field of the `ChannelReady` and `ChannelClosed` events is now
+  required. Events persisted by LDK Node v0.1.0 and prior that are missing this field will
+  fail to deserialize.
+
 # 0.7.0 - Dec. 3, 2025
 This seventh minor release introduces numerous new features, bug fixes, and API improvements. In particular, it adds support for channel Splicing, Async Payments, as well as sourcing chain data from a Bitcoin Core REST backend.
 

src/event.rs

@@ -248,9 +248,7 @@ pub enum Event {
 		/// The `user_channel_id` of the channel.
 		user_channel_id: UserChannelId,
 		/// The `node_id` of the channel counterparty.
-		///
-		/// This will be `None` for events serialized by LDK Node v0.1.0 and prior.
-		counterparty_node_id: Option<PublicKey>,
+		counterparty_node_id: PublicKey,
 		/// The outpoint of the channel's funding transaction.
 		///
 		/// This represents the channel's current funding output, which may change when the
@@ -267,9 +265,7 @@ pub enum Event {
 		/// The `user_channel_id` of the channel.
 		user_channel_id: UserChannelId,
 		/// The `node_id` of the channel counterparty.
-		///
-		/// This will be `None` for events serialized by LDK Node v0.1.0 and prior.
-		counterparty_node_id: Option<PublicKey>,
+		counterparty_node_id: PublicKey,
 		/// This will be `None` for events serialized by LDK Node v0.2.1 and prior.
 		reason: Option<ClosureReason>,
 		/// The channel's capacity in satoshis.
@@ -330,7 +326,7 @@ impl_writeable_tlv_based_enum!(Event,
 	},
 	(3, ChannelReady) => {
 		(0, channel_id, required),
-		(1, counterparty_node_id, option),
+		(1, counterparty_node_id, required),
 		(2, user_channel_id, required),
 		(3, funding_txo, option),
 	},
@@ -343,7 +339,7 @@ impl_writeable_tlv_based_enum!(Event,
 	},
 	(5, ChannelClosed) => {
 		(0, channel_id, required),
-		(1, counterparty_node_id, option),
+		(1, counterparty_node_id, required),
 		(2, user_channel_id, required),
 		(3, reason, upgradable_option),
 		(5, channel_capacity_sats, option),
@@ -1624,7 +1620,7 @@ where
 				let event = Event::ChannelReady {
 					channel_id,
 					user_channel_id: UserChannelId(user_channel_id),
-					counterparty_node_id: Some(counterparty_node_id),
+					counterparty_node_id,
 					funding_txo,
 				};
 				match self.event_queue.add_event(event).await {
@@ -1685,7 +1681,8 @@ where
 				let event = Event::ChannelClosed {
 					channel_id,
 					user_channel_id,
-					counterparty_node_id,
+					counterparty_node_id: counterparty_node_id
+						.expect("counterparty_node_id must be set for closed channels"),
 					reason: Some(reason),
 					channel_capacity_sats,
 					channel_funding_txo: funding_txo,
@@ -1993,6 +1990,7 @@ mod tests {
 	use std::sync::atomic::{AtomicU16, Ordering};
 	use std::time::Duration;
 
+	use bitcoin::secp256k1::{Secp256k1, SecretKey};
 	use lightning::util::test_utils::TestLogger;
 
 	use super::*;
@@ -2006,10 +2004,13 @@ mod tests {
 		let event_queue = Arc::new(EventQueue::new(Arc::clone(&store), Arc::clone(&logger)));
 		assert_eq!(event_queue.next_event(), None);
 
+		let secp = Secp256k1::new();
+		let counterparty_node_id =
+			PublicKey::from_secret_key(&secp, &SecretKey::from_slice(&[1u8; 32]).unwrap());
 		let expected_event = Event::ChannelReady {
 			channel_id: ChannelId([23u8; 32]),
 			user_channel_id: UserChannelId(2323),
-			counterparty_node_id: None,
+			counterparty_node_id,
 			funding_txo: None,
 		};
 		event_queue.add_event(expected_event.clone()).await.unwrap();
@@ -2044,10 +2045,13 @@ mod tests {
 		let event_queue = Arc::new(EventQueue::new(Arc::clone(&store), Arc::clone(&logger)));
 		assert_eq!(event_queue.next_event(), None);
 
+		let secp = Secp256k1::new();
+		let counterparty_node_id =
+			PublicKey::from_secret_key(&secp, &SecretKey::from_slice(&[1u8; 32]).unwrap());
 		let expected_event = Event::ChannelReady {
 			channel_id: ChannelId([23u8; 32]),
 			user_channel_id: UserChannelId(2323),
-			counterparty_node_id: None,
+			counterparty_node_id,
 			funding_txo: None,
 		};
 

tests/common/mod.rs

@@ -130,7 +130,7 @@ macro_rules! expect_channel_ready_event {
 		match event {
 			ref e @ Event::ChannelReady { user_channel_id, counterparty_node_id, .. } => {
 				println!("{} got event {:?}", $node.node_id(), e);
-				assert_eq!(counterparty_node_id, Some($counterparty_node_id));
+				assert_eq!(counterparty_node_id, $counterparty_node_id);
 				$node.event_handled().unwrap();
 				user_channel_id
 			},
@@ -167,8 +167,7 @@ macro_rules! expect_channel_ready_events {
 			}
 		}
 		assert!(
-			ids.contains(&Some($counterparty_node_id_a))
-				&& ids.contains(&Some($counterparty_node_id_b)),
+			ids.contains(&$counterparty_node_id_a) && ids.contains(&$counterparty_node_id_b),
 			"Expected ChannelReady events from {:?} and {:?}, but got {:?}",
 			$counterparty_node_id_a,
 			$counterparty_node_id_b,

tests/reorg_test.rs

@@ -112,11 +112,11 @@ proptest! {
 				let next_node = nodes.get((i + 1) % nodes.len()).unwrap();
 				let prev_node = nodes.get((i + nodes.len() - 1) % nodes.len()).unwrap();
 
-				assert!(user_channels.get(&Some(next_node.node_id())) != None);
-				assert!(user_channels.get(&Some(prev_node.node_id())) != None);
+				assert!(user_channels.get(&next_node.node_id()) != None);
+				assert!(user_channels.get(&prev_node.node_id()) != None);
 
 				let user_channel_id =
-					user_channels.get(&Some(next_node.node_id())).expect("Missing user channel for node");
+					user_channels.get(&next_node.node_id()).expect("Missing user channel for node");
 				node_channels_id.insert(node.node_id(), *user_channel_id);
 			}