Merge pull request #2134 from jbesraa/add_fromstr_to_netaddress
[rust-lightning] / lightning / src / routing / router.rs
index bf854aed63745b0bbfd7d5749ffa8704c705c4ac..9c5fe8e1f9bd3dab59033644591a4a59b49d173b 100644 (file)
@@ -16,26 +16,26 @@ use bitcoin::hashes::sha256::Hash as Sha256;
 use crate::blinded_path::{BlindedHop, BlindedPath};
 use crate::ln::PaymentHash;
 use crate::ln::channelmanager::{ChannelDetails, PaymentId};
-use crate::ln::features::{Bolt12InvoiceFeatures, ChannelFeatures, InvoiceFeatures, NodeFeatures};
+use crate::ln::features::{Bolt11InvoiceFeatures, Bolt12InvoiceFeatures, ChannelFeatures, NodeFeatures};
 use crate::ln::msgs::{DecodeError, ErrorAction, LightningError, MAX_VALUE_MSAT};
-use crate::offers::invoice::BlindedPayInfo;
+use crate::offers::invoice::{BlindedPayInfo, Bolt12Invoice};
 use crate::routing::gossip::{DirectedChannelInfo, EffectiveCapacity, ReadOnlyNetworkGraph, NetworkGraph, NodeId, RoutingFees};
-use crate::routing::scoring::{ChannelUsage, LockableScore, Score};
+use crate::routing::scoring::{ChannelUsage, LockableScore, ScoreLookUp};
 use crate::util::ser::{Writeable, Readable, ReadableArgs, Writer};
 use crate::util::logger::{Level, Logger};
 use crate::util::chacha20::ChaCha20;
 
 use crate::io;
 use crate::prelude::*;
-use crate::sync::{Mutex, MutexGuard};
+use crate::sync::Mutex;
 use alloc::collections::BinaryHeap;
 use core::{cmp, fmt};
 use core::ops::Deref;
 
 /// A [`Router`] implemented using [`find_route`].
-pub struct DefaultRouter<G: Deref<Target = NetworkGraph<L>>, L: Deref, S: Deref, SP: Sized, Sc: Score<ScoreParams = SP>> where
+pub struct DefaultRouter<G: Deref<Target = NetworkGraph<L>>, L: Deref, S: Deref, SP: Sized, Sc: ScoreLookUp<ScoreParams = SP>> where
        L::Target: Logger,
-       S::Target: for <'a> LockableScore<'a, Locked = MutexGuard<'a, Sc>>,
+       S::Target: for <'a> LockableScore<'a, ScoreLookUp = Sc>,
 {
        network_graph: G,
        logger: L,
@@ -44,9 +44,9 @@ pub struct DefaultRouter<G: Deref<Target = NetworkGraph<L>>, L: Deref, S: Deref,
        score_params: SP
 }
 
-impl<G: Deref<Target = NetworkGraph<L>>, L: Deref, S: Deref, SP: Sized, Sc: Score<ScoreParams = SP>> DefaultRouter<G, L, S, SP, Sc> where
+impl<G: Deref<Target = NetworkGraph<L>>, L: Deref, S: Deref, SP: Sized, Sc: ScoreLookUp<ScoreParams = SP>> DefaultRouter<G, L, S, SP, Sc> where
        L::Target: Logger,
-       S::Target: for <'a> LockableScore<'a, Locked = MutexGuard<'a, Sc>>,
+       S::Target: for <'a> LockableScore<'a, ScoreLookUp = Sc>,
 {
        /// Creates a new router.
        pub fn new(network_graph: G, logger: L, random_seed_bytes: [u8; 32], scorer: S, score_params: SP) -> Self {
@@ -55,16 +55,16 @@ impl<G: Deref<Target = NetworkGraph<L>>, L: Deref, S: Deref, SP: Sized, Sc: Scor
        }
 }
 
-impl< G: Deref<Target = NetworkGraph<L>>, L: Deref, S: Deref,  SP: Sized, Sc: Score<ScoreParams = SP>> Router for DefaultRouter<G, L, S, SP, Sc> where
+impl< G: Deref<Target = NetworkGraph<L>>, L: Deref, S: Deref, SP: Sized, Sc: ScoreLookUp<ScoreParams = SP>> Router for DefaultRouter<G, L, S, SP, Sc> where
        L::Target: Logger,
-       S::Target: for <'a> LockableScore<'a, Locked = MutexGuard<'a, Sc>>,
+       S::Target: for <'a> LockableScore<'a, ScoreLookUp = Sc>,
 {
        fn find_route(
                &self,
                payer: &PublicKey,
                params: &RouteParameters,
                first_hops: Option<&[&ChannelDetails]>,
-               inflight_htlcs: &InFlightHtlcs
+               inflight_htlcs: InFlightHtlcs
        ) -> Result<Route, LightningError> {
                let random_seed_bytes = {
                        let mut locked_random_seed_bytes = self.random_seed_bytes.lock().unwrap();
@@ -73,7 +73,7 @@ impl< G: Deref<Target = NetworkGraph<L>>, L: Deref, S: Deref,  SP: Sized, Sc: Sc
                };
                find_route(
                        payer, params, &self.network_graph, first_hops, &*self.logger,
-                       &ScorerAccountingForInFlightHtlcs::new(self.scorer.lock(), inflight_htlcs),
+                       &ScorerAccountingForInFlightHtlcs::new(self.scorer.read_lock(), &inflight_htlcs),
                        &self.score_params,
                        &random_seed_bytes
                )
@@ -82,35 +82,42 @@ impl< G: Deref<Target = NetworkGraph<L>>, L: Deref, S: Deref,  SP: Sized, Sc: Sc
 
 /// A trait defining behavior for routing a payment.
 pub trait Router {
-       /// Finds a [`Route`] between `payer` and `payee` for a payment with the given values.
+       /// Finds a [`Route`] for a payment between the given `payer` and a payee.
+       ///
+       /// The `payee` and the payment's value are given in [`RouteParameters::payment_params`]
+       /// and [`RouteParameters::final_value_msat`], respectively.
        fn find_route(
                &self, payer: &PublicKey, route_params: &RouteParameters,
-               first_hops: Option<&[&ChannelDetails]>, inflight_htlcs: &InFlightHtlcs
+               first_hops: Option<&[&ChannelDetails]>, inflight_htlcs: InFlightHtlcs
        ) -> Result<Route, LightningError>;
-       /// Finds a [`Route`] between `payer` and `payee` for a payment with the given values. Includes
-       /// `PaymentHash` and `PaymentId` to be able to correlate the request with a specific payment.
+       /// Finds a [`Route`] for a payment between the given `payer` and a payee.
+       ///
+       /// The `payee` and the payment's value are given in [`RouteParameters::payment_params`]
+       /// and [`RouteParameters::final_value_msat`], respectively.
+       ///
+       /// Includes a [`PaymentHash`] and a [`PaymentId`] to be able to correlate the request with a specific
+       /// payment.
        fn find_route_with_id(
                &self, payer: &PublicKey, route_params: &RouteParameters,
-               first_hops: Option<&[&ChannelDetails]>, inflight_htlcs: &InFlightHtlcs,
+               first_hops: Option<&[&ChannelDetails]>, inflight_htlcs: InFlightHtlcs,
                _payment_hash: PaymentHash, _payment_id: PaymentId
        ) -> Result<Route, LightningError> {
                self.find_route(payer, route_params, first_hops, inflight_htlcs)
        }
 }
 
-/// [`Score`] implementation that factors in in-flight HTLC liquidity.
+/// [`ScoreLookUp`] implementation that factors in in-flight HTLC liquidity.
 ///
-/// Useful for custom [`Router`] implementations to wrap their [`Score`] on-the-fly when calling
+/// Useful for custom [`Router`] implementations to wrap their [`ScoreLookUp`] on-the-fly when calling
 /// [`find_route`].
 ///
-/// [`Score`]: crate::routing::scoring::Score
-pub struct ScorerAccountingForInFlightHtlcs<'a, S: Score> {
+/// [`ScoreLookUp`]: crate::routing::scoring::ScoreLookUp
+pub struct ScorerAccountingForInFlightHtlcs<'a, SP: Sized, Sc: 'a + ScoreLookUp<ScoreParams = SP>, S: Deref<Target = Sc>> {
        scorer: S,
        // Maps a channel's short channel id and its direction to the liquidity used up.
        inflight_htlcs: &'a InFlightHtlcs,
 }
-
-impl<'a, S: Score> ScorerAccountingForInFlightHtlcs<'a, S> {
+impl<'a, SP: Sized, Sc: ScoreLookUp<ScoreParams = SP>, S: Deref<Target = Sc>> ScorerAccountingForInFlightHtlcs<'a, SP, Sc, S> {
        /// Initialize a new `ScorerAccountingForInFlightHtlcs`.
        pub fn new(scorer: S, inflight_htlcs: &'a InFlightHtlcs) -> Self {
                ScorerAccountingForInFlightHtlcs {
@@ -121,12 +128,12 @@ impl<'a, S: Score> ScorerAccountingForInFlightHtlcs<'a, S> {
 }
 
 #[cfg(c_bindings)]
-impl<'a, S: Score> Writeable for ScorerAccountingForInFlightHtlcs<'a, S> {
+impl<'a, SP: Sized, Sc: ScoreLookUp<ScoreParams = SP>, S: Deref<Target = Sc>> Writeable for ScorerAccountingForInFlightHtlcs<'a, SP, Sc, S> {
        fn write<W: Writer>(&self, writer: &mut W) -> Result<(), io::Error> { self.scorer.write(writer) }
 }
 
-impl<'a, S: Score> Score for ScorerAccountingForInFlightHtlcs<'a, S> {
-       type ScoreParams = S::ScoreParams;
+impl<'a, SP: Sized, Sc: 'a + ScoreLookUp<ScoreParams = SP>, S: Deref<Target = Sc>> ScoreLookUp for ScorerAccountingForInFlightHtlcs<'a, SP, Sc, S> {
+       type ScoreParams = Sc::ScoreParams;
        fn channel_penalty_msat(&self, short_channel_id: u64, source: &NodeId, target: &NodeId, usage: ChannelUsage, score_params: &Self::ScoreParams) -> u64 {
                if let Some(used_liquidity) = self.inflight_htlcs.used_liquidity_msat(
                        source, target, short_channel_id
@@ -141,22 +148,6 @@ impl<'a, S: Score> Score for ScorerAccountingForInFlightHtlcs<'a, S> {
                        self.scorer.channel_penalty_msat(short_channel_id, source, target, usage, score_params)
                }
        }
-
-       fn payment_path_failed(&mut self, path: &Path, short_channel_id: u64) {
-               self.scorer.payment_path_failed(path, short_channel_id)
-       }
-
-       fn payment_path_successful(&mut self, path: &Path) {
-               self.scorer.payment_path_successful(path)
-       }
-
-       fn probe_failed(&mut self, path: &Path, short_channel_id: u64) {
-               self.scorer.probe_failed(path, short_channel_id)
-       }
-
-       fn probe_successful(&mut self, path: &Path) {
-               self.scorer.probe_successful(path)
-       }
 }
 
 /// A data structure for tracking in-flight HTLCs. May be used during pathfinding to account for
@@ -204,6 +195,15 @@ impl InFlightHtlcs {
                }
        }
 
+       /// Adds a known HTLC given the public key of the HTLC source, target, and short channel
+       /// id.
+       pub fn add_inflight_htlc(&mut self, source: &NodeId, target: &NodeId, channel_scid: u64, used_msat: u64){
+               self.0
+                       .entry((channel_scid, source < target))
+                       .and_modify(|used_liquidity_msat| *used_liquidity_msat += used_msat)
+                       .or_insert(used_msat);
+       }
+
        /// Returns liquidity in msat given the public key of the HTLC source, target, and short channel
        /// id.
        pub fn used_liquidity_msat(&self, source: &NodeId, target: &NodeId, channel_scid: u64) -> Option<u64> {
@@ -262,9 +262,9 @@ impl_writeable_tlv_based!(RouteHop, {
 });
 
 /// The blinded portion of a [`Path`], if we're routing to a recipient who provided blinded paths in
-/// their BOLT12 [`Invoice`].
+/// their [`Bolt12Invoice`].
 ///
-/// [`Invoice`]: crate::offers::invoice::Invoice
+/// [`Bolt12Invoice`]: crate::offers::invoice::Bolt12Invoice
 #[derive(Clone, Debug, Hash, PartialEq, Eq)]
 pub struct BlindedTail {
        /// The hops of the [`BlindedPath`] provided by the recipient.
@@ -283,7 +283,7 @@ pub struct BlindedTail {
 }
 
 impl_writeable_tlv_based!(BlindedTail, {
-       (0, hops, vec_type),
+       (0, hops, required_vec),
        (2, blinding_point, required),
        (4, excess_final_cltv_expiry_delta, required),
        (6, final_value_msat, required),
@@ -337,25 +337,34 @@ pub struct Route {
        /// [`BlindedTail`]s are present, then the pubkey of the last [`RouteHop`] in each path must be
        /// the same.
        pub paths: Vec<Path>,
-       /// The `payment_params` parameter passed to [`find_route`].
-       /// This is used by `ChannelManager` to track information which may be required for retries,
-       /// provided back to you via [`Event::PaymentPathFailed`].
+       /// The `route_params` parameter passed to [`find_route`].
+       ///
+       /// This is used by `ChannelManager` to track information which may be required for retries.
        ///
-       /// [`Event::PaymentPathFailed`]: crate::events::Event::PaymentPathFailed
-       pub payment_params: Option<PaymentParameters>,
+       /// Will be `None` for objects serialized with LDK versions prior to 0.0.117.
+       pub route_params: Option<RouteParameters>,
 }
 
 impl Route {
        /// Returns the total amount of fees paid on this [`Route`].
        ///
-       /// This doesn't include any extra payment made to the recipient, which can happen in excess of
-       /// the amount passed to [`find_route`]'s `params.final_value_msat`.
+       /// For objects serialized with LDK 0.0.117 and after, this includes any extra payment made to
+       /// the recipient, which can happen in excess of the amount passed to [`find_route`] via
+       /// [`RouteParameters::final_value_msat`], if we had to reach the [`htlc_minimum_msat`] limits.
+       ///
+       /// [`htlc_minimum_msat`]: https://github.com/lightning/bolts/blob/master/07-routing-gossip.md#the-channel_update-message
        pub fn get_total_fees(&self) -> u64 {
-               self.paths.iter().map(|path| path.fee_msat()).sum()
+               let overpaid_value_msat = self.route_params.as_ref()
+                       .map_or(0, |p| self.get_total_amount().saturating_sub(p.final_value_msat));
+               overpaid_value_msat + self.paths.iter().map(|path| path.fee_msat()).sum::<u64>()
        }
 
-       /// Returns the total amount paid on this [`Route`], excluding the fees. Might be more than
-       /// requested if we had to reach htlc_minimum_msat.
+       /// Returns the total amount paid on this [`Route`], excluding the fees.
+       ///
+       /// Might be more than requested as part of the given [`RouteParameters::final_value_msat`] if
+       /// we had to reach the [`htlc_minimum_msat`] limits.
+       ///
+       /// [`htlc_minimum_msat`]: https://github.com/lightning/bolts/blob/master/07-routing-gossip.md#the-channel_update-message
        pub fn get_total_amount(&self) -> u64 {
                self.paths.iter().map(|path| path.final_value_msat()).sum()
        }
@@ -385,8 +394,11 @@ impl Writeable for Route {
                        }
                }
                write_tlv_fields!(writer, {
-                       (1, self.payment_params, option),
+                       // For compatibility with LDK versions prior to 0.0.117, we take the individual
+                       // RouteParameters' fields and reconstruct them on read.
+                       (1, self.route_params.as_ref().map(|p| &p.payment_params), option),
                        (2, blinded_tails, optional_vec),
+                       (3, self.route_params.as_ref().map(|p| p.final_value_msat), option),
                });
                Ok(())
        }
@@ -410,28 +422,35 @@ impl Readable for Route {
                                cmp::min(min_final_cltv_expiry_delta, hops.last().unwrap().cltv_expiry_delta);
                        paths.push(Path { hops, blinded_tail: None });
                }
-               _init_and_read_tlv_fields!(reader, {
+               _init_and_read_len_prefixed_tlv_fields!(reader, {
                        (1, payment_params, (option: ReadableArgs, min_final_cltv_expiry_delta)),
                        (2, blinded_tails, optional_vec),
+                       (3, final_value_msat, option),
                });
                let blinded_tails = blinded_tails.unwrap_or(Vec::new());
                if blinded_tails.len() != 0 {
                        if blinded_tails.len() != paths.len() { return Err(DecodeError::InvalidValue) }
-                       for (mut path, blinded_tail_opt) in paths.iter_mut().zip(blinded_tails.into_iter()) {
+                       for (path, blinded_tail_opt) in paths.iter_mut().zip(blinded_tails.into_iter()) {
                                path.blinded_tail = blinded_tail_opt;
                        }
                }
-               Ok(Route { paths, payment_params })
+
+               // If we previously wrote the corresponding fields, reconstruct RouteParameters.
+               let route_params = match (payment_params, final_value_msat) {
+                       (Some(payment_params), Some(final_value_msat)) => {
+                               Some(RouteParameters { payment_params, final_value_msat })
+                       }
+                       _ => None,
+               };
+
+               Ok(Route { paths, route_params })
        }
 }
 
 /// Parameters needed to find a [`Route`].
 ///
-/// Passed to [`find_route`] and [`build_route_from_hops`], but also provided in
-/// [`Event::PaymentPathFailed`].
-///
-/// [`Event::PaymentPathFailed`]: crate::events::Event::PaymentPathFailed
-#[derive(Clone, Debug, PartialEq, Eq)]
+/// Passed to [`find_route`] and [`build_route_from_hops`].
+#[derive(Clone, Debug, Hash, PartialEq, Eq)]
 pub struct RouteParameters {
        /// The parameters of the failed payment path.
        pub payment_params: PaymentParameters,
@@ -440,6 +459,13 @@ pub struct RouteParameters {
        pub final_value_msat: u64,
 }
 
+impl RouteParameters {
+       /// Constructs [`RouteParameters`] from the given [`PaymentParameters`] and a payment amount.
+       pub fn from_payment_params_and_value(payment_params: PaymentParameters, final_value_msat: u64) -> Self {
+               Self { payment_params, final_value_msat }
+       }
+}
+
 impl Writeable for RouteParameters {
        fn write<W: Writer>(&self, writer: &mut W) -> Result<(), io::Error> {
                write_tlv_fields!(writer, {
@@ -455,7 +481,7 @@ impl Writeable for RouteParameters {
 
 impl Readable for RouteParameters {
        fn read<R: io::Read>(reader: &mut R) -> Result<Self, DecodeError> {
-               _init_and_read_tlv_fields!(reader, {
+               _init_and_read_len_prefixed_tlv_fields!(reader, {
                        (0, payment_params, (required: ReadableArgs, 0)),
                        (2, final_value_msat, required),
                        (4, final_cltv_delta, option),
@@ -481,6 +507,8 @@ pub const DEFAULT_MAX_TOTAL_CLTV_EXPIRY_DELTA: u32 = 1008;
 // limits, but for now more than 10 paths likely carries too much one-path failure.
 pub const DEFAULT_MAX_PATH_COUNT: u8 = 10;
 
+const DEFAULT_MAX_CHANNEL_SATURATION_POW_HALF: u8 = 2;
+
 // The median hop CLTV expiry delta currently seen in the network.
 const MEDIAN_HOP_CLTV_EXPIRY_DELTA: u32 = 40;
 
@@ -548,10 +576,10 @@ impl Writeable for PaymentParameters {
                        (1, self.max_total_cltv_expiry_delta, required),
                        (2, self.payee.features(), option),
                        (3, self.max_path_count, required),
-                       (4, *clear_hints, vec_type),
+                       (4, *clear_hints, required_vec),
                        (5, self.max_channel_saturation_power_of_half, required),
                        (6, self.expiry_time, option),
-                       (7, self.previously_failed_channels, vec_type),
+                       (7, self.previously_failed_channels, required_vec),
                        (8, *blinded_hints, optional_vec),
                        (9, self.payee.final_cltv_expiry_delta(), option),
                });
@@ -561,19 +589,18 @@ impl Writeable for PaymentParameters {
 
 impl ReadableArgs<u32> for PaymentParameters {
        fn read<R: io::Read>(reader: &mut R, default_final_cltv_expiry_delta: u32) -> Result<Self, DecodeError> {
-               _init_and_read_tlv_fields!(reader, {
+               _init_and_read_len_prefixed_tlv_fields!(reader, {
                        (0, payee_pubkey, option),
                        (1, max_total_cltv_expiry_delta, (default_value, DEFAULT_MAX_TOTAL_CLTV_EXPIRY_DELTA)),
                        (2, features, (option: ReadableArgs, payee_pubkey.is_some())),
                        (3, max_path_count, (default_value, DEFAULT_MAX_PATH_COUNT)),
-                       (4, route_hints, vec_type),
-                       (5, max_channel_saturation_power_of_half, (default_value, 2)),
+                       (4, clear_route_hints, required_vec),
+                       (5, max_channel_saturation_power_of_half, (default_value, DEFAULT_MAX_CHANNEL_SATURATION_POW_HALF)),
                        (6, expiry_time, option),
-                       (7, previously_failed_channels, vec_type),
+                       (7, previously_failed_channels, optional_vec),
                        (8, blinded_route_hints, optional_vec),
                        (9, final_cltv_expiry_delta, (default_value, default_final_cltv_expiry_delta)),
                });
-               let clear_route_hints = route_hints.unwrap_or(vec![]);
                let blinded_route_hints = blinded_route_hints.unwrap_or(vec![]);
                let payee = if blinded_route_hints.len() != 0 {
                        if clear_route_hints.len() != 0 || payee_pubkey.is_some() { return Err(DecodeError::InvalidValue) }
@@ -612,7 +639,7 @@ impl PaymentParameters {
                        expiry_time: None,
                        max_total_cltv_expiry_delta: DEFAULT_MAX_TOTAL_CLTV_EXPIRY_DELTA,
                        max_path_count: DEFAULT_MAX_PATH_COUNT,
-                       max_channel_saturation_power_of_half: 2,
+                       max_channel_saturation_power_of_half: DEFAULT_MAX_CHANNEL_SATURATION_POW_HALF,
                        previously_failed_channels: Vec::new(),
                }
        }
@@ -621,15 +648,57 @@ impl PaymentParameters {
        ///
        /// The `final_cltv_expiry_delta` should match the expected final CLTV delta the recipient has
        /// provided.
-       pub fn for_keysend(payee_pubkey: PublicKey, final_cltv_expiry_delta: u32) -> Self {
-               Self::from_node_id(payee_pubkey, final_cltv_expiry_delta).with_bolt11_features(InvoiceFeatures::for_keysend()).expect("PaymentParameters::from_node_id should always initialize the payee as unblinded")
+       ///
+       /// Note that MPP keysend is not widely supported yet. The `allow_mpp` lets you choose
+       /// whether your router will be allowed to find a multi-part route for this payment. If you
+       /// set `allow_mpp` to true, you should ensure a payment secret is set on send, likely via
+       /// [`RecipientOnionFields::secret_only`].
+       ///
+       /// [`RecipientOnionFields::secret_only`]: crate::ln::channelmanager::RecipientOnionFields::secret_only
+       pub fn for_keysend(payee_pubkey: PublicKey, final_cltv_expiry_delta: u32, allow_mpp: bool) -> Self {
+               Self::from_node_id(payee_pubkey, final_cltv_expiry_delta)
+                       .with_bolt11_features(Bolt11InvoiceFeatures::for_keysend(allow_mpp))
+                       .expect("PaymentParameters::from_node_id should always initialize the payee as unblinded")
+       }
+
+       /// Creates parameters for paying to a blinded payee from the provided invoice. Sets
+       /// [`Payee::Blinded::route_hints`], [`Payee::Blinded::features`], and
+       /// [`PaymentParameters::expiry_time`].
+       pub fn from_bolt12_invoice(invoice: &Bolt12Invoice) -> Self {
+               Self::blinded(invoice.payment_paths().to_vec())
+                       .with_bolt12_features(invoice.invoice_features().clone()).unwrap()
+                       .with_expiry_time(invoice.created_at().as_secs().saturating_add(invoice.relative_expiry().as_secs()))
        }
 
-       /// Includes the payee's features. Errors if the parameters were initialized with blinded payment
-       /// paths.
+       /// Creates parameters for paying to a blinded payee from the provided blinded route hints.
+       pub fn blinded(blinded_route_hints: Vec<(BlindedPayInfo, BlindedPath)>) -> Self {
+               Self {
+                       payee: Payee::Blinded { route_hints: blinded_route_hints, features: None },
+                       expiry_time: None,
+                       max_total_cltv_expiry_delta: DEFAULT_MAX_TOTAL_CLTV_EXPIRY_DELTA,
+                       max_path_count: DEFAULT_MAX_PATH_COUNT,
+                       max_channel_saturation_power_of_half: DEFAULT_MAX_CHANNEL_SATURATION_POW_HALF,
+                       previously_failed_channels: Vec::new(),
+               }
+       }
+
+       /// Includes the payee's features. Errors if the parameters were not initialized with
+       /// [`PaymentParameters::from_bolt12_invoice`].
+       ///
+       /// This is not exported to bindings users since bindings don't support move semantics
+       pub fn with_bolt12_features(self, features: Bolt12InvoiceFeatures) -> Result<Self, ()> {
+               match self.payee {
+                       Payee::Clear { .. } => Err(()),
+                       Payee::Blinded { route_hints, .. } =>
+                               Ok(Self { payee: Payee::Blinded { route_hints, features: Some(features) }, ..self })
+               }
+       }
+
+       /// Includes the payee's features. Errors if the parameters were initialized with
+       /// [`PaymentParameters::from_bolt12_invoice`].
        ///
        /// This is not exported to bindings users since bindings don't support move semantics
-       pub fn with_bolt11_features(self, features: InvoiceFeatures) -> Result<Self, ()> {
+       pub fn with_bolt11_features(self, features: Bolt11InvoiceFeatures) -> Result<Self, ()> {
                match self.payee {
                        Payee::Blinded { .. } => Err(()),
                        Payee::Clear { route_hints, node_id, final_cltv_expiry_delta, .. } =>
@@ -642,7 +711,7 @@ impl PaymentParameters {
        }
 
        /// Includes hints for routing to the payee. Errors if the parameters were initialized with
-       /// blinded payment paths.
+       /// [`PaymentParameters::from_bolt12_invoice`].
        ///
        /// This is not exported to bindings users since bindings don't support move semantics
        pub fn with_route_hints(self, route_hints: Vec<RouteHint>) -> Result<Self, ()> {
@@ -678,7 +747,8 @@ impl PaymentParameters {
                Self { max_path_count, ..self }
        }
 
-       /// Includes a limit for the maximum number of payment paths that may be used.
+       /// Includes a limit for the maximum share of a channel's total capacity that can be sent over, as
+       /// a power of 1/2. See [`PaymentParameters::max_channel_saturation_power_of_half`].
        ///
        /// This is not exported to bindings users since bindings don't support move semantics
        pub fn with_max_channel_saturation_power_of_half(self, max_channel_saturation_power_of_half: u8) -> Self {
@@ -714,7 +784,7 @@ pub enum Payee {
                /// does not contain any features.
                ///
                /// [`for_keysend`]: PaymentParameters::for_keysend
-               features: Option<InvoiceFeatures>,
+               features: Option<Bolt11InvoiceFeatures>,
                /// The minimum CLTV delta at the end of the route. This value must not be zero.
                final_cltv_expiry_delta: u32,
        },
@@ -751,14 +821,27 @@ impl Payee {
                        _ => None,
                }
        }
+       fn blinded_route_hints(&self) -> &[(BlindedPayInfo, BlindedPath)] {
+               match self {
+                       Self::Blinded { route_hints, .. } => &route_hints[..],
+                       Self::Clear { .. } => &[]
+               }
+       }
+
+       fn unblinded_route_hints(&self) -> &[RouteHint] {
+               match self {
+                       Self::Blinded { .. } => &[],
+                       Self::Clear { route_hints, .. } => &route_hints[..]
+               }
+       }
 }
 
 enum FeaturesRef<'a> {
-       Bolt11(&'a InvoiceFeatures),
+       Bolt11(&'a Bolt11InvoiceFeatures),
        Bolt12(&'a Bolt12InvoiceFeatures),
 }
 enum Features {
-       Bolt11(InvoiceFeatures),
+       Bolt11(Bolt11InvoiceFeatures),
        Bolt12(Bolt12InvoiceFeatures),
 }
 
@@ -769,7 +852,7 @@ impl Features {
                        _ => None,
                }
        }
-       fn bolt11(self) -> Option<InvoiceFeatures> {
+       fn bolt11(self) -> Option<Bolt11InvoiceFeatures> {
                match self {
                        Self::Bolt11(f) => Some(f),
                        _ => None,
@@ -895,18 +978,34 @@ enum CandidateRouteHop<'a> {
                info: DirectedChannelInfo<'a>,
                short_channel_id: u64,
        },
-       /// A hop to the payee found in the payment invoice, though not necessarily a direct channel.
+       /// A hop to the payee found in the BOLT 11 payment invoice, though not necessarily a direct
+       /// channel.
        PrivateHop {
                hint: &'a RouteHintHop,
-       }
+       },
+       /// The payee's identity is concealed behind blinded paths provided in a BOLT 12 invoice.
+       Blinded {
+               hint: &'a (BlindedPayInfo, BlindedPath),
+               hint_idx: usize,
+       },
+       /// Similar to [`Self::Blinded`], but the path here has 1 blinded hop. `BlindedPayInfo` provided
+       /// for 1-hop blinded paths is ignored because it is meant to apply to the hops *between* the
+       /// introduction node and the destination. Useful for tracking that we need to include a blinded
+       /// path at the end of our [`Route`].
+       OneHopBlinded {
+               hint: &'a (BlindedPayInfo, BlindedPath),
+               hint_idx: usize,
+       },
 }
 
 impl<'a> CandidateRouteHop<'a> {
-       fn short_channel_id(&self) -> u64 {
+       fn short_channel_id(&self) -> Option<u64> {
                match self {
-                       CandidateRouteHop::FirstHop { details } => details.get_outbound_payment_scid().unwrap(),
-                       CandidateRouteHop::PublicHop { short_channel_id, .. } => *short_channel_id,
-                       CandidateRouteHop::PrivateHop { hint } => hint.short_channel_id,
+                       CandidateRouteHop::FirstHop { details } => Some(details.get_outbound_payment_scid().unwrap()),
+                       CandidateRouteHop::PublicHop { short_channel_id, .. } => Some(*short_channel_id),
+                       CandidateRouteHop::PrivateHop { hint } => Some(hint.short_channel_id),
+                       CandidateRouteHop::Blinded { .. } => None,
+                       CandidateRouteHop::OneHopBlinded { .. } => None,
                }
        }
 
@@ -916,6 +1015,8 @@ impl<'a> CandidateRouteHop<'a> {
                        CandidateRouteHop::FirstHop { details } => details.counterparty.features.to_context(),
                        CandidateRouteHop::PublicHop { info, .. } => info.channel().features.clone(),
                        CandidateRouteHop::PrivateHop { .. } => ChannelFeatures::empty(),
+                       CandidateRouteHop::Blinded { .. } => ChannelFeatures::empty(),
+                       CandidateRouteHop::OneHopBlinded { .. } => ChannelFeatures::empty(),
                }
        }
 
@@ -924,6 +1025,8 @@ impl<'a> CandidateRouteHop<'a> {
                        CandidateRouteHop::FirstHop { .. } => 0,
                        CandidateRouteHop::PublicHop { info, .. } => info.direction().cltv_expiry_delta as u32,
                        CandidateRouteHop::PrivateHop { hint } => hint.cltv_expiry_delta as u32,
+                       CandidateRouteHop::Blinded { hint, .. } => hint.0.cltv_expiry_delta as u32,
+                       CandidateRouteHop::OneHopBlinded { .. } => 0,
                }
        }
 
@@ -932,6 +1035,8 @@ impl<'a> CandidateRouteHop<'a> {
                        CandidateRouteHop::FirstHop { details } => details.next_outbound_htlc_minimum_msat,
                        CandidateRouteHop::PublicHop { info, .. } => info.direction().htlc_minimum_msat,
                        CandidateRouteHop::PrivateHop { hint } => hint.htlc_minimum_msat.unwrap_or(0),
+                       CandidateRouteHop::Blinded { hint, .. } => hint.0.htlc_minimum_msat,
+                       CandidateRouteHop::OneHopBlinded { .. } => 0,
                }
        }
 
@@ -942,6 +1047,14 @@ impl<'a> CandidateRouteHop<'a> {
                        },
                        CandidateRouteHop::PublicHop { info, .. } => info.direction().fees,
                        CandidateRouteHop::PrivateHop { hint } => hint.fees,
+                       CandidateRouteHop::Blinded { hint, .. } => {
+                               RoutingFees {
+                                       base_msat: hint.0.fee_base_msat,
+                                       proportional_millionths: hint.0.fee_proportional_millionths
+                               }
+                       },
+                       CandidateRouteHop::OneHopBlinded { .. } =>
+                               RoutingFees { base_msat: 0, proportional_millionths: 0 },
                }
        }
 
@@ -951,11 +1064,41 @@ impl<'a> CandidateRouteHop<'a> {
                                liquidity_msat: details.next_outbound_htlc_limit_msat,
                        },
                        CandidateRouteHop::PublicHop { info, .. } => info.effective_capacity(),
-                       CandidateRouteHop::PrivateHop { .. } => EffectiveCapacity::Infinite,
+                       CandidateRouteHop::PrivateHop { hint: RouteHintHop { htlc_maximum_msat: Some(max), .. }} =>
+                               EffectiveCapacity::HintMaxHTLC { amount_msat: *max },
+                       CandidateRouteHop::PrivateHop { hint: RouteHintHop { htlc_maximum_msat: None, .. }} =>
+                               EffectiveCapacity::Infinite,
+                       CandidateRouteHop::Blinded { hint, .. } =>
+                               EffectiveCapacity::HintMaxHTLC { amount_msat: hint.0.htlc_maximum_msat },
+                       CandidateRouteHop::OneHopBlinded { .. } => EffectiveCapacity::Infinite,
+               }
+       }
+
+       fn id(&self, channel_direction: bool /* src_node_id < target_node_id */) -> CandidateHopId {
+               match self {
+                       CandidateRouteHop::Blinded { hint_idx, .. } => CandidateHopId::Blinded(*hint_idx),
+                       CandidateRouteHop::OneHopBlinded { hint_idx, .. } => CandidateHopId::Blinded(*hint_idx),
+                       _ => CandidateHopId::Clear((self.short_channel_id().unwrap(), channel_direction)),
+               }
+       }
+       fn blinded_path(&self) -> Option<&'a BlindedPath> {
+               match self {
+                       CandidateRouteHop::Blinded { hint, .. } | CandidateRouteHop::OneHopBlinded { hint, .. } => {
+                               Some(&hint.1)
+                       },
+                       _ => None,
                }
        }
 }
 
+#[derive(Clone, Copy, Eq, Hash, Ord, PartialOrd, PartialEq)]
+enum CandidateHopId {
+       /// Contains (scid, src_node_id < target_node_id)
+       Clear((u64, bool)),
+       /// Index of the blinded route hint in [`Payee::Blinded::route_hints`].
+       Blinded(usize),
+}
+
 #[inline]
 fn max_htlc_from_capacity(capacity: EffectiveCapacity, max_channel_saturation_power_of_half: u8) -> u64 {
        let saturation_shift: u32 = max_channel_saturation_power_of_half as u32;
@@ -963,8 +1106,11 @@ fn max_htlc_from_capacity(capacity: EffectiveCapacity, max_channel_saturation_po
                EffectiveCapacity::ExactLiquidity { liquidity_msat } => liquidity_msat,
                EffectiveCapacity::Infinite => u64::max_value(),
                EffectiveCapacity::Unknown => EffectiveCapacity::Unknown.as_msat(),
-               EffectiveCapacity::MaximumHTLC { amount_msat } =>
+               EffectiveCapacity::AdvertisedMaxHTLC { amount_msat } =>
                        amount_msat.checked_shr(saturation_shift).unwrap_or(0),
+               // Treat htlc_maximum_msat from a route hint as an exact liquidity amount, since the invoice is
+               // expected to have been generated from up-to-date capacity information.
+               EffectiveCapacity::HintMaxHTLC { amount_msat } => amount_msat,
                EffectiveCapacity::Total { capacity_msat, htlc_maximum_msat } =>
                        cmp::min(capacity_msat.checked_shr(saturation_shift).unwrap_or(0), htlc_maximum_msat),
        }
@@ -1101,7 +1247,7 @@ impl<'a> PaymentPath<'a> {
                                cur_hop_fees_msat = self.hops.get(i + 1).unwrap().0.hop_use_fee_msat;
                        }
 
-                       let mut cur_hop = &mut self.hops.get_mut(i).unwrap().0;
+                       let cur_hop = &mut self.hops.get_mut(i).unwrap().0;
                        cur_hop.next_hops_fee_msat = total_fee_paid_msat;
                        // Overpay in fees if we can't save these funds due to htlc_minimum_msat.
                        // We try to account for htlc_minimum_msat in scoring (add_entry!), so that nodes don't
@@ -1192,12 +1338,75 @@ impl fmt::Display for LoggedPayeePubkey {
        }
 }
 
+struct LoggedCandidateHop<'a>(&'a CandidateRouteHop<'a>);
+impl<'a> fmt::Display for LoggedCandidateHop<'a> {
+       fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+               match self.0 {
+                       CandidateRouteHop::Blinded { hint, .. } | CandidateRouteHop::OneHopBlinded { hint, .. } => {
+                               "blinded route hint with introduction node id ".fmt(f)?;
+                               hint.1.introduction_node_id.fmt(f)?;
+                               " and blinding point ".fmt(f)?;
+                               hint.1.blinding_point.fmt(f)
+                       },
+                       CandidateRouteHop::FirstHop { .. } => {
+                               "first hop with SCID ".fmt(f)?;
+                               self.0.short_channel_id().unwrap().fmt(f)
+                       },
+                       CandidateRouteHop::PrivateHop { .. } => {
+                               "route hint with SCID ".fmt(f)?;
+                               self.0.short_channel_id().unwrap().fmt(f)
+                       },
+                       _ => {
+                               "SCID ".fmt(f)?;
+                               self.0.short_channel_id().unwrap().fmt(f)
+                       },
+               }
+       }
+}
+
+#[inline]
+fn sort_first_hop_channels(
+       channels: &mut Vec<&ChannelDetails>, used_liquidities: &HashMap<CandidateHopId, u64>,
+       recommended_value_msat: u64, our_node_pubkey: &PublicKey
+) {
+       // Sort the first_hops channels to the same node(s) in priority order of which channel we'd
+       // most like to use.
+       //
+       // First, if channels are below `recommended_value_msat`, sort them in descending order,
+       // preferring larger channels to avoid splitting the payment into more MPP parts than is
+       // required.
+       //
+       // Second, because simply always sorting in descending order would always use our largest
+       // available outbound capacity, needlessly fragmenting our available channel capacities,
+       // sort channels above `recommended_value_msat` in ascending order, preferring channels
+       // which have enough, but not too much, capacity for the payment.
+       //
+       // Available outbound balances factor in liquidity already reserved for previously found paths.
+       channels.sort_unstable_by(|chan_a, chan_b| {
+               let chan_a_outbound_limit_msat = chan_a.next_outbound_htlc_limit_msat
+                       .saturating_sub(*used_liquidities.get(&CandidateHopId::Clear((chan_a.get_outbound_payment_scid().unwrap(),
+                       our_node_pubkey < &chan_a.counterparty.node_id))).unwrap_or(&0));
+               let chan_b_outbound_limit_msat = chan_b.next_outbound_htlc_limit_msat
+                       .saturating_sub(*used_liquidities.get(&CandidateHopId::Clear((chan_b.get_outbound_payment_scid().unwrap(),
+                       our_node_pubkey < &chan_b.counterparty.node_id))).unwrap_or(&0));
+               if chan_b_outbound_limit_msat < recommended_value_msat || chan_a_outbound_limit_msat < recommended_value_msat {
+                       // Sort in descending order
+                       chan_b_outbound_limit_msat.cmp(&chan_a_outbound_limit_msat)
+               } else {
+                       // Sort in ascending order
+                       chan_a_outbound_limit_msat.cmp(&chan_b_outbound_limit_msat)
+               }
+       });
+}
+
 /// Finds a route from us (payer) to the given target node (payee).
 ///
-/// If the payee provided features in their invoice, they should be provided via `params.payee`.
+/// If the payee provided features in their invoice, they should be provided via the `payee` field
+/// in the given [`RouteParameters::payment_params`].
 /// Without this, MPP will only be used if the payee's features are available in the network graph.
 ///
-/// Private routing paths between a public node and the target may be included in `params.payee`.
+/// Private routing paths between a public node and the target may be included in the `payee` field
+/// of [`RouteParameters::payment_params`].
 ///
 /// If some channels aren't announced, it may be useful to fill in `first_hops` with the results
 /// from [`ChannelManager::list_usable_channels`]. If it is filled in, the view of these channels
@@ -1207,45 +1416,41 @@ impl fmt::Display for LoggedPayeePubkey {
 /// However, the enabled/disabled bit on such channels as well as the `htlc_minimum_msat` /
 /// `htlc_maximum_msat` *are* checked as they may change based on the receiving node.
 ///
-/// # Note
-///
-/// May be used to re-compute a [`Route`] when handling a [`Event::PaymentPathFailed`]. Any
-/// adjustments to the [`NetworkGraph`] and channel scores should be made prior to calling this
-/// function.
-///
 /// # Panics
 ///
-/// Panics if first_hops contains channels without short_channel_ids;
+/// Panics if first_hops contains channels without `short_channel_id`s;
 /// [`ChannelManager::list_usable_channels`] will never include such channels.
 ///
 /// [`ChannelManager::list_usable_channels`]: crate::ln::channelmanager::ChannelManager::list_usable_channels
 /// [`Event::PaymentPathFailed`]: crate::events::Event::PaymentPathFailed
 /// [`NetworkGraph`]: crate::routing::gossip::NetworkGraph
-pub fn find_route<L: Deref, GL: Deref, S: Score>(
+pub fn find_route<L: Deref, GL: Deref, S: ScoreLookUp>(
        our_node_pubkey: &PublicKey, route_params: &RouteParameters,
        network_graph: &NetworkGraph<GL>, first_hops: Option<&[&ChannelDetails]>, logger: L,
        scorer: &S, score_params: &S::ScoreParams, random_seed_bytes: &[u8; 32]
 ) -> Result<Route, LightningError>
 where L::Target: Logger, GL::Target: Logger {
        let graph_lock = network_graph.read_only();
-       let mut route = get_route(our_node_pubkey, &route_params.payment_params, &graph_lock, first_hops,
-               route_params.final_value_msat, logger, scorer, score_params,
-               random_seed_bytes)?;
+       let mut route = get_route(our_node_pubkey, &route_params, &graph_lock, first_hops, logger,
+               scorer, score_params, random_seed_bytes)?;
        add_random_cltv_offset(&mut route, &route_params.payment_params, &graph_lock, random_seed_bytes);
        Ok(route)
 }
 
-pub(crate) fn get_route<L: Deref, S: Score>(
-       our_node_pubkey: &PublicKey, payment_params: &PaymentParameters, network_graph: &ReadOnlyNetworkGraph,
-       first_hops: Option<&[&ChannelDetails]>, final_value_msat: u64, logger: L, scorer: &S, score_params: &S::ScoreParams,
+pub(crate) fn get_route<L: Deref, S: ScoreLookUp>(
+       our_node_pubkey: &PublicKey, route_params: &RouteParameters, network_graph: &ReadOnlyNetworkGraph,
+       first_hops: Option<&[&ChannelDetails]>, logger: L, scorer: &S, score_params: &S::ScoreParams,
        _random_seed_bytes: &[u8; 32]
 ) -> Result<Route, LightningError>
 where L::Target: Logger {
+
+       let payment_params = &route_params.payment_params;
+       let final_value_msat = route_params.final_value_msat;
        // If we're routing to a blinded recipient, we won't have their node id. Therefore, keep the
        // unblinded payee id as an option. We also need a non-optional "payee id" for path construction,
        // so use a dummy id for this in the blinded case.
        let payee_node_id_opt = payment_params.payee.node_id().map(|pk| NodeId::from_pubkey(&pk));
-       const DUMMY_BLINDED_PAYEE_ID: [u8; 33] = [42u8; 33];
+       const DUMMY_BLINDED_PAYEE_ID: [u8; 33] = [2; 33];
        let maybe_dummy_payee_pk = payment_params.payee.node_id().unwrap_or_else(|| PublicKey::from_slice(&DUMMY_BLINDED_PAYEE_ID).unwrap());
        let maybe_dummy_payee_node_id = NodeId::from_pubkey(&maybe_dummy_payee_pk);
        let our_node_id = NodeId::from_pubkey(&our_node_pubkey);
@@ -1272,8 +1477,23 @@ where L::Target: Logger {
                                }
                        }
                },
-               _ => return Err(LightningError{err: "Routing to blinded paths isn't supported yet".to_owned(), action: ErrorAction::IgnoreError}),
-
+               Payee::Blinded { route_hints, .. } => {
+                       if route_hints.iter().all(|(_, path)| &path.introduction_node_id == our_node_pubkey) {
+                               return Err(LightningError{err: "Cannot generate a route to blinded paths if we are the introduction node to all of them".to_owned(), action: ErrorAction::IgnoreError});
+                       }
+                       for (_, blinded_path) in route_hints.iter() {
+                               if blinded_path.blinded_hops.len() == 0 {
+                                       return Err(LightningError{err: "0-hop blinded path provided".to_owned(), action: ErrorAction::IgnoreError});
+                               } else if &blinded_path.introduction_node_id == our_node_pubkey {
+                                       log_info!(logger, "Got blinded path with ourselves as the introduction node, ignoring");
+                               } else if blinded_path.blinded_hops.len() == 1 &&
+                                       route_hints.iter().any( |(_, p)| p.blinded_hops.len() == 1
+                                               && p.introduction_node_id != blinded_path.introduction_node_id)
+                               {
+                                       return Err(LightningError{err: format!("1-hop blinded paths must all have matching introduction node ids"), action: ErrorAction::IgnoreError});
+                               }
+                       }
+               }
        }
        let final_cltv_expiry_delta = payment_params.payee.final_cltv_expiry_delta().unwrap_or(0);
        if payment_params.max_total_cltv_expiry_delta <= final_cltv_expiry_delta {
@@ -1425,11 +1645,12 @@ where L::Target: Logger {
        // drop the requirement by setting this to 0.
        let mut channel_saturation_pow_half = payment_params.max_channel_saturation_power_of_half;
 
-       // Keep track of how much liquidity has been used in selected channels. Used to determine
-       // if the channel can be used by additional MPP paths or to inform path finding decisions. It is
-       // aware of direction *only* to ensure that the correct htlc_maximum_msat value is used. Hence,
-       // liquidity used in one direction will not offset any used in the opposite direction.
-       let mut used_channel_liquidities: HashMap<(u64, bool), u64> =
+       // Keep track of how much liquidity has been used in selected channels or blinded paths. Used to
+       // determine if the channel can be used by additional MPP paths or to inform path finding
+       // decisions. It is aware of direction *only* to ensure that the correct htlc_maximum_msat value
+       // is used. Hence, liquidity used in one direction will not offset any used in the opposite
+       // direction.
+       let mut used_liquidities: HashMap<CandidateHopId, u64> =
                HashMap::with_capacity(network_nodes.len());
 
        // Keeping track of how much value we already collected across other paths. Helps to decide
@@ -1437,31 +1658,19 @@ where L::Target: Logger {
        let mut already_collected_value_msat = 0;
 
        for (_, channels) in first_hop_targets.iter_mut() {
-               // Sort the first_hops channels to the same node(s) in priority order of which channel we'd
-               // most like to use.
-               //
-               // First, if channels are below `recommended_value_msat`, sort them in descending order,
-               // preferring larger channels to avoid splitting the payment into more MPP parts than is
-               // required.
-               //
-               // Second, because simply always sorting in descending order would always use our largest
-               // available outbound capacity, needlessly fragmenting our available channel capacities,
-               // sort channels above `recommended_value_msat` in ascending order, preferring channels
-               // which have enough, but not too much, capacity for the payment.
-               channels.sort_unstable_by(|chan_a, chan_b| {
-                       if chan_b.next_outbound_htlc_limit_msat < recommended_value_msat || chan_a.next_outbound_htlc_limit_msat < recommended_value_msat {
-                               // Sort in descending order
-                               chan_b.next_outbound_htlc_limit_msat.cmp(&chan_a.next_outbound_htlc_limit_msat)
-                       } else {
-                               // Sort in ascending order
-                               chan_a.next_outbound_htlc_limit_msat.cmp(&chan_b.next_outbound_htlc_limit_msat)
-                       }
-               });
+               sort_first_hop_channels(channels, &used_liquidities, recommended_value_msat,
+                       our_node_pubkey);
        }
 
        log_trace!(logger, "Building path from {} to payer {} for value {} msat.",
                LoggedPayeePubkey(payment_params.payee.node_id()), our_node_pubkey, final_value_msat);
 
+       // Remember how many candidates we ignored to allow for some logging afterwards.
+       let mut num_ignored_value_contribution = 0;
+       let mut num_ignored_path_length_limit = 0;
+       let mut num_ignored_cltv_delta_limit = 0;
+       let mut num_ignored_previously_failed = 0;
+
        macro_rules! add_entry {
                // Adds entry which goes from $src_node_id to $dest_node_id over the $candidate hop.
                // $next_hops_fee_msat represents the fees paid for using all the channels *after* this one,
@@ -1470,14 +1679,15 @@ where L::Target: Logger {
                ( $candidate: expr, $src_node_id: expr, $dest_node_id: expr, $next_hops_fee_msat: expr,
                        $next_hops_value_contribution: expr, $next_hops_path_htlc_minimum_msat: expr,
                        $next_hops_path_penalty_msat: expr, $next_hops_cltv_delta: expr, $next_hops_path_length: expr ) => { {
-                       // We "return" whether we updated the path at the end, via this:
-                       let mut did_add_update_path_to_src_node = false;
+                       // We "return" whether we updated the path at the end, and how much we can route via
+                       // this channel, via this:
+                       let mut did_add_update_path_to_src_node = None;
                        // Channels to self should not be used. This is more of belt-and-suspenders, because in
                        // practice these cases should be caught earlier:
                        // - for regular channels at channel announcement (TODO)
                        // - for first and last hops early in get_route
                        if $src_node_id != $dest_node_id {
-                               let short_channel_id = $candidate.short_channel_id();
+                               let scid_opt = $candidate.short_channel_id();
                                let effective_capacity = $candidate.effective_capacity();
                                let htlc_maximum_msat = max_htlc_from_capacity(effective_capacity, channel_saturation_pow_half);
 
@@ -1489,8 +1699,8 @@ where L::Target: Logger {
                                // if the amount being transferred over this path is lower.
                                // We do this for now, but this is a subject for removal.
                                if let Some(mut available_value_contribution_msat) = htlc_maximum_msat.checked_sub($next_hops_fee_msat) {
-                                       let used_liquidity_msat = used_channel_liquidities
-                                               .get(&(short_channel_id, $src_node_id < $dest_node_id))
+                                       let used_liquidity_msat = used_liquidities
+                                               .get(&$candidate.id($src_node_id < $dest_node_id))
                                                .map_or(0, |used_liquidity_msat| {
                                                        available_value_contribution_msat = available_value_contribution_msat
                                                                .saturating_sub(*used_liquidity_msat);
@@ -1532,16 +1742,40 @@ where L::Target: Logger {
                                                 (amount_to_transfer_over_msat < $next_hops_path_htlc_minimum_msat &&
                                                  recommended_value_msat > $next_hops_path_htlc_minimum_msat));
 
-                                       let payment_failed_on_this_channel =
-                                               payment_params.previously_failed_channels.contains(&short_channel_id);
+                                       let payment_failed_on_this_channel = scid_opt.map_or(false,
+                                               |scid| payment_params.previously_failed_channels.contains(&scid));
+
+                                       let should_log_candidate = match $candidate {
+                                               CandidateRouteHop::FirstHop { .. } => true,
+                                               CandidateRouteHop::PrivateHop { .. } => true,
+                                               CandidateRouteHop::Blinded { .. } => true,
+                                               _ => false,
+                                       };
 
                                        // If HTLC minimum is larger than the amount we're going to transfer, we shouldn't
                                        // bother considering this channel. If retrying with recommended_value_msat may
                                        // allow us to hit the HTLC minimum limit, set htlc_minimum_limit so that we go
                                        // around again with a higher amount.
-                                       if !contributes_sufficient_value || exceeds_max_path_length ||
-                                               exceeds_cltv_delta_limit || payment_failed_on_this_channel {
-                                               // Path isn't useful, ignore it and move on.
+                                       if !contributes_sufficient_value {
+                                               if should_log_candidate {
+                                                       log_trace!(logger, "Ignoring {} due to insufficient value contribution.", LoggedCandidateHop(&$candidate));
+                                               }
+                                               num_ignored_value_contribution += 1;
+                                       } else if exceeds_max_path_length {
+                                               if should_log_candidate {
+                                                       log_trace!(logger, "Ignoring {} due to exceeding maximum path length limit.", LoggedCandidateHop(&$candidate));
+                                               }
+                                               num_ignored_path_length_limit += 1;
+                                       } else if exceeds_cltv_delta_limit {
+                                               if should_log_candidate {
+                                                       log_trace!(logger, "Ignoring {} due to exceeding CLTV delta limit.", LoggedCandidateHop(&$candidate));
+                                               }
+                                               num_ignored_cltv_delta_limit += 1;
+                                       } else if payment_failed_on_this_channel {
+                                               if should_log_candidate {
+                                                       log_trace!(logger, "Ignoring {} due to a failed previous payment attempt.", LoggedCandidateHop(&$candidate));
+                                               }
+                                               num_ignored_previously_failed += 1;
                                        } else if may_overpay_to_meet_path_minimum_msat {
                                                hit_minimum_limit = true;
                                        } else if over_path_minimum_msat {
@@ -1602,9 +1836,9 @@ where L::Target: Logger {
                                                                inflight_htlc_msat: used_liquidity_msat,
                                                                effective_capacity,
                                                        };
-                                                       let channel_penalty_msat = scorer.channel_penalty_msat(
-                                                               short_channel_id, &$src_node_id, &$dest_node_id, channel_usage, score_params
-                                                       );
+                                                       let channel_penalty_msat = scid_opt.map_or(0,
+                                                               |scid| scorer.channel_penalty_msat(scid, &$src_node_id, &$dest_node_id,
+                                                                       channel_usage, score_params));
                                                        let path_penalty_msat = $next_hops_path_penalty_msat
                                                                .saturating_add(channel_penalty_msat);
                                                        let new_graph_node = RouteGraphNode {
@@ -1652,7 +1886,7 @@ where L::Target: Logger {
                                                                {
                                                                        old_entry.value_contribution_msat = value_contribution_msat;
                                                                }
-                                                               did_add_update_path_to_src_node = true;
+                                                               did_add_update_path_to_src_node = Some(value_contribution_msat);
                                                        } else if old_entry.was_processed && new_cost < old_cost {
                                                                #[cfg(all(not(ldk_bench), any(test, fuzzing)))]
                                                                {
@@ -1761,7 +1995,7 @@ where L::Target: Logger {
 
        // TODO: diversify by nodes (so that all paths aren't doomed if one node is offline).
        'paths_collection: loop {
-               // For every new path, start from scratch, except for used_channel_liquidities, which
+               // For every new path, start from scratch, except for used_liquidities, which
                // helps to avoid reusing previously selected paths in future iterations.
                targets.clear();
                dist.clear();
@@ -1773,9 +2007,9 @@ where L::Target: Logger {
                        for details in first_channels {
                                let candidate = CandidateRouteHop::FirstHop { details };
                                let added = add_entry!(candidate, our_node_id, payee, 0, path_value_msat,
-                                                                       0, 0u64, 0, 0);
-                               log_trace!(logger, "{} direct route to payee via SCID {}",
-                                               if added { "Added" } else { "Skipped" }, candidate.short_channel_id());
+                                                                       0, 0u64, 0, 0).is_some();
+                               log_trace!(logger, "{} direct route to payee via {}",
+                                               if added { "Added" } else { "Skipped" }, LoggedCandidateHop(&candidate));
                        }
                }));
 
@@ -1796,11 +2030,43 @@ where L::Target: Logger {
                // If a caller provided us with last hops, add them to routing targets. Since this happens
                // earlier than general path finding, they will be somewhat prioritized, although currently
                // it matters only if the fees are exactly the same.
-               let route_hints = match &payment_params.payee {
-                       Payee::Clear { route_hints, .. } => route_hints,
-                       _ => return Err(LightningError{err: "Routing to blinded paths isn't supported yet".to_owned(), action: ErrorAction::IgnoreError}),
-               };
-               for route in route_hints.iter().filter(|route| !route.0.is_empty()) {
+               for (hint_idx, hint) in payment_params.payee.blinded_route_hints().iter().enumerate() {
+                       let intro_node_id = NodeId::from_pubkey(&hint.1.introduction_node_id);
+                       let have_intro_node_in_graph =
+                               // Only add the hops in this route to our candidate set if either
+                               // we have a direct channel to the first hop or the first hop is
+                               // in the regular network graph.
+                               first_hop_targets.get(&intro_node_id).is_some() ||
+                               network_nodes.get(&intro_node_id).is_some();
+                       if !have_intro_node_in_graph { continue }
+                       let candidate = if hint.1.blinded_hops.len() == 1 {
+                               CandidateRouteHop::OneHopBlinded { hint, hint_idx }
+                       } else { CandidateRouteHop::Blinded { hint, hint_idx } };
+                       let mut path_contribution_msat = path_value_msat;
+                       if let Some(hop_used_msat) = add_entry!(candidate, intro_node_id, maybe_dummy_payee_node_id,
+                               0, path_contribution_msat, 0, 0_u64, 0, 0)
+                       {
+                               path_contribution_msat = hop_used_msat;
+                       } else { continue }
+                       if let Some(first_channels) = first_hop_targets.get_mut(&NodeId::from_pubkey(&hint.1.introduction_node_id)) {
+                               sort_first_hop_channels(first_channels, &used_liquidities, recommended_value_msat,
+                                       our_node_pubkey);
+                               for details in first_channels {
+                                       let first_hop_candidate = CandidateRouteHop::FirstHop { details };
+                                       let blinded_path_fee = match compute_fees(path_contribution_msat, candidate.fees()) {
+                                               Some(fee) => fee,
+                                               None => continue
+                                       };
+                                       add_entry!(first_hop_candidate, our_node_id, intro_node_id, blinded_path_fee,
+                                               path_contribution_msat, candidate.htlc_minimum_msat(), 0_u64,
+                                               candidate.cltv_expiry_delta(),
+                                               candidate.blinded_path().map_or(1, |bp| bp.blinded_hops.len() as u8));
+                               }
+                       }
+               }
+               for route in payment_params.payee.unblinded_route_hints().iter()
+                       .filter(|route| !route.0.is_empty())
+               {
                        let first_hop_in_route = &(route.0)[0];
                        let have_hop_src_in_graph =
                                // Only add the hops in this route to our candidate set if either
@@ -1820,6 +2086,7 @@ where L::Target: Logger {
                                let mut aggregate_next_hops_path_penalty_msat: u64 = 0;
                                let mut aggregate_next_hops_cltv_delta: u32 = 0;
                                let mut aggregate_next_hops_path_length: u8 = 0;
+                               let mut aggregate_path_contribution_msat = path_value_msat;
 
                                for (idx, (hop, prev_hop_id)) in hop_iter.zip(prev_hop_iter).enumerate() {
                                        let source = NodeId::from_pubkey(&hop.src_node_id);
@@ -1833,18 +2100,22 @@ where L::Target: Logger {
                                                })
                                                .unwrap_or_else(|| CandidateRouteHop::PrivateHop { hint: hop });
 
-                                       if !add_entry!(candidate, source, target, aggregate_next_hops_fee_msat,
-                                                               path_value_msat, aggregate_next_hops_path_htlc_minimum_msat,
-                                                               aggregate_next_hops_path_penalty_msat,
-                                                               aggregate_next_hops_cltv_delta, aggregate_next_hops_path_length) {
+                                       if let Some(hop_used_msat) = add_entry!(candidate, source, target,
+                                               aggregate_next_hops_fee_msat, aggregate_path_contribution_msat,
+                                               aggregate_next_hops_path_htlc_minimum_msat, aggregate_next_hops_path_penalty_msat,
+                                               aggregate_next_hops_cltv_delta, aggregate_next_hops_path_length)
+                                       {
+                                               aggregate_path_contribution_msat = hop_used_msat;
+                                       } else {
                                                // If this hop was not used then there is no use checking the preceding
                                                // hops in the RouteHint. We can break by just searching for a direct
                                                // channel between last checked hop and first_hop_targets.
                                                hop_used = false;
                                        }
 
-                                       let used_liquidity_msat = used_channel_liquidities
-                                               .get(&(hop.short_channel_id, source < target)).copied().unwrap_or(0);
+                                       let used_liquidity_msat = used_liquidities
+                                               .get(&candidate.id(source < target)).copied()
+                                               .unwrap_or(0);
                                        let channel_usage = ChannelUsage {
                                                amount_msat: final_value_msat + aggregate_next_hops_fee_msat,
                                                inflight_htlc_msat: used_liquidity_msat,
@@ -1863,14 +2134,15 @@ where L::Target: Logger {
                                                .saturating_add(1);
 
                                        // Searching for a direct channel between last checked hop and first_hop_targets
-                                       if let Some(first_channels) = first_hop_targets.get(&NodeId::from_pubkey(&prev_hop_id)) {
+                                       if let Some(first_channels) = first_hop_targets.get_mut(&NodeId::from_pubkey(&prev_hop_id)) {
+                                               sort_first_hop_channels(first_channels, &used_liquidities,
+                                                       recommended_value_msat, our_node_pubkey);
                                                for details in first_channels {
-                                                       let candidate = CandidateRouteHop::FirstHop { details };
-                                                       add_entry!(candidate, our_node_id, NodeId::from_pubkey(&prev_hop_id),
-                                                               aggregate_next_hops_fee_msat, path_value_msat,
-                                                               aggregate_next_hops_path_htlc_minimum_msat,
-                                                               aggregate_next_hops_path_penalty_msat, aggregate_next_hops_cltv_delta,
-                                                               aggregate_next_hops_path_length);
+                                                       let first_hop_candidate = CandidateRouteHop::FirstHop { details };
+                                                       add_entry!(first_hop_candidate, our_node_id, NodeId::from_pubkey(&prev_hop_id),
+                                                               aggregate_next_hops_fee_msat, aggregate_path_contribution_msat,
+                                                               aggregate_next_hops_path_htlc_minimum_msat, aggregate_next_hops_path_penalty_msat,
+                                                               aggregate_next_hops_cltv_delta, aggregate_next_hops_path_length);
                                                }
                                        }
 
@@ -1903,12 +2175,15 @@ where L::Target: Logger {
                                                // Note that we *must* check if the last hop was added as `add_entry`
                                                // always assumes that the third argument is a node to which we have a
                                                // path.
-                                               if let Some(first_channels) = first_hop_targets.get(&NodeId::from_pubkey(&hop.src_node_id)) {
+                                               if let Some(first_channels) = first_hop_targets.get_mut(&NodeId::from_pubkey(&hop.src_node_id)) {
+                                                       sort_first_hop_channels(first_channels, &used_liquidities,
+                                                               recommended_value_msat, our_node_pubkey);
                                                        for details in first_channels {
-                                                               let candidate = CandidateRouteHop::FirstHop { details };
-                                                               add_entry!(candidate, our_node_id,
+                                                               let first_hop_candidate = CandidateRouteHop::FirstHop { details };
+                                                               add_entry!(first_hop_candidate, our_node_id,
                                                                        NodeId::from_pubkey(&hop.src_node_id),
-                                                                       aggregate_next_hops_fee_msat, path_value_msat,
+                                                                       aggregate_next_hops_fee_msat,
+                                                                       aggregate_path_contribution_msat,
                                                                        aggregate_next_hops_path_htlc_minimum_msat,
                                                                        aggregate_next_hops_path_penalty_msat,
                                                                        aggregate_next_hops_cltv_delta,
@@ -1947,10 +2222,12 @@ where L::Target: Logger {
                                        let mut features_set = false;
                                        if let Some(first_channels) = first_hop_targets.get(&ordered_hops.last().unwrap().0.node_id) {
                                                for details in first_channels {
-                                                       if details.get_outbound_payment_scid().unwrap() == ordered_hops.last().unwrap().0.candidate.short_channel_id() {
-                                                               ordered_hops.last_mut().unwrap().1 = details.counterparty.features.to_context();
-                                                               features_set = true;
-                                                               break;
+                                                       if let Some(scid) = ordered_hops.last().unwrap().0.candidate.short_channel_id() {
+                                                               if details.get_outbound_payment_scid().unwrap() == scid {
+                                                                       ordered_hops.last_mut().unwrap().1 = details.counterparty.features.to_context();
+                                                                       features_set = true;
+                                                                       break;
+                                                               }
                                                        }
                                                }
                                        }
@@ -2019,8 +2296,8 @@ where L::Target: Logger {
                                        .chain(payment_path.hops.iter().map(|(hop, _)| &hop.node_id));
                                for (prev_hop, (hop, _)) in prev_hop_iter.zip(payment_path.hops.iter()) {
                                        let spent_on_hop_msat = value_contribution_msat + hop.next_hops_fee_msat;
-                                       let used_liquidity_msat = used_channel_liquidities
-                                               .entry((hop.candidate.short_channel_id(), *prev_hop < hop.node_id))
+                                       let used_liquidity_msat = used_liquidities
+                                               .entry(hop.candidate.id(*prev_hop < hop.node_id))
                                                .and_modify(|used_liquidity_msat| *used_liquidity_msat += spent_on_hop_msat)
                                                .or_insert(spent_on_hop_msat);
                                        let hop_capacity = hop.candidate.effective_capacity();
@@ -2036,11 +2313,12 @@ where L::Target: Logger {
                                        // If we weren't capped by hitting a liquidity limit on a channel in the path,
                                        // we'll probably end up picking the same path again on the next iteration.
                                        // Decrease the available liquidity of a hop in the middle of the path.
-                                       let victim_scid = payment_path.hops[(payment_path.hops.len()) / 2].0.candidate.short_channel_id();
+                                       let victim_candidate = &payment_path.hops[(payment_path.hops.len()) / 2].0.candidate;
                                        let exhausted = u64::max_value();
-                                       log_trace!(logger, "Disabling channel {} for future path building iterations to avoid duplicates.", victim_scid);
-                                       *used_channel_liquidities.entry((victim_scid, false)).or_default() = exhausted;
-                                       *used_channel_liquidities.entry((victim_scid, true)).or_default() = exhausted;
+                                       log_trace!(logger, "Disabling route candidate {} for future path building iterations to
+                                               avoid duplicates.", LoggedCandidateHop(victim_candidate));
+                                       *used_liquidities.entry(victim_candidate.id(false)).or_default() = exhausted;
+                                       *used_liquidities.entry(victim_candidate.id(true)).or_default() = exhausted;
                                }
 
                                // Track the total amount all our collected paths allow to send so that we know
@@ -2105,6 +2383,12 @@ where L::Target: Logger {
                }
        }
 
+       let num_ignored_total = num_ignored_value_contribution + num_ignored_path_length_limit +
+               num_ignored_cltv_delta_limit + num_ignored_previously_failed;
+       if num_ignored_total > 0 {
+               log_trace!(logger, "Ignored {} candidate hops due to insufficient value contribution, {} due to path length limit, {} due to CLTV delta limit, {} due to previous payment failure. Total: {} ignored candidates.", num_ignored_value_contribution, num_ignored_path_length_limit, num_ignored_cltv_delta_limit, num_ignored_previously_failed, num_ignored_total);
+       }
+
        // Step (5).
        if payment_paths.len() == 0 {
                return Err(LightningError{err: "Failed to find a path to the given destination".to_owned(), action: ErrorAction::IgnoreError});
@@ -2168,63 +2452,68 @@ where L::Target: Logger {
        // compare both SCIDs and NodeIds as individual nodes may use random aliases causing collisions
        // across nodes.
        selected_route.sort_unstable_by_key(|path| {
-               let mut key = [0u64; MAX_PATH_LENGTH_ESTIMATE as usize];
+               let mut key = [CandidateHopId::Clear((42, true)) ; MAX_PATH_LENGTH_ESTIMATE as usize];
                debug_assert!(path.hops.len() <= key.len());
-               for (scid, key) in path.hops.iter().map(|h| h.0.candidate.short_channel_id()).zip(key.iter_mut()) {
+               for (scid, key) in path.hops.iter() .map(|h| h.0.candidate.id(true)).zip(key.iter_mut()) {
                        *key = scid;
                }
                key
        });
        for idx in 0..(selected_route.len() - 1) {
                if idx + 1 >= selected_route.len() { break; }
-               if iter_equal(selected_route[idx    ].hops.iter().map(|h| (h.0.candidate.short_channel_id(), h.0.node_id)),
-                             selected_route[idx + 1].hops.iter().map(|h| (h.0.candidate.short_channel_id(), h.0.node_id))) {
+               if iter_equal(selected_route[idx    ].hops.iter().map(|h| (h.0.candidate.id(true), h.0.node_id)),
+                             selected_route[idx + 1].hops.iter().map(|h| (h.0.candidate.id(true), h.0.node_id))) {
                        let new_value = selected_route[idx].get_value_msat() + selected_route[idx + 1].get_value_msat();
                        selected_route[idx].update_value_and_recompute_fees(new_value);
                        selected_route.remove(idx + 1);
                }
        }
 
-       let mut selected_paths = Vec::<Vec<Result<RouteHop, LightningError>>>::new();
+       let mut paths = Vec::new();
        for payment_path in selected_route {
-               let mut path = payment_path.hops.iter().map(|(payment_hop, node_features)| {
-                       Ok(RouteHop {
-                               pubkey: PublicKey::from_slice(payment_hop.node_id.as_slice()).map_err(|_| LightningError{err: format!("Public key {:?} is invalid", &payment_hop.node_id), action: ErrorAction::IgnoreAndLog(Level::Trace)})?,
+               let mut hops = Vec::with_capacity(payment_path.hops.len());
+               for (hop, node_features) in payment_path.hops.iter()
+                       .filter(|(h, _)| h.candidate.short_channel_id().is_some())
+               {
+                       hops.push(RouteHop {
+                               pubkey: PublicKey::from_slice(hop.node_id.as_slice()).map_err(|_| LightningError{err: format!("Public key {:?} is invalid", &hop.node_id), action: ErrorAction::IgnoreAndLog(Level::Trace)})?,
                                node_features: node_features.clone(),
-                               short_channel_id: payment_hop.candidate.short_channel_id(),
-                               channel_features: payment_hop.candidate.features(),
-                               fee_msat: payment_hop.fee_msat,
-                               cltv_expiry_delta: payment_hop.candidate.cltv_expiry_delta(),
-                       })
-               }).collect::<Vec<_>>();
+                               short_channel_id: hop.candidate.short_channel_id().unwrap(),
+                               channel_features: hop.candidate.features(),
+                               fee_msat: hop.fee_msat,
+                               cltv_expiry_delta: hop.candidate.cltv_expiry_delta(),
+                       });
+               }
+               let mut final_cltv_delta = final_cltv_expiry_delta;
+               let blinded_tail = payment_path.hops.last().and_then(|(h, _)| {
+                       if let Some(blinded_path) = h.candidate.blinded_path() {
+                               final_cltv_delta = h.candidate.cltv_expiry_delta();
+                               Some(BlindedTail {
+                                       hops: blinded_path.blinded_hops.clone(),
+                                       blinding_point: blinded_path.blinding_point,
+                                       excess_final_cltv_expiry_delta: 0,
+                                       final_value_msat: h.fee_msat,
+                               })
+                       } else { None }
+               });
                // Propagate the cltv_expiry_delta one hop backwards since the delta from the current hop is
                // applicable for the previous hop.
-               path.iter_mut().rev().fold(final_cltv_expiry_delta, |prev_cltv_expiry_delta, hop| {
-                       core::mem::replace(&mut hop.as_mut().unwrap().cltv_expiry_delta, prev_cltv_expiry_delta)
+               hops.iter_mut().rev().fold(final_cltv_delta, |prev_cltv_expiry_delta, hop| {
+                       core::mem::replace(&mut hop.cltv_expiry_delta, prev_cltv_expiry_delta)
                });
-               selected_paths.push(path);
+
+               paths.push(Path { hops, blinded_tail });
        }
        // Make sure we would never create a route with more paths than we allow.
-       debug_assert!(selected_paths.len() <= payment_params.max_path_count.into());
+       debug_assert!(paths.len() <= payment_params.max_path_count.into());
 
        if let Some(node_features) = payment_params.payee.node_features() {
-               for path in selected_paths.iter_mut() {
-                       if let Ok(route_hop) = path.last_mut().unwrap() {
-                               route_hop.node_features = node_features.clone();
-                       }
+               for path in paths.iter_mut() {
+                       path.hops.last_mut().unwrap().node_features = node_features.clone();
                }
        }
 
-       let mut paths: Vec<Path> = Vec::new();
-       for results_vec in selected_paths {
-               let mut hops = Vec::with_capacity(results_vec.len());
-               for res in results_vec { hops.push(res?); }
-               paths.push(Path { hops, blinded_tail: None });
-       }
-       let route = Route {
-               paths,
-               payment_params: Some(payment_params.clone()),
-       };
+       let route = Route { paths, route_params: Some(route_params.clone()) };
        log_info!(logger, "Got route: {}", log_route!(route));
        Ok(route)
 }
@@ -2329,17 +2618,15 @@ pub fn build_route_from_hops<L: Deref, GL: Deref>(
 ) -> Result<Route, LightningError>
 where L::Target: Logger, GL::Target: Logger {
        let graph_lock = network_graph.read_only();
-       let mut route = build_route_from_hops_internal(
-               our_node_pubkey, hops, &route_params.payment_params, &graph_lock,
-               route_params.final_value_msat, logger, random_seed_bytes)?;
+       let mut route = build_route_from_hops_internal(our_node_pubkey, hops, &route_params,
+               &graph_lock, logger, random_seed_bytes)?;
        add_random_cltv_offset(&mut route, &route_params.payment_params, &graph_lock, random_seed_bytes);
        Ok(route)
 }
 
 fn build_route_from_hops_internal<L: Deref>(
-       our_node_pubkey: &PublicKey, hops: &[PublicKey], payment_params: &PaymentParameters,
-       network_graph: &ReadOnlyNetworkGraph, final_value_msat: u64, logger: L,
-       random_seed_bytes: &[u8; 32]
+       our_node_pubkey: &PublicKey, hops: &[PublicKey], route_params: &RouteParameters,
+       network_graph: &ReadOnlyNetworkGraph, logger: L, random_seed_bytes: &[u8; 32],
 ) -> Result<Route, LightningError> where L::Target: Logger {
 
        struct HopScorer {
@@ -2347,7 +2634,7 @@ fn build_route_from_hops_internal<L: Deref>(
                hop_ids: [Option<NodeId>; MAX_PATH_LENGTH_ESTIMATE as usize],
        }
 
-       impl Score for HopScorer {
+       impl ScoreLookUp for HopScorer {
                type ScoreParams = ();
                fn channel_penalty_msat(&self, _short_channel_id: u64, source: &NodeId, target: &NodeId,
                        _usage: ChannelUsage, _score_params: &Self::ScoreParams) -> u64
@@ -2365,14 +2652,6 @@ fn build_route_from_hops_internal<L: Deref>(
                        }
                        u64::max_value()
                }
-
-               fn payment_path_failed(&mut self, _path: &Path, _short_channel_id: u64) {}
-
-               fn payment_path_successful(&mut self, _path: &Path) {}
-
-               fn probe_failed(&mut self, _path: &Path, _short_channel_id: u64) {}
-
-               fn probe_successful(&mut self, _path: &Path) {}
        }
 
        impl<'a> Writeable for HopScorer {
@@ -2394,8 +2673,7 @@ fn build_route_from_hops_internal<L: Deref>(
 
        let scorer = HopScorer { our_node_id, hop_ids };
 
-       get_route(our_node_pubkey, payment_params, network_graph, None, final_value_msat,
-               logger, &scorer, &(), random_seed_bytes)
+       get_route(our_node_pubkey, route_params, network_graph, None, logger, &scorer, &(), random_seed_bytes)
 }
 
 #[cfg(test)]
@@ -2405,14 +2683,16 @@ mod tests {
        use crate::routing::utxo::UtxoResult;
        use crate::routing::router::{get_route, build_route_from_hops_internal, add_random_cltv_offset, default_node_features,
                BlindedTail, InFlightHtlcs, Path, PaymentParameters, Route, RouteHint, RouteHintHop, RouteHop, RoutingFees,
-               DEFAULT_MAX_TOTAL_CLTV_EXPIRY_DELTA, MAX_PATH_LENGTH_ESTIMATE};
-       use crate::routing::scoring::{ChannelUsage, FixedPenaltyScorer, Score, ProbabilisticScorer, ProbabilisticScoringFeeParameters, ProbabilisticScoringDecayParameters};
+               DEFAULT_MAX_TOTAL_CLTV_EXPIRY_DELTA, MAX_PATH_LENGTH_ESTIMATE, RouteParameters};
+       use crate::routing::scoring::{ChannelUsage, FixedPenaltyScorer, ScoreLookUp, ProbabilisticScorer, ProbabilisticScoringFeeParameters, ProbabilisticScoringDecayParameters};
        use crate::routing::test_utils::{add_channel, add_or_update_node, build_graph, build_line_graph, id_to_feature_flags, get_nodes, update_channel};
        use crate::chain::transaction::OutPoint;
        use crate::sign::EntropySource;
-       use crate::ln::features::{ChannelFeatures, InitFeatures, NodeFeatures};
+       use crate::ln::ChannelId;
+       use crate::ln::features::{BlindedHopFeatures, Bolt12InvoiceFeatures, ChannelFeatures, InitFeatures, NodeFeatures};
        use crate::ln::msgs::{ErrorAction, LightningError, UnsignedChannelUpdate, MAX_VALUE_MSAT};
        use crate::ln::channelmanager;
+       use crate::offers::invoice::BlindedPayInfo;
        use crate::util::config::UserConfig;
        use crate::util::test_utils as ln_test_utils;
        use crate::util::chacha20::ChaCha20;
@@ -2441,7 +2721,7 @@ mod tests {
        fn get_channel_details(short_channel_id: Option<u64>, node_id: PublicKey,
                        features: InitFeatures, outbound_capacity_msat: u64) -> channelmanager::ChannelDetails {
                channelmanager::ChannelDetails {
-                       channel_id: [0; 32],
+                       channel_id: ChannelId::new_zero(),
                        counterparty: channelmanager::ChannelCounterparty {
                                features,
                                node_id,
@@ -2457,7 +2737,6 @@ mod tests {
                        inbound_scid_alias: None,
                        channel_value_satoshis: 0,
                        user_channel_id: 0,
-                       balance_msat: 0,
                        outbound_capacity_msat,
                        next_outbound_htlc_limit_msat: outbound_capacity_msat,
                        next_outbound_htlc_minimum_msat: 0,
@@ -2471,7 +2750,8 @@ mod tests {
                        inbound_htlc_minimum_msat: None,
                        inbound_htlc_maximum_msat: None,
                        config: None,
-                       feerate_sat_per_1000_weight: None
+                       feerate_sat_per_1000_weight: None,
+                       channel_shutdown_state: Some(channelmanager::ChannelShutdownState::NotShuttingDown),
                }
        }
 
@@ -2486,11 +2766,17 @@ mod tests {
 
                // Simple route to 2 via 1
 
-               if let Err(LightningError{err, action: ErrorAction::IgnoreError}) = get_route(&our_id, &payment_params, &network_graph.read_only(), None, 0, Arc::clone(&logger), &scorer, &(), &random_seed_bytes) {
-                       assert_eq!(err, "Cannot send a payment of 0 msat");
+               let route_params = RouteParameters::from_payment_params_and_value(
+                       payment_params.clone(), 0);
+               if let Err(LightningError{err, action: ErrorAction::IgnoreError}) = get_route(&our_id,
+                       &route_params, &network_graph.read_only(), None, Arc::clone(&logger), &scorer, &(),
+                       &random_seed_bytes) {
+                               assert_eq!(err, "Cannot send a payment of 0 msat");
                } else { panic!(); }
 
-               let route = get_route(&our_id, &payment_params, &network_graph.read_only(), None, 100, Arc::clone(&logger), &scorer, &(), &random_seed_bytes).unwrap();
+               let route_params = RouteParameters::from_payment_params_and_value(payment_params, 100);
+               let route = get_route(&our_id, &route_params, &network_graph.read_only(), None,
+                       Arc::clone(&logger), &scorer, &(), &random_seed_bytes).unwrap();
                assert_eq!(route.paths[0].hops.len(), 2);
 
                assert_eq!(route.paths[0].hops[0].pubkey, nodes[1]);
@@ -2521,12 +2807,15 @@ mod tests {
 
                let our_chans = vec![get_channel_details(Some(2), our_id, InitFeatures::from_le_bytes(vec![0b11]), 100000)];
 
-               if let Err(LightningError{err, action: ErrorAction::IgnoreError}) =
-                       get_route(&our_id, &payment_params, &network_graph.read_only(), Some(&our_chans.iter().collect::<Vec<_>>()), 100, Arc::clone(&logger), &scorer, &(), &random_seed_bytes) {
-                       assert_eq!(err, "First hop cannot have our_node_pubkey as a destination.");
+               let route_params = RouteParameters::from_payment_params_and_value(payment_params, 100);
+               if let Err(LightningError{err, action: ErrorAction::IgnoreError}) = get_route(&our_id,
+                       &route_params, &network_graph.read_only(), Some(&our_chans.iter().collect::<Vec<_>>()),
+                       Arc::clone(&logger), &scorer, &(), &random_seed_bytes) {
+                               assert_eq!(err, "First hop cannot have our_node_pubkey as a destination.");
                } else { panic!(); }
-
-               let route = get_route(&our_id, &payment_params, &network_graph.read_only(), None, 100, Arc::clone(&logger), &scorer, &(), &random_seed_bytes).unwrap();
+               let route = get_route(&our_id, &route_params, &network_graph.read_only(), None,
+                       Arc::clone(&logger), &scorer, &(), &random_seed_bytes).unwrap();
                assert_eq!(route.paths[0].hops.len(), 2);
        }
 
@@ -2634,8 +2923,12 @@ mod tests {
                });
 
                // Not possible to send 199_999_999, because the minimum on channel=2 is 200_000_000.
-               if let Err(LightningError{err, action: ErrorAction::IgnoreError}) = get_route(&our_id, &payment_params, &network_graph.read_only(), None, 199_999_999, Arc::clone(&logger), &scorer, &(), &random_seed_bytes) {
-                       assert_eq!(err, "Failed to find a path to the given destination");
+               let route_params = RouteParameters::from_payment_params_and_value(
+                       payment_params, 199_999_999);
+               if let Err(LightningError{err, action: ErrorAction::IgnoreError}) = get_route(&our_id,
+                       &route_params, &network_graph.read_only(), None, Arc::clone(&logger), &scorer, &(),
+                       &random_seed_bytes) {
+                               assert_eq!(err, "Failed to find a path to the given destination");
                } else { panic!(); }
 
                // Lift the restriction on the first hop.
@@ -2653,7 +2946,8 @@ mod tests {
                });
 
                // A payment above the minimum should pass
-               let route = get_route(&our_id, &payment_params, &network_graph.read_only(), None, 199_999_999, Arc::clone(&logger), &scorer, &(), &random_seed_bytes).unwrap();
+               let route = get_route(&our_id, &route_params, &network_graph.read_only(), None,
+                       Arc::clone(&logger), &scorer, &(), &random_seed_bytes).unwrap();
                assert_eq!(route.paths[0].hops.len(), 2);
        }
 
@@ -2735,7 +3029,10 @@ mod tests {
                        excess_data: Vec::new()
                });
 
-               let route = get_route(&our_id, &payment_params, &network_graph.read_only(), None, 60_000, Arc::clone(&logger), &scorer, &(), &random_seed_bytes).unwrap();
+               let route_params = RouteParameters::from_payment_params_and_value(
+                       payment_params.clone(), 60_000);
+               let route = get_route(&our_id, &route_params, &network_graph.read_only(), None,
+                       Arc::clone(&logger), &scorer, &(), &random_seed_bytes).unwrap();
                // Overpay fees to hit htlc_minimum_msat.
                let overpaid_fees = route.paths[0].hops[0].fee_msat + route.paths[1].hops[0].fee_msat;
                // TODO: this could be better balanced to overpay 10k and not 15k.
@@ -2780,14 +3077,17 @@ mod tests {
                        excess_data: Vec::new()
                });
 
-               let route = get_route(&our_id, &payment_params, &network_graph.read_only(), None, 60_000, Arc::clone(&logger), &scorer, &(), &random_seed_bytes).unwrap();
+               let route = get_route(&our_id, &route_params, &network_graph.read_only(), None,
+                       Arc::clone(&logger), &scorer, &(), &random_seed_bytes).unwrap();
                // Fine to overpay for htlc_minimum_msat if it allows us to save fee.
                assert_eq!(route.paths.len(), 1);
                assert_eq!(route.paths[0].hops[0].short_channel_id, 12);
                let fees = route.paths[0].hops[0].fee_msat;
                assert_eq!(fees, 5_000);
 
-               let route = get_route(&our_id, &payment_params, &network_graph.read_only(), None, 50_000, Arc::clone(&logger), &scorer, &(), &random_seed_bytes).unwrap();
+               let route_params = RouteParameters::from_payment_params_and_value(payment_params, 50_000);
+               let route = get_route(&our_id, &route_params, &network_graph.read_only(), None,
+                       Arc::clone(&logger), &scorer, &(), &random_seed_bytes).unwrap();
                // Not fine to overpay for htlc_minimum_msat if it requires paying more than fee on
                // the other channel.
                assert_eq!(route.paths.len(), 1);
@@ -2832,13 +3132,19 @@ mod tests {
                });
 
                // If all the channels require some features we don't understand, route should fail
-               if let Err(LightningError{err, action: ErrorAction::IgnoreError}) = get_route(&our_id, &payment_params, &network_graph.read_only(), None, 100, Arc::clone(&logger), &scorer, &(), &random_seed_bytes) {
-                       assert_eq!(err, "Failed to find a path to the given destination");
+               let route_params = RouteParameters::from_payment_params_and_value(payment_params, 100);
+               if let Err(LightningError{err, action: ErrorAction::IgnoreError}) = get_route(&our_id,
+                       &route_params, &network_graph.read_only(), None, Arc::clone(&logger), &scorer, &(),
+                       &random_seed_bytes) {
+                               assert_eq!(err, "Failed to find a path to the given destination");
                } else { panic!(); }
 
                // If we specify a channel to node7, that overrides our local channel view and that gets used
-               let our_chans = vec![get_channel_details(Some(42), nodes[7].clone(), InitFeatures::from_le_bytes(vec![0b11]), 250_000_000)];
-               let route = get_route(&our_id, &payment_params, &network_graph.read_only(), Some(&our_chans.iter().collect::<Vec<_>>()), 100, Arc::clone(&logger), &scorer, &(), &random_seed_bytes).unwrap();
+               let our_chans = vec![get_channel_details(Some(42), nodes[7].clone(),
+                       InitFeatures::from_le_bytes(vec![0b11]), 250_000_000)];
+               let route = get_route(&our_id, &route_params, &network_graph.read_only(),
+                       Some(&our_chans.iter().collect::<Vec<_>>()), Arc::clone(&logger), &scorer, &(),
+                       &random_seed_bytes).unwrap();
                assert_eq!(route.paths[0].hops.len(), 2);
 
                assert_eq!(route.paths[0].hops[0].pubkey, nodes[7]);
@@ -2873,13 +3179,19 @@ mod tests {
                add_or_update_node(&gossip_sync, &secp_ctx, &privkeys[7], unknown_features.clone(), 1);
 
                // If all nodes require some features we don't understand, route should fail
-               if let Err(LightningError{err, action: ErrorAction::IgnoreError}) = get_route(&our_id, &payment_params, &network_graph.read_only(), None, 100, Arc::clone(&logger), &scorer, &(), &random_seed_bytes) {
-                       assert_eq!(err, "Failed to find a path to the given destination");
+               let route_params = RouteParameters::from_payment_params_and_value(payment_params, 100);
+               if let Err(LightningError{err, action: ErrorAction::IgnoreError}) = get_route(&our_id,
+                       &route_params, &network_graph.read_only(), None, Arc::clone(&logger), &scorer, &(),
+                       &random_seed_bytes) {
+                               assert_eq!(err, "Failed to find a path to the given destination");
                } else { panic!(); }
 
                // If we specify a channel to node7, that overrides our local channel view and that gets used
-               let our_chans = vec![get_channel_details(Some(42), nodes[7].clone(), InitFeatures::from_le_bytes(vec![0b11]), 250_000_000)];
-               let route = get_route(&our_id, &payment_params, &network_graph.read_only(), Some(&our_chans.iter().collect::<Vec<_>>()), 100, Arc::clone(&logger), &scorer, &(), &random_seed_bytes).unwrap();
+               let our_chans = vec![get_channel_details(Some(42), nodes[7].clone(),
+                       InitFeatures::from_le_bytes(vec![0b11]), 250_000_000)];
+               let route = get_route(&our_id, &route_params, &network_graph.read_only(),
+                       Some(&our_chans.iter().collect::<Vec<_>>()), Arc::clone(&logger), &scorer, &(),
+                       &random_seed_bytes).unwrap();
                assert_eq!(route.paths[0].hops.len(), 2);
 
                assert_eq!(route.paths[0].hops[0].pubkey, nodes[7]);
@@ -2911,7 +3223,9 @@ mod tests {
 
                // Route to 1 via 2 and 3 because our channel to 1 is disabled
                let payment_params = PaymentParameters::from_node_id(nodes[0], 42);
-               let route = get_route(&our_id, &payment_params, &network_graph.read_only(), None, 100, Arc::clone(&logger), &scorer, &(), &random_seed_bytes).unwrap();
+               let route_params = RouteParameters::from_payment_params_and_value(payment_params, 100);
+               let route = get_route(&our_id, &route_params, &network_graph.read_only(), None,
+                       Arc::clone(&logger), &scorer, &(), &random_seed_bytes).unwrap();
                assert_eq!(route.paths[0].hops.len(), 3);
 
                assert_eq!(route.paths[0].hops[0].pubkey, nodes[1]);
@@ -2937,8 +3251,12 @@ mod tests {
 
                // If we specify a channel to node7, that overrides our local channel view and that gets used
                let payment_params = PaymentParameters::from_node_id(nodes[2], 42);
-               let our_chans = vec![get_channel_details(Some(42), nodes[7].clone(), InitFeatures::from_le_bytes(vec![0b11]), 250_000_000)];
-               let route = get_route(&our_id, &payment_params, &network_graph.read_only(), Some(&our_chans.iter().collect::<Vec<_>>()), 100, Arc::clone(&logger), &scorer, &(), &random_seed_bytes).unwrap();
+               let route_params = RouteParameters::from_payment_params_and_value(payment_params, 100);
+               let our_chans = vec![get_channel_details(Some(42), nodes[7].clone(),
+                       InitFeatures::from_le_bytes(vec![0b11]), 250_000_000)];
+               let route = get_route(&our_id, &route_params, &network_graph.read_only(),
+                       Some(&our_chans.iter().collect::<Vec<_>>()), Arc::clone(&logger), &scorer, &(),
+                       &random_seed_bytes).unwrap();
                assert_eq!(route.paths[0].hops.len(), 2);
 
                assert_eq!(route.paths[0].hops[0].pubkey, nodes[7]);
@@ -3060,14 +3378,21 @@ mod tests {
                let mut invalid_last_hops = last_hops_multi_private_channels(&nodes);
                invalid_last_hops.push(invalid_last_hop);
                {
-                       let payment_params = PaymentParameters::from_node_id(nodes[6], 42).with_route_hints(invalid_last_hops).unwrap();
-                       if let Err(LightningError{err, action: ErrorAction::IgnoreError}) = get_route(&our_id, &payment_params, &network_graph.read_only(), None, 100, Arc::clone(&logger), &scorer, &(), &random_seed_bytes) {
-                               assert_eq!(err, "Route hint cannot have the payee as the source.");
+                       let payment_params = PaymentParameters::from_node_id(nodes[6], 42)
+                               .with_route_hints(invalid_last_hops).unwrap();
+                       let route_params = RouteParameters::from_payment_params_and_value(payment_params, 100);
+                       if let Err(LightningError{err, action: ErrorAction::IgnoreError}) = get_route(&our_id,
+                               &route_params, &network_graph.read_only(), None, Arc::clone(&logger), &scorer, &(),
+                               &random_seed_bytes) {
+                                       assert_eq!(err, "Route hint cannot have the payee as the source.");
                        } else { panic!(); }
                }
 
-               let payment_params = PaymentParameters::from_node_id(nodes[6], 42).with_route_hints(last_hops_multi_private_channels(&nodes)).unwrap();
-               let route = get_route(&our_id, &payment_params, &network_graph.read_only(), None, 100, Arc::clone(&logger), &scorer, &(), &random_seed_bytes).unwrap();
+               let payment_params = PaymentParameters::from_node_id(nodes[6], 42)
+                       .with_route_hints(last_hops_multi_private_channels(&nodes)).unwrap();
+               let route_params = RouteParameters::from_payment_params_and_value(payment_params, 100);
+               let route = get_route(&our_id, &route_params, &network_graph.read_only(), None,
+                       Arc::clone(&logger), &scorer, &(), &random_seed_bytes).unwrap();
                assert_eq!(route.paths[0].hops.len(), 5);
 
                assert_eq!(route.paths[0].hops[0].pubkey, nodes[1]);
@@ -3142,8 +3467,9 @@ mod tests {
                let random_seed_bytes = keys_manager.get_secure_random_bytes();
 
                // Test handling of an empty RouteHint passed in Invoice.
-
-               let route = get_route(&our_id, &payment_params, &network_graph.read_only(), None, 100, Arc::clone(&logger), &scorer, &(), &random_seed_bytes).unwrap();
+               let route_params = RouteParameters::from_payment_params_and_value(payment_params, 100);
+               let route = get_route(&our_id, &route_params, &network_graph.read_only(), None,
+                       Arc::clone(&logger), &scorer, &(), &random_seed_bytes).unwrap();
                assert_eq!(route.paths[0].hops.len(), 5);
 
                assert_eq!(route.paths[0].hops[0].pubkey, nodes[1]);
@@ -3249,7 +3575,9 @@ mod tests {
                        excess_data: Vec::new()
                });
 
-               let route = get_route(&our_id, &payment_params, &network_graph.read_only(), None, 100, Arc::clone(&logger), &scorer, &(), &random_seed_bytes).unwrap();
+               let route_params = RouteParameters::from_payment_params_and_value(payment_params, 100);
+               let route = get_route(&our_id, &route_params, &network_graph.read_only(), None,
+                       Arc::clone(&logger), &scorer, &(), &random_seed_bytes).unwrap();
                assert_eq!(route.paths[0].hops.len(), 4);
 
                assert_eq!(route.paths[0].hops[0].pubkey, nodes[1]);
@@ -3321,7 +3649,9 @@ mod tests {
                        excess_data: Vec::new()
                });
 
-               let route = get_route(&our_id, &payment_params, &network_graph.read_only(), None, 100, Arc::clone(&logger), &scorer, &(), &[42u8; 32]).unwrap();
+               let route_params = RouteParameters::from_payment_params_and_value(payment_params, 100);
+               let route = get_route(&our_id, &route_params, &network_graph.read_only(), None,
+                       Arc::clone(&logger), &scorer, &(), &[42u8; 32]).unwrap();
                assert_eq!(route.paths[0].hops.len(), 4);
 
                assert_eq!(route.paths[0].hops[0].pubkey, nodes[1]);
@@ -3403,7 +3733,9 @@ mod tests {
                // This test shows that public routes can be present in the invoice
                // which would be handled in the same manner.
 
-               let route = get_route(&our_id, &payment_params, &network_graph.read_only(), None, 100, Arc::clone(&logger), &scorer, &(), &random_seed_bytes).unwrap();
+               let route_params = RouteParameters::from_payment_params_and_value(payment_params, 100);
+               let route = get_route(&our_id, &route_params, &network_graph.read_only(), None,
+                       Arc::clone(&logger), &scorer, &(), &random_seed_bytes).unwrap();
                assert_eq!(route.paths[0].hops.len(), 5);
 
                assert_eq!(route.paths[0].hops[0].pubkey, nodes[1]);
@@ -3455,8 +3787,12 @@ mod tests {
                // Simple test with outbound channel to 4 to test that last_hops and first_hops connect
                let our_chans = vec![get_channel_details(Some(42), nodes[3].clone(), InitFeatures::from_le_bytes(vec![0b11]), 250_000_000)];
                let mut last_hops = last_hops(&nodes);
-               let payment_params = PaymentParameters::from_node_id(nodes[6], 42).with_route_hints(last_hops.clone()).unwrap();
-               let route = get_route(&our_id, &payment_params, &network_graph.read_only(), Some(&our_chans.iter().collect::<Vec<_>>()), 100, Arc::clone(&logger), &scorer, &(), &random_seed_bytes).unwrap();
+               let payment_params = PaymentParameters::from_node_id(nodes[6], 42)
+                       .with_route_hints(last_hops.clone()).unwrap();
+               let route_params = RouteParameters::from_payment_params_and_value(payment_params, 100);
+               let route = get_route(&our_id, &route_params, &network_graph.read_only(),
+                       Some(&our_chans.iter().collect::<Vec<_>>()), Arc::clone(&logger), &scorer, &(),
+                       &random_seed_bytes).unwrap();
                assert_eq!(route.paths[0].hops.len(), 2);
 
                assert_eq!(route.paths[0].hops[0].pubkey, nodes[3]);
@@ -3476,8 +3812,12 @@ mod tests {
                last_hops[0].0[0].fees.base_msat = 1000;
 
                // Revert to via 6 as the fee on 8 goes up
-               let payment_params = PaymentParameters::from_node_id(nodes[6], 42).with_route_hints(last_hops).unwrap();
-               let route = get_route(&our_id, &payment_params, &network_graph.read_only(), None, 100, Arc::clone(&logger), &scorer, &(), &random_seed_bytes).unwrap();
+               let payment_params = PaymentParameters::from_node_id(nodes[6], 42)
+                       .with_route_hints(last_hops).unwrap();
+               let route_params = RouteParameters::from_payment_params_and_value(
+                       payment_params.clone(), 100);
+               let route = get_route(&our_id, &route_params, &network_graph.read_only(), None,
+                       Arc::clone(&logger), &scorer, &(), &random_seed_bytes).unwrap();
                assert_eq!(route.paths[0].hops.len(), 4);
 
                assert_eq!(route.paths[0].hops[0].pubkey, nodes[1]);
@@ -3511,7 +3851,9 @@ mod tests {
                assert_eq!(route.paths[0].hops[3].channel_features.le_flags(), &Vec::<u8>::new()); // We can't learn any flags from invoices, sadly
 
                // ...but still use 8 for larger payments as 6 has a variable feerate
-               let route = get_route(&our_id, &payment_params, &network_graph.read_only(), None, 2000, Arc::clone(&logger), &scorer, &(), &random_seed_bytes).unwrap();
+               let route_params = RouteParameters::from_payment_params_and_value(payment_params, 2000);
+               let route = get_route(&our_id, &route_params, &network_graph.read_only(), None,
+                       Arc::clone(&logger), &scorer, &(), &random_seed_bytes).unwrap();
                assert_eq!(route.paths[0].hops.len(), 5);
 
                assert_eq!(route.paths[0].hops[0].pubkey, nodes[1]);
@@ -3576,8 +3918,10 @@ mod tests {
                let random_seed_bytes = keys_manager.get_secure_random_bytes();
                let logger = ln_test_utils::TestLogger::new();
                let network_graph = NetworkGraph::new(Network::Testnet, &logger);
-               let route = get_route(&source_node_id, &payment_params, &network_graph.read_only(),
-                               Some(&our_chans.iter().collect::<Vec<_>>()), route_val, &logger, &scorer, &(), &random_seed_bytes);
+               let route_params = RouteParameters::from_payment_params_and_value(payment_params, route_val);
+               let route = get_route(&source_node_id, &route_params, &network_graph.read_only(),
+                               Some(&our_chans.iter().collect::<Vec<_>>()), &logger, &scorer, &(),
+                               &random_seed_bytes);
                route
        }
 
@@ -3629,7 +3973,7 @@ mod tests {
        fn available_amount_while_routing_test() {
                // Tests whether we choose the correct available channel amount while routing.
 
-               let (secp_ctx, network_graph, mut gossip_sync, chain_monitor, logger) = build_graph();
+               let (secp_ctx, network_graph, gossip_sync, chain_monitor, logger) = build_graph();
                let (our_privkey, our_id, privkeys, nodes) = get_nodes(&secp_ctx);
                let scorer = ln_test_utils::TestScorer::new();
                let keys_manager = ln_test_utils::TestKeysInterface::new(&[0u8; 32], Network::Testnet);
@@ -3698,15 +4042,21 @@ mod tests {
 
                {
                        // Attempt to route more than available results in a failure.
+                       let route_params = RouteParameters::from_payment_params_and_value(
+                               payment_params.clone(), 250_000_001);
                        if let Err(LightningError{err, action: ErrorAction::IgnoreError}) = get_route(
-                                       &our_id, &payment_params, &network_graph.read_only(), None, 250_000_001, Arc::clone(&logger), &scorer, &(), &random_seed_bytes) {
-                               assert_eq!(err, "Failed to find a sufficient route to the given destination");
+                                       &our_id, &route_params, &network_graph.read_only(), None,
+                                       Arc::clone(&logger), &scorer, &(), &random_seed_bytes) {
+                                               assert_eq!(err, "Failed to find a sufficient route to the given destination");
                        } else { panic!(); }
                }
 
                {
                        // Now, attempt to route an exact amount we have should be fine.
-                       let route = get_route(&our_id, &payment_params, &network_graph.read_only(), None, 250_000_000, Arc::clone(&logger), &scorer, &(),&random_seed_bytes).unwrap();
+                       let route_params = RouteParameters::from_payment_params_and_value(
+                               payment_params.clone(), 250_000_000);
+                       let route = get_route(&our_id, &route_params, &network_graph.read_only(), None,
+                               Arc::clone(&logger), &scorer, &(),&random_seed_bytes).unwrap();
                        assert_eq!(route.paths.len(), 1);
                        let path = route.paths.last().unwrap();
                        assert_eq!(path.hops.len(), 2);
@@ -3734,15 +4084,23 @@ mod tests {
 
                {
                        // Attempt to route more than available results in a failure.
+                       let route_params = RouteParameters::from_payment_params_and_value(
+                               payment_params.clone(), 200_000_001);
                        if let Err(LightningError{err, action: ErrorAction::IgnoreError}) = get_route(
-                                       &our_id, &payment_params, &network_graph.read_only(), Some(&our_chans.iter().collect::<Vec<_>>()), 200_000_001, Arc::clone(&logger), &scorer, &(), &random_seed_bytes) {
-                               assert_eq!(err, "Failed to find a sufficient route to the given destination");
+                                       &our_id, &route_params, &network_graph.read_only(),
+                                       Some(&our_chans.iter().collect::<Vec<_>>()), Arc::clone(&logger), &scorer,
+                                       &(), &random_seed_bytes) {
+                                               assert_eq!(err, "Failed to find a sufficient route to the given destination");
                        } else { panic!(); }
                }
 
                {
                        // Now, attempt to route an exact amount we have should be fine.
-                       let route = get_route(&our_id, &payment_params, &network_graph.read_only(), Some(&our_chans.iter().collect::<Vec<_>>()), 200_000_000, Arc::clone(&logger), &scorer, &(), &random_seed_bytes).unwrap();
+                       let route_params = RouteParameters::from_payment_params_and_value(
+                               payment_params.clone(), 200_000_000);
+                       let route = get_route(&our_id, &route_params, &network_graph.read_only(),
+                               Some(&our_chans.iter().collect::<Vec<_>>()), Arc::clone(&logger), &scorer, &(),
+                               &random_seed_bytes).unwrap();
                        assert_eq!(route.paths.len(), 1);
                        let path = route.paths.last().unwrap();
                        assert_eq!(path.hops.len(), 2);
@@ -3781,15 +4139,21 @@ mod tests {
 
                {
                        // Attempt to route more than available results in a failure.
+                       let route_params = RouteParameters::from_payment_params_and_value(
+                               payment_params.clone(), 15_001);
                        if let Err(LightningError{err, action: ErrorAction::IgnoreError}) = get_route(
-                                       &our_id, &payment_params, &network_graph.read_only(), None, 15_001, Arc::clone(&logger), &scorer, &(), &random_seed_bytes) {
-                               assert_eq!(err, "Failed to find a sufficient route to the given destination");
+                                       &our_id, &route_params, &network_graph.read_only(), None, Arc::clone(&logger),
+                                       &scorer, &(), &random_seed_bytes) {
+                                               assert_eq!(err, "Failed to find a sufficient route to the given destination");
                        } else { panic!(); }
                }
 
                {
                        // Now, attempt to route an exact amount we have should be fine.
-                       let route = get_route(&our_id, &payment_params, &network_graph.read_only(), None, 15_000, Arc::clone(&logger), &scorer, &(), &random_seed_bytes).unwrap();
+                       let route_params = RouteParameters::from_payment_params_and_value(
+                               payment_params.clone(), 15_000);
+                       let route = get_route(&our_id, &route_params, &network_graph.read_only(), None,
+                               Arc::clone(&logger), &scorer, &(), &random_seed_bytes).unwrap();
                        assert_eq!(route.paths.len(), 1);
                        let path = route.paths.last().unwrap();
                        assert_eq!(path.hops.len(), 2);
@@ -3852,15 +4216,21 @@ mod tests {
 
                {
                        // Attempt to route more than available results in a failure.
+                       let route_params = RouteParameters::from_payment_params_and_value(
+                               payment_params.clone(), 15_001);
                        if let Err(LightningError{err, action: ErrorAction::IgnoreError}) = get_route(
-                                       &our_id, &payment_params, &network_graph.read_only(), None, 15_001, Arc::clone(&logger), &scorer, &(), &random_seed_bytes) {
-                               assert_eq!(err, "Failed to find a sufficient route to the given destination");
+                                       &our_id, &route_params, &network_graph.read_only(), None, Arc::clone(&logger),
+                                       &scorer, &(), &random_seed_bytes) {
+                                               assert_eq!(err, "Failed to find a sufficient route to the given destination");
                        } else { panic!(); }
                }
 
                {
                        // Now, attempt to route an exact amount we have should be fine.
-                       let route = get_route(&our_id, &payment_params, &network_graph.read_only(), None, 15_000, Arc::clone(&logger), &scorer, &(), &random_seed_bytes).unwrap();
+                       let route_params = RouteParameters::from_payment_params_and_value(
+                               payment_params.clone(), 15_000);
+                       let route = get_route(&our_id, &route_params, &network_graph.read_only(), None,
+                               Arc::clone(&logger), &scorer, &(), &random_seed_bytes).unwrap();
                        assert_eq!(route.paths.len(), 1);
                        let path = route.paths.last().unwrap();
                        assert_eq!(path.hops.len(), 2);
@@ -3884,15 +4254,21 @@ mod tests {
 
                {
                        // Attempt to route more than available results in a failure.
+                       let route_params = RouteParameters::from_payment_params_and_value(
+                               payment_params.clone(), 10_001);
                        if let Err(LightningError{err, action: ErrorAction::IgnoreError}) = get_route(
-                                       &our_id, &payment_params, &network_graph.read_only(), None, 10_001, Arc::clone(&logger), &scorer, &(), &random_seed_bytes) {
-                               assert_eq!(err, "Failed to find a sufficient route to the given destination");
+                                       &our_id, &route_params, &network_graph.read_only(), None, Arc::clone(&logger),
+                                       &scorer, &(), &random_seed_bytes) {
+                                               assert_eq!(err, "Failed to find a sufficient route to the given destination");
                        } else { panic!(); }
                }
 
                {
                        // Now, attempt to route an exact amount we have should be fine.
-                       let route = get_route(&our_id, &payment_params, &network_graph.read_only(), None, 10_000, Arc::clone(&logger), &scorer, &(), &random_seed_bytes).unwrap();
+                       let route_params = RouteParameters::from_payment_params_and_value(
+                               payment_params.clone(), 10_000);
+                       let route = get_route(&our_id, &route_params, &network_graph.read_only(), None,
+                               Arc::clone(&logger), &scorer, &(), &random_seed_bytes).unwrap();
                        assert_eq!(route.paths.len(), 1);
                        let path = route.paths.last().unwrap();
                        assert_eq!(path.hops.len(), 2);
@@ -3996,15 +4372,21 @@ mod tests {
                });
                {
                        // Attempt to route more than available results in a failure.
+                       let route_params = RouteParameters::from_payment_params_and_value(
+                               payment_params.clone(), 60_000);
                        if let Err(LightningError{err, action: ErrorAction::IgnoreError}) = get_route(
-                                       &our_id, &payment_params, &network_graph.read_only(), None, 60_000, Arc::clone(&logger), &scorer, &(), &random_seed_bytes) {
-                               assert_eq!(err, "Failed to find a sufficient route to the given destination");
+                                       &our_id, &route_params, &network_graph.read_only(), None, Arc::clone(&logger),
+                                       &scorer, &(), &random_seed_bytes) {
+                                               assert_eq!(err, "Failed to find a sufficient route to the given destination");
                        } else { panic!(); }
                }
 
                {
                        // Now, attempt to route 49 sats (just a bit below the capacity).
-                       let route = get_route(&our_id, &payment_params, &network_graph.read_only(), None, 49_000, Arc::clone(&logger), &scorer, &(), &random_seed_bytes).unwrap();
+                       let route_params = RouteParameters::from_payment_params_and_value(
+                               payment_params.clone(), 49_000);
+                       let route = get_route(&our_id, &route_params, &network_graph.read_only(), None,
+                               Arc::clone(&logger), &scorer, &(), &random_seed_bytes).unwrap();
                        assert_eq!(route.paths.len(), 1);
                        let mut total_amount_paid_msat = 0;
                        for path in &route.paths {
@@ -4017,7 +4399,10 @@ mod tests {
 
                {
                        // Attempt to route an exact amount is also fine
-                       let route = get_route(&our_id, &payment_params, &network_graph.read_only(), None, 50_000, Arc::clone(&logger), &scorer, &(), &random_seed_bytes).unwrap();
+                       let route_params = RouteParameters::from_payment_params_and_value(
+                               payment_params, 50_000);
+                       let route = get_route(&our_id, &route_params, &network_graph.read_only(), None,
+                               Arc::clone(&logger), &scorer, &(), &random_seed_bytes).unwrap();
                        assert_eq!(route.paths.len(), 1);
                        let mut total_amount_paid_msat = 0;
                        for path in &route.paths {
@@ -4065,7 +4450,10 @@ mod tests {
                });
 
                {
-                       let route = get_route(&our_id, &payment_params, &network_graph.read_only(), None, 50_000, Arc::clone(&logger), &scorer, &(), &random_seed_bytes).unwrap();
+                       let route_params = RouteParameters::from_payment_params_and_value(
+                               payment_params, 50_000);
+                       let route = get_route(&our_id, &route_params, &network_graph.read_only(), None,
+                               Arc::clone(&logger), &scorer, &(), &random_seed_bytes).unwrap();
                        assert_eq!(route.paths.len(), 1);
                        let mut total_amount_paid_msat = 0;
                        for path in &route.paths {
@@ -4079,14 +4467,66 @@ mod tests {
 
        #[test]
        fn simple_mpp_route_test() {
+               let (secp_ctx, _, _, _, _) = build_graph();
+               let (_, _, _, nodes) = get_nodes(&secp_ctx);
+               let config = UserConfig::default();
+               let clear_payment_params = PaymentParameters::from_node_id(nodes[2], 42)
+                       .with_bolt11_features(channelmanager::provided_invoice_features(&config)).unwrap();
+               do_simple_mpp_route_test(clear_payment_params);
+
+               // MPP to a 1-hop blinded path for nodes[2]
+               let bolt12_features: Bolt12InvoiceFeatures = channelmanager::provided_invoice_features(&config).to_context();
+               let blinded_path = BlindedPath {
+                       introduction_node_id: nodes[2],
+                       blinding_point: ln_test_utils::pubkey(42),
+                       blinded_hops: vec![BlindedHop { blinded_node_id: ln_test_utils::pubkey(42 as u8), encrypted_payload: Vec::new() }],
+               };
+               let blinded_payinfo = BlindedPayInfo { // These fields are ignored for 1-hop blinded paths
+                       fee_base_msat: 0,
+                       fee_proportional_millionths: 0,
+                       htlc_minimum_msat: 0,
+                       htlc_maximum_msat: 0,
+                       cltv_expiry_delta: 0,
+                       features: BlindedHopFeatures::empty(),
+               };
+               let one_hop_blinded_payment_params = PaymentParameters::blinded(vec![(blinded_payinfo.clone(), blinded_path.clone())])
+                       .with_bolt12_features(bolt12_features.clone()).unwrap();
+               do_simple_mpp_route_test(one_hop_blinded_payment_params.clone());
+
+               // MPP to 3 2-hop blinded paths
+               let mut blinded_path_node_0 = blinded_path.clone();
+               blinded_path_node_0.introduction_node_id = nodes[0];
+               blinded_path_node_0.blinded_hops.push(blinded_path.blinded_hops[0].clone());
+               let mut node_0_payinfo = blinded_payinfo.clone();
+               node_0_payinfo.htlc_maximum_msat = 50_000;
+
+               let mut blinded_path_node_7 = blinded_path_node_0.clone();
+               blinded_path_node_7.introduction_node_id = nodes[7];
+               let mut node_7_payinfo = blinded_payinfo.clone();
+               node_7_payinfo.htlc_maximum_msat = 60_000;
+
+               let mut blinded_path_node_1 = blinded_path_node_0.clone();
+               blinded_path_node_1.introduction_node_id = nodes[1];
+               let mut node_1_payinfo = blinded_payinfo.clone();
+               node_1_payinfo.htlc_maximum_msat = 180_000;
+
+               let two_hop_blinded_payment_params = PaymentParameters::blinded(
+                       vec![
+                               (node_0_payinfo, blinded_path_node_0),
+                               (node_7_payinfo, blinded_path_node_7),
+                               (node_1_payinfo, blinded_path_node_1)
+                       ])
+                       .with_bolt12_features(bolt12_features).unwrap();
+               do_simple_mpp_route_test(two_hop_blinded_payment_params);
+       }
+
+
+       fn do_simple_mpp_route_test(payment_params: PaymentParameters) {
                let (secp_ctx, network_graph, gossip_sync, _, logger) = build_graph();
                let (our_privkey, our_id, privkeys, nodes) = get_nodes(&secp_ctx);
                let scorer = ln_test_utils::TestScorer::new();
                let keys_manager = ln_test_utils::TestKeysInterface::new(&[0u8; 32], Network::Testnet);
                let random_seed_bytes = keys_manager.get_secure_random_bytes();
-               let config = UserConfig::default();
-               let payment_params = PaymentParameters::from_node_id(nodes[2], 42)
-                       .with_bolt11_features(channelmanager::provided_invoice_features(&config)).unwrap();
 
                // We need a route consisting of 3 paths:
                // From our node to node2 via node0, node7, node1 (three paths one hop each).
@@ -4178,8 +4618,10 @@ mod tests {
 
                {
                        // Attempt to route more than available results in a failure.
+                       let route_params = RouteParameters::from_payment_params_and_value(
+                               payment_params.clone(), 300_000);
                        if let Err(LightningError{err, action: ErrorAction::IgnoreError}) = get_route(
-                               &our_id, &payment_params, &network_graph.read_only(), None, 300_000,
+                               &our_id, &route_params, &network_graph.read_only(), None,
                                Arc::clone(&logger), &scorer, &(), &random_seed_bytes) {
                                        assert_eq!(err, "Failed to find a sufficient route to the given destination");
                        } else { panic!(); }
@@ -4188,8 +4630,10 @@ mod tests {
                {
                        // Attempt to route while setting max_path_count to 0 results in a failure.
                        let zero_payment_params = payment_params.clone().with_max_path_count(0);
+                       let route_params = RouteParameters::from_payment_params_and_value(
+                               zero_payment_params, 100);
                        if let Err(LightningError{err, action: ErrorAction::IgnoreError}) = get_route(
-                               &our_id, &zero_payment_params, &network_graph.read_only(), None, 100,
+                               &our_id, &route_params, &network_graph.read_only(), None,
                                Arc::clone(&logger), &scorer, &(), &random_seed_bytes) {
                                        assert_eq!(err, "Can't find a route with no paths allowed.");
                        } else { panic!(); }
@@ -4200,8 +4644,10 @@ mod tests {
                        // This is the case because the minimal_value_contribution_msat would require each path
                        // to account for 1/3 of the total value, which is violated by 2 out of 3 paths.
                        let fail_payment_params = payment_params.clone().with_max_path_count(3);
+                       let route_params = RouteParameters::from_payment_params_and_value(
+                               fail_payment_params, 250_000);
                        if let Err(LightningError{err, action: ErrorAction::IgnoreError}) = get_route(
-                               &our_id, &fail_payment_params, &network_graph.read_only(), None, 250_000,
+                               &our_id, &route_params, &network_graph.read_only(), None,
                                Arc::clone(&logger), &scorer, &(), &random_seed_bytes) {
                                        assert_eq!(err, "Failed to find a sufficient route to the given destination");
                        } else { panic!(); }
@@ -4210,13 +4656,19 @@ mod tests {
                {
                        // Now, attempt to route 250 sats (just a bit below the capacity).
                        // Our algorithm should provide us with these 3 paths.
-                       let route = get_route(&our_id, &payment_params, &network_graph.read_only(), None,
-                               250_000, Arc::clone(&logger), &scorer, &(), &random_seed_bytes).unwrap();
+                       let route_params = RouteParameters::from_payment_params_and_value(
+                               payment_params.clone(), 250_000);
+                       let route = get_route(&our_id, &route_params, &network_graph.read_only(), None,
+                               Arc::clone(&logger), &scorer, &(), &random_seed_bytes).unwrap();
                        assert_eq!(route.paths.len(), 3);
                        let mut total_amount_paid_msat = 0;
                        for path in &route.paths {
-                               assert_eq!(path.hops.len(), 2);
-                               assert_eq!(path.hops.last().unwrap().pubkey, nodes[2]);
+                               if let Some(bt) = &path.blinded_tail {
+                                       assert_eq!(path.hops.len() + if bt.hops.len() == 1 { 0 } else { 1 }, 2);
+                               } else {
+                                       assert_eq!(path.hops.len(), 2);
+                                       assert_eq!(path.hops.last().unwrap().pubkey, nodes[2]);
+                               }
                                total_amount_paid_msat += path.final_value_msat();
                        }
                        assert_eq!(total_amount_paid_msat, 250_000);
@@ -4224,13 +4676,29 @@ mod tests {
 
                {
                        // Attempt to route an exact amount is also fine
-                       let route = get_route(&our_id, &payment_params, &network_graph.read_only(), None,
-                               290_000, Arc::clone(&logger), &scorer, &(), &random_seed_bytes).unwrap();
+                       let route_params = RouteParameters::from_payment_params_and_value(
+                               payment_params.clone(), 290_000);
+                       let route = get_route(&our_id, &route_params, &network_graph.read_only(), None,
+                               Arc::clone(&logger), &scorer, &(), &random_seed_bytes).unwrap();
                        assert_eq!(route.paths.len(), 3);
                        let mut total_amount_paid_msat = 0;
                        for path in &route.paths {
-                               assert_eq!(path.hops.len(), 2);
-                               assert_eq!(path.hops.last().unwrap().pubkey, nodes[2]);
+                               if payment_params.payee.blinded_route_hints().len() != 0 {
+                                       assert!(path.blinded_tail.is_some()) } else { assert!(path.blinded_tail.is_none()) }
+                               if let Some(bt) = &path.blinded_tail {
+                                       assert_eq!(path.hops.len() + if bt.hops.len() == 1 { 0 } else { 1 }, 2);
+                                       if bt.hops.len() > 1 {
+                                               assert_eq!(path.hops.last().unwrap().pubkey,
+                                                       payment_params.payee.blinded_route_hints().iter()
+                                                               .find(|(p, _)| p.htlc_maximum_msat == path.final_value_msat())
+                                                               .map(|(_, p)| p.introduction_node_id).unwrap());
+                                       } else {
+                                               assert_eq!(path.hops.last().unwrap().pubkey, nodes[2]);
+                                       }
+                               } else {
+                                       assert_eq!(path.hops.len(), 2);
+                                       assert_eq!(path.hops.last().unwrap().pubkey, nodes[2]);
+                               }
                                total_amount_paid_msat += path.final_value_msat();
                        }
                        assert_eq!(total_amount_paid_msat, 290_000);
@@ -4245,7 +4713,8 @@ mod tests {
                let keys_manager = ln_test_utils::TestKeysInterface::new(&[0u8; 32], Network::Testnet);
                let random_seed_bytes = keys_manager.get_secure_random_bytes();
                let config = UserConfig::default();
-               let payment_params = PaymentParameters::from_node_id(nodes[3], 42).with_bolt11_features(channelmanager::provided_invoice_features(&config)).unwrap();
+               let payment_params = PaymentParameters::from_node_id(nodes[3], 42)
+                       .with_bolt11_features(channelmanager::provided_invoice_features(&config)).unwrap();
 
                // We need a route consisting of 3 paths:
                // From our node to node3 via {node0, node2}, {node7, node2, node4} and {node7, node2}.
@@ -4380,16 +4849,22 @@ mod tests {
 
                {
                        // Attempt to route more than available results in a failure.
+                       let route_params = RouteParameters::from_payment_params_and_value(
+                               payment_params.clone(), 350_000);
                        if let Err(LightningError{err, action: ErrorAction::IgnoreError}) = get_route(
-                                       &our_id, &payment_params, &network_graph.read_only(), None, 350_000, Arc::clone(&logger), &scorer, &(), &random_seed_bytes) {
-                               assert_eq!(err, "Failed to find a sufficient route to the given destination");
+                                       &our_id, &route_params, &network_graph.read_only(), None, Arc::clone(&logger),
+                                       &scorer, &(), &random_seed_bytes) {
+                                               assert_eq!(err, "Failed to find a sufficient route to the given destination");
                        } else { panic!(); }
                }
 
                {
                        // Now, attempt to route 300 sats (exact amount we can route).
                        // Our algorithm should provide us with these 3 paths, 100 sats each.
-                       let route = get_route(&our_id, &payment_params, &network_graph.read_only(), None, 300_000, Arc::clone(&logger), &scorer, &(), &random_seed_bytes).unwrap();
+                       let route_params = RouteParameters::from_payment_params_and_value(
+                               payment_params, 300_000);
+                       let route = get_route(&our_id, &route_params, &network_graph.read_only(), None,
+                               Arc::clone(&logger), &scorer, &(), &random_seed_bytes).unwrap();
                        assert_eq!(route.paths.len(), 3);
 
                        let mut total_amount_paid_msat = 0;
@@ -4550,7 +5025,10 @@ mod tests {
                {
                        // Now, attempt to route 180 sats.
                        // Our algorithm should provide us with these 2 paths.
-                       let route = get_route(&our_id, &payment_params, &network_graph.read_only(), None, 180_000, Arc::clone(&logger), &scorer, &(), &random_seed_bytes).unwrap();
+                       let route_params = RouteParameters::from_payment_params_and_value(
+                               payment_params, 180_000);
+                       let route = get_route(&our_id, &route_params, &network_graph.read_only(), None,
+                               Arc::clone(&logger), &scorer, &(), &random_seed_bytes).unwrap();
                        assert_eq!(route.paths.len(), 2);
 
                        let mut total_value_transferred_msat = 0;
@@ -4720,15 +5198,20 @@ mod tests {
 
                {
                        // Attempt to route more than available results in a failure.
+                       let route_params = RouteParameters::from_payment_params_and_value(
+                               payment_params.clone(), 210_000);
                        if let Err(LightningError{err, action: ErrorAction::IgnoreError}) = get_route(
-                                       &our_id, &payment_params, &network_graph.read_only(), None, 210_000, Arc::clone(&logger), &scorer, &(), &random_seed_bytes) {
-                               assert_eq!(err, "Failed to find a sufficient route to the given destination");
+                                       &our_id, &route_params, &network_graph.read_only(), None, Arc::clone(&logger),
+                                       &scorer, &(), &random_seed_bytes) {
+                                               assert_eq!(err, "Failed to find a sufficient route to the given destination");
                        } else { panic!(); }
                }
 
                {
                        // Now, attempt to route 200 sats (exact amount we can route).
-                       let route = get_route(&our_id, &payment_params, &network_graph.read_only(), None, 200_000, Arc::clone(&logger), &scorer, &(), &random_seed_bytes).unwrap();
+                       let route_params = RouteParameters::from_payment_params_and_value(payment_params, 200_000);
+                       let route = get_route(&our_id, &route_params, &network_graph.read_only(), None,
+                               Arc::clone(&logger), &scorer, &(), &random_seed_bytes).unwrap();
                        assert_eq!(route.paths.len(), 2);
 
                        let mut total_amount_paid_msat = 0;
@@ -4828,7 +5311,10 @@ mod tests {
 
                // Get a route for 100 sats and check that we found the MPP route no problem and didn't
                // overpay at all.
-               let mut route = get_route(&our_id, &payment_params, &network_graph.read_only(), None, 100_000, Arc::clone(&logger), &scorer, &(), &random_seed_bytes).unwrap();
+               let route_params = RouteParameters::from_payment_params_and_value(
+                       payment_params, 100_000);
+               let mut route = get_route(&our_id, &route_params, &network_graph.read_only(), None,
+                       Arc::clone(&logger), &scorer, &(), &random_seed_bytes).unwrap();
                assert_eq!(route.paths.len(), 2);
                route.paths.sort_by_key(|path| path.hops[0].short_channel_id);
                // Paths are manually ordered ordered by SCID, so:
@@ -4946,16 +5432,22 @@ mod tests {
 
                {
                        // Attempt to route more than available results in a failure.
+                       let route_params = RouteParameters::from_payment_params_and_value(
+                               payment_params.clone(), 150_000);
                        if let Err(LightningError{err, action: ErrorAction::IgnoreError}) = get_route(
-                                       &our_id, &payment_params, &network_graph.read_only(), None, 150_000, Arc::clone(&logger), &scorer, &(), &random_seed_bytes) {
-                               assert_eq!(err, "Failed to find a sufficient route to the given destination");
+                                       &our_id, &route_params, &network_graph.read_only(), None, Arc::clone(&logger),
+                                       &scorer, &(), &random_seed_bytes) {
+                                               assert_eq!(err, "Failed to find a sufficient route to the given destination");
                        } else { panic!(); }
                }
 
                {
                        // Now, attempt to route 125 sats (just a bit below the capacity of 3 channels).
                        // Our algorithm should provide us with these 3 paths.
-                       let route = get_route(&our_id, &payment_params, &network_graph.read_only(), None, 125_000, Arc::clone(&logger), &scorer, &(), &random_seed_bytes).unwrap();
+                       let route_params = RouteParameters::from_payment_params_and_value(
+                               payment_params.clone(), 125_000);
+                       let route = get_route(&our_id, &route_params, &network_graph.read_only(), None,
+                               Arc::clone(&logger), &scorer, &(), &random_seed_bytes).unwrap();
                        assert_eq!(route.paths.len(), 3);
                        let mut total_amount_paid_msat = 0;
                        for path in &route.paths {
@@ -4968,7 +5460,10 @@ mod tests {
 
                {
                        // Attempt to route without the last small cheap channel
-                       let route = get_route(&our_id, &payment_params, &network_graph.read_only(), None, 90_000, Arc::clone(&logger), &scorer, &(), &random_seed_bytes).unwrap();
+                       let route_params = RouteParameters::from_payment_params_and_value(
+                               payment_params, 90_000);
+                       let route = get_route(&our_id, &route_params, &network_graph.read_only(), None,
+                               Arc::clone(&logger), &scorer, &(), &random_seed_bytes).unwrap();
                        assert_eq!(route.paths.len(), 2);
                        let mut total_amount_paid_msat = 0;
                        for path in &route.paths {
@@ -5107,7 +5602,10 @@ mod tests {
 
                {
                        // Now ensure the route flows simply over nodes 1 and 4 to 6.
-                       let route = get_route(&our_id, &payment_params, &network.read_only(), None, 10_000, Arc::clone(&logger), &scorer, &(), &random_seed_bytes).unwrap();
+                       let route_params = RouteParameters::from_payment_params_and_value(
+                               payment_params, 10_000);
+                       let route = get_route(&our_id, &route_params, &network.read_only(), None,
+                               Arc::clone(&logger), &scorer, &(), &random_seed_bytes).unwrap();
                        assert_eq!(route.paths.len(), 1);
                        assert_eq!(route.paths[0].hops.len(), 3);
 
@@ -5178,7 +5676,10 @@ mod tests {
                {
                        // Now, attempt to route 90 sats, which is exactly 90 sats at the last hop, plus the
                        // 200% fee charged channel 13 in the 1-to-2 direction.
-                       let route = get_route(&our_id, &payment_params, &network_graph.read_only(), None, 90_000, Arc::clone(&logger), &scorer, &(), &random_seed_bytes).unwrap();
+                       let route_params = RouteParameters::from_payment_params_and_value(
+                               payment_params, 90_000);
+                       let route = get_route(&our_id, &route_params, &network_graph.read_only(), None,
+                               Arc::clone(&logger), &scorer, &(), &random_seed_bytes).unwrap();
                        assert_eq!(route.paths.len(), 1);
                        assert_eq!(route.paths[0].hops.len(), 2);
 
@@ -5244,7 +5745,10 @@ mod tests {
                        // Now, attempt to route 90 sats, hitting the htlc_minimum on channel 4, but
                        // overshooting the htlc_maximum on channel 2. Thus, we should pick the (absurdly
                        // expensive) channels 12-13 path.
-                       let route = get_route(&our_id, &payment_params, &network_graph.read_only(), None, 90_000, Arc::clone(&logger), &scorer, &(), &random_seed_bytes).unwrap();
+                       let route_params = RouteParameters::from_payment_params_and_value(
+                               payment_params, 90_000);
+                       let route = get_route(&our_id, &route_params, &network_graph.read_only(), None,
+                               Arc::clone(&logger), &scorer, &(), &random_seed_bytes).unwrap();
                        assert_eq!(route.paths.len(), 1);
                        assert_eq!(route.paths[0].hops.len(), 2);
 
@@ -5283,10 +5787,12 @@ mod tests {
                let random_seed_bytes = keys_manager.get_secure_random_bytes();
 
                {
-                       let route = get_route(&our_id, &payment_params, &network_graph.read_only(), Some(&[
+                       let route_params = RouteParameters::from_payment_params_and_value(
+                               payment_params.clone(), 100_000);
+                       let route = get_route(&our_id, &route_params, &network_graph.read_only(), Some(&[
                                &get_channel_details(Some(3), nodes[0], channelmanager::provided_init_features(&config), 200_000),
                                &get_channel_details(Some(2), nodes[0], channelmanager::provided_init_features(&config), 10_000),
-                       ]), 100_000, Arc::clone(&logger), &scorer, &(), &random_seed_bytes).unwrap();
+                       ]), Arc::clone(&logger), &scorer, &(), &random_seed_bytes).unwrap();
                        assert_eq!(route.paths.len(), 1);
                        assert_eq!(route.paths[0].hops.len(), 1);
 
@@ -5295,10 +5801,12 @@ mod tests {
                        assert_eq!(route.paths[0].hops[0].fee_msat, 100_000);
                }
                {
-                       let route = get_route(&our_id, &payment_params, &network_graph.read_only(), Some(&[
+                       let route_params = RouteParameters::from_payment_params_and_value(
+                               payment_params.clone(), 100_000);
+                       let route = get_route(&our_id, &route_params, &network_graph.read_only(), Some(&[
                                &get_channel_details(Some(3), nodes[0], channelmanager::provided_init_features(&config), 50_000),
                                &get_channel_details(Some(2), nodes[0], channelmanager::provided_init_features(&config), 50_000),
-                       ]), 100_000, Arc::clone(&logger), &scorer, &(), &random_seed_bytes).unwrap();
+                       ]), Arc::clone(&logger), &scorer, &(), &random_seed_bytes).unwrap();
                        assert_eq!(route.paths.len(), 2);
                        assert_eq!(route.paths[0].hops.len(), 1);
                        assert_eq!(route.paths[1].hops.len(), 1);
@@ -5321,7 +5829,9 @@ mod tests {
                        // If we have several options above the 3xpayment value threshold, we should pick the
                        // smallest of them, avoiding further fragmenting our available outbound balance to
                        // this node.
-                       let route = get_route(&our_id, &payment_params, &network_graph.read_only(), Some(&[
+                       let route_params = RouteParameters::from_payment_params_and_value(
+                               payment_params, 100_000);
+                       let route = get_route(&our_id, &route_params, &network_graph.read_only(), Some(&[
                                &get_channel_details(Some(2), nodes[0], channelmanager::provided_init_features(&config), 50_000),
                                &get_channel_details(Some(3), nodes[0], channelmanager::provided_init_features(&config), 50_000),
                                &get_channel_details(Some(5), nodes[0], channelmanager::provided_init_features(&config), 50_000),
@@ -5330,7 +5840,7 @@ mod tests {
                                &get_channel_details(Some(8), nodes[0], channelmanager::provided_init_features(&config), 50_000),
                                &get_channel_details(Some(9), nodes[0], channelmanager::provided_init_features(&config), 50_000),
                                &get_channel_details(Some(4), nodes[0], channelmanager::provided_init_features(&config), 1_000_000),
-                       ]), 100_000, Arc::clone(&logger), &scorer, &(), &random_seed_bytes).unwrap();
+                       ]), Arc::clone(&logger), &scorer, &(), &random_seed_bytes).unwrap();
                        assert_eq!(route.paths.len(), 1);
                        assert_eq!(route.paths[0].hops.len(), 1);
 
@@ -5350,10 +5860,10 @@ mod tests {
                let scorer = ln_test_utils::TestScorer::new();
                let keys_manager = ln_test_utils::TestKeysInterface::new(&[0u8; 32], Network::Testnet);
                let random_seed_bytes = keys_manager.get_secure_random_bytes();
-               let route = get_route(
-                       &our_id, &payment_params, &network_graph.read_only(), None, 100,
-                       Arc::clone(&logger), &scorer, &(), &random_seed_bytes
-               ).unwrap();
+               let route_params = RouteParameters::from_payment_params_and_value(
+                       payment_params.clone(), 100);
+               let route = get_route( &our_id, &route_params, &network_graph.read_only(), None,
+                       Arc::clone(&logger), &scorer, &(), &random_seed_bytes).unwrap();
                let path = route.paths[0].hops.iter().map(|hop| hop.short_channel_id).collect::<Vec<_>>();
 
                assert_eq!(route.get_total_fees(), 100);
@@ -5363,10 +5873,10 @@ mod tests {
                // Applying a 100 msat penalty to each hop results in taking channels 7 and 10 to nodes[6]
                // from nodes[2] rather than channel 6, 11, and 8, even though the longer path is cheaper.
                let scorer = FixedPenaltyScorer::with_penalty(100);
-               let route = get_route(
-                       &our_id, &payment_params, &network_graph.read_only(), None, 100,
-                       Arc::clone(&logger), &scorer, &(), &random_seed_bytes
-               ).unwrap();
+               let route_params = RouteParameters::from_payment_params_and_value(
+                       payment_params, 100);
+               let route = get_route( &our_id, &route_params, &network_graph.read_only(), None,
+                       Arc::clone(&logger), &scorer, &(), &random_seed_bytes).unwrap();
                let path = route.paths[0].hops.iter().map(|hop| hop.short_channel_id).collect::<Vec<_>>();
 
                assert_eq!(route.get_total_fees(), 300);
@@ -5382,16 +5892,11 @@ mod tests {
        impl Writeable for BadChannelScorer {
                fn write<W: Writer>(&self, _w: &mut W) -> Result<(), crate::io::Error> { unimplemented!() }
        }
-       impl Score for BadChannelScorer {
+       impl ScoreLookUp for BadChannelScorer {
                type ScoreParams = ();
                fn channel_penalty_msat(&self, short_channel_id: u64, _: &NodeId, _: &NodeId, _: ChannelUsage, _score_params:&Self::ScoreParams) -> u64 {
                        if short_channel_id == self.short_channel_id { u64::max_value() } else { 0 }
                }
-
-               fn payment_path_failed(&mut self, _path: &Path, _short_channel_id: u64) {}
-               fn payment_path_successful(&mut self, _path: &Path) {}
-               fn probe_failed(&mut self, _path: &Path, _short_channel_id: u64) {}
-               fn probe_successful(&mut self, _path: &Path) {}
        }
 
        struct BadNodeScorer {
@@ -5403,16 +5908,11 @@ mod tests {
                fn write<W: Writer>(&self, _w: &mut W) -> Result<(), crate::io::Error> { unimplemented!() }
        }
 
-       impl Score for BadNodeScorer {
+       impl ScoreLookUp for BadNodeScorer {
                type ScoreParams = ();
                fn channel_penalty_msat(&self, _: u64, _: &NodeId, target: &NodeId, _: ChannelUsage, _score_params:&Self::ScoreParams) -> u64 {
                        if *target == self.node_id { u64::max_value() } else { 0 }
                }
-
-               fn payment_path_failed(&mut self, _path: &Path, _short_channel_id: u64) {}
-               fn payment_path_successful(&mut self, _path: &Path) {}
-               fn probe_failed(&mut self, _path: &Path, _short_channel_id: u64) {}
-               fn probe_successful(&mut self, _path: &Path) {}
        }
 
        #[test]
@@ -5426,10 +5926,10 @@ mod tests {
                let scorer = ln_test_utils::TestScorer::new();
                let keys_manager = ln_test_utils::TestKeysInterface::new(&[0u8; 32], Network::Testnet);
                let random_seed_bytes = keys_manager.get_secure_random_bytes();
-               let route = get_route(
-                       &our_id, &payment_params, &network_graph, None, 100,
-                       Arc::clone(&logger), &scorer, &(), &random_seed_bytes
-               ).unwrap();
+               let route_params = RouteParameters::from_payment_params_and_value(
+                       payment_params, 100);
+               let route = get_route( &our_id, &route_params, &network_graph, None, Arc::clone(&logger),
+                       &scorer, &(), &random_seed_bytes).unwrap();
                let path = route.paths[0].hops.iter().map(|hop| hop.short_channel_id).collect::<Vec<_>>();
 
                assert_eq!(route.get_total_fees(), 100);
@@ -5438,10 +5938,8 @@ mod tests {
 
                // A different path to nodes[6] exists if channel 6 cannot be routed over.
                let scorer = BadChannelScorer { short_channel_id: 6 };
-               let route = get_route(
-                       &our_id, &payment_params, &network_graph, None, 100,
-                       Arc::clone(&logger), &scorer, &(), &random_seed_bytes
-               ).unwrap();
+               let route = get_route( &our_id, &route_params, &network_graph, None, Arc::clone(&logger),
+                       &scorer, &(), &random_seed_bytes).unwrap();
                let path = route.paths[0].hops.iter().map(|hop| hop.short_channel_id).collect::<Vec<_>>();
 
                assert_eq!(route.get_total_fees(), 300);
@@ -5450,14 +5948,12 @@ mod tests {
 
                // A path to nodes[6] does not exist if nodes[2] cannot be routed through.
                let scorer = BadNodeScorer { node_id: NodeId::from_pubkey(&nodes[2]) };
-               match get_route(
-                       &our_id, &payment_params, &network_graph, None, 100,
-                       Arc::clone(&logger), &scorer, &(), &random_seed_bytes
-               ) {
-                       Err(LightningError { err, .. } ) => {
-                               assert_eq!(err, "Failed to find a path to the given destination");
-                       },
-                       Ok(_) => panic!("Expected error"),
+               match get_route( &our_id, &route_params, &network_graph, None, Arc::clone(&logger),
+                       &scorer, &(), &random_seed_bytes) {
+                               Err(LightningError { err, .. } ) => {
+                                       assert_eq!(err, "Failed to find a path to the given destination");
+                               },
+                               Ok(_) => panic!("Expected error"),
                }
        }
 
@@ -5481,7 +5977,7 @@ mod tests {
                                        short_channel_id: 0, fee_msat: 225, cltv_expiry_delta: 0
                                },
                        ], blinded_tail: None }],
-                       payment_params: None,
+                       route_params: None,
                };
 
                assert_eq!(route.get_total_fees(), 250);
@@ -5514,7 +6010,7 @@ mod tests {
                                        short_channel_id: 0, fee_msat: 150, cltv_expiry_delta: 0
                                },
                        ], blinded_tail: None }],
-                       payment_params: None,
+                       route_params: None,
                };
 
                assert_eq!(route.get_total_fees(), 200);
@@ -5526,7 +6022,7 @@ mod tests {
                // In an earlier version of `Route::get_total_fees` and `Route::get_total_amount`, they
                // would both panic if the route was completely empty. We test to ensure they return 0
                // here, even though its somewhat nonsensical as a route.
-               let route = Route { paths: Vec::new(), payment_params: None };
+               let route = Route { paths: Vec::new(), route_params: None };
 
                assert_eq!(route.get_total_fees(), 0);
                assert_eq!(route.get_total_amount(), 0);
@@ -5546,7 +6042,10 @@ mod tests {
                        .with_max_total_cltv_expiry_delta(feasible_max_total_cltv_delta);
                let keys_manager = ln_test_utils::TestKeysInterface::new(&[0u8; 32], Network::Testnet);
                let random_seed_bytes = keys_manager.get_secure_random_bytes();
-               let route = get_route(&our_id, &feasible_payment_params, &network_graph, None, 100, Arc::clone(&logger), &scorer, &(), &random_seed_bytes).unwrap();
+               let route_params = RouteParameters::from_payment_params_and_value(
+                       feasible_payment_params, 100);
+               let route = get_route(&our_id, &route_params, &network_graph, None, Arc::clone(&logger),
+                       &scorer, &(), &random_seed_bytes).unwrap();
                let path = route.paths[0].hops.iter().map(|hop| hop.short_channel_id).collect::<Vec<_>>();
                assert_ne!(path.len(), 0);
 
@@ -5554,7 +6053,10 @@ mod tests {
                let fail_max_total_cltv_delta = 23;
                let fail_payment_params = PaymentParameters::from_node_id(nodes[6], 0).with_route_hints(last_hops(&nodes)).unwrap()
                        .with_max_total_cltv_expiry_delta(fail_max_total_cltv_delta);
-               match get_route(&our_id, &fail_payment_params, &network_graph, None, 100, Arc::clone(&logger), &scorer, &(), &random_seed_bytes)
+               let route_params = RouteParameters::from_payment_params_and_value(
+                       fail_payment_params, 100);
+               match get_route(&our_id, &route_params, &network_graph, None, Arc::clone(&logger), &scorer,
+                       &(), &random_seed_bytes)
                {
                        Err(LightningError { err, .. } ) => {
                                assert_eq!(err, "Failed to find a path to the given destination");
@@ -5579,9 +6081,16 @@ mod tests {
 
                // We should be able to find a route initially, and then after we fail a few random
                // channels eventually we won't be able to any longer.
-               assert!(get_route(&our_id, &payment_params, &network_graph, None, 100, Arc::clone(&logger), &scorer, &(), &random_seed_bytes).is_ok());
+               let route_params = RouteParameters::from_payment_params_and_value(
+                       payment_params.clone(), 100);
+               assert!(get_route(&our_id, &route_params, &network_graph, None, Arc::clone(&logger),
+                       &scorer, &(), &random_seed_bytes).is_ok());
                loop {
-                       if let Ok(route) = get_route(&our_id, &payment_params, &network_graph, None, 100, Arc::clone(&logger), &scorer, &(), &random_seed_bytes) {
+                       let route_params = RouteParameters::from_payment_params_and_value(
+                               payment_params.clone(), 100);
+                       if let Ok(route) = get_route(&our_id, &route_params, &network_graph, None,
+                               Arc::clone(&logger), &scorer, &(), &random_seed_bytes)
+                       {
                                for chan in route.paths[0].hops.iter() {
                                        assert!(!payment_params.previously_failed_channels.contains(&chan.short_channel_id));
                                }
@@ -5604,15 +6113,19 @@ mod tests {
 
                // First check we can actually create a long route on this graph.
                let feasible_payment_params = PaymentParameters::from_node_id(nodes[18], 0);
-               let route = get_route(&our_id, &feasible_payment_params, &network_graph, None, 100,
-                       Arc::clone(&logger), &scorer, &(), &random_seed_bytes).unwrap();
+               let route_params = RouteParameters::from_payment_params_and_value(
+                       feasible_payment_params, 100);
+               let route = get_route(&our_id, &route_params, &network_graph, None, Arc::clone(&logger),
+                       &scorer, &(), &random_seed_bytes).unwrap();
                let path = route.paths[0].hops.iter().map(|hop| hop.short_channel_id).collect::<Vec<_>>();
                assert!(path.len() == MAX_PATH_LENGTH_ESTIMATE.into());
 
                // But we can't create a path surpassing the MAX_PATH_LENGTH_ESTIMATE limit.
                let fail_payment_params = PaymentParameters::from_node_id(nodes[19], 0);
-               match get_route(&our_id, &fail_payment_params, &network_graph, None, 100,
-                       Arc::clone(&logger), &scorer, &(), &random_seed_bytes)
+               let route_params = RouteParameters::from_payment_params_and_value(
+                       fail_payment_params, 100);
+               match get_route(&our_id, &route_params, &network_graph, None, Arc::clone(&logger), &scorer,
+                       &(), &random_seed_bytes)
                {
                        Err(LightningError { err, .. } ) => {
                                assert_eq!(err, "Failed to find a path to the given destination");
@@ -5631,7 +6144,10 @@ mod tests {
                let payment_params = PaymentParameters::from_node_id(nodes[6], 42).with_route_hints(last_hops(&nodes)).unwrap();
                let keys_manager = ln_test_utils::TestKeysInterface::new(&[0u8; 32], Network::Testnet);
                let random_seed_bytes = keys_manager.get_secure_random_bytes();
-               let route = get_route(&our_id, &payment_params, &network_graph.read_only(), None, 100, Arc::clone(&logger), &scorer, &(), &random_seed_bytes).unwrap();
+               let route_params = RouteParameters::from_payment_params_and_value(
+                       payment_params.clone(), 100);
+               let route = get_route(&our_id, &route_params, &network_graph.read_only(), None,
+                       Arc::clone(&logger), &scorer, &(), &random_seed_bytes).unwrap();
                assert_eq!(route.paths.len(), 1);
 
                let cltv_expiry_deltas_before = route.paths[0].hops.iter().map(|h| h.cltv_expiry_delta).collect::<Vec<u32>>();
@@ -5665,8 +6181,10 @@ mod tests {
                let keys_manager = ln_test_utils::TestKeysInterface::new(&[4u8; 32], Network::Testnet);
                let random_seed_bytes = keys_manager.get_secure_random_bytes();
 
-               let mut route = get_route(&our_id, &payment_params, &network_graph, None, 100,
-                                                                 Arc::clone(&logger), &scorer, &(), &random_seed_bytes).unwrap();
+               let route_params = RouteParameters::from_payment_params_and_value(
+                       payment_params.clone(), 100);
+               let mut route = get_route(&our_id, &route_params, &network_graph, None,
+                       Arc::clone(&logger), &scorer, &(), &random_seed_bytes).unwrap();
                add_random_cltv_offset(&mut route, &payment_params, &network_graph, &random_seed_bytes);
 
                let mut path_plausibility = vec![];
@@ -5730,8 +6248,9 @@ mod tests {
 
                let payment_params = PaymentParameters::from_node_id(nodes[3], 0);
                let hops = [nodes[1], nodes[2], nodes[4], nodes[3]];
-               let route = build_route_from_hops_internal(&our_id, &hops, &payment_params,
-                        &network_graph, 100, Arc::clone(&logger), &random_seed_bytes).unwrap();
+               let route_params = RouteParameters::from_payment_params_and_value(payment_params, 100);
+               let route = build_route_from_hops_internal(&our_id, &hops, &route_params, &network_graph,
+                       Arc::clone(&logger), &random_seed_bytes).unwrap();
                let route_hop_pubkeys = route.paths[0].hops.iter().map(|hop| hop.pubkey).collect::<Vec<_>>();
                assert_eq!(hops.len(), route.paths[0].hops.len());
                for (idx, hop_pubkey) in hops.iter().enumerate() {
@@ -5778,7 +6297,10 @@ mod tests {
                let keys_manager = ln_test_utils::TestKeysInterface::new(&[0u8; 32], Network::Testnet);
                let random_seed_bytes = keys_manager.get_secure_random_bytes();
                // 100,000 sats is less than the available liquidity on each channel, set above.
-               let route = get_route(&our_id, &payment_params, &network_graph.read_only(), None, 100_000_000, Arc::clone(&logger), &scorer, &ProbabilisticScoringFeeParameters::default(), &random_seed_bytes).unwrap();
+               let route_params = RouteParameters::from_payment_params_and_value(
+                       payment_params, 100_000_000);
+               let route = get_route(&our_id, &route_params, &network_graph.read_only(), None,
+                       Arc::clone(&logger), &scorer, &ProbabilisticScoringFeeParameters::default(), &random_seed_bytes).unwrap();
                assert_eq!(route.paths.len(), 2);
                assert!((route.paths[0].hops[1].short_channel_id == 4 && route.paths[1].hops[1].short_channel_id == 13) ||
                        (route.paths[1].hops[1].short_channel_id == 4 && route.paths[0].hops[1].short_channel_id == 13));
@@ -5809,7 +6331,7 @@ mod tests {
 
                let params = ProbabilisticScoringFeeParameters::default();
                let mut scorer = ProbabilisticScorer::new(ProbabilisticScoringDecayParameters::default(), &graph, &logger);
-               let features = super::InvoiceFeatures::empty();
+               let features = super::Bolt11InvoiceFeatures::empty();
 
                super::bench_utils::generate_test_routes(&graph, &mut scorer, &params, features, random_init_seed(), 0, 2);
        }
@@ -5879,20 +6401,184 @@ mod tests {
 
                // Then check we can get a normal route
                let payment_params = PaymentParameters::from_node_id(nodes[10], 42);
-               let route = get_route(&our_id, &payment_params, &network_graph.read_only(), None, 100, Arc::clone(&logger), &scorer, &scorer_params,&random_seed_bytes);
+               let route_params = RouteParameters::from_payment_params_and_value(
+                       payment_params, 100);
+               let route = get_route(&our_id, &route_params, &network_graph.read_only(), None,
+                       Arc::clone(&logger), &scorer, &scorer_params, &random_seed_bytes);
                assert!(route.is_ok());
 
                // Then check that we can't get a route if we ban an intermediate node.
                scorer_params.add_banned(&NodeId::from_pubkey(&nodes[3]));
-               let route = get_route(&our_id, &payment_params, &network_graph.read_only(), None, 100, Arc::clone(&logger), &scorer, &scorer_params,&random_seed_bytes);
+               let route = get_route(&our_id, &route_params, &network_graph.read_only(), None,
+                       Arc::clone(&logger), &scorer, &scorer_params, &random_seed_bytes);
                assert!(route.is_err());
 
                // Finally make sure we can route again, when we remove the ban.
                scorer_params.remove_banned(&NodeId::from_pubkey(&nodes[3]));
-               let route = get_route(&our_id, &payment_params, &network_graph.read_only(), None, 100, Arc::clone(&logger), &scorer, &scorer_params,&random_seed_bytes);
+               let route = get_route(&our_id, &route_params, &network_graph.read_only(), None,
+                       Arc::clone(&logger), &scorer, &scorer_params, &random_seed_bytes);
                assert!(route.is_ok());
        }
 
+       #[test]
+       fn abide_by_route_hint_max_htlc() {
+               // Check that we abide by any htlc_maximum_msat provided in the route hints of the payment
+               // params in the final route.
+               let (secp_ctx, network_graph, _, _, logger) = build_graph();
+               let netgraph = network_graph.read_only();
+               let (_, our_id, _, nodes) = get_nodes(&secp_ctx);
+               let scorer = ln_test_utils::TestScorer::new();
+               let keys_manager = ln_test_utils::TestKeysInterface::new(&[0u8; 32], Network::Testnet);
+               let random_seed_bytes = keys_manager.get_secure_random_bytes();
+               let config = UserConfig::default();
+
+               let max_htlc_msat = 50_000;
+               let route_hint_1 = RouteHint(vec![RouteHintHop {
+                       src_node_id: nodes[2],
+                       short_channel_id: 42,
+                       fees: RoutingFees {
+                               base_msat: 100,
+                               proportional_millionths: 0,
+                       },
+                       cltv_expiry_delta: 10,
+                       htlc_minimum_msat: None,
+                       htlc_maximum_msat: Some(max_htlc_msat),
+               }]);
+               let dest_node_id = ln_test_utils::pubkey(42);
+               let payment_params = PaymentParameters::from_node_id(dest_node_id, 42)
+                       .with_route_hints(vec![route_hint_1.clone()]).unwrap()
+                       .with_bolt11_features(channelmanager::provided_invoice_features(&config)).unwrap();
+
+               // Make sure we'll error if our route hints don't have enough liquidity according to their
+               // htlc_maximum_msat.
+               let route_params = RouteParameters::from_payment_params_and_value(
+                       payment_params, max_htlc_msat + 1);
+               if let Err(LightningError{err, action: ErrorAction::IgnoreError}) = get_route(&our_id,
+                       &route_params, &netgraph, None, Arc::clone(&logger), &scorer, &(),
+                       &random_seed_bytes)
+               {
+                       assert_eq!(err, "Failed to find a sufficient route to the given destination");
+               } else { panic!(); }
+
+               // Make sure we'll split an MPP payment across route hints if their htlc_maximum_msat warrants.
+               let mut route_hint_2 = route_hint_1.clone();
+               route_hint_2.0[0].short_channel_id = 43;
+               let payment_params = PaymentParameters::from_node_id(dest_node_id, 42)
+                       .with_route_hints(vec![route_hint_1, route_hint_2]).unwrap()
+                       .with_bolt11_features(channelmanager::provided_invoice_features(&config)).unwrap();
+               let route_params = RouteParameters::from_payment_params_and_value(
+                       payment_params, max_htlc_msat + 1);
+               let route = get_route(&our_id, &route_params, &netgraph, None, Arc::clone(&logger),
+                       &scorer, &(), &random_seed_bytes).unwrap();
+               assert_eq!(route.paths.len(), 2);
+               assert!(route.paths[0].hops.last().unwrap().fee_msat <= max_htlc_msat);
+               assert!(route.paths[1].hops.last().unwrap().fee_msat <= max_htlc_msat);
+       }
+
+       #[test]
+       fn direct_channel_to_hints_with_max_htlc() {
+               // Check that if we have a first hop channel peer that's connected to multiple provided route
+               // hints, that we properly split the payment between the route hints if needed.
+               let logger = Arc::new(ln_test_utils::TestLogger::new());
+               let network_graph = Arc::new(NetworkGraph::new(Network::Testnet, Arc::clone(&logger)));
+               let scorer = ln_test_utils::TestScorer::new();
+               let keys_manager = ln_test_utils::TestKeysInterface::new(&[0u8; 32], Network::Testnet);
+               let random_seed_bytes = keys_manager.get_secure_random_bytes();
+               let config = UserConfig::default();
+
+               let our_node_id = ln_test_utils::pubkey(42);
+               let intermed_node_id = ln_test_utils::pubkey(43);
+               let first_hop = vec![get_channel_details(Some(42), intermed_node_id, InitFeatures::from_le_bytes(vec![0b11]), 10_000_000)];
+
+               let amt_msat = 900_000;
+               let max_htlc_msat = 500_000;
+               let route_hint_1 = RouteHint(vec![RouteHintHop {
+                       src_node_id: intermed_node_id,
+                       short_channel_id: 44,
+                       fees: RoutingFees {
+                               base_msat: 100,
+                               proportional_millionths: 0,
+                       },
+                       cltv_expiry_delta: 10,
+                       htlc_minimum_msat: None,
+                       htlc_maximum_msat: Some(max_htlc_msat),
+               }, RouteHintHop {
+                       src_node_id: intermed_node_id,
+                       short_channel_id: 45,
+                       fees: RoutingFees {
+                               base_msat: 100,
+                               proportional_millionths: 0,
+                       },
+                       cltv_expiry_delta: 10,
+                       htlc_minimum_msat: None,
+                       // Check that later route hint max htlcs don't override earlier ones
+                       htlc_maximum_msat: Some(max_htlc_msat - 50),
+               }]);
+               let mut route_hint_2 = route_hint_1.clone();
+               route_hint_2.0[0].short_channel_id = 46;
+               route_hint_2.0[1].short_channel_id = 47;
+               let dest_node_id = ln_test_utils::pubkey(44);
+               let payment_params = PaymentParameters::from_node_id(dest_node_id, 42)
+                       .with_route_hints(vec![route_hint_1, route_hint_2]).unwrap()
+                       .with_bolt11_features(channelmanager::provided_invoice_features(&config)).unwrap();
+
+               let route_params = RouteParameters::from_payment_params_and_value(
+                       payment_params, amt_msat);
+               let route = get_route(&our_node_id, &route_params, &network_graph.read_only(),
+                       Some(&first_hop.iter().collect::<Vec<_>>()), Arc::clone(&logger), &scorer, &(),
+                       &random_seed_bytes).unwrap();
+               assert_eq!(route.paths.len(), 2);
+               assert!(route.paths[0].hops.last().unwrap().fee_msat <= max_htlc_msat);
+               assert!(route.paths[1].hops.last().unwrap().fee_msat <= max_htlc_msat);
+               assert_eq!(route.get_total_amount(), amt_msat);
+
+               // Re-run but with two first hop channels connected to the same route hint peers that must be
+               // split between.
+               let first_hops = vec![
+                       get_channel_details(Some(42), intermed_node_id, InitFeatures::from_le_bytes(vec![0b11]), amt_msat - 10),
+                       get_channel_details(Some(43), intermed_node_id, InitFeatures::from_le_bytes(vec![0b11]), amt_msat - 10),
+               ];
+               let route = get_route(&our_node_id, &route_params, &network_graph.read_only(),
+                       Some(&first_hops.iter().collect::<Vec<_>>()), Arc::clone(&logger), &scorer, &(),
+                       &random_seed_bytes).unwrap();
+               assert_eq!(route.paths.len(), 2);
+               assert!(route.paths[0].hops.last().unwrap().fee_msat <= max_htlc_msat);
+               assert!(route.paths[1].hops.last().unwrap().fee_msat <= max_htlc_msat);
+               assert_eq!(route.get_total_amount(), amt_msat);
+
+               // Make sure this works for blinded route hints.
+               let blinded_path = BlindedPath {
+                       introduction_node_id: intermed_node_id,
+                       blinding_point: ln_test_utils::pubkey(42),
+                       blinded_hops: vec![
+                               BlindedHop { blinded_node_id: ln_test_utils::pubkey(42), encrypted_payload: vec![] },
+                               BlindedHop { blinded_node_id: ln_test_utils::pubkey(43), encrypted_payload: vec![] },
+                       ],
+               };
+               let blinded_payinfo = BlindedPayInfo {
+                       fee_base_msat: 100,
+                       fee_proportional_millionths: 0,
+                       htlc_minimum_msat: 1,
+                       htlc_maximum_msat: max_htlc_msat,
+                       cltv_expiry_delta: 10,
+                       features: BlindedHopFeatures::empty(),
+               };
+               let bolt12_features: Bolt12InvoiceFeatures = channelmanager::provided_invoice_features(&config).to_context();
+               let payment_params = PaymentParameters::blinded(vec![
+                       (blinded_payinfo.clone(), blinded_path.clone()),
+                       (blinded_payinfo.clone(), blinded_path.clone())])
+                       .with_bolt12_features(bolt12_features).unwrap();
+               let route_params = RouteParameters::from_payment_params_and_value(
+                       payment_params, amt_msat);
+               let route = get_route(&our_node_id, &route_params, &network_graph.read_only(),
+                       Some(&first_hops.iter().collect::<Vec<_>>()), Arc::clone(&logger), &scorer, &(),
+                       &random_seed_bytes).unwrap();
+               assert_eq!(route.paths.len(), 2);
+               assert!(route.paths[0].hops.last().unwrap().fee_msat <= max_htlc_msat);
+               assert!(route.paths[1].hops.last().unwrap().fee_msat <= max_htlc_msat);
+               assert_eq!(route.get_total_amount(), amt_msat);
+       }
+
        #[test]
        fn blinded_route_ser() {
                let blinded_path_1 = BlindedPath {
@@ -5935,7 +6621,7 @@ mod tests {
                                fee_msat: 100,
                                cltv_expiry_delta: 0,
                        }], blinded_tail: None }],
-                       payment_params: None,
+                       route_params: None,
                };
                let encoded_route = route.encode();
                let decoded_route: Route = Readable::read(&mut Cursor::new(&encoded_route[..])).unwrap();
@@ -6029,7 +6715,7 @@ mod tests {
                                excess_final_cltv_expiry_delta: 0,
                                final_value_msat: 200,
                        }),
-               }], payment_params: None};
+               }], route_params: None};
 
                let payment_params = PaymentParameters::from_node_id(ln_test_utils::pubkey(47), 18);
                let (_, network_graph, _, _, _) = build_line_graph();
@@ -6037,6 +6723,354 @@ mod tests {
                assert_eq!(route.paths[0].blinded_tail.as_ref().unwrap().excess_final_cltv_expiry_delta, 40);
                assert_eq!(route.paths[0].hops.last().unwrap().cltv_expiry_delta, 40);
        }
+
+       #[test]
+       fn simple_blinded_route_hints() {
+               do_simple_blinded_route_hints(1);
+               do_simple_blinded_route_hints(2);
+               do_simple_blinded_route_hints(3);
+       }
+
+       fn do_simple_blinded_route_hints(num_blinded_hops: usize) {
+               // Check that we can generate a route to a blinded path with the expected hops.
+               let (secp_ctx, network, _, _, logger) = build_graph();
+               let (_, our_id, _, nodes) = get_nodes(&secp_ctx);
+               let network_graph = network.read_only();
+
+               let scorer = ln_test_utils::TestScorer::new();
+               let keys_manager = ln_test_utils::TestKeysInterface::new(&[0u8; 32], Network::Testnet);
+               let random_seed_bytes = keys_manager.get_secure_random_bytes();
+
+               let mut blinded_path = BlindedPath {
+                       introduction_node_id: nodes[2],
+                       blinding_point: ln_test_utils::pubkey(42),
+                       blinded_hops: Vec::with_capacity(num_blinded_hops),
+               };
+               for i in 0..num_blinded_hops {
+                       blinded_path.blinded_hops.push(
+                               BlindedHop { blinded_node_id: ln_test_utils::pubkey(42 + i as u8), encrypted_payload: Vec::new() },
+                       );
+               }
+               let blinded_payinfo = BlindedPayInfo {
+                       fee_base_msat: 100,
+                       fee_proportional_millionths: 500,
+                       htlc_minimum_msat: 1000,
+                       htlc_maximum_msat: 100_000_000,
+                       cltv_expiry_delta: 15,
+                       features: BlindedHopFeatures::empty(),
+               };
+
+               let payment_params = PaymentParameters::blinded(vec![(blinded_payinfo.clone(), blinded_path.clone())]);
+               let route_params = RouteParameters::from_payment_params_and_value(
+                       payment_params, 1001);
+               let route = get_route(&our_id, &route_params, &network_graph, None, Arc::clone(&logger),
+                       &scorer, &(), &random_seed_bytes).unwrap();
+               assert_eq!(route.paths.len(), 1);
+               assert_eq!(route.paths[0].hops.len(), 2);
+
+               let tail = route.paths[0].blinded_tail.as_ref().unwrap();
+               assert_eq!(tail.hops, blinded_path.blinded_hops);
+               assert_eq!(tail.excess_final_cltv_expiry_delta, 0);
+               assert_eq!(tail.final_value_msat, 1001);
+
+               let final_hop = route.paths[0].hops.last().unwrap();
+               assert_eq!(final_hop.pubkey, blinded_path.introduction_node_id);
+               if tail.hops.len() > 1 {
+                       assert_eq!(final_hop.fee_msat,
+                               blinded_payinfo.fee_base_msat as u64 + blinded_payinfo.fee_proportional_millionths as u64 * tail.final_value_msat / 1000000);
+                       assert_eq!(final_hop.cltv_expiry_delta, blinded_payinfo.cltv_expiry_delta as u32);
+               } else {
+                       assert_eq!(final_hop.fee_msat, 0);
+                       assert_eq!(final_hop.cltv_expiry_delta, 0);
+               }
+       }
+
+       #[test]
+       fn blinded_path_routing_errors() {
+               // Check that we can generate a route to a blinded path with the expected hops.
+               let (secp_ctx, network, _, _, logger) = build_graph();
+               let (_, our_id, _, nodes) = get_nodes(&secp_ctx);
+               let network_graph = network.read_only();
+
+               let scorer = ln_test_utils::TestScorer::new();
+               let keys_manager = ln_test_utils::TestKeysInterface::new(&[0u8; 32], Network::Testnet);
+               let random_seed_bytes = keys_manager.get_secure_random_bytes();
+
+               let mut invalid_blinded_path = BlindedPath {
+                       introduction_node_id: nodes[2],
+                       blinding_point: ln_test_utils::pubkey(42),
+                       blinded_hops: vec![
+                               BlindedHop { blinded_node_id: ln_test_utils::pubkey(43), encrypted_payload: vec![0; 43] },
+                       ],
+               };
+               let blinded_payinfo = BlindedPayInfo {
+                       fee_base_msat: 100,
+                       fee_proportional_millionths: 500,
+                       htlc_minimum_msat: 1000,
+                       htlc_maximum_msat: 100_000_000,
+                       cltv_expiry_delta: 15,
+                       features: BlindedHopFeatures::empty(),
+               };
+
+               let mut invalid_blinded_path_2 = invalid_blinded_path.clone();
+               invalid_blinded_path_2.introduction_node_id = ln_test_utils::pubkey(45);
+               let payment_params = PaymentParameters::blinded(vec![
+                       (blinded_payinfo.clone(), invalid_blinded_path.clone()),
+                       (blinded_payinfo.clone(), invalid_blinded_path_2)]);
+               let route_params = RouteParameters::from_payment_params_and_value(payment_params, 1001);
+               match get_route(&our_id, &route_params, &network_graph, None, Arc::clone(&logger),
+                       &scorer, &(), &random_seed_bytes)
+               {
+                       Err(LightningError { err, .. }) => {
+                               assert_eq!(err, "1-hop blinded paths must all have matching introduction node ids");
+                       },
+                       _ => panic!("Expected error")
+               }
+
+               invalid_blinded_path.introduction_node_id = our_id;
+               let payment_params = PaymentParameters::blinded(vec![(blinded_payinfo.clone(), invalid_blinded_path.clone())]);
+               let route_params = RouteParameters::from_payment_params_and_value(payment_params, 1001);
+               match get_route(&our_id, &route_params, &network_graph, None, Arc::clone(&logger), &scorer,
+                       &(), &random_seed_bytes)
+               {
+                       Err(LightningError { err, .. }) => {
+                               assert_eq!(err, "Cannot generate a route to blinded paths if we are the introduction node to all of them");
+                       },
+                       _ => panic!("Expected error")
+               }
+
+               invalid_blinded_path.introduction_node_id = ln_test_utils::pubkey(46);
+               invalid_blinded_path.blinded_hops.clear();
+               let payment_params = PaymentParameters::blinded(vec![(blinded_payinfo, invalid_blinded_path)]);
+               let route_params = RouteParameters::from_payment_params_and_value(payment_params, 1001);
+               match get_route(&our_id, &route_params, &network_graph, None, Arc::clone(&logger), &scorer,
+                       &(), &random_seed_bytes)
+               {
+                       Err(LightningError { err, .. }) => {
+                               assert_eq!(err, "0-hop blinded path provided");
+                       },
+                       _ => panic!("Expected error")
+               }
+       }
+
+       #[test]
+       fn matching_intro_node_paths_provided() {
+               // Check that if multiple blinded paths with the same intro node are provided in payment
+               // parameters, we'll return the correct paths in the resulting MPP route.
+               let (secp_ctx, network, _, _, logger) = build_graph();
+               let (_, our_id, _, nodes) = get_nodes(&secp_ctx);
+               let network_graph = network.read_only();
+
+               let scorer = ln_test_utils::TestScorer::new();
+               let keys_manager = ln_test_utils::TestKeysInterface::new(&[0u8; 32], Network::Testnet);
+               let random_seed_bytes = keys_manager.get_secure_random_bytes();
+               let config = UserConfig::default();
+
+               let bolt12_features: Bolt12InvoiceFeatures = channelmanager::provided_invoice_features(&config).to_context();
+               let blinded_path_1 = BlindedPath {
+                       introduction_node_id: nodes[2],
+                       blinding_point: ln_test_utils::pubkey(42),
+                       blinded_hops: vec![
+                               BlindedHop { blinded_node_id: ln_test_utils::pubkey(42 as u8), encrypted_payload: Vec::new() },
+                               BlindedHop { blinded_node_id: ln_test_utils::pubkey(42 as u8), encrypted_payload: Vec::new() }
+                       ],
+               };
+               let blinded_payinfo_1 = BlindedPayInfo {
+                       fee_base_msat: 0,
+                       fee_proportional_millionths: 0,
+                       htlc_minimum_msat: 0,
+                       htlc_maximum_msat: 30_000,
+                       cltv_expiry_delta: 0,
+                       features: BlindedHopFeatures::empty(),
+               };
+
+               let mut blinded_path_2 = blinded_path_1.clone();
+               blinded_path_2.blinding_point = ln_test_utils::pubkey(43);
+               let mut blinded_payinfo_2 = blinded_payinfo_1.clone();
+               blinded_payinfo_2.htlc_maximum_msat = 70_000;
+
+               let blinded_hints = vec![
+                       (blinded_payinfo_1.clone(), blinded_path_1.clone()),
+                       (blinded_payinfo_2.clone(), blinded_path_2.clone()),
+               ];
+               let payment_params = PaymentParameters::blinded(blinded_hints.clone())
+                       .with_bolt12_features(bolt12_features.clone()).unwrap();
+
+               let route_params = RouteParameters::from_payment_params_and_value(payment_params, 100_000);
+               let route = get_route(&our_id, &route_params, &network_graph, None, Arc::clone(&logger),
+                       &scorer, &(), &random_seed_bytes).unwrap();
+               assert_eq!(route.paths.len(), 2);
+               let mut total_amount_paid_msat = 0;
+               for path in route.paths.into_iter() {
+                       assert_eq!(path.hops.last().unwrap().pubkey, nodes[2]);
+                       if let Some(bt) = &path.blinded_tail {
+                               assert_eq!(bt.blinding_point,
+                                       blinded_hints.iter().find(|(p, _)| p.htlc_maximum_msat == path.final_value_msat())
+                                               .map(|(_, bp)| bp.blinding_point).unwrap());
+                       } else { panic!(); }
+                       total_amount_paid_msat += path.final_value_msat();
+               }
+               assert_eq!(total_amount_paid_msat, 100_000);
+       }
+
+       #[test]
+       fn direct_to_intro_node() {
+               // This previously caused a debug panic in the router when asserting
+               // `used_liquidity_msat <= hop_max_msat`, because when adding first_hop<>blinded_route_hint
+               // direct channels we failed to account for the fee charged for use of the blinded path.
+
+               // Build a graph:
+               // node0 -1(1)2 - node1
+               // such that there isn't enough liquidity to reach node1, but the router thinks there is if it
+               // doesn't account for the blinded path fee.
+
+               let secp_ctx = Secp256k1::new();
+               let logger = Arc::new(ln_test_utils::TestLogger::new());
+               let network_graph = Arc::new(NetworkGraph::new(Network::Testnet, Arc::clone(&logger)));
+               let gossip_sync = P2PGossipSync::new(Arc::clone(&network_graph), None, Arc::clone(&logger));
+               let scorer = ln_test_utils::TestScorer::new();
+               let keys_manager = ln_test_utils::TestKeysInterface::new(&[0u8; 32], Network::Testnet);
+               let random_seed_bytes = keys_manager.get_secure_random_bytes();
+
+               let amt_msat = 10_000_000;
+               let (_, _, privkeys, nodes) = get_nodes(&secp_ctx);
+               add_channel(&gossip_sync, &secp_ctx, &privkeys[0], &privkeys[1],
+                       ChannelFeatures::from_le_bytes(id_to_feature_flags(1)), 1);
+               update_channel(&gossip_sync, &secp_ctx, &privkeys[0], UnsignedChannelUpdate {
+                       chain_hash: genesis_block(Network::Testnet).header.block_hash(),
+                       short_channel_id: 1,
+                       timestamp: 1,
+                       flags: 0,
+                       cltv_expiry_delta: 42,
+                       htlc_minimum_msat: 1_000,
+                       htlc_maximum_msat: 10_000_000,
+                       fee_base_msat: 800,
+                       fee_proportional_millionths: 0,
+                       excess_data: Vec::new()
+               });
+               update_channel(&gossip_sync, &secp_ctx, &privkeys[1], UnsignedChannelUpdate {
+                       chain_hash: genesis_block(Network::Testnet).header.block_hash(),
+                       short_channel_id: 1,
+                       timestamp: 1,
+                       flags: 1,
+                       cltv_expiry_delta: 42,
+                       htlc_minimum_msat: 1_000,
+                       htlc_maximum_msat: 10_000_000,
+                       fee_base_msat: 800,
+                       fee_proportional_millionths: 0,
+                       excess_data: Vec::new()
+               });
+               let first_hops = vec![
+                       get_channel_details(Some(1), nodes[1], InitFeatures::from_le_bytes(vec![0b11]), 10_000_000)];
+
+               let blinded_path = BlindedPath {
+                       introduction_node_id: nodes[1],
+                       blinding_point: ln_test_utils::pubkey(42),
+                       blinded_hops: vec![
+                               BlindedHop { blinded_node_id: ln_test_utils::pubkey(42 as u8), encrypted_payload: Vec::new() },
+                               BlindedHop { blinded_node_id: ln_test_utils::pubkey(42 as u8), encrypted_payload: Vec::new() }
+                       ],
+               };
+               let blinded_payinfo = BlindedPayInfo {
+                       fee_base_msat: 1000,
+                       fee_proportional_millionths: 0,
+                       htlc_minimum_msat: 1000,
+                       htlc_maximum_msat: MAX_VALUE_MSAT,
+                       cltv_expiry_delta: 0,
+                       features: BlindedHopFeatures::empty(),
+               };
+               let blinded_hints = vec![(blinded_payinfo.clone(), blinded_path)];
+
+               let payment_params = PaymentParameters::blinded(blinded_hints.clone());
+
+               let netgraph = network_graph.read_only();
+               let route_params = RouteParameters::from_payment_params_and_value(
+                       payment_params.clone(), amt_msat);
+               if let Err(LightningError { err, .. }) = get_route(&nodes[0], &route_params, &netgraph,
+                       Some(&first_hops.iter().collect::<Vec<_>>()), Arc::clone(&logger), &scorer, &(),
+                       &random_seed_bytes) {
+                               assert_eq!(err, "Failed to find a path to the given destination");
+               } else { panic!("Expected error") }
+
+               // Sending an exact amount accounting for the blinded path fee works.
+               let amt_minus_blinded_path_fee = amt_msat - blinded_payinfo.fee_base_msat as u64;
+               let route_params = RouteParameters::from_payment_params_and_value(
+                       payment_params, amt_minus_blinded_path_fee);
+               let route = get_route(&nodes[0], &route_params, &netgraph,
+                       Some(&first_hops.iter().collect::<Vec<_>>()), Arc::clone(&logger), &scorer, &(),
+                       &random_seed_bytes).unwrap();
+               assert_eq!(route.get_total_fees(), blinded_payinfo.fee_base_msat as u64);
+               assert_eq!(route.get_total_amount(), amt_minus_blinded_path_fee);
+       }
+
+       #[test]
+       fn direct_to_matching_intro_nodes() {
+               // This previously caused us to enter `unreachable` code in the following situation:
+               // 1. We add a route candidate for intro_node contributing a high amount
+               // 2. We add a first_hop<>intro_node route candidate for the same high amount
+               // 3. We see a cheaper blinded route hint for the same intro node but a much lower contribution
+               //    amount, and update our route candidate for intro_node for the lower amount
+               // 4. We then attempt to update the aforementioned first_hop<>intro_node route candidate for the
+               //    lower contribution amount, but fail (this was previously caused by failure to account for
+               //    blinded path fees when adding first_hop<>intro_node candidates)
+               // 5. We go to construct the path from these route candidates and our first_hop<>intro_node
+               //    candidate still thinks its path is contributing the original higher amount. This caused us
+               //    to hit an `unreachable` overflow when calculating the cheaper intro_node fees over the
+               //    larger amount
+               let secp_ctx = Secp256k1::new();
+               let logger = Arc::new(ln_test_utils::TestLogger::new());
+               let network_graph = Arc::new(NetworkGraph::new(Network::Testnet, Arc::clone(&logger)));
+               let scorer = ln_test_utils::TestScorer::new();
+               let keys_manager = ln_test_utils::TestKeysInterface::new(&[0u8; 32], Network::Testnet);
+               let random_seed_bytes = keys_manager.get_secure_random_bytes();
+               let config = UserConfig::default();
+
+               // Values are taken from the fuzz input that uncovered this panic.
+               let amt_msat = 21_7020_5185_1403_2640;
+               let (_, _, _, nodes) = get_nodes(&secp_ctx);
+               let first_hops = vec![
+                       get_channel_details(Some(1), nodes[1], channelmanager::provided_init_features(&config),
+                               18446744073709551615)];
+
+               let blinded_path = BlindedPath {
+                       introduction_node_id: nodes[1],
+                       blinding_point: ln_test_utils::pubkey(42),
+                       blinded_hops: vec![
+                               BlindedHop { blinded_node_id: ln_test_utils::pubkey(42 as u8), encrypted_payload: Vec::new() },
+                               BlindedHop { blinded_node_id: ln_test_utils::pubkey(42 as u8), encrypted_payload: Vec::new() }
+                       ],
+               };
+               let blinded_payinfo = BlindedPayInfo {
+                       fee_base_msat: 5046_2720,
+                       fee_proportional_millionths: 0,
+                       htlc_minimum_msat: 4503_5996_2737_0496,
+                       htlc_maximum_msat: 45_0359_9627_3704_9600,
+                       cltv_expiry_delta: 0,
+                       features: BlindedHopFeatures::empty(),
+               };
+               let mut blinded_hints = vec![
+                       (blinded_payinfo.clone(), blinded_path.clone()),
+                       (blinded_payinfo.clone(), blinded_path.clone()),
+               ];
+               blinded_hints[1].0.fee_base_msat = 419_4304;
+               blinded_hints[1].0.fee_proportional_millionths = 257;
+               blinded_hints[1].0.htlc_minimum_msat = 280_8908_6115_8400;
+               blinded_hints[1].0.htlc_maximum_msat = 2_8089_0861_1584_0000;
+               blinded_hints[1].0.cltv_expiry_delta = 0;
+
+               let bolt12_features: Bolt12InvoiceFeatures = channelmanager::provided_invoice_features(&config).to_context();
+               let payment_params = PaymentParameters::blinded(blinded_hints.clone())
+                       .with_bolt12_features(bolt12_features.clone()).unwrap();
+
+               let netgraph = network_graph.read_only();
+               let route_params = RouteParameters::from_payment_params_and_value(
+                       payment_params, amt_msat);
+               let route = get_route(&nodes[0], &route_params, &netgraph,
+                       Some(&first_hops.iter().collect::<Vec<_>>()), Arc::clone(&logger), &scorer, &(),
+                       &random_seed_bytes).unwrap();
+               assert_eq!(route.get_total_fees(), blinded_payinfo.fee_base_msat as u64);
+               assert_eq!(route.get_total_amount(), amt_msat);
+       }
 }
 
 #[cfg(all(any(test, ldk_bench), not(feature = "no-std")))]
@@ -6048,9 +7082,11 @@ pub(crate) mod bench_utils {
        use bitcoin::secp256k1::{PublicKey, Secp256k1, SecretKey};
 
        use crate::chain::transaction::OutPoint;
+       use crate::routing::scoring::ScoreUpdate;
        use crate::sign::{EntropySource, KeysManager};
+       use crate::ln::ChannelId;
        use crate::ln::channelmanager::{self, ChannelCounterparty, ChannelDetails};
-       use crate::ln::features::InvoiceFeatures;
+       use crate::ln::features::Bolt11InvoiceFeatures;
        use crate::routing::gossip::NetworkGraph;
        use crate::util::config::UserConfig;
        use crate::util::ser::ReadableArgs;
@@ -6102,7 +7138,7 @@ pub(crate) mod bench_utils {
        #[inline]
        pub(crate) fn first_hop(node_id: PublicKey) -> ChannelDetails {
                ChannelDetails {
-                       channel_id: [0; 32],
+                       channel_id: ChannelId::new_zero(),
                        counterparty: ChannelCounterparty {
                                features: channelmanager::provided_init_features(&UserConfig::default()),
                                node_id,
@@ -6120,7 +7156,6 @@ pub(crate) mod bench_utils {
                        outbound_scid_alias: None,
                        channel_value_satoshis: 10_000_000_000,
                        user_channel_id: 0,
-                       balance_msat: 10_000_000_000,
                        outbound_capacity_msat: 10_000_000_000,
                        next_outbound_htlc_minimum_msat: 0,
                        next_outbound_htlc_limit_msat: 10_000_000_000,
@@ -6137,11 +7172,12 @@ pub(crate) mod bench_utils {
                        inbound_htlc_maximum_msat: None,
                        config: None,
                        feerate_sat_per_1000_weight: None,
+                       channel_shutdown_state: Some(channelmanager::ChannelShutdownState::NotShuttingDown),
                }
        }
 
-       pub(crate) fn generate_test_routes<S: Score>(graph: &NetworkGraph<&TestLogger>, scorer: &mut S,
-               score_params: &S::ScoreParams, features: InvoiceFeatures, mut seed: u64,
+       pub(crate) fn generate_test_routes<S: ScoreLookUp + ScoreUpdate>(graph: &NetworkGraph<&TestLogger>, scorer: &mut S,
+               score_params: &S::ScoreParams, features: Bolt11InvoiceFeatures, mut seed: u64,
                starting_amount: u64, route_count: usize,
        ) -> Vec<(ChannelDetails, PaymentParameters, u64)> {
                let payer = payer_pubkey();
@@ -6163,10 +7199,12 @@ pub(crate) mod bench_utils {
                                let params = PaymentParameters::from_node_id(dst, 42)
                                        .with_bolt11_features(features.clone()).unwrap();
                                let first_hop = first_hop(src);
-                               let amt = starting_amount + seed % 1_000_000;
+                               let amt_msat = starting_amount + seed % 1_000_000;
+                               let route_params = RouteParameters::from_payment_params_and_value(
+                                       params.clone(), amt_msat);
                                let path_exists =
-                                       get_route(&payer, &params, &graph.read_only(), Some(&[&first_hop]),
-                                               amt, &TestLogger::new(), &scorer, score_params, &random_seed_bytes).is_ok();
+                                       get_route(&payer, &route_params, &graph.read_only(), Some(&[&first_hop]),
+                                               &TestLogger::new(), scorer, score_params, &random_seed_bytes).is_ok();
                                if path_exists {
                                        // ...and seed the scorer with success and failure data...
                                        seed = seed.overflowing_mul(6364136223846793005).0.overflowing_add(1).0;
@@ -6178,10 +7216,11 @@ pub(crate) mod bench_utils {
                                                let mpp_features = channelmanager::provided_invoice_features(&UserConfig::default());
                                                let params = PaymentParameters::from_node_id(dst, 42)
                                                        .with_bolt11_features(mpp_features).unwrap();
-
-                                               let route_res = get_route(&payer, &params, &graph.read_only(),
-                                                       Some(&[&first_hop]), score_amt, &TestLogger::new(), &scorer,
-                                                       score_params, &random_seed_bytes);
+                                               let route_params = RouteParameters::from_payment_params_and_value(
+                                                       params.clone(), score_amt);
+                                               let route_res = get_route(&payer, &route_params, &graph.read_only(),
+                                                       Some(&[&first_hop]), &TestLogger::new(), scorer, score_params,
+                                                       &random_seed_bytes);
                                                if let Ok(route) = route_res {
                                                        for path in route.paths {
                                                                if seed & 0x80 == 0 {
@@ -6198,7 +7237,7 @@ pub(crate) mod bench_utils {
                                                score_amt /= 100;
                                        }
 
-                                       route_endpoints.push((first_hop, params, amt));
+                                       route_endpoints.push((first_hop, params, amt_msat));
                                        break;
                                }
                        }
@@ -6207,9 +7246,11 @@ pub(crate) mod bench_utils {
                // Because we've changed channel scores, it's possible we'll take different routes to the
                // selected destinations, possibly causing us to fail because, eg, the newly-selected path
                // requires a too-high CLTV delta.
-               route_endpoints.retain(|(first_hop, params, amt)| {
-                       get_route(&payer, params, &graph.read_only(), Some(&[first_hop]), *amt,
-                               &TestLogger::new(), &scorer, score_params, &random_seed_bytes).is_ok()
+               route_endpoints.retain(|(first_hop, params, amt_msat)| {
+                       let route_params = RouteParameters::from_payment_params_and_value(
+                               params.clone(), *amt_msat);
+                       get_route(&payer, &route_params, &graph.read_only(), Some(&[first_hop]),
+                               &TestLogger::new(), scorer, score_params, &random_seed_bytes).is_ok()
                });
                route_endpoints.truncate(route_count);
                assert_eq!(route_endpoints.len(), route_count);
@@ -6220,9 +7261,10 @@ pub(crate) mod bench_utils {
 #[cfg(ldk_bench)]
 pub mod benches {
        use super::*;
+       use crate::routing::scoring::{ScoreUpdate, ScoreLookUp};
        use crate::sign::{EntropySource, KeysManager};
        use crate::ln::channelmanager;
-       use crate::ln::features::InvoiceFeatures;
+       use crate::ln::features::Bolt11InvoiceFeatures;
        use crate::routing::gossip::NetworkGraph;
        use crate::routing::scoring::{FixedPenaltyScorer, ProbabilisticScorer, ProbabilisticScoringFeeParameters, ProbabilisticScoringDecayParameters};
        use crate::util::config::UserConfig;
@@ -6240,7 +7282,7 @@ pub mod benches {
                let logger = TestLogger::new();
                let network_graph = bench_utils::read_network_graph(&logger).unwrap();
                let scorer = FixedPenaltyScorer::with_penalty(0);
-               generate_routes(bench, &network_graph, scorer, &(), InvoiceFeatures::empty(), 0,
+               generate_routes(bench, &network_graph, scorer, &(), Bolt11InvoiceFeatures::empty(), 0,
                        "generate_routes_with_zero_penalty_scorer");
        }
 
@@ -6258,7 +7300,7 @@ pub mod benches {
                let network_graph = bench_utils::read_network_graph(&logger).unwrap();
                let params = ProbabilisticScoringFeeParameters::default();
                let scorer = ProbabilisticScorer::new(ProbabilisticScoringDecayParameters::default(), &network_graph, &logger);
-               generate_routes(bench, &network_graph, scorer, &params, InvoiceFeatures::empty(), 0,
+               generate_routes(bench, &network_graph, scorer, &params, Bolt11InvoiceFeatures::empty(), 0,
                        "generate_routes_with_probabilistic_scorer");
        }
 
@@ -6282,9 +7324,9 @@ pub mod benches {
                        "generate_large_mpp_routes_with_probabilistic_scorer");
        }
 
-       fn generate_routes<S: Score>(
+       fn generate_routes<S: ScoreLookUp + ScoreUpdate>(
                bench: &mut Criterion, graph: &NetworkGraph<&TestLogger>, mut scorer: S,
-               score_params: &S::ScoreParams, features: InvoiceFeatures, starting_amount: u64,
+               score_params: &S::ScoreParams, features: Bolt11InvoiceFeatures, starting_amount: u64,
                bench_name: &'static str,
        ) {
                let payer = bench_utils::payer_pubkey();
@@ -6298,7 +7340,8 @@ pub mod benches {
                let mut idx = 0;
                bench.bench_function(bench_name, |b| b.iter(|| {
                        let (first_hop, params, amt) = &route_endpoints[idx % route_endpoints.len()];
-                       assert!(get_route(&payer, params, &graph.read_only(), Some(&[first_hop]), *amt,
+                       let route_params = RouteParameters::from_payment_params_and_value(params.clone(), *amt);
+                       assert!(get_route(&payer, &route_params, &graph.read_only(), Some(&[first_hop]),
                                &DummyLogger{}, &scorer, score_params, &random_seed_bytes).is_ok());
                        idx += 1;
                }));