Add LSPS5 webhook notification support

Integrates LSPS5 (BLIP-0055) from lightning-liquidity to enable
webhook-based push notifications for clients.

- Add event system integration for LSPS5 events
- Expose public API for webhook management

This allows client developers to register webhook endpoints
with their LSP to receive notifications when their app is offline.

Author: Camillarhi

src/builder.rs

@@ -61,7 +61,8 @@ use crate::io::{
 	self, PAYMENT_INFO_PERSISTENCE_PRIMARY_NAMESPACE, PAYMENT_INFO_PERSISTENCE_SECONDARY_NAMESPACE,
 };
 use crate::liquidity::{
-	LSPS1ClientConfig, LSPS2ClientConfig, LSPS2ServiceConfig, LiquiditySourceBuilder,
+	LSPS1ClientConfig, LSPS2ClientConfig, LSPS2ServiceConfig, LSPS5ClientConfig,
+	LiquiditySourceBuilder,
 };
 use crate::logger::{log_error, LdkLogger, LogLevel, LogWriter, Logger};
 use crate::message_handler::NodeCustomMessageHandler;
@@ -71,7 +72,8 @@ use crate::runtime::Runtime;
 use crate::tx_broadcaster::TransactionBroadcaster;
 use crate::types::{
 	ChainMonitor, ChannelManager, DynStore, DynStoreWrapper, GossipSync, Graph, KeysManager,
-	MessageRouter, OnionMessenger, PaymentStore, PeerManager, Persister, SyncAndAsyncKVStore,
+	LSPS5ServiceConfig, MessageRouter, OnionMessenger, PaymentStore, PeerManager, Persister,
+	SyncAndAsyncKVStore,
 };
 use crate::wallet::persist::KVStoreWalletPersister;
 use crate::wallet::Wallet;
@@ -119,6 +121,10 @@ struct LiquiditySourceConfig {
 	lsps2_client: Option<LSPS2ClientConfig>,
 	// Act as an LSPS2 service.
 	lsps2_service: Option<LSPS2ServiceConfig>,
+	// Act as an LSPS5 client connecting to the given service.
+	lsps5_client: Option<LSPS5ClientConfig>,
+	// Act as an LSPS5 service.
+	lsps5_service: Option<LSPS5ServiceConfig>,
 }
 
 #[derive(Clone)]
@@ -444,6 +450,36 @@ impl NodeBuilder {
 		self
 	}
 
+	/// Configures the [`Node`] instance to source webhook notifications from the given
+	/// [bLIP-55 / LSPS5] service.
+	///
+	/// This allows the client to register webhook endpoints with the LSP to receive
+	/// push notifications for Lightning events when the client is offline.
+	///
+	/// [bLIP-55 / LSPS5]: https://github.com/lightning/blips/blob/master/blip-0055.md
+	pub fn set_liquidity_source_lsps5(
+		&mut self, node_id: PublicKey, address: SocketAddress,
+	) -> &mut Self {
+		let liquidity_source_config =
+			self.liquidity_source_config.get_or_insert(LiquiditySourceConfig::default());
+		let lsps5_client_config = LSPS5ClientConfig { node_id, address };
+		liquidity_source_config.lsps5_client = Some(lsps5_client_config);
+		self
+	}
+
+	/// Configures the [`Node`] instance to provide an [LSPS5] service, enabling clients
+	/// to register webhooks for push notifications.
+	///
+	/// [LSPS5]: https://github.com/lightning/blips/blob/master/blip-0055.md
+	pub fn set_liquidity_provider_lsps5(
+		&mut self, service_config: LSPS5ServiceConfig,
+	) -> &mut Self {
+		let liquidity_source_config =
+			self.liquidity_source_config.get_or_insert(LiquiditySourceConfig::default());
+		liquidity_source_config.lsps5_service = Some(service_config);
+		self
+	}
+
 	/// Sets the used storage directory path.
 	pub fn set_storage_dir_path(&mut self, storage_dir_path: String) -> &mut Self {
 		self.config.storage_dir_path = storage_dir_path;
@@ -1547,6 +1583,14 @@ fn build_with_store_internal(
 				liquidity_source_builder.lsps2_service(promise_secret, config.clone())
 			});
 
+			lsc.lsps5_client.as_ref().map(|config| {
+				liquidity_source_builder.lsps5_client(config.node_id, config.address.clone())
+			});
+
+			lsc.lsps5_service
+				.as_ref()
+				.map(|config| liquidity_source_builder.lsps5_service(config.clone()));
+
 			let liquidity_source = runtime
 				.block_on(async move { liquidity_source_builder.build().await.map(Arc::new) })?;
 			let custom_message_handler =

src/error.rs

@@ -127,6 +127,10 @@ pub enum Error {
 	InvalidBlindedPaths,
 	/// Asynchronous payment services are disabled.
 	AsyncPaymentServicesDisabled,
+	/// Failed to set a webhook with the LSP.
+	LiquiditySetWebhookFailed,
+	/// Failed to remove a webhook with the LSP.
+	LiquidityRemoveWebhookFailed,
 }
 
 impl fmt::Display for Error {
@@ -205,6 +209,12 @@ impl fmt::Display for Error {
 			Self::AsyncPaymentServicesDisabled => {
 				write!(f, "Asynchronous payment services are disabled.")
 			},
+			Self::LiquiditySetWebhookFailed => {
+				write!(f, "Failed to set a webhook with the LSP.")
+			},
+			Self::LiquidityRemoveWebhookFailed => {
+				write!(f, "Failed to remove a webhook with the LSP.")
+			},
 		}
 	}
 }

src/lib.rs

@@ -146,7 +146,7 @@ use lightning::ln::msgs::SocketAddress;
 use lightning::routing::gossip::NodeAlias;
 use lightning::util::persist::KVStoreSync;
 use lightning_background_processor::process_events_async;
-use liquidity::{LSPS1Liquidity, LiquiditySource};
+use liquidity::{LSPS1Liquidity, LSPS5Liquidity, LiquiditySource};
 use logger::{log_debug, log_error, log_info, log_trace, LdkLogger, Logger};
 use payment::asynchronous::om_mailbox::OnionMessageMailbox;
 use payment::asynchronous::static_invoice_store::StaticInvoiceStore;
@@ -1004,6 +1004,32 @@ impl Node {
 		))
 	}
 
+	/// Returns a liquidity handler allowing to handle webhooks and notifications via the [bLIP-55 / LSPS5] protocol.
+	///
+	/// [bLIP-55 / LSPS5]: https://github.com/lightning/blips/blob/master/blip-0055.md
+	#[cfg(not(feature = "uniffi"))]
+	pub fn lsps5_liquidity(&self) -> LSPS5Liquidity {
+		LSPS5Liquidity::new(
+			Arc::clone(&self.runtime),
+			Arc::clone(&self.connection_manager),
+			self.liquidity_source.clone(),
+			Arc::clone(&self.logger),
+		)
+	}
+
+	/// Returns a liquidity handler allowing to handle webhooks and notifications via the [bLIP-55 / LSPS5] protocol.
+	///
+	/// [bLIP-55 / LSPS5]: https://github.com/lightning/blips/blob/master/blip-0055.md
+	#[cfg(feature = "uniffi")]
+	pub fn lsps5_liquidity(&self) -> Arc<LSPS5Liquidity> {
+		Arc::new(LSPS5Liquidity::new(
+			Arc::clone(&self.runtime),
+			Arc::clone(&self.connection_manager),
+			self.liquidity_source.clone(),
+			Arc::clone(&self.logger),
+		))
+	}
+
 	/// Retrieve a list of known channels.
 	pub fn list_channels(&self) -> Vec<ChannelDetails> {
 		self.channel_manager.list_channels().into_iter().map(|c| c.into()).collect()