Add SplicePending event

diff --git a/lightning/src/events/mod.rs b/lightning/src/events/mod.rs
index d7a13d5..25669e2 100644
--- a/lightning/src/events/mod.rs
+++ b/lightning/src/events/mod.rs
@@ -1502,6 +1502,37 @@ pub enum Event {
 		/// [`ChainMonitor::get_claimable_balances`]: crate::chain::chainmonitor::ChainMonitor::get_claimable_balances
 		last_local_balance_msat: Option<u64>,
 	},
+	/// Used to indicate that a splice for the given `channel_id` has been negotiated and its
+	/// funding transaction has been broadcast.
+	///
+	/// The splice is then considered pending until both parties have seen enough confirmations to
+	/// consider the funding locked. Once this occurs, an [`Event::ChannelReady`] will be emitted.
+	///
+	/// Any UTXOs spent by the splice cannot be reused except by an RBF attempt for the same channel.
+	///
+	/// # Failure Behavior and Persistence
+	/// This event will eventually be replayed after failures-to-handle (i.e., the event handler
+	/// returning `Err(ReplayEvent ())`) and will be persisted across restarts.
+	SplicePending {
+		/// The `channel_id` of the channel that has a pending splice funding transaction.
+		channel_id: ChannelId,
+		/// The `user_channel_id` value passed in to [`ChannelManager::create_channel`] for outbound
+		/// channels, or to [`ChannelManager::accept_inbound_channel`] for inbound channels if
+		/// [`UserConfig::manually_accept_inbound_channels`] config flag is set to true. Otherwise
+		/// `user_channel_id` will be randomized for an inbound channel.
+		///
+		/// [`ChannelManager::create_channel`]: crate::ln::channelmanager::ChannelManager::create_channel
+		/// [`ChannelManager::accept_inbound_channel`]: crate::ln::channelmanager::ChannelManager::accept_inbound_channel
+		/// [`UserConfig::manually_accept_inbound_channels`]: crate::util::config::UserConfig::manually_accept_inbound_channels
+		user_channel_id: u128,
+		/// The `node_id` of the channel counterparty.
+		counterparty_node_id: PublicKey,
+		/// The outpoint of the channel's splice funding transaction.
+		new_funding_txo: OutPoint,
+		/// The features that this channel will operate with. Currently, these will be the same
+		/// features that the channel was opened with, but in the future splices may change them.
+		channel_type: ChannelTypeFeatures,
+	},
 	/// Used to indicate to the user that they can abandon the funding transaction and recycle the
 	/// inputs for another purpose.
 	///
@@ -2228,6 +2259,22 @@ impl Writeable for Event {
 				// We never write out FundingTransactionReadyForSigning events as they will be regenerated when
 				// necessary.
 			},
+			&Event::SplicePending {
+				ref channel_id,
+				ref user_channel_id,
+				ref counterparty_node_id,
+				ref new_funding_txo,
+				ref channel_type,
+			} => {
+				50u8.write(writer)?;
+				write_tlv_fields!(writer, {
+					(1, channel_id, required),
+					(3, channel_type, required),
+					(5, user_channel_id, required),
+					(7, counterparty_node_id, required),
+					(9, new_funding_txo, required),
+				});
+			},
 			// Note that, going forward, all new events must only write data inside of
 			// `write_tlv_fields`. Versions 0.0.101+ will ignore odd-numbered events that write
 			// data via `write_tlv_fields`.
@@ -2810,6 +2857,26 @@ impl MaybeReadable for Event {
 			47u8 => Ok(None),
 			// Note that we do not write a length-prefixed TLV for FundingTransactionReadyForSigning events.
 			49u8 => Ok(None),
+			50u8 => {
+				let mut f = || {
+					_init_and_read_len_prefixed_tlv_fields!(reader, {
+						(1, channel_id, required),
+						(3, channel_type, required),
+						(5, user_channel_id, required),
+						(7, counterparty_node_id, required),
+						(9, new_funding_txo, required),
+					});
+
+					Ok(Some(Event::SplicePending {
+						channel_id: channel_id.0.unwrap(),
+						user_channel_id: user_channel_id.0.unwrap(),
+						counterparty_node_id: counterparty_node_id.0.unwrap(),
+						new_funding_txo: new_funding_txo.0.unwrap(),
+						channel_type: channel_type.0.unwrap(),
+					}))
+				};
+				f()
+			},
 			// Versions prior to 0.0.100 did not ignore odd types, instead returning InvalidValue.
 			// Version 0.0.100 failed to properly ignore odd types, possibly resulting in corrupt
 			// reads.