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Drop max_inbound_htlc_value_in_flight_percent_of_channel #878

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Merged
tnull merged 1 commit into from
Apr 29, 2026
Merged

Drop max_inbound_htlc_value_in_flight_percent_of_channel #878

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28 changes: 14 additions & 14 deletions Cargo.toml
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Original file line numberDiff line numberDiff line change
Expand Up@@ -40,18 +40,18 @@ default = []
#lightning-macros = { version = "0.2.0" }
#lightning-dns-resolver = { version = "0.3.0" }

lightning = { git = "https://github.com/lightningdevkit/rust-lightning", rev = "044f3fab42e3085edecd40f0c9b369093edb7133", features = ["std"] }
lightning-types = { git = "https://github.com/lightningdevkit/rust-lightning", rev = "044f3fab42e3085edecd40f0c9b369093edb7133" }
lightning-invoice = { git = "https://github.com/lightningdevkit/rust-lightning", rev = "044f3fab42e3085edecd40f0c9b369093edb7133", features = ["std"] }
lightning-net-tokio = { git = "https://github.com/lightningdevkit/rust-lightning", rev = "044f3fab42e3085edecd40f0c9b369093edb7133" }
lightning-persister = { git = "https://github.com/lightningdevkit/rust-lightning", rev = "044f3fab42e3085edecd40f0c9b369093edb7133", features = ["tokio"] }
lightning-background-processor = { git = "https://github.com/lightningdevkit/rust-lightning", rev = "044f3fab42e3085edecd40f0c9b369093edb7133" }
lightning-rapid-gossip-sync = { git = "https://github.com/lightningdevkit/rust-lightning", rev = "044f3fab42e3085edecd40f0c9b369093edb7133" }
lightning-block-sync = { git = "https://github.com/lightningdevkit/rust-lightning", rev = "044f3fab42e3085edecd40f0c9b369093edb7133", features = ["rest-client", "rpc-client", "tokio"] }
lightning-transaction-sync = { git = "https://github.com/lightningdevkit/rust-lightning", rev = "044f3fab42e3085edecd40f0c9b369093edb7133", features = ["esplora-async-https", "time", "electrum-rustls-ring"] }
lightning-liquidity = { git = "https://github.com/lightningdevkit/rust-lightning", rev = "044f3fab42e3085edecd40f0c9b369093edb7133", features = ["std"] }
lightning-macros = { git = "https://github.com/lightningdevkit/rust-lightning", rev = "044f3fab42e3085edecd40f0c9b369093edb7133" }
lightning-dns-resolver = { git = "https://github.com/lightningdevkit/rust-lightning", rev = "044f3fab42e3085edecd40f0c9b369093edb7133" }
lightning = { git = "https://github.com/lightningdevkit/rust-lightning", rev = "369a2cf9c8ef810deea0cd2b4cf6ed0691b78144", features = ["std"] }
lightning-types = { git = "https://github.com/lightningdevkit/rust-lightning", rev = "369a2cf9c8ef810deea0cd2b4cf6ed0691b78144" }
lightning-invoice = { git = "https://github.com/lightningdevkit/rust-lightning", rev = "369a2cf9c8ef810deea0cd2b4cf6ed0691b78144", features = ["std"] }
lightning-net-tokio = { git = "https://github.com/lightningdevkit/rust-lightning", rev = "369a2cf9c8ef810deea0cd2b4cf6ed0691b78144" }
lightning-persister = { git = "https://github.com/lightningdevkit/rust-lightning", rev = "369a2cf9c8ef810deea0cd2b4cf6ed0691b78144", features = ["tokio"] }
lightning-background-processor = { git = "https://github.com/lightningdevkit/rust-lightning", rev = "369a2cf9c8ef810deea0cd2b4cf6ed0691b78144" }
lightning-rapid-gossip-sync = { git = "https://github.com/lightningdevkit/rust-lightning", rev = "369a2cf9c8ef810deea0cd2b4cf6ed0691b78144" }
lightning-block-sync = { git = "https://github.com/lightningdevkit/rust-lightning", rev = "369a2cf9c8ef810deea0cd2b4cf6ed0691b78144", features = ["rest-client", "rpc-client", "tokio"] }
lightning-transaction-sync = { git = "https://github.com/lightningdevkit/rust-lightning", rev = "369a2cf9c8ef810deea0cd2b4cf6ed0691b78144", features = ["esplora-async-https", "time", "electrum-rustls-ring"] }
lightning-liquidity = { git = "https://github.com/lightningdevkit/rust-lightning", rev = "369a2cf9c8ef810deea0cd2b4cf6ed0691b78144", features = ["std"] }
lightning-macros = { git = "https://github.com/lightningdevkit/rust-lightning", rev = "369a2cf9c8ef810deea0cd2b4cf6ed0691b78144" }
lightning-dns-resolver = { git = "https://github.com/lightningdevkit/rust-lightning", rev = "369a2cf9c8ef810deea0cd2b4cf6ed0691b78144" }

bdk_chain = { version = "0.23.0", default-features = false, features = ["std"] }
bdk_esplora = { version = "0.22.0", default-features = false, features = ["async-https-rustls", "tokio"]}
Expand DownExpand Up@@ -81,13 +81,13 @@ async-trait = { version = "0.1", default-features = false }
vss-client = { package = "vss-client-ng", version = "0.5" }
prost = { version = "0.11.6", default-features = false}
#bitcoin-payment-instructions = { version = "0.6" }
bitcoin-payment-instructions = { git = "https://github.com/jkczyz/bitcoin-payment-instructions", rev = "340c535a600f7c43bef4c9f910edac4085f2e70c" }
bitcoin-payment-instructions = { git = "https://github.com/jkczyz/bitcoin-payment-instructions", rev = "679dac50cc0d81ec4d31da94b93d467e5308f16a" }

[target.'cfg(windows)'.dependencies]
winapi = { version = "0.3", features = ["winbase"] }

[dev-dependencies]
lightning = { git = "https://github.com/lightningdevkit/rust-lightning", rev = "044f3fab42e3085edecd40f0c9b369093edb7133", features = ["std", "_test_utils"] }
lightning = { git = "https://github.com/lightningdevkit/rust-lightning", rev = "369a2cf9c8ef810deea0cd2b4cf6ed0691b78144", features = ["std", "_test_utils"] }
rand = { version = "0.9.2", default-features = false, features = ["std", "thread_rng", "os_rng"] }
proptest = "1.0.0"
regex = "1.5.6"
Expand Down
5 changes: 0 additions & 5 deletions src/builder.rs
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Original file line numberDiff line numberDiff line change
Expand Up@@ -1657,11 +1657,6 @@ fn build_with_store_internal(

// If we act as an LSPS2 service, we allow forwarding to unannounced channels.
user_config.accept_forwards_to_priv_channels = true;

// If we act as an LSPS2 service, set the HTLC-value-in-flight to 100% of the channel value
// to ensure we can forward the initial payment.
user_config.channel_handshake_config.max_inbound_htlc_value_in_flight_percent_of_channel =
100;
Comment on lines -1670 to -1673

@tankyleotankyleoApr 28, 2026

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To confirm here I don't think setting 100% here would have helped as that maximum only applies to the inbound HTLCs on that channel. To make sure that 100% of the value can be allocated to outbound HTLCs from the LSP's perspective as the comment describes, the user needs to set their max_inbound to 100%.

So seems to me the intention of the code did not match the comment ?

@jkczyzjkczyzApr 28, 2026

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Hmm... yeah it does seem that way.

}

if let Some(role) = async_payments_role {
Expand Down
24 changes: 13 additions & 11 deletions src/event.rs
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Original file line numberDiff line numberDiff line change
Expand Up@@ -26,9 +26,7 @@ use lightning::ln::channelmanager::{PaymentId, TrustedChannelFeatures};
use lightning::ln::types::ChannelId;
use lightning::routing::gossip::NodeId;
use lightning::sign::EntropySource;
use lightning::util::config::{
ChannelConfigOverrides, ChannelConfigUpdate, ChannelHandshakeConfigUpdate,
};
use lightning::util::config::{ChannelConfigOverrides, ChannelConfigUpdate};
use lightning::util::errors::APIError;
use lightning::util::persist::KVStore;
use lightning::util::ser::{Readable, ReadableArgs, Writeable, Writer};
Expand DownExpand Up@@ -1273,20 +1271,24 @@ where
if lsp_node_id == counterparty_node_id {
// When we're an LSPS2 client, allow claiming underpaying HTLCs as the LSP will skim off some fee. We'll
// check that they don't take too much before claiming.
//
// We also set maximum allowed inbound HTLC value in flight
// to 100%. We should eventually be able to set this on a per-channel basis, but for
// now we just bump the default for all channels.
channel_override_config = Some(ChannelConfigOverrides {
handshake_overrides: Some(ChannelHandshakeConfigUpdate {
max_inbound_htlc_value_in_flight_percent_of_channel: Some(100),
..Default::default()
}),
update_overrides: Some(ChannelConfigUpdate {
accept_underpaying_htlcs: Some(true),
..Default::default()
}),
..Default::default()

@tankyleotankyleoApr 28, 2026

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nit: as elsewhere, maybe a quick debug_assert here on the 100% value ? Up to @tnull

});

// LSPS2 channels are unannounced; rely on LDK's default of 100%
// inbound HTLC value-in-flight so the LSP can forward the initial
// payment in full.
debug_assert_eq!(
self.channel_manager
.get_current_config()
.channel_handshake_config
.unannounced_channel_max_inbound_htlc_value_in_flight_percentage,
100
);
}
}
let res = if allow_0conf {
Expand Down
15 changes: 9 additions & 6 deletions src/lib.rs
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Original file line numberDiff line numberDiff line change
Expand Up@@ -1195,13 +1195,16 @@ impl Node {
let mut user_config = default_user_config(&self.config);
user_config.channel_handshake_config.announce_for_forwarding = announce_for_forwarding;
user_config.channel_config = (channel_config.unwrap_or_default()).clone().into();
// We set the max inflight to 100% for private channels.

@tankyleotankyleoApr 28, 2026

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nit: similar here, would it be worth adding a debug_assert to guard against any changes away from this behavior ?

// FIXME: LDK will default to this behavior soon, too, at which point we should drop this
// manual override.

// Unannounced channels rely on LDK's default of 100% inbound HTLC value-in-flight
// to support large initial payments via LSPS2.
if !announce_for_forwarding {
user_config
.channel_handshake_config
.max_inbound_htlc_value_in_flight_percent_of_channel = 100;
debug_assert_eq!(
user_config
.channel_handshake_config
.unannounced_channel_max_inbound_htlc_value_in_flight_percentage,
100
);
}

let push_msat = push_to_counterparty_msat.unwrap_or(0);
Expand Down
7 changes: 5 additions & 2 deletions src/liquidity.rs
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Expand Up@@ -781,13 +781,16 @@ where

let mut config = self.channel_manager.get_current_config().clone();

// We set these LSP-specific values during Node building, here we're making sure it's actually set.
// If we act as an LSPS2 service, the HTLC-value-in-flight must be 100% of the
// channel value to ensure we can forward the initial payment. That cap only
// applies to unannounced channels, so the channel must also be unannounced.
debug_assert_eq!(
config
.channel_handshake_config
.max_inbound_htlc_value_in_flight_percent_of_channel,
.unannounced_channel_max_inbound_htlc_value_in_flight_percentage,
100
);
debug_assert!(!config.channel_handshake_config.announce_for_forwarding);
debug_assert!(config.accept_forwards_to_priv_channels);

@tankyleotankyleoApr 28, 2026

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nit: can we add a debug_assert here on announce_for_forwarding = false ? IIUC right now we inherit announce_for_forwarding = false here because of the default in rust-lightning, but would be good to confirm this here I think.

This is to make sure that the 100% cap actually gets applied to the channel opened by the LSPS2 service.


// We set the forwarding fee to 0 for now as we're getting paid by the channel fee.
Expand Down
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Drop `max_inbound_htlc_value_in_flight_percent_of_channel ` by jkczyz · Pull Request #878 · lightningdevkit/ldk-node · GitHub
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Drop max_inbound_htlc_value_in_flight_percent_of_channel #878

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 Merged

tnull
merged 1 commit into

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Apr 29, 2026
 Merged


Drop max_inbound_htlc_value_in_flight_percent_of_channel #878
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28 changes: 14 additions & 14 deletions
Cargo.toml

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Original file line numberDiff line numberDiff line change
Expand Up@@ -40,18 +40,18 @@ default = []
#lightning-macros = { version = "0.2.0" }
#lightning-dns-resolver = { version = "0.3.0" }

lightning = { git = "https://github.com/lightningdevkit/rust-lightning", rev = "044f3fab42e3085edecd40f0c9b369093edb7133", features = ["std"] }
lightning-types = { git = "https://github.com/lightningdevkit/rust-lightning", rev = "044f3fab42e3085edecd40f0c9b369093edb7133" }
lightning-invoice = { git = "https://github.com/lightningdevkit/rust-lightning", rev = "044f3fab42e3085edecd40f0c9b369093edb7133", features = ["std"] }
lightning-net-tokio = { git = "https://github.com/lightningdevkit/rust-lightning", rev = "044f3fab42e3085edecd40f0c9b369093edb7133" }
lightning-persister = { git = "https://github.com/lightningdevkit/rust-lightning", rev = "044f3fab42e3085edecd40f0c9b369093edb7133", features = ["tokio"] }
lightning-background-processor = { git = "https://github.com/lightningdevkit/rust-lightning", rev = "044f3fab42e3085edecd40f0c9b369093edb7133" }
lightning-rapid-gossip-sync = { git = "https://github.com/lightningdevkit/rust-lightning", rev = "044f3fab42e3085edecd40f0c9b369093edb7133" }
lightning-block-sync = { git = "https://github.com/lightningdevkit/rust-lightning", rev = "044f3fab42e3085edecd40f0c9b369093edb7133", features = ["rest-client", "rpc-client", "tokio"] }
lightning-transaction-sync = { git = "https://github.com/lightningdevkit/rust-lightning", rev = "044f3fab42e3085edecd40f0c9b369093edb7133", features = ["esplora-async-https", "time", "electrum-rustls-ring"] }
lightning-liquidity = { git = "https://github.com/lightningdevkit/rust-lightning", rev = "044f3fab42e3085edecd40f0c9b369093edb7133", features = ["std"] }
lightning-macros = { git = "https://github.com/lightningdevkit/rust-lightning", rev = "044f3fab42e3085edecd40f0c9b369093edb7133" }
lightning-dns-resolver = { git = "https://github.com/lightningdevkit/rust-lightning", rev = "044f3fab42e3085edecd40f0c9b369093edb7133" }
lightning = { git = "https://github.com/lightningdevkit/rust-lightning", rev = "369a2cf9c8ef810deea0cd2b4cf6ed0691b78144", features = ["std"] }
lightning-types = { git = "https://github.com/lightningdevkit/rust-lightning", rev = "369a2cf9c8ef810deea0cd2b4cf6ed0691b78144" }
lightning-invoice = { git = "https://github.com/lightningdevkit/rust-lightning", rev = "369a2cf9c8ef810deea0cd2b4cf6ed0691b78144", features = ["std"] }
lightning-net-tokio = { git = "https://github.com/lightningdevkit/rust-lightning", rev = "369a2cf9c8ef810deea0cd2b4cf6ed0691b78144" }
lightning-persister = { git = "https://github.com/lightningdevkit/rust-lightning", rev = "369a2cf9c8ef810deea0cd2b4cf6ed0691b78144", features = ["tokio"] }
lightning-background-processor = { git = "https://github.com/lightningdevkit/rust-lightning", rev = "369a2cf9c8ef810deea0cd2b4cf6ed0691b78144" }
lightning-rapid-gossip-sync = { git = "https://github.com/lightningdevkit/rust-lightning", rev = "369a2cf9c8ef810deea0cd2b4cf6ed0691b78144" }
lightning-block-sync = { git = "https://github.com/lightningdevkit/rust-lightning", rev = "369a2cf9c8ef810deea0cd2b4cf6ed0691b78144", features = ["rest-client", "rpc-client", "tokio"] }
lightning-transaction-sync = { git = "https://github.com/lightningdevkit/rust-lightning", rev = "369a2cf9c8ef810deea0cd2b4cf6ed0691b78144", features = ["esplora-async-https", "time", "electrum-rustls-ring"] }
lightning-liquidity = { git = "https://github.com/lightningdevkit/rust-lightning", rev = "369a2cf9c8ef810deea0cd2b4cf6ed0691b78144", features = ["std"] }
lightning-macros = { git = "https://github.com/lightningdevkit/rust-lightning", rev = "369a2cf9c8ef810deea0cd2b4cf6ed0691b78144" }
lightning-dns-resolver = { git = "https://github.com/lightningdevkit/rust-lightning", rev = "369a2cf9c8ef810deea0cd2b4cf6ed0691b78144" }

bdk_chain = { version = "0.23.0", default-features = false, features = ["std"] }
bdk_esplora = { version = "0.22.0", default-features = false, features = ["async-https-rustls", "tokio"]}
Expand DownExpand Up@@ -81,13 +81,13 @@ async-trait = { version = "0.1", default-features = false }
vss-client = { package = "vss-client-ng", version = "0.5" }
prost = { version = "0.11.6", default-features = false}
#bitcoin-payment-instructions = { version = "0.6" }
bitcoin-payment-instructions = { git = "https://github.com/jkczyz/bitcoin-payment-instructions", rev = "340c535a600f7c43bef4c9f910edac4085f2e70c" }
bitcoin-payment-instructions = { git = "https://github.com/jkczyz/bitcoin-payment-instructions", rev = "679dac50cc0d81ec4d31da94b93d467e5308f16a" }

[target.'cfg(windows)'.dependencies]
winapi = { version = "0.3", features = ["winbase"] }

[dev-dependencies]
lightning = { git = "https://github.com/lightningdevkit/rust-lightning", rev = "044f3fab42e3085edecd40f0c9b369093edb7133", features = ["std", "_test_utils"] }
lightning = { git = "https://github.com/lightningdevkit/rust-lightning", rev = "369a2cf9c8ef810deea0cd2b4cf6ed0691b78144", features = ["std", "_test_utils"] }
rand = { version = "0.9.2", default-features = false, features = ["std", "thread_rng", "os_rng"] }
proptest = "1.0.0"
regex = "1.5.6"
Expand Down

5 changes: 0 additions & 5 deletions
src/builder.rs

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Original file line numberDiff line numberDiff line change
Expand Up@@ -1657,11 +1657,6 @@ fn build_with_store_internal(

 // If we act as an LSPS2 service, we allow forwarding to unannounced channels.
 user_config.accept_forwards_to_priv_channels = true;

 // If we act as an LSPS2 service, set the HTLC-value-in-flight to 100% of the channel value
 // to ensure we can forward the initial payment.
 user_config.channel_handshake_config.max_inbound_htlc_value_in_flight_percent_of_channel =
 100;

Comment on lines

-1670
 to 
-1673

@tankyleotankyleoApr 28, 2026

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To confirm here I don't think setting 100% here would have helped as that maximum only applies to the inbound HTLCs on that channel. To make sure that 100% of the value can be allocated to outbound HTLCs from the LSP's perspective as the comment describes, the user needs to set their max_inbound to 100%.
So seems to me the intention of the code did not match the comment ?
@jkczyzjkczyzApr 28, 2026

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Hmm... yeah it does seem that way.
	}

	if let Some(role) = async_payments_role {
Expand Down

24 changes: 13 additions & 11 deletions
src/event.rs

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Original file line numberDiff line numberDiff line change
Expand Up@@ -26,9 +26,7 @@ use lightning::ln::channelmanager::{PaymentId, TrustedChannelFeatures};
use lightning::ln::types::ChannelId;
use lightning::routing::gossip::NodeId;
use lightning::sign::EntropySource;
use lightning::util::config::{
	ChannelConfigOverrides, ChannelConfigUpdate, ChannelHandshakeConfigUpdate,
};
use lightning::util::config::{ChannelConfigOverrides, ChannelConfigUpdate};
use lightning::util::errors::APIError;
use lightning::util::persist::KVStore;
use lightning::util::ser::{Readable, ReadableArgs, Writeable, Writer};
Expand DownExpand Up@@ -1273,20 +1271,24 @@ where
 if lsp_node_id == counterparty_node_id {
 // When we're an LSPS2 client, allow claiming underpaying HTLCs as the LSP will skim off some fee. We'll
 // check that they don't take too much before claiming.
 //
 // We also set maximum allowed inbound HTLC value in flight
 // to 100%. We should eventually be able to set this on a per-channel basis, but for
 // now we just bump the default for all channels.
 channel_override_config = Some(ChannelConfigOverrides {
 handshake_overrides: Some(ChannelHandshakeConfigUpdate {
 max_inbound_htlc_value_in_flight_percent_of_channel: Some(100),
 ..Default::default()
 }),
 update_overrides: Some(ChannelConfigUpdate {
 accept_underpaying_htlcs: Some(true),
 ..Default::default()
 }),
 ..Default::default()
@tankyleotankyleoApr 28, 2026

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nit: as elsewhere, maybe a quick debug_assert here on the 100% value ? Up to @tnull
 });

 // LSPS2 channels are unannounced; rely on LDK's default of 100%
 // inbound HTLC value-in-flight so the LSP can forward the initial
 // payment in full.
 debug_assert_eq!(
 self.channel_manager
 .get_current_config()
 .channel_handshake_config
 .unannounced_channel_max_inbound_htlc_value_in_flight_percentage,
 100
 );
 }
 }
 let res = if allow_0conf {
Expand Down

15 changes: 9 additions & 6 deletions
src/lib.rs

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Original file line numberDiff line numberDiff line change
Expand Up@@ -1195,13 +1195,16 @@ impl Node {
 let mut user_config = default_user_config(&self.config);
 user_config.channel_handshake_config.announce_for_forwarding = announce_for_forwarding;
 user_config.channel_config = (channel_config.unwrap_or_default()).clone().into();
 // We set the max inflight to 100% for private channels.
@tankyleotankyleoApr 28, 2026

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nit: similar here, would it be worth adding a debug_assert to guard against any changes away from this behavior ?
 // FIXME: LDK will default to this behavior soon, too, at which point we should drop this
 // manual override.

 // Unannounced channels rely on LDK's default of 100% inbound HTLC value-in-flight
 // to support large initial payments via LSPS2.
 if !announce_for_forwarding {
 user_config
 .channel_handshake_config
 .max_inbound_htlc_value_in_flight_percent_of_channel = 100;
 debug_assert_eq!(
 user_config
 .channel_handshake_config
 .unannounced_channel_max_inbound_htlc_value_in_flight_percentage,
 100
 );
 }

 let push_msat = push_to_counterparty_msat.unwrap_or(0);
Expand Down

7 changes: 5 additions & 2 deletions
src/liquidity.rs

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Original file line numberDiff line numberDiff line change
Expand Up@@ -781,13 +781,16 @@ where

 let mut config = self.channel_manager.get_current_config().clone();

 // We set these LSP-specific values during Node building, here we're making sure it's actually set.
 // If we act as an LSPS2 service, the HTLC-value-in-flight must be 100% of the
 // channel value to ensure we can forward the initial payment. That cap only
 // applies to unannounced channels, so the channel must also be unannounced.
 debug_assert_eq!(
 config
 .channel_handshake_config
 .max_inbound_htlc_value_in_flight_percent_of_channel,
 .unannounced_channel_max_inbound_htlc_value_in_flight_percentage,
 100
 );
 debug_assert!(!config.channel_handshake_config.announce_for_forwarding);
 debug_assert!(config.accept_forwards_to_priv_channels);
@tankyleotankyleoApr 28, 2026

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nit: can we add a debug_assert here on announce_for_forwarding = false ? IIUC right now we inherit announce_for_forwarding = false here because of the default in rust-lightning, but would be good to confirm this here I think.
This is to make sure that the 100% cap actually gets applied to the channel opened by the LSPS2 service.

 // We set the forwarding fee to 0 for now as we're getting paid by the channel fee.
Expand Down
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Drop `max_inbound_htlc_value_in_flight_percent_of_channel ` by jkczyz · Pull Request #878 · lightningdevkit/ldk-node · GitHub
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Drop max_inbound_htlc_value_in_flight_percent_of_channel #878

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Apr 29, 2026
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Drop max_inbound_htlc_value_in_flight_percent_of_channel #878
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28 changes: 14 additions & 14 deletions
Cargo.toml

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Original file line numberDiff line numberDiff line change
Expand Up@@ -40,18 +40,18 @@ default = []
#lightning-macros = { version = "0.2.0" }
#lightning-dns-resolver = { version = "0.3.0" }

lightning = { git = "https://github.com/lightningdevkit/rust-lightning", rev = "044f3fab42e3085edecd40f0c9b369093edb7133", features = ["std"] }
lightning-types = { git = "https://github.com/lightningdevkit/rust-lightning", rev = "044f3fab42e3085edecd40f0c9b369093edb7133" }
lightning-invoice = { git = "https://github.com/lightningdevkit/rust-lightning", rev = "044f3fab42e3085edecd40f0c9b369093edb7133", features = ["std"] }
lightning-net-tokio = { git = "https://github.com/lightningdevkit/rust-lightning", rev = "044f3fab42e3085edecd40f0c9b369093edb7133" }
lightning-persister = { git = "https://github.com/lightningdevkit/rust-lightning", rev = "044f3fab42e3085edecd40f0c9b369093edb7133", features = ["tokio"] }
lightning-background-processor = { git = "https://github.com/lightningdevkit/rust-lightning", rev = "044f3fab42e3085edecd40f0c9b369093edb7133" }
lightning-rapid-gossip-sync = { git = "https://github.com/lightningdevkit/rust-lightning", rev = "044f3fab42e3085edecd40f0c9b369093edb7133" }
lightning-block-sync = { git = "https://github.com/lightningdevkit/rust-lightning", rev = "044f3fab42e3085edecd40f0c9b369093edb7133", features = ["rest-client", "rpc-client", "tokio"] }
lightning-transaction-sync = { git = "https://github.com/lightningdevkit/rust-lightning", rev = "044f3fab42e3085edecd40f0c9b369093edb7133", features = ["esplora-async-https", "time", "electrum-rustls-ring"] }
lightning-liquidity = { git = "https://github.com/lightningdevkit/rust-lightning", rev = "044f3fab42e3085edecd40f0c9b369093edb7133", features = ["std"] }
lightning-macros = { git = "https://github.com/lightningdevkit/rust-lightning", rev = "044f3fab42e3085edecd40f0c9b369093edb7133" }
lightning-dns-resolver = { git = "https://github.com/lightningdevkit/rust-lightning", rev = "044f3fab42e3085edecd40f0c9b369093edb7133" }
lightning = { git = "https://github.com/lightningdevkit/rust-lightning", rev = "369a2cf9c8ef810deea0cd2b4cf6ed0691b78144", features = ["std"] }
lightning-types = { git = "https://github.com/lightningdevkit/rust-lightning", rev = "369a2cf9c8ef810deea0cd2b4cf6ed0691b78144" }
lightning-invoice = { git = "https://github.com/lightningdevkit/rust-lightning", rev = "369a2cf9c8ef810deea0cd2b4cf6ed0691b78144", features = ["std"] }
lightning-net-tokio = { git = "https://github.com/lightningdevkit/rust-lightning", rev = "369a2cf9c8ef810deea0cd2b4cf6ed0691b78144" }
lightning-persister = { git = "https://github.com/lightningdevkit/rust-lightning", rev = "369a2cf9c8ef810deea0cd2b4cf6ed0691b78144", features = ["tokio"] }
lightning-background-processor = { git = "https://github.com/lightningdevkit/rust-lightning", rev = "369a2cf9c8ef810deea0cd2b4cf6ed0691b78144" }
lightning-rapid-gossip-sync = { git = "https://github.com/lightningdevkit/rust-lightning", rev = "369a2cf9c8ef810deea0cd2b4cf6ed0691b78144" }
lightning-block-sync = { git = "https://github.com/lightningdevkit/rust-lightning", rev = "369a2cf9c8ef810deea0cd2b4cf6ed0691b78144", features = ["rest-client", "rpc-client", "tokio"] }
lightning-transaction-sync = { git = "https://github.com/lightningdevkit/rust-lightning", rev = "369a2cf9c8ef810deea0cd2b4cf6ed0691b78144", features = ["esplora-async-https", "time", "electrum-rustls-ring"] }
lightning-liquidity = { git = "https://github.com/lightningdevkit/rust-lightning", rev = "369a2cf9c8ef810deea0cd2b4cf6ed0691b78144", features = ["std"] }
lightning-macros = { git = "https://github.com/lightningdevkit/rust-lightning", rev = "369a2cf9c8ef810deea0cd2b4cf6ed0691b78144" }
lightning-dns-resolver = { git = "https://github.com/lightningdevkit/rust-lightning", rev = "369a2cf9c8ef810deea0cd2b4cf6ed0691b78144" }

bdk_chain = { version = "0.23.0", default-features = false, features = ["std"] }
bdk_esplora = { version = "0.22.0", default-features = false, features = ["async-https-rustls", "tokio"]}
Expand DownExpand Up@@ -81,13 +81,13 @@ async-trait = { version = "0.1", default-features = false }
vss-client = { package = "vss-client-ng", version = "0.5" }
prost = { version = "0.11.6", default-features = false}
#bitcoin-payment-instructions = { version = "0.6" }
bitcoin-payment-instructions = { git = "https://github.com/jkczyz/bitcoin-payment-instructions", rev = "340c535a600f7c43bef4c9f910edac4085f2e70c" }
bitcoin-payment-instructions = { git = "https://github.com/jkczyz/bitcoin-payment-instructions", rev = "679dac50cc0d81ec4d31da94b93d467e5308f16a" }

[target.'cfg(windows)'.dependencies]
winapi = { version = "0.3", features = ["winbase"] }

[dev-dependencies]
lightning = { git = "https://github.com/lightningdevkit/rust-lightning", rev = "044f3fab42e3085edecd40f0c9b369093edb7133", features = ["std", "_test_utils"] }
lightning = { git = "https://github.com/lightningdevkit/rust-lightning", rev = "369a2cf9c8ef810deea0cd2b4cf6ed0691b78144", features = ["std", "_test_utils"] }
rand = { version = "0.9.2", default-features = false, features = ["std", "thread_rng", "os_rng"] }
proptest = "1.0.0"
regex = "1.5.6"
Expand Down

5 changes: 0 additions & 5 deletions
src/builder.rs

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Original file line numberDiff line numberDiff line change
Expand Up@@ -1657,11 +1657,6 @@ fn build_with_store_internal(

 // If we act as an LSPS2 service, we allow forwarding to unannounced channels.
 user_config.accept_forwards_to_priv_channels = true;

 // If we act as an LSPS2 service, set the HTLC-value-in-flight to 100% of the channel value
 // to ensure we can forward the initial payment.
 user_config.channel_handshake_config.max_inbound_htlc_value_in_flight_percent_of_channel =
 100;

Comment on lines

-1670
 to 
-1673

@tankyleotankyleoApr 28, 2026

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To confirm here I don't think setting 100% here would have helped as that maximum only applies to the inbound HTLCs on that channel. To make sure that 100% of the value can be allocated to outbound HTLCs from the LSP's perspective as the comment describes, the user needs to set their max_inbound to 100%.
So seems to me the intention of the code did not match the comment ?
@jkczyzjkczyzApr 28, 2026

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Hmm... yeah it does seem that way.
	}

	if let Some(role) = async_payments_role {
Expand Down

24 changes: 13 additions & 11 deletions
src/event.rs

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Original file line numberDiff line numberDiff line change
Expand Up@@ -26,9 +26,7 @@ use lightning::ln::channelmanager::{PaymentId, TrustedChannelFeatures};
use lightning::ln::types::ChannelId;
use lightning::routing::gossip::NodeId;
use lightning::sign::EntropySource;
use lightning::util::config::{
	ChannelConfigOverrides, ChannelConfigUpdate, ChannelHandshakeConfigUpdate,
};
use lightning::util::config::{ChannelConfigOverrides, ChannelConfigUpdate};
use lightning::util::errors::APIError;
use lightning::util::persist::KVStore;
use lightning::util::ser::{Readable, ReadableArgs, Writeable, Writer};
Expand DownExpand Up@@ -1273,20 +1271,24 @@ where
 if lsp_node_id == counterparty_node_id {
 // When we're an LSPS2 client, allow claiming underpaying HTLCs as the LSP will skim off some fee. We'll
 // check that they don't take too much before claiming.
 //
 // We also set maximum allowed inbound HTLC value in flight
 // to 100%. We should eventually be able to set this on a per-channel basis, but for
 // now we just bump the default for all channels.
 channel_override_config = Some(ChannelConfigOverrides {
 handshake_overrides: Some(ChannelHandshakeConfigUpdate {
 max_inbound_htlc_value_in_flight_percent_of_channel: Some(100),
 ..Default::default()
 }),
 update_overrides: Some(ChannelConfigUpdate {
 accept_underpaying_htlcs: Some(true),
 ..Default::default()
 }),
 ..Default::default()
@tankyleotankyleoApr 28, 2026

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nit: as elsewhere, maybe a quick debug_assert here on the 100% value ? Up to @tnull
 });

 // LSPS2 channels are unannounced; rely on LDK's default of 100%
 // inbound HTLC value-in-flight so the LSP can forward the initial
 // payment in full.
 debug_assert_eq!(
 self.channel_manager
 .get_current_config()
 .channel_handshake_config
 .unannounced_channel_max_inbound_htlc_value_in_flight_percentage,
 100
 );
 }
 }
 let res = if allow_0conf {
Expand Down

15 changes: 9 additions & 6 deletions
src/lib.rs

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Original file line numberDiff line numberDiff line change
Expand Up@@ -1195,13 +1195,16 @@ impl Node {
 let mut user_config = default_user_config(&self.config);
 user_config.channel_handshake_config.announce_for_forwarding = announce_for_forwarding;
 user_config.channel_config = (channel_config.unwrap_or_default()).clone().into();
 // We set the max inflight to 100% for private channels.
@tankyleotankyleoApr 28, 2026

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nit: similar here, would it be worth adding a debug_assert to guard against any changes away from this behavior ?
 // FIXME: LDK will default to this behavior soon, too, at which point we should drop this
 // manual override.

 // Unannounced channels rely on LDK's default of 100% inbound HTLC value-in-flight
 // to support large initial payments via LSPS2.
 if !announce_for_forwarding {
 user_config
 .channel_handshake_config
 .max_inbound_htlc_value_in_flight_percent_of_channel = 100;
 debug_assert_eq!(
 user_config
 .channel_handshake_config
 .unannounced_channel_max_inbound_htlc_value_in_flight_percentage,
 100
 );
 }

 let push_msat = push_to_counterparty_msat.unwrap_or(0);
Expand Down

7 changes: 5 additions & 2 deletions
src/liquidity.rs

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Original file line numberDiff line numberDiff line change
Expand Up@@ -781,13 +781,16 @@ where

 let mut config = self.channel_manager.get_current_config().clone();

 // We set these LSP-specific values during Node building, here we're making sure it's actually set.
 // If we act as an LSPS2 service, the HTLC-value-in-flight must be 100% of the
 // channel value to ensure we can forward the initial payment. That cap only
 // applies to unannounced channels, so the channel must also be unannounced.
 debug_assert_eq!(
 config
 .channel_handshake_config
 .max_inbound_htlc_value_in_flight_percent_of_channel,
 .unannounced_channel_max_inbound_htlc_value_in_flight_percentage,
 100
 );
 debug_assert!(!config.channel_handshake_config.announce_for_forwarding);
 debug_assert!(config.accept_forwards_to_priv_channels);
@tankyleotankyleoApr 28, 2026

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nit: can we add a debug_assert here on announce_for_forwarding = false ? IIUC right now we inherit announce_for_forwarding = false here because of the default in rust-lightning, but would be good to confirm this here I think.
This is to make sure that the 100% cap actually gets applied to the channel opened by the LSPS2 service.

 // We set the forwarding fee to 0 for now as we're getting paid by the channel fee.
Expand Down
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Drop `max_inbound_htlc_value_in_flight_percent_of_channel ` by jkczyz · Pull Request #878 · lightningdevkit/ldk-node · GitHub
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Drop max_inbound_htlc_value_in_flight_percent_of_channel #878

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 Merged

tnull
merged 1 commit into

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Apr 29, 2026
 Merged


Drop max_inbound_htlc_value_in_flight_percent_of_channel #878
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28 changes: 14 additions & 14 deletions
Cargo.toml

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Original file line numberDiff line numberDiff line change
Expand Up@@ -40,18 +40,18 @@ default = []
#lightning-macros = { version = "0.2.0" }
#lightning-dns-resolver = { version = "0.3.0" }

lightning = { git = "https://github.com/lightningdevkit/rust-lightning", rev = "044f3fab42e3085edecd40f0c9b369093edb7133", features = ["std"] }
lightning-types = { git = "https://github.com/lightningdevkit/rust-lightning", rev = "044f3fab42e3085edecd40f0c9b369093edb7133" }
lightning-invoice = { git = "https://github.com/lightningdevkit/rust-lightning", rev = "044f3fab42e3085edecd40f0c9b369093edb7133", features = ["std"] }
lightning-net-tokio = { git = "https://github.com/lightningdevkit/rust-lightning", rev = "044f3fab42e3085edecd40f0c9b369093edb7133" }
lightning-persister = { git = "https://github.com/lightningdevkit/rust-lightning", rev = "044f3fab42e3085edecd40f0c9b369093edb7133", features = ["tokio"] }
lightning-background-processor = { git = "https://github.com/lightningdevkit/rust-lightning", rev = "044f3fab42e3085edecd40f0c9b369093edb7133" }
lightning-rapid-gossip-sync = { git = "https://github.com/lightningdevkit/rust-lightning", rev = "044f3fab42e3085edecd40f0c9b369093edb7133" }
lightning-block-sync = { git = "https://github.com/lightningdevkit/rust-lightning", rev = "044f3fab42e3085edecd40f0c9b369093edb7133", features = ["rest-client", "rpc-client", "tokio"] }
lightning-transaction-sync = { git = "https://github.com/lightningdevkit/rust-lightning", rev = "044f3fab42e3085edecd40f0c9b369093edb7133", features = ["esplora-async-https", "time", "electrum-rustls-ring"] }
lightning-liquidity = { git = "https://github.com/lightningdevkit/rust-lightning", rev = "044f3fab42e3085edecd40f0c9b369093edb7133", features = ["std"] }
lightning-macros = { git = "https://github.com/lightningdevkit/rust-lightning", rev = "044f3fab42e3085edecd40f0c9b369093edb7133" }
lightning-dns-resolver = { git = "https://github.com/lightningdevkit/rust-lightning", rev = "044f3fab42e3085edecd40f0c9b369093edb7133" }
lightning = { git = "https://github.com/lightningdevkit/rust-lightning", rev = "369a2cf9c8ef810deea0cd2b4cf6ed0691b78144", features = ["std"] }
lightning-types = { git = "https://github.com/lightningdevkit/rust-lightning", rev = "369a2cf9c8ef810deea0cd2b4cf6ed0691b78144" }
lightning-invoice = { git = "https://github.com/lightningdevkit/rust-lightning", rev = "369a2cf9c8ef810deea0cd2b4cf6ed0691b78144", features = ["std"] }
lightning-net-tokio = { git = "https://github.com/lightningdevkit/rust-lightning", rev = "369a2cf9c8ef810deea0cd2b4cf6ed0691b78144" }
lightning-persister = { git = "https://github.com/lightningdevkit/rust-lightning", rev = "369a2cf9c8ef810deea0cd2b4cf6ed0691b78144", features = ["tokio"] }
lightning-background-processor = { git = "https://github.com/lightningdevkit/rust-lightning", rev = "369a2cf9c8ef810deea0cd2b4cf6ed0691b78144" }
lightning-rapid-gossip-sync = { git = "https://github.com/lightningdevkit/rust-lightning", rev = "369a2cf9c8ef810deea0cd2b4cf6ed0691b78144" }
lightning-block-sync = { git = "https://github.com/lightningdevkit/rust-lightning", rev = "369a2cf9c8ef810deea0cd2b4cf6ed0691b78144", features = ["rest-client", "rpc-client", "tokio"] }
lightning-transaction-sync = { git = "https://github.com/lightningdevkit/rust-lightning", rev = "369a2cf9c8ef810deea0cd2b4cf6ed0691b78144", features = ["esplora-async-https", "time", "electrum-rustls-ring"] }
lightning-liquidity = { git = "https://github.com/lightningdevkit/rust-lightning", rev = "369a2cf9c8ef810deea0cd2b4cf6ed0691b78144", features = ["std"] }
lightning-macros = { git = "https://github.com/lightningdevkit/rust-lightning", rev = "369a2cf9c8ef810deea0cd2b4cf6ed0691b78144" }
lightning-dns-resolver = { git = "https://github.com/lightningdevkit/rust-lightning", rev = "369a2cf9c8ef810deea0cd2b4cf6ed0691b78144" }

bdk_chain = { version = "0.23.0", default-features = false, features = ["std"] }
bdk_esplora = { version = "0.22.0", default-features = false, features = ["async-https-rustls", "tokio"]}
Expand DownExpand Up@@ -81,13 +81,13 @@ async-trait = { version = "0.1", default-features = false }
vss-client = { package = "vss-client-ng", version = "0.5" }
prost = { version = "0.11.6", default-features = false}
#bitcoin-payment-instructions = { version = "0.6" }
bitcoin-payment-instructions = { git = "https://github.com/jkczyz/bitcoin-payment-instructions", rev = "340c535a600f7c43bef4c9f910edac4085f2e70c" }
bitcoin-payment-instructions = { git = "https://github.com/jkczyz/bitcoin-payment-instructions", rev = "679dac50cc0d81ec4d31da94b93d467e5308f16a" }

[target.'cfg(windows)'.dependencies]
winapi = { version = "0.3", features = ["winbase"] }

[dev-dependencies]
lightning = { git = "https://github.com/lightningdevkit/rust-lightning", rev = "044f3fab42e3085edecd40f0c9b369093edb7133", features = ["std", "_test_utils"] }
lightning = { git = "https://github.com/lightningdevkit/rust-lightning", rev = "369a2cf9c8ef810deea0cd2b4cf6ed0691b78144", features = ["std", "_test_utils"] }
rand = { version = "0.9.2", default-features = false, features = ["std", "thread_rng", "os_rng"] }
proptest = "1.0.0"
regex = "1.5.6"
Expand Down

5 changes: 0 additions & 5 deletions
src/builder.rs

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Original file line numberDiff line numberDiff line change
Expand Up@@ -1657,11 +1657,6 @@ fn build_with_store_internal(

 // If we act as an LSPS2 service, we allow forwarding to unannounced channels.
 user_config.accept_forwards_to_priv_channels = true;

 // If we act as an LSPS2 service, set the HTLC-value-in-flight to 100% of the channel value
 // to ensure we can forward the initial payment.
 user_config.channel_handshake_config.max_inbound_htlc_value_in_flight_percent_of_channel =
 100;

Comment on lines

-1670
 to 
-1673

@tankyleotankyleoApr 28, 2026

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To confirm here I don't think setting 100% here would have helped as that maximum only applies to the inbound HTLCs on that channel. To make sure that 100% of the value can be allocated to outbound HTLCs from the LSP's perspective as the comment describes, the user needs to set their max_inbound to 100%.
So seems to me the intention of the code did not match the comment ?
@jkczyzjkczyzApr 28, 2026

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Hmm... yeah it does seem that way.
	}

	if let Some(role) = async_payments_role {
Expand Down

24 changes: 13 additions & 11 deletions
src/event.rs

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Original file line numberDiff line numberDiff line change
Expand Up@@ -26,9 +26,7 @@ use lightning::ln::channelmanager::{PaymentId, TrustedChannelFeatures};
use lightning::ln::types::ChannelId;
use lightning::routing::gossip::NodeId;
use lightning::sign::EntropySource;
use lightning::util::config::{
	ChannelConfigOverrides, ChannelConfigUpdate, ChannelHandshakeConfigUpdate,
};
use lightning::util::config::{ChannelConfigOverrides, ChannelConfigUpdate};
use lightning::util::errors::APIError;
use lightning::util::persist::KVStore;
use lightning::util::ser::{Readable, ReadableArgs, Writeable, Writer};
Expand DownExpand Up@@ -1273,20 +1271,24 @@ where
 if lsp_node_id == counterparty_node_id {
 // When we're an LSPS2 client, allow claiming underpaying HTLCs as the LSP will skim off some fee. We'll
 // check that they don't take too much before claiming.
 //
 // We also set maximum allowed inbound HTLC value in flight
 // to 100%. We should eventually be able to set this on a per-channel basis, but for
 // now we just bump the default for all channels.
 channel_override_config = Some(ChannelConfigOverrides {
 handshake_overrides: Some(ChannelHandshakeConfigUpdate {
 max_inbound_htlc_value_in_flight_percent_of_channel: Some(100),
 ..Default::default()
 }),
 update_overrides: Some(ChannelConfigUpdate {
 accept_underpaying_htlcs: Some(true),
 ..Default::default()
 }),
 ..Default::default()
@tankyleotankyleoApr 28, 2026

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nit: as elsewhere, maybe a quick debug_assert here on the 100% value ? Up to @tnull
 });

 // LSPS2 channels are unannounced; rely on LDK's default of 100%
 // inbound HTLC value-in-flight so the LSP can forward the initial
 // payment in full.
 debug_assert_eq!(
 self.channel_manager
 .get_current_config()
 .channel_handshake_config
 .unannounced_channel_max_inbound_htlc_value_in_flight_percentage,
 100
 );
 }
 }
 let res = if allow_0conf {
Expand Down

15 changes: 9 additions & 6 deletions
src/lib.rs

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Original file line numberDiff line numberDiff line change
Expand Up@@ -1195,13 +1195,16 @@ impl Node {
 let mut user_config = default_user_config(&self.config);
 user_config.channel_handshake_config.announce_for_forwarding = announce_for_forwarding;
 user_config.channel_config = (channel_config.unwrap_or_default()).clone().into();
 // We set the max inflight to 100% for private channels.
@tankyleotankyleoApr 28, 2026

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nit: similar here, would it be worth adding a debug_assert to guard against any changes away from this behavior ?
 // FIXME: LDK will default to this behavior soon, too, at which point we should drop this
 // manual override.

 // Unannounced channels rely on LDK's default of 100% inbound HTLC value-in-flight
 // to support large initial payments via LSPS2.
 if !announce_for_forwarding {
 user_config
 .channel_handshake_config
 .max_inbound_htlc_value_in_flight_percent_of_channel = 100;
 debug_assert_eq!(
 user_config
 .channel_handshake_config
 .unannounced_channel_max_inbound_htlc_value_in_flight_percentage,
 100
 );
 }

 let push_msat = push_to_counterparty_msat.unwrap_or(0);
Expand Down

7 changes: 5 additions & 2 deletions
src/liquidity.rs

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Original file line numberDiff line numberDiff line change
Expand Up@@ -781,13 +781,16 @@ where

 let mut config = self.channel_manager.get_current_config().clone();

 // We set these LSP-specific values during Node building, here we're making sure it's actually set.
 // If we act as an LSPS2 service, the HTLC-value-in-flight must be 100% of the
 // channel value to ensure we can forward the initial payment. That cap only
 // applies to unannounced channels, so the channel must also be unannounced.
 debug_assert_eq!(
 config
 .channel_handshake_config
 .max_inbound_htlc_value_in_flight_percent_of_channel,
 .unannounced_channel_max_inbound_htlc_value_in_flight_percentage,
 100
 );
 debug_assert!(!config.channel_handshake_config.announce_for_forwarding);
 debug_assert!(config.accept_forwards_to_priv_channels);
@tankyleotankyleoApr 28, 2026

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nit: can we add a debug_assert here on announce_for_forwarding = false ? IIUC right now we inherit announce_for_forwarding = false here because of the default in rust-lightning, but would be good to confirm this here I think.
This is to make sure that the 100% cap actually gets applied to the channel opened by the LSPS2 service.

 // We set the forwarding fee to 0 for now as we're getting paid by the channel fee.
Expand Down
Loading

, 'i');
if (__m === '*' || __re.test(location.href)) {
// Strip utm_, fbclid, gclid, etc. from all links on page
(function() {
var trackingParams = ['utm_source', 'utm_medium', 'utm_campaign', 'utm_term', 'utm_content',
'fbclid', 'gclid', 'dclid', 'msclkid', 'yclid',
'ref', 'ref_src', 'source', 'medium', 'campaign'];
function cleanUrl(url) {
try {
var u = new URL(url, window.location.origin);
var changed = false;
trackingParams.forEach(function(p) {
if (u.searchParams.has(p)) {
u.searchParams.delete(p);
changed = true;
}
});
return changed ? u.toString() : url;
} catch (e) {
return url;
}
}
function cleanLinks() {
document.querySelectorAll('a[href]').forEach(function(a) {
var clean = cleanUrl(a.href);
if (clean !== a.href) a.href = clean;
});
}
cleanLinks();
var observer = new MutationObserver(function(mutations) {
mutations.forEach(function(m) {
m.addedNodes.forEach(function(node) {
if (node.nodeType === 1) {
if (node.tagName === 'A') cleanLinks();
node.querySelectorAll('a[href]').forEach(function(a) {
var clean = cleanUrl(a.href);
if (clean !== a.href) a.href = clean;
});
}
});
});
});
observer.observe(document.body, { childList: true, subtree: true });
})();
}
} catch(__e) { console.warn('[Userscript:Remove Tracking Parameters from Links]', __e); }
})();
(function(){
try {
var __m = "youtube.com";
var __re = new RegExp('^' + "youtube\\.com" + '
Drop `max_inbound_htlc_value_in_flight_percent_of_channel ` by jkczyz · Pull Request #878 · lightningdevkit/ldk-node · GitHub
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Drop max_inbound_htlc_value_in_flight_percent_of_channel #878

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 Merged

tnull
merged 1 commit into

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Apr 29, 2026
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Drop max_inbound_htlc_value_in_flight_percent_of_channel #878
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28 changes: 14 additions & 14 deletions
Cargo.toml

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Original file line numberDiff line numberDiff line change
Expand Up@@ -40,18 +40,18 @@ default = []
#lightning-macros = { version = "0.2.0" }
#lightning-dns-resolver = { version = "0.3.0" }

lightning = { git = "https://github.com/lightningdevkit/rust-lightning", rev = "044f3fab42e3085edecd40f0c9b369093edb7133", features = ["std"] }
lightning-types = { git = "https://github.com/lightningdevkit/rust-lightning", rev = "044f3fab42e3085edecd40f0c9b369093edb7133" }
lightning-invoice = { git = "https://github.com/lightningdevkit/rust-lightning", rev = "044f3fab42e3085edecd40f0c9b369093edb7133", features = ["std"] }
lightning-net-tokio = { git = "https://github.com/lightningdevkit/rust-lightning", rev = "044f3fab42e3085edecd40f0c9b369093edb7133" }
lightning-persister = { git = "https://github.com/lightningdevkit/rust-lightning", rev = "044f3fab42e3085edecd40f0c9b369093edb7133", features = ["tokio"] }
lightning-background-processor = { git = "https://github.com/lightningdevkit/rust-lightning", rev = "044f3fab42e3085edecd40f0c9b369093edb7133" }
lightning-rapid-gossip-sync = { git = "https://github.com/lightningdevkit/rust-lightning", rev = "044f3fab42e3085edecd40f0c9b369093edb7133" }
lightning-block-sync = { git = "https://github.com/lightningdevkit/rust-lightning", rev = "044f3fab42e3085edecd40f0c9b369093edb7133", features = ["rest-client", "rpc-client", "tokio"] }
lightning-transaction-sync = { git = "https://github.com/lightningdevkit/rust-lightning", rev = "044f3fab42e3085edecd40f0c9b369093edb7133", features = ["esplora-async-https", "time", "electrum-rustls-ring"] }
lightning-liquidity = { git = "https://github.com/lightningdevkit/rust-lightning", rev = "044f3fab42e3085edecd40f0c9b369093edb7133", features = ["std"] }
lightning-macros = { git = "https://github.com/lightningdevkit/rust-lightning", rev = "044f3fab42e3085edecd40f0c9b369093edb7133" }
lightning-dns-resolver = { git = "https://github.com/lightningdevkit/rust-lightning", rev = "044f3fab42e3085edecd40f0c9b369093edb7133" }
lightning = { git = "https://github.com/lightningdevkit/rust-lightning", rev = "369a2cf9c8ef810deea0cd2b4cf6ed0691b78144", features = ["std"] }
lightning-types = { git = "https://github.com/lightningdevkit/rust-lightning", rev = "369a2cf9c8ef810deea0cd2b4cf6ed0691b78144" }
lightning-invoice = { git = "https://github.com/lightningdevkit/rust-lightning", rev = "369a2cf9c8ef810deea0cd2b4cf6ed0691b78144", features = ["std"] }
lightning-net-tokio = { git = "https://github.com/lightningdevkit/rust-lightning", rev = "369a2cf9c8ef810deea0cd2b4cf6ed0691b78144" }
lightning-persister = { git = "https://github.com/lightningdevkit/rust-lightning", rev = "369a2cf9c8ef810deea0cd2b4cf6ed0691b78144", features = ["tokio"] }
lightning-background-processor = { git = "https://github.com/lightningdevkit/rust-lightning", rev = "369a2cf9c8ef810deea0cd2b4cf6ed0691b78144" }
lightning-rapid-gossip-sync = { git = "https://github.com/lightningdevkit/rust-lightning", rev = "369a2cf9c8ef810deea0cd2b4cf6ed0691b78144" }
lightning-block-sync = { git = "https://github.com/lightningdevkit/rust-lightning", rev = "369a2cf9c8ef810deea0cd2b4cf6ed0691b78144", features = ["rest-client", "rpc-client", "tokio"] }
lightning-transaction-sync = { git = "https://github.com/lightningdevkit/rust-lightning", rev = "369a2cf9c8ef810deea0cd2b4cf6ed0691b78144", features = ["esplora-async-https", "time", "electrum-rustls-ring"] }
lightning-liquidity = { git = "https://github.com/lightningdevkit/rust-lightning", rev = "369a2cf9c8ef810deea0cd2b4cf6ed0691b78144", features = ["std"] }
lightning-macros = { git = "https://github.com/lightningdevkit/rust-lightning", rev = "369a2cf9c8ef810deea0cd2b4cf6ed0691b78144" }
lightning-dns-resolver = { git = "https://github.com/lightningdevkit/rust-lightning", rev = "369a2cf9c8ef810deea0cd2b4cf6ed0691b78144" }

bdk_chain = { version = "0.23.0", default-features = false, features = ["std"] }
bdk_esplora = { version = "0.22.0", default-features = false, features = ["async-https-rustls", "tokio"]}
Expand DownExpand Up@@ -81,13 +81,13 @@ async-trait = { version = "0.1", default-features = false }
vss-client = { package = "vss-client-ng", version = "0.5" }
prost = { version = "0.11.6", default-features = false}
#bitcoin-payment-instructions = { version = "0.6" }
bitcoin-payment-instructions = { git = "https://github.com/jkczyz/bitcoin-payment-instructions", rev = "340c535a600f7c43bef4c9f910edac4085f2e70c" }
bitcoin-payment-instructions = { git = "https://github.com/jkczyz/bitcoin-payment-instructions", rev = "679dac50cc0d81ec4d31da94b93d467e5308f16a" }

[target.'cfg(windows)'.dependencies]
winapi = { version = "0.3", features = ["winbase"] }

[dev-dependencies]
lightning = { git = "https://github.com/lightningdevkit/rust-lightning", rev = "044f3fab42e3085edecd40f0c9b369093edb7133", features = ["std", "_test_utils"] }
lightning = { git = "https://github.com/lightningdevkit/rust-lightning", rev = "369a2cf9c8ef810deea0cd2b4cf6ed0691b78144", features = ["std", "_test_utils"] }
rand = { version = "0.9.2", default-features = false, features = ["std", "thread_rng", "os_rng"] }
proptest = "1.0.0"
regex = "1.5.6"
Expand Down

5 changes: 0 additions & 5 deletions
src/builder.rs

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Original file line numberDiff line numberDiff line change
Expand Up@@ -1657,11 +1657,6 @@ fn build_with_store_internal(

 // If we act as an LSPS2 service, we allow forwarding to unannounced channels.
 user_config.accept_forwards_to_priv_channels = true;

 // If we act as an LSPS2 service, set the HTLC-value-in-flight to 100% of the channel value
 // to ensure we can forward the initial payment.
 user_config.channel_handshake_config.max_inbound_htlc_value_in_flight_percent_of_channel =
 100;

Comment on lines

-1670
 to 
-1673

@tankyleotankyleoApr 28, 2026

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To confirm here I don't think setting 100% here would have helped as that maximum only applies to the inbound HTLCs on that channel. To make sure that 100% of the value can be allocated to outbound HTLCs from the LSP's perspective as the comment describes, the user needs to set their max_inbound to 100%.
So seems to me the intention of the code did not match the comment ?
@jkczyzjkczyzApr 28, 2026

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Hmm... yeah it does seem that way.
	}

	if let Some(role) = async_payments_role {
Expand Down

24 changes: 13 additions & 11 deletions
src/event.rs

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Original file line numberDiff line numberDiff line change
Expand Up@@ -26,9 +26,7 @@ use lightning::ln::channelmanager::{PaymentId, TrustedChannelFeatures};
use lightning::ln::types::ChannelId;
use lightning::routing::gossip::NodeId;
use lightning::sign::EntropySource;
use lightning::util::config::{
	ChannelConfigOverrides, ChannelConfigUpdate, ChannelHandshakeConfigUpdate,
};
use lightning::util::config::{ChannelConfigOverrides, ChannelConfigUpdate};
use lightning::util::errors::APIError;
use lightning::util::persist::KVStore;
use lightning::util::ser::{Readable, ReadableArgs, Writeable, Writer};
Expand DownExpand Up@@ -1273,20 +1271,24 @@ where
 if lsp_node_id == counterparty_node_id {
 // When we're an LSPS2 client, allow claiming underpaying HTLCs as the LSP will skim off some fee. We'll
 // check that they don't take too much before claiming.
 //
 // We also set maximum allowed inbound HTLC value in flight
 // to 100%. We should eventually be able to set this on a per-channel basis, but for
 // now we just bump the default for all channels.
 channel_override_config = Some(ChannelConfigOverrides {
 handshake_overrides: Some(ChannelHandshakeConfigUpdate {
 max_inbound_htlc_value_in_flight_percent_of_channel: Some(100),
 ..Default::default()
 }),
 update_overrides: Some(ChannelConfigUpdate {
 accept_underpaying_htlcs: Some(true),
 ..Default::default()
 }),
 ..Default::default()
@tankyleotankyleoApr 28, 2026

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nit: as elsewhere, maybe a quick debug_assert here on the 100% value ? Up to @tnull
 });

 // LSPS2 channels are unannounced; rely on LDK's default of 100%
 // inbound HTLC value-in-flight so the LSP can forward the initial
 // payment in full.
 debug_assert_eq!(
 self.channel_manager
 .get_current_config()
 .channel_handshake_config
 .unannounced_channel_max_inbound_htlc_value_in_flight_percentage,
 100
 );
 }
 }
 let res = if allow_0conf {
Expand Down

15 changes: 9 additions & 6 deletions
src/lib.rs

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Original file line numberDiff line numberDiff line change
Expand Up@@ -1195,13 +1195,16 @@ impl Node {
 let mut user_config = default_user_config(&self.config);
 user_config.channel_handshake_config.announce_for_forwarding = announce_for_forwarding;
 user_config.channel_config = (channel_config.unwrap_or_default()).clone().into();
 // We set the max inflight to 100% for private channels.
@tankyleotankyleoApr 28, 2026

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nit: similar here, would it be worth adding a debug_assert to guard against any changes away from this behavior ?
 // FIXME: LDK will default to this behavior soon, too, at which point we should drop this
 // manual override.

 // Unannounced channels rely on LDK's default of 100% inbound HTLC value-in-flight
 // to support large initial payments via LSPS2.
 if !announce_for_forwarding {
 user_config
 .channel_handshake_config
 .max_inbound_htlc_value_in_flight_percent_of_channel = 100;
 debug_assert_eq!(
 user_config
 .channel_handshake_config
 .unannounced_channel_max_inbound_htlc_value_in_flight_percentage,
 100
 );
 }

 let push_msat = push_to_counterparty_msat.unwrap_or(0);
Expand Down

7 changes: 5 additions & 2 deletions
src/liquidity.rs

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Original file line numberDiff line numberDiff line change
Expand Up@@ -781,13 +781,16 @@ where

 let mut config = self.channel_manager.get_current_config().clone();

 // We set these LSP-specific values during Node building, here we're making sure it's actually set.
 // If we act as an LSPS2 service, the HTLC-value-in-flight must be 100% of the
 // channel value to ensure we can forward the initial payment. That cap only
 // applies to unannounced channels, so the channel must also be unannounced.
 debug_assert_eq!(
 config
 .channel_handshake_config
 .max_inbound_htlc_value_in_flight_percent_of_channel,
 .unannounced_channel_max_inbound_htlc_value_in_flight_percentage,
 100
 );
 debug_assert!(!config.channel_handshake_config.announce_for_forwarding);
 debug_assert!(config.accept_forwards_to_priv_channels);
@tankyleotankyleoApr 28, 2026

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nit: can we add a debug_assert here on announce_for_forwarding = false ? IIUC right now we inherit announce_for_forwarding = false here because of the default in rust-lightning, but would be good to confirm this here I think.
This is to make sure that the 100% cap actually gets applied to the channel opened by the LSPS2 service.

 // We set the forwarding fee to 0 for now as we're getting paid by the channel fee.
Expand Down
Loading

, 'i');
if (__m === '*' || __re.test(location.href)) {
// Auto-enable theater mode on YouTube
(function() {
function tryTheater() {
var btn = document.querySelector('button[aria-label="Theater mode"], ytd-player #player button[title="Theater mode"]');
if (btn && !btn.classList.contains('activated')) {
btn.click();
}
}
// Try immediately
tryTheater();
// Try after navigation (SPA)
var lastUrl = location.href;
setInterval(function() {
if (location.href !== lastUrl) {
lastUrl = location.href;
setTimeout(tryTheater, 500);
}
}, 1000);
// Also try on player load
var observer = new MutationObserver(tryTheater);
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var __re = new RegExp('^' + ".*" + '
Drop `max_inbound_htlc_value_in_flight_percent_of_channel ` by jkczyz · Pull Request #878 · lightningdevkit/ldk-node · GitHub
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Drop max_inbound_htlc_value_in_flight_percent_of_channel #878

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tnull
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Apr 29, 2026
 Merged


Drop max_inbound_htlc_value_in_flight_percent_of_channel #878
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28 changes: 14 additions & 14 deletions
Cargo.toml

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Original file line numberDiff line numberDiff line change
Expand Up@@ -40,18 +40,18 @@ default = []
#lightning-macros = { version = "0.2.0" }
#lightning-dns-resolver = { version = "0.3.0" }

lightning = { git = "https://github.com/lightningdevkit/rust-lightning", rev = "044f3fab42e3085edecd40f0c9b369093edb7133", features = ["std"] }
lightning-types = { git = "https://github.com/lightningdevkit/rust-lightning", rev = "044f3fab42e3085edecd40f0c9b369093edb7133" }
lightning-invoice = { git = "https://github.com/lightningdevkit/rust-lightning", rev = "044f3fab42e3085edecd40f0c9b369093edb7133", features = ["std"] }
lightning-net-tokio = { git = "https://github.com/lightningdevkit/rust-lightning", rev = "044f3fab42e3085edecd40f0c9b369093edb7133" }
lightning-persister = { git = "https://github.com/lightningdevkit/rust-lightning", rev = "044f3fab42e3085edecd40f0c9b369093edb7133", features = ["tokio"] }
lightning-background-processor = { git = "https://github.com/lightningdevkit/rust-lightning", rev = "044f3fab42e3085edecd40f0c9b369093edb7133" }
lightning-rapid-gossip-sync = { git = "https://github.com/lightningdevkit/rust-lightning", rev = "044f3fab42e3085edecd40f0c9b369093edb7133" }
lightning-block-sync = { git = "https://github.com/lightningdevkit/rust-lightning", rev = "044f3fab42e3085edecd40f0c9b369093edb7133", features = ["rest-client", "rpc-client", "tokio"] }
lightning-transaction-sync = { git = "https://github.com/lightningdevkit/rust-lightning", rev = "044f3fab42e3085edecd40f0c9b369093edb7133", features = ["esplora-async-https", "time", "electrum-rustls-ring"] }
lightning-liquidity = { git = "https://github.com/lightningdevkit/rust-lightning", rev = "044f3fab42e3085edecd40f0c9b369093edb7133", features = ["std"] }
lightning-macros = { git = "https://github.com/lightningdevkit/rust-lightning", rev = "044f3fab42e3085edecd40f0c9b369093edb7133" }
lightning-dns-resolver = { git = "https://github.com/lightningdevkit/rust-lightning", rev = "044f3fab42e3085edecd40f0c9b369093edb7133" }
lightning = { git = "https://github.com/lightningdevkit/rust-lightning", rev = "369a2cf9c8ef810deea0cd2b4cf6ed0691b78144", features = ["std"] }
lightning-types = { git = "https://github.com/lightningdevkit/rust-lightning", rev = "369a2cf9c8ef810deea0cd2b4cf6ed0691b78144" }
lightning-invoice = { git = "https://github.com/lightningdevkit/rust-lightning", rev = "369a2cf9c8ef810deea0cd2b4cf6ed0691b78144", features = ["std"] }
lightning-net-tokio = { git = "https://github.com/lightningdevkit/rust-lightning", rev = "369a2cf9c8ef810deea0cd2b4cf6ed0691b78144" }
lightning-persister = { git = "https://github.com/lightningdevkit/rust-lightning", rev = "369a2cf9c8ef810deea0cd2b4cf6ed0691b78144", features = ["tokio"] }
lightning-background-processor = { git = "https://github.com/lightningdevkit/rust-lightning", rev = "369a2cf9c8ef810deea0cd2b4cf6ed0691b78144" }
lightning-rapid-gossip-sync = { git = "https://github.com/lightningdevkit/rust-lightning", rev = "369a2cf9c8ef810deea0cd2b4cf6ed0691b78144" }
lightning-block-sync = { git = "https://github.com/lightningdevkit/rust-lightning", rev = "369a2cf9c8ef810deea0cd2b4cf6ed0691b78144", features = ["rest-client", "rpc-client", "tokio"] }
lightning-transaction-sync = { git = "https://github.com/lightningdevkit/rust-lightning", rev = "369a2cf9c8ef810deea0cd2b4cf6ed0691b78144", features = ["esplora-async-https", "time", "electrum-rustls-ring"] }
lightning-liquidity = { git = "https://github.com/lightningdevkit/rust-lightning", rev = "369a2cf9c8ef810deea0cd2b4cf6ed0691b78144", features = ["std"] }
lightning-macros = { git = "https://github.com/lightningdevkit/rust-lightning", rev = "369a2cf9c8ef810deea0cd2b4cf6ed0691b78144" }
lightning-dns-resolver = { git = "https://github.com/lightningdevkit/rust-lightning", rev = "369a2cf9c8ef810deea0cd2b4cf6ed0691b78144" }

bdk_chain = { version = "0.23.0", default-features = false, features = ["std"] }
bdk_esplora = { version = "0.22.0", default-features = false, features = ["async-https-rustls", "tokio"]}
Expand DownExpand Up@@ -81,13 +81,13 @@ async-trait = { version = "0.1", default-features = false }
vss-client = { package = "vss-client-ng", version = "0.5" }
prost = { version = "0.11.6", default-features = false}
#bitcoin-payment-instructions = { version = "0.6" }
bitcoin-payment-instructions = { git = "https://github.com/jkczyz/bitcoin-payment-instructions", rev = "340c535a600f7c43bef4c9f910edac4085f2e70c" }
bitcoin-payment-instructions = { git = "https://github.com/jkczyz/bitcoin-payment-instructions", rev = "679dac50cc0d81ec4d31da94b93d467e5308f16a" }

[target.'cfg(windows)'.dependencies]
winapi = { version = "0.3", features = ["winbase"] }

[dev-dependencies]
lightning = { git = "https://github.com/lightningdevkit/rust-lightning", rev = "044f3fab42e3085edecd40f0c9b369093edb7133", features = ["std", "_test_utils"] }
lightning = { git = "https://github.com/lightningdevkit/rust-lightning", rev = "369a2cf9c8ef810deea0cd2b4cf6ed0691b78144", features = ["std", "_test_utils"] }
rand = { version = "0.9.2", default-features = false, features = ["std", "thread_rng", "os_rng"] }
proptest = "1.0.0"
regex = "1.5.6"
Expand Down

5 changes: 0 additions & 5 deletions
src/builder.rs

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Original file line numberDiff line numberDiff line change
Expand Up@@ -1657,11 +1657,6 @@ fn build_with_store_internal(

 // If we act as an LSPS2 service, we allow forwarding to unannounced channels.
 user_config.accept_forwards_to_priv_channels = true;

 // If we act as an LSPS2 service, set the HTLC-value-in-flight to 100% of the channel value
 // to ensure we can forward the initial payment.
 user_config.channel_handshake_config.max_inbound_htlc_value_in_flight_percent_of_channel =
 100;

Comment on lines

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 to 
-1673

@tankyleotankyleoApr 28, 2026

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To confirm here I don't think setting 100% here would have helped as that maximum only applies to the inbound HTLCs on that channel. To make sure that 100% of the value can be allocated to outbound HTLCs from the LSP's perspective as the comment describes, the user needs to set their max_inbound to 100%.
So seems to me the intention of the code did not match the comment ?
@jkczyzjkczyzApr 28, 2026

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Hmm... yeah it does seem that way.
	}

	if let Some(role) = async_payments_role {
Expand Down

24 changes: 13 additions & 11 deletions
src/event.rs

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Original file line numberDiff line numberDiff line change
Expand Up@@ -26,9 +26,7 @@ use lightning::ln::channelmanager::{PaymentId, TrustedChannelFeatures};
use lightning::ln::types::ChannelId;
use lightning::routing::gossip::NodeId;
use lightning::sign::EntropySource;
use lightning::util::config::{
	ChannelConfigOverrides, ChannelConfigUpdate, ChannelHandshakeConfigUpdate,
};
use lightning::util::config::{ChannelConfigOverrides, ChannelConfigUpdate};
use lightning::util::errors::APIError;
use lightning::util::persist::KVStore;
use lightning::util::ser::{Readable, ReadableArgs, Writeable, Writer};
Expand DownExpand Up@@ -1273,20 +1271,24 @@ where
 if lsp_node_id == counterparty_node_id {
 // When we're an LSPS2 client, allow claiming underpaying HTLCs as the LSP will skim off some fee. We'll
 // check that they don't take too much before claiming.
 //
 // We also set maximum allowed inbound HTLC value in flight
 // to 100%. We should eventually be able to set this on a per-channel basis, but for
 // now we just bump the default for all channels.
 channel_override_config = Some(ChannelConfigOverrides {
 handshake_overrides: Some(ChannelHandshakeConfigUpdate {
 max_inbound_htlc_value_in_flight_percent_of_channel: Some(100),
 ..Default::default()
 }),
 update_overrides: Some(ChannelConfigUpdate {
 accept_underpaying_htlcs: Some(true),
 ..Default::default()
 }),
 ..Default::default()
@tankyleotankyleoApr 28, 2026

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nit: as elsewhere, maybe a quick debug_assert here on the 100% value ? Up to @tnull
 });

 // LSPS2 channels are unannounced; rely on LDK's default of 100%
 // inbound HTLC value-in-flight so the LSP can forward the initial
 // payment in full.
 debug_assert_eq!(
 self.channel_manager
 .get_current_config()
 .channel_handshake_config
 .unannounced_channel_max_inbound_htlc_value_in_flight_percentage,
 100
 );
 }
 }
 let res = if allow_0conf {
Expand Down

15 changes: 9 additions & 6 deletions
src/lib.rs

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Original file line numberDiff line numberDiff line change
Expand Up@@ -1195,13 +1195,16 @@ impl Node {
 let mut user_config = default_user_config(&self.config);
 user_config.channel_handshake_config.announce_for_forwarding = announce_for_forwarding;
 user_config.channel_config = (channel_config.unwrap_or_default()).clone().into();
 // We set the max inflight to 100% for private channels.
@tankyleotankyleoApr 28, 2026

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nit: similar here, would it be worth adding a debug_assert to guard against any changes away from this behavior ?
 // FIXME: LDK will default to this behavior soon, too, at which point we should drop this
 // manual override.

 // Unannounced channels rely on LDK's default of 100% inbound HTLC value-in-flight
 // to support large initial payments via LSPS2.
 if !announce_for_forwarding {
 user_config
 .channel_handshake_config
 .max_inbound_htlc_value_in_flight_percent_of_channel = 100;
 debug_assert_eq!(
 user_config
 .channel_handshake_config
 .unannounced_channel_max_inbound_htlc_value_in_flight_percentage,
 100
 );
 }

 let push_msat = push_to_counterparty_msat.unwrap_or(0);
Expand Down

7 changes: 5 additions & 2 deletions
src/liquidity.rs

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Original file line numberDiff line numberDiff line change
Expand Up@@ -781,13 +781,16 @@ where

 let mut config = self.channel_manager.get_current_config().clone();

 // We set these LSP-specific values during Node building, here we're making sure it's actually set.
 // If we act as an LSPS2 service, the HTLC-value-in-flight must be 100% of the
 // channel value to ensure we can forward the initial payment. That cap only
 // applies to unannounced channels, so the channel must also be unannounced.
 debug_assert_eq!(
 config
 .channel_handshake_config
 .max_inbound_htlc_value_in_flight_percent_of_channel,
 .unannounced_channel_max_inbound_htlc_value_in_flight_percentage,
 100
 );
 debug_assert!(!config.channel_handshake_config.announce_for_forwarding);
 debug_assert!(config.accept_forwards_to_priv_channels);
@tankyleotankyleoApr 28, 2026

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nit: can we add a debug_assert here on announce_for_forwarding = false ? IIUC right now we inherit announce_for_forwarding = false here because of the default in rust-lightning, but would be good to confirm this here I think.
This is to make sure that the 100% cap actually gets applied to the channel opened by the LSPS2 service.

 // We set the forwarding fee to 0 for now as we're getting paid by the channel fee.
Expand Down
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document.querySelectorAll('header, nav, [role="banner"], .header, .navbar, .sticky, .fixed-top, [style*="position: fixed"], [style*="position:sticky"]').forEach(function(el) {
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el.style.position = 'static';
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} catch(__e) { console.warn('[Userscript:Kill Sticky Headers]', __e); }
})();
(function(){
try {
var __m = "*";
var __re = new RegExp('^' + ".*" + '
Drop `max_inbound_htlc_value_in_flight_percent_of_channel ` by jkczyz · Pull Request #878 · lightningdevkit/ldk-node · GitHub
Skip to content
Drop max_inbound_htlc_value_in_flight_percent_of_channel #878

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 Merged

tnull
merged 1 commit into

from

Apr 29, 2026
 Merged


Drop max_inbound_htlc_value_in_flight_percent_of_channel #878
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28 changes: 14 additions & 14 deletions
Cargo.toml

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Original file line numberDiff line numberDiff line change
Expand Up@@ -40,18 +40,18 @@ default = []
#lightning-macros = { version = "0.2.0" }
#lightning-dns-resolver = { version = "0.3.0" }

lightning = { git = "https://github.com/lightningdevkit/rust-lightning", rev = "044f3fab42e3085edecd40f0c9b369093edb7133", features = ["std"] }
lightning-types = { git = "https://github.com/lightningdevkit/rust-lightning", rev = "044f3fab42e3085edecd40f0c9b369093edb7133" }
lightning-invoice = { git = "https://github.com/lightningdevkit/rust-lightning", rev = "044f3fab42e3085edecd40f0c9b369093edb7133", features = ["std"] }
lightning-net-tokio = { git = "https://github.com/lightningdevkit/rust-lightning", rev = "044f3fab42e3085edecd40f0c9b369093edb7133" }
lightning-persister = { git = "https://github.com/lightningdevkit/rust-lightning", rev = "044f3fab42e3085edecd40f0c9b369093edb7133", features = ["tokio"] }
lightning-background-processor = { git = "https://github.com/lightningdevkit/rust-lightning", rev = "044f3fab42e3085edecd40f0c9b369093edb7133" }
lightning-rapid-gossip-sync = { git = "https://github.com/lightningdevkit/rust-lightning", rev = "044f3fab42e3085edecd40f0c9b369093edb7133" }
lightning-block-sync = { git = "https://github.com/lightningdevkit/rust-lightning", rev = "044f3fab42e3085edecd40f0c9b369093edb7133", features = ["rest-client", "rpc-client", "tokio"] }
lightning-transaction-sync = { git = "https://github.com/lightningdevkit/rust-lightning", rev = "044f3fab42e3085edecd40f0c9b369093edb7133", features = ["esplora-async-https", "time", "electrum-rustls-ring"] }
lightning-liquidity = { git = "https://github.com/lightningdevkit/rust-lightning", rev = "044f3fab42e3085edecd40f0c9b369093edb7133", features = ["std"] }
lightning-macros = { git = "https://github.com/lightningdevkit/rust-lightning", rev = "044f3fab42e3085edecd40f0c9b369093edb7133" }
lightning-dns-resolver = { git = "https://github.com/lightningdevkit/rust-lightning", rev = "044f3fab42e3085edecd40f0c9b369093edb7133" }
lightning = { git = "https://github.com/lightningdevkit/rust-lightning", rev = "369a2cf9c8ef810deea0cd2b4cf6ed0691b78144", features = ["std"] }
lightning-types = { git = "https://github.com/lightningdevkit/rust-lightning", rev = "369a2cf9c8ef810deea0cd2b4cf6ed0691b78144" }
lightning-invoice = { git = "https://github.com/lightningdevkit/rust-lightning", rev = "369a2cf9c8ef810deea0cd2b4cf6ed0691b78144", features = ["std"] }
lightning-net-tokio = { git = "https://github.com/lightningdevkit/rust-lightning", rev = "369a2cf9c8ef810deea0cd2b4cf6ed0691b78144" }
lightning-persister = { git = "https://github.com/lightningdevkit/rust-lightning", rev = "369a2cf9c8ef810deea0cd2b4cf6ed0691b78144", features = ["tokio"] }
lightning-background-processor = { git = "https://github.com/lightningdevkit/rust-lightning", rev = "369a2cf9c8ef810deea0cd2b4cf6ed0691b78144" }
lightning-rapid-gossip-sync = { git = "https://github.com/lightningdevkit/rust-lightning", rev = "369a2cf9c8ef810deea0cd2b4cf6ed0691b78144" }
lightning-block-sync = { git = "https://github.com/lightningdevkit/rust-lightning", rev = "369a2cf9c8ef810deea0cd2b4cf6ed0691b78144", features = ["rest-client", "rpc-client", "tokio"] }
lightning-transaction-sync = { git = "https://github.com/lightningdevkit/rust-lightning", rev = "369a2cf9c8ef810deea0cd2b4cf6ed0691b78144", features = ["esplora-async-https", "time", "electrum-rustls-ring"] }
lightning-liquidity = { git = "https://github.com/lightningdevkit/rust-lightning", rev = "369a2cf9c8ef810deea0cd2b4cf6ed0691b78144", features = ["std"] }
lightning-macros = { git = "https://github.com/lightningdevkit/rust-lightning", rev = "369a2cf9c8ef810deea0cd2b4cf6ed0691b78144" }
lightning-dns-resolver = { git = "https://github.com/lightningdevkit/rust-lightning", rev = "369a2cf9c8ef810deea0cd2b4cf6ed0691b78144" }

bdk_chain = { version = "0.23.0", default-features = false, features = ["std"] }
bdk_esplora = { version = "0.22.0", default-features = false, features = ["async-https-rustls", "tokio"]}
Expand DownExpand Up@@ -81,13 +81,13 @@ async-trait = { version = "0.1", default-features = false }
vss-client = { package = "vss-client-ng", version = "0.5" }
prost = { version = "0.11.6", default-features = false}
#bitcoin-payment-instructions = { version = "0.6" }
bitcoin-payment-instructions = { git = "https://github.com/jkczyz/bitcoin-payment-instructions", rev = "340c535a600f7c43bef4c9f910edac4085f2e70c" }
bitcoin-payment-instructions = { git = "https://github.com/jkczyz/bitcoin-payment-instructions", rev = "679dac50cc0d81ec4d31da94b93d467e5308f16a" }

[target.'cfg(windows)'.dependencies]
winapi = { version = "0.3", features = ["winbase"] }

[dev-dependencies]
lightning = { git = "https://github.com/lightningdevkit/rust-lightning", rev = "044f3fab42e3085edecd40f0c9b369093edb7133", features = ["std", "_test_utils"] }
lightning = { git = "https://github.com/lightningdevkit/rust-lightning", rev = "369a2cf9c8ef810deea0cd2b4cf6ed0691b78144", features = ["std", "_test_utils"] }
rand = { version = "0.9.2", default-features = false, features = ["std", "thread_rng", "os_rng"] }
proptest = "1.0.0"
regex = "1.5.6"
Expand Down

5 changes: 0 additions & 5 deletions
src/builder.rs

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Open in desktop

Original file line numberDiff line numberDiff line change
Expand Up@@ -1657,11 +1657,6 @@ fn build_with_store_internal(

 // If we act as an LSPS2 service, we allow forwarding to unannounced channels.
 user_config.accept_forwards_to_priv_channels = true;

 // If we act as an LSPS2 service, set the HTLC-value-in-flight to 100% of the channel value
 // to ensure we can forward the initial payment.
 user_config.channel_handshake_config.max_inbound_htlc_value_in_flight_percent_of_channel =
 100;

Comment on lines

-1670
 to 
-1673

@tankyleotankyleoApr 28, 2026

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To confirm here I don't think setting 100% here would have helped as that maximum only applies to the inbound HTLCs on that channel. To make sure that 100% of the value can be allocated to outbound HTLCs from the LSP's perspective as the comment describes, the user needs to set their max_inbound to 100%.
So seems to me the intention of the code did not match the comment ?
@jkczyzjkczyzApr 28, 2026

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Hmm... yeah it does seem that way.
	}

	if let Some(role) = async_payments_role {
Expand Down

24 changes: 13 additions & 11 deletions
src/event.rs

View file


Open in desktop

Original file line numberDiff line numberDiff line change
Expand Up@@ -26,9 +26,7 @@ use lightning::ln::channelmanager::{PaymentId, TrustedChannelFeatures};
use lightning::ln::types::ChannelId;
use lightning::routing::gossip::NodeId;
use lightning::sign::EntropySource;
use lightning::util::config::{
	ChannelConfigOverrides, ChannelConfigUpdate, ChannelHandshakeConfigUpdate,
};
use lightning::util::config::{ChannelConfigOverrides, ChannelConfigUpdate};
use lightning::util::errors::APIError;
use lightning::util::persist::KVStore;
use lightning::util::ser::{Readable, ReadableArgs, Writeable, Writer};
Expand DownExpand Up@@ -1273,20 +1271,24 @@ where
 if lsp_node_id == counterparty_node_id {
 // When we're an LSPS2 client, allow claiming underpaying HTLCs as the LSP will skim off some fee. We'll
 // check that they don't take too much before claiming.
 //
 // We also set maximum allowed inbound HTLC value in flight
 // to 100%. We should eventually be able to set this on a per-channel basis, but for
 // now we just bump the default for all channels.
 channel_override_config = Some(ChannelConfigOverrides {
 handshake_overrides: Some(ChannelHandshakeConfigUpdate {
 max_inbound_htlc_value_in_flight_percent_of_channel: Some(100),
 ..Default::default()
 }),
 update_overrides: Some(ChannelConfigUpdate {
 accept_underpaying_htlcs: Some(true),
 ..Default::default()
 }),
 ..Default::default()
@tankyleotankyleoApr 28, 2026

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nit: as elsewhere, maybe a quick debug_assert here on the 100% value ? Up to @tnull
 });

 // LSPS2 channels are unannounced; rely on LDK's default of 100%
 // inbound HTLC value-in-flight so the LSP can forward the initial
 // payment in full.
 debug_assert_eq!(
 self.channel_manager
 .get_current_config()
 .channel_handshake_config
 .unannounced_channel_max_inbound_htlc_value_in_flight_percentage,
 100
 );
 }
 }
 let res = if allow_0conf {
Expand Down

15 changes: 9 additions & 6 deletions
src/lib.rs

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Original file line numberDiff line numberDiff line change
Expand Up@@ -1195,13 +1195,16 @@ impl Node {
 let mut user_config = default_user_config(&self.config);
 user_config.channel_handshake_config.announce_for_forwarding = announce_for_forwarding;
 user_config.channel_config = (channel_config.unwrap_or_default()).clone().into();
 // We set the max inflight to 100% for private channels.
@tankyleotankyleoApr 28, 2026

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nit: similar here, would it be worth adding a debug_assert to guard against any changes away from this behavior ?
 // FIXME: LDK will default to this behavior soon, too, at which point we should drop this
 // manual override.

 // Unannounced channels rely on LDK's default of 100% inbound HTLC value-in-flight
 // to support large initial payments via LSPS2.
 if !announce_for_forwarding {
 user_config
 .channel_handshake_config
 .max_inbound_htlc_value_in_flight_percent_of_channel = 100;
 debug_assert_eq!(
 user_config
 .channel_handshake_config
 .unannounced_channel_max_inbound_htlc_value_in_flight_percentage,
 100
 );
 }

 let push_msat = push_to_counterparty_msat.unwrap_or(0);
Expand Down

7 changes: 5 additions & 2 deletions
src/liquidity.rs

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Original file line numberDiff line numberDiff line change
Expand Up@@ -781,13 +781,16 @@ where

 let mut config = self.channel_manager.get_current_config().clone();

 // We set these LSP-specific values during Node building, here we're making sure it's actually set.
 // If we act as an LSPS2 service, the HTLC-value-in-flight must be 100% of the
 // channel value to ensure we can forward the initial payment. That cap only
 // applies to unannounced channels, so the channel must also be unannounced.
 debug_assert_eq!(
 config
 .channel_handshake_config
 .max_inbound_htlc_value_in_flight_percent_of_channel,
 .unannounced_channel_max_inbound_htlc_value_in_flight_percentage,
 100
 );
 debug_assert!(!config.channel_handshake_config.announce_for_forwarding);
 debug_assert!(config.accept_forwards_to_priv_channels);
@tankyleotankyleoApr 28, 2026

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nit: can we add a debug_assert here on announce_for_forwarding = false ? IIUC right now we inherit announce_for_forwarding = false here because of the default in rust-lightning, but would be good to confirm this here I think.
This is to make sure that the 100% cap actually gets applied to the channel opened by the LSPS2 service.

 // We set the forwarding fee to 0 for now as we're getting paid by the channel fee.
Expand Down
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Drop `max_inbound_htlc_value_in_flight_percent_of_channel ` by jkczyz · Pull Request #878 · lightningdevkit/ldk-node · GitHub
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tnull
merged 1 commit into

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Apr 29, 2026
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Drop max_inbound_htlc_value_in_flight_percent_of_channel #878
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28 changes: 14 additions & 14 deletions
Cargo.toml

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Original file line numberDiff line numberDiff line change
Expand Up@@ -40,18 +40,18 @@ default = []
#lightning-macros = { version = "0.2.0" }
#lightning-dns-resolver = { version = "0.3.0" }

lightning = { git = "https://github.com/lightningdevkit/rust-lightning", rev = "044f3fab42e3085edecd40f0c9b369093edb7133", features = ["std"] }
lightning-types = { git = "https://github.com/lightningdevkit/rust-lightning", rev = "044f3fab42e3085edecd40f0c9b369093edb7133" }
lightning-invoice = { git = "https://github.com/lightningdevkit/rust-lightning", rev = "044f3fab42e3085edecd40f0c9b369093edb7133", features = ["std"] }
lightning-net-tokio = { git = "https://github.com/lightningdevkit/rust-lightning", rev = "044f3fab42e3085edecd40f0c9b369093edb7133" }
lightning-persister = { git = "https://github.com/lightningdevkit/rust-lightning", rev = "044f3fab42e3085edecd40f0c9b369093edb7133", features = ["tokio"] }
lightning-background-processor = { git = "https://github.com/lightningdevkit/rust-lightning", rev = "044f3fab42e3085edecd40f0c9b369093edb7133" }
lightning-rapid-gossip-sync = { git = "https://github.com/lightningdevkit/rust-lightning", rev = "044f3fab42e3085edecd40f0c9b369093edb7133" }
lightning-block-sync = { git = "https://github.com/lightningdevkit/rust-lightning", rev = "044f3fab42e3085edecd40f0c9b369093edb7133", features = ["rest-client", "rpc-client", "tokio"] }
lightning-transaction-sync = { git = "https://github.com/lightningdevkit/rust-lightning", rev = "044f3fab42e3085edecd40f0c9b369093edb7133", features = ["esplora-async-https", "time", "electrum-rustls-ring"] }
lightning-liquidity = { git = "https://github.com/lightningdevkit/rust-lightning", rev = "044f3fab42e3085edecd40f0c9b369093edb7133", features = ["std"] }
lightning-macros = { git = "https://github.com/lightningdevkit/rust-lightning", rev = "044f3fab42e3085edecd40f0c9b369093edb7133" }
lightning-dns-resolver = { git = "https://github.com/lightningdevkit/rust-lightning", rev = "044f3fab42e3085edecd40f0c9b369093edb7133" }
lightning = { git = "https://github.com/lightningdevkit/rust-lightning", rev = "369a2cf9c8ef810deea0cd2b4cf6ed0691b78144", features = ["std"] }
lightning-types = { git = "https://github.com/lightningdevkit/rust-lightning", rev = "369a2cf9c8ef810deea0cd2b4cf6ed0691b78144" }
lightning-invoice = { git = "https://github.com/lightningdevkit/rust-lightning", rev = "369a2cf9c8ef810deea0cd2b4cf6ed0691b78144", features = ["std"] }
lightning-net-tokio = { git = "https://github.com/lightningdevkit/rust-lightning", rev = "369a2cf9c8ef810deea0cd2b4cf6ed0691b78144" }
lightning-persister = { git = "https://github.com/lightningdevkit/rust-lightning", rev = "369a2cf9c8ef810deea0cd2b4cf6ed0691b78144", features = ["tokio"] }
lightning-background-processor = { git = "https://github.com/lightningdevkit/rust-lightning", rev = "369a2cf9c8ef810deea0cd2b4cf6ed0691b78144" }
lightning-rapid-gossip-sync = { git = "https://github.com/lightningdevkit/rust-lightning", rev = "369a2cf9c8ef810deea0cd2b4cf6ed0691b78144" }
lightning-block-sync = { git = "https://github.com/lightningdevkit/rust-lightning", rev = "369a2cf9c8ef810deea0cd2b4cf6ed0691b78144", features = ["rest-client", "rpc-client", "tokio"] }
lightning-transaction-sync = { git = "https://github.com/lightningdevkit/rust-lightning", rev = "369a2cf9c8ef810deea0cd2b4cf6ed0691b78144", features = ["esplora-async-https", "time", "electrum-rustls-ring"] }
lightning-liquidity = { git = "https://github.com/lightningdevkit/rust-lightning", rev = "369a2cf9c8ef810deea0cd2b4cf6ed0691b78144", features = ["std"] }
lightning-macros = { git = "https://github.com/lightningdevkit/rust-lightning", rev = "369a2cf9c8ef810deea0cd2b4cf6ed0691b78144" }
lightning-dns-resolver = { git = "https://github.com/lightningdevkit/rust-lightning", rev = "369a2cf9c8ef810deea0cd2b4cf6ed0691b78144" }

bdk_chain = { version = "0.23.0", default-features = false, features = ["std"] }
bdk_esplora = { version = "0.22.0", default-features = false, features = ["async-https-rustls", "tokio"]}
Expand DownExpand Up@@ -81,13 +81,13 @@ async-trait = { version = "0.1", default-features = false }
vss-client = { package = "vss-client-ng", version = "0.5" }
prost = { version = "0.11.6", default-features = false}
#bitcoin-payment-instructions = { version = "0.6" }
bitcoin-payment-instructions = { git = "https://github.com/jkczyz/bitcoin-payment-instructions", rev = "340c535a600f7c43bef4c9f910edac4085f2e70c" }
bitcoin-payment-instructions = { git = "https://github.com/jkczyz/bitcoin-payment-instructions", rev = "679dac50cc0d81ec4d31da94b93d467e5308f16a" }

[target.'cfg(windows)'.dependencies]
winapi = { version = "0.3", features = ["winbase"] }

[dev-dependencies]
lightning = { git = "https://github.com/lightningdevkit/rust-lightning", rev = "044f3fab42e3085edecd40f0c9b369093edb7133", features = ["std", "_test_utils"] }
lightning = { git = "https://github.com/lightningdevkit/rust-lightning", rev = "369a2cf9c8ef810deea0cd2b4cf6ed0691b78144", features = ["std", "_test_utils"] }
rand = { version = "0.9.2", default-features = false, features = ["std", "thread_rng", "os_rng"] }
proptest = "1.0.0"
regex = "1.5.6"
Expand Down

5 changes: 0 additions & 5 deletions
src/builder.rs

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Original file line numberDiff line numberDiff line change
Expand Up@@ -1657,11 +1657,6 @@ fn build_with_store_internal(

 // If we act as an LSPS2 service, we allow forwarding to unannounced channels.
 user_config.accept_forwards_to_priv_channels = true;

 // If we act as an LSPS2 service, set the HTLC-value-in-flight to 100% of the channel value
 // to ensure we can forward the initial payment.
 user_config.channel_handshake_config.max_inbound_htlc_value_in_flight_percent_of_channel =
 100;

Comment on lines

-1670
 to 
-1673

@tankyleotankyleoApr 28, 2026

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To confirm here I don't think setting 100% here would have helped as that maximum only applies to the inbound HTLCs on that channel. To make sure that 100% of the value can be allocated to outbound HTLCs from the LSP's perspective as the comment describes, the user needs to set their max_inbound to 100%.
So seems to me the intention of the code did not match the comment ?
@jkczyzjkczyzApr 28, 2026

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Hmm... yeah it does seem that way.
	}

	if let Some(role) = async_payments_role {
Expand Down

24 changes: 13 additions & 11 deletions
src/event.rs

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Original file line numberDiff line numberDiff line change
Expand Up@@ -26,9 +26,7 @@ use lightning::ln::channelmanager::{PaymentId, TrustedChannelFeatures};
use lightning::ln::types::ChannelId;
use lightning::routing::gossip::NodeId;
use lightning::sign::EntropySource;
use lightning::util::config::{
	ChannelConfigOverrides, ChannelConfigUpdate, ChannelHandshakeConfigUpdate,
};
use lightning::util::config::{ChannelConfigOverrides, ChannelConfigUpdate};
use lightning::util::errors::APIError;
use lightning::util::persist::KVStore;
use lightning::util::ser::{Readable, ReadableArgs, Writeable, Writer};
Expand DownExpand Up@@ -1273,20 +1271,24 @@ where
 if lsp_node_id == counterparty_node_id {
 // When we're an LSPS2 client, allow claiming underpaying HTLCs as the LSP will skim off some fee. We'll
 // check that they don't take too much before claiming.
 //
 // We also set maximum allowed inbound HTLC value in flight
 // to 100%. We should eventually be able to set this on a per-channel basis, but for
 // now we just bump the default for all channels.
 channel_override_config = Some(ChannelConfigOverrides {
 handshake_overrides: Some(ChannelHandshakeConfigUpdate {
 max_inbound_htlc_value_in_flight_percent_of_channel: Some(100),
 ..Default::default()
 }),
 update_overrides: Some(ChannelConfigUpdate {
 accept_underpaying_htlcs: Some(true),
 ..Default::default()
 }),
 ..Default::default()
@tankyleotankyleoApr 28, 2026

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nit: as elsewhere, maybe a quick debug_assert here on the 100% value ? Up to @tnull
 });

 // LSPS2 channels are unannounced; rely on LDK's default of 100%
 // inbound HTLC value-in-flight so the LSP can forward the initial
 // payment in full.
 debug_assert_eq!(
 self.channel_manager
 .get_current_config()
 .channel_handshake_config
 .unannounced_channel_max_inbound_htlc_value_in_flight_percentage,
 100
 );
 }
 }
 let res = if allow_0conf {
Expand Down

15 changes: 9 additions & 6 deletions
src/lib.rs

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Original file line numberDiff line numberDiff line change
Expand Up@@ -1195,13 +1195,16 @@ impl Node {
 let mut user_config = default_user_config(&self.config);
 user_config.channel_handshake_config.announce_for_forwarding = announce_for_forwarding;
 user_config.channel_config = (channel_config.unwrap_or_default()).clone().into();
 // We set the max inflight to 100% for private channels.
@tankyleotankyleoApr 28, 2026

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nit: similar here, would it be worth adding a debug_assert to guard against any changes away from this behavior ?
 // FIXME: LDK will default to this behavior soon, too, at which point we should drop this
 // manual override.

 // Unannounced channels rely on LDK's default of 100% inbound HTLC value-in-flight
 // to support large initial payments via LSPS2.
 if !announce_for_forwarding {
 user_config
 .channel_handshake_config
 .max_inbound_htlc_value_in_flight_percent_of_channel = 100;
 debug_assert_eq!(
 user_config
 .channel_handshake_config
 .unannounced_channel_max_inbound_htlc_value_in_flight_percentage,
 100
 );
 }

 let push_msat = push_to_counterparty_msat.unwrap_or(0);
Expand Down

7 changes: 5 additions & 2 deletions
src/liquidity.rs

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Original file line numberDiff line numberDiff line change
Expand Up@@ -781,13 +781,16 @@ where

 let mut config = self.channel_manager.get_current_config().clone();

 // We set these LSP-specific values during Node building, here we're making sure it's actually set.
 // If we act as an LSPS2 service, the HTLC-value-in-flight must be 100% of the
 // channel value to ensure we can forward the initial payment. That cap only
 // applies to unannounced channels, so the channel must also be unannounced.
 debug_assert_eq!(
 config
 .channel_handshake_config
 .max_inbound_htlc_value_in_flight_percent_of_channel,
 .unannounced_channel_max_inbound_htlc_value_in_flight_percentage,
 100
 );
 debug_assert!(!config.channel_handshake_config.announce_for_forwarding);
 debug_assert!(config.accept_forwards_to_priv_channels);
@tankyleotankyleoApr 28, 2026

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nit: can we add a debug_assert here on announce_for_forwarding = false ? IIUC right now we inherit announce_for_forwarding = false here because of the default in rust-lightning, but would be good to confirm this here I think.
This is to make sure that the 100% cap actually gets applied to the channel opened by the LSPS2 service.

 // We set the forwarding fee to 0 for now as we're getting paid by the channel fee.
Expand Down
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