Use new NoopAddHtlc TLV when sending assets with default above-dust anchor amt

go.mod

@@ -128,7 +128,7 @@ require (
 	github.com/lightninglabs/lightning-node-connect/gbn v1.0.1 // indirect
 	github.com/lightninglabs/lightning-node-connect/mailbox v1.0.1 // indirect
 	github.com/lightninglabs/neutrino v0.16.1 // indirect
-	github.com/lightningnetwork/lightning-onion v1.2.1-0.20240712235311-98bd56499dfb // indirect
+	github.com/lightningnetwork/lightning-onion v1.2.1-0.20240815225420-8b40adf04ab9 // indirect
 	github.com/lightningnetwork/lnd/healthcheck v1.2.6 // indirect
 	github.com/lightningnetwork/lnd/kvdb v1.4.16 // indirect
 	github.com/lightningnetwork/lnd/queue v1.1.1 // indirect
@@ -217,3 +217,7 @@ replace github.com/golang-migrate/migrate/v4 => github.com/lightninglabs/migrate
 
 // Note this is a temproary replace and will be removed when taprpc is tagged.
 replace github.com/lightninglabs/taproot-assets/taprpc => ./taprpc
+
+replace github.com/lightningnetwork/lnd => github.com/GeorgeTsagk/lnd v0.0.0-20250626140435-ed6a7abee9af
+
+replace github.com/lightningnetwork/lnd/sqldb => github.com/GeorgeTsagk/lnd/sqldb v0.0.0-20250626140435-ed6a7abee9af

go.sum

@@ -603,6 +603,10 @@ github.com/BurntSushi/toml v0.3.1/go.mod h1:xHWCNGjB5oqiDr8zfno3MHue2Ht5sIBksp03
 github.com/BurntSushi/toml v1.3.2 h1:o7IhLm0Msx3BaB+n3Ag7L8EVlByGnpq14C4YWiu/gL8=
 github.com/BurntSushi/toml v1.3.2/go.mod h1:CxXYINrC8qIiEnFrOxCa7Jy5BFHlXnUU2pbicEuybxQ=
 github.com/BurntSushi/xgb v0.0.0-20160522181843-27f122750802/go.mod h1:IVnqGOEym/WlBOVXweHU+Q+/VP0lqqI8lqeDx9IjBqo=
+github.com/GeorgeTsagk/lnd v0.0.0-20250626140435-ed6a7abee9af h1:NukAv3Ldq6GBOFH+ozrntQ4Pv9gEJ5GiGtpfI6KkxhU=
+github.com/GeorgeTsagk/lnd v0.0.0-20250626140435-ed6a7abee9af/go.mod h1:FelbuiQdzwyEbHng3XsODMBKfXUGgz6JZcWtN9uwuE4=
+github.com/GeorgeTsagk/lnd/sqldb v0.0.0-20250626140435-ed6a7abee9af h1:O3HkVpUPI6SrC+zSF7Esc1Drqhor2Yndi8Bx2QUO9A8=
+github.com/GeorgeTsagk/lnd/sqldb v0.0.0-20250626140435-ed6a7abee9af/go.mod h1:c/vWoQfcxu6FAfHzGajkIQi7CEIeIZFhhH4DYh1BJpc=
 github.com/JohnCGriffin/overflow v0.0.0-20211019200055-46fa312c352c/go.mod h1:X0CRv0ky0k6m906ixxpzmDRLvX58TFUKS2eePweuyxk=
 github.com/Masterminds/semver/v3 v3.1.1/go.mod h1:VPu/7SZ7ePZ3QOrcuXROw5FAcLl4a0cBrbBpGY/8hQs=
 github.com/Masterminds/semver/v3 v3.2.0 h1:3MEsd0SM6jqZojhjLWWeBY+Kcjy9i6MQAeY7YgDP83g=
@@ -1147,10 +1151,8 @@ github.com/lightninglabs/neutrino/cache v1.1.2 h1:C9DY/DAPaPxbFC+xNNEI/z1SJY9GS3
 github.com/lightninglabs/neutrino/cache v1.1.2/go.mod h1:XJNcgdOw1LQnanGjw8Vj44CvguYA25IMKjWFZczwZuo=
 github.com/lightninglabs/protobuf-go-hex-display v1.34.2-hex-display h1:w7FM5LH9Z6CpKxl13mS48idsu6F+cEZf0lkyiV+Dq9g=
 github.com/lightninglabs/protobuf-go-hex-display v1.34.2-hex-display/go.mod h1:qYOHts0dSfpeUzUFpOMr/WGzszTmLH+DiWniOlNbLDw=
-github.com/lightningnetwork/lightning-onion v1.2.1-0.20240712235311-98bd56499dfb h1:yfM05S8DXKhuCBp5qSMZdtSwvJ+GFzl94KbXMNB1JDY=
-github.com/lightningnetwork/lightning-onion v1.2.1-0.20240712235311-98bd56499dfb/go.mod h1:c0kvRShutpj3l6B9WtTsNTBUtjSmjZXbJd9ZBRQOSKI=
-github.com/lightningnetwork/lnd v0.19.1-beta.rc1.0.20250623232057-b48e2763a798 h1:nSnOCqilf+ynsJlTOVOoNXEhjjxTrvcv6jxMyUlZJJE=
-github.com/lightningnetwork/lnd v0.19.1-beta.rc1.0.20250623232057-b48e2763a798/go.mod h1:iHZ/FHFK00BqV6qgDkZZfqWE3LGtgE0U5KdO5WrM+eQ=
+github.com/lightningnetwork/lightning-onion v1.2.1-0.20240815225420-8b40adf04ab9 h1:6D3LrdagJweLLdFm1JNodZsBk6iU4TTsBBFLQ4yiXfI=
+github.com/lightningnetwork/lightning-onion v1.2.1-0.20240815225420-8b40adf04ab9/go.mod h1:EDqJ3MuZIbMq0QI1czTIKDJ/GS8S14RXPwapHw8cw6w=
 github.com/lightningnetwork/lnd/cert v1.2.2 h1:71YK6hogeJtxSxw2teq3eGeuy4rHGKcFf0d0Uy4qBjI=
 github.com/lightningnetwork/lnd/cert v1.2.2/go.mod h1:jQmFn/Ez4zhDgq2hnYSw8r35bqGVxViXhX6Cd7HXM6U=
 github.com/lightningnetwork/lnd/clock v1.1.1 h1:OfR3/zcJd2RhH0RU+zX/77c0ZiOnIMsDIBjgjWdZgA0=
@@ -1163,8 +1165,6 @@ github.com/lightningnetwork/lnd/kvdb v1.4.16 h1:9BZgWdDfjmHRHLS97cz39bVuBAqMc4/p
 github.com/lightningnetwork/lnd/kvdb v1.4.16/go.mod h1:HW+bvwkxNaopkz3oIgBV6NEnV4jCEZCACFUcNg4xSjM=
 github.com/lightningnetwork/lnd/queue v1.1.1 h1:99ovBlpM9B0FRCGYJo6RSFDlt8/vOkQQZznVb18iNMI=
 github.com/lightningnetwork/lnd/queue v1.1.1/go.mod h1:7A6nC1Qrm32FHuhx/mi1cieAiBZo5O6l8IBIoQxvkz4=
-github.com/lightningnetwork/lnd/sqldb v1.0.10 h1:ZLV7TGwjnKupVfCd+DJ43MAc9BKVSFCnvhpSPGKdN3M=
-github.com/lightningnetwork/lnd/sqldb v1.0.10/go.mod h1:c/vWoQfcxu6FAfHzGajkIQi7CEIeIZFhhH4DYh1BJpc=
 github.com/lightningnetwork/lnd/ticker v1.1.1 h1:J/b6N2hibFtC7JLV77ULQp++QLtCwT6ijJlbdiZFbSM=
 github.com/lightningnetwork/lnd/ticker v1.1.1/go.mod h1:waPTRAAcwtu7Ji3+3k+u/xH5GHovTsCoSVpho0KDvdA=
 github.com/lightningnetwork/lnd/tlv v1.3.2 h1:MO4FCk7F4k5xPMqVZF6Nb/kOpxlwPrUQpYjmyKny5s0=

rfqmsg/aux_features.go

@@ -0,0 +1,9 @@
+//go:build !dev
+
+package rfqmsg
+
+var (
+	// UseNoOpHTLCs is set to false, as we don't want to enable it for
+	// production builds.
+	UseNoOpHTLCs = false
+)

rfqmsg/aux_features_dev.go

@@ -0,0 +1,8 @@
+//go:build dev
+
+package rfqmsg
+
+var (
+	// UseNoOpHTLCs is set to true, as we want to enable it for dev builds.
+	UseNoOpHTLCs = true
+)

rfqmsg/records.go

@@ -12,6 +12,7 @@ import (
 	"github.com/lightninglabs/taproot-assets/asset"
 	"github.com/lightninglabs/taproot-assets/fn"
 	"github.com/lightninglabs/taproot-assets/rfqmath"
+	"github.com/lightningnetwork/lnd/lnwallet"
 	"github.com/lightningnetwork/lnd/lnwire"
 	"github.com/lightningnetwork/lnd/tlv"
 )
@@ -59,6 +60,13 @@ type Htlc struct {
 
 	// RfqID is the RFQ ID that corresponds to the HTLC.
 	RfqID tlv.OptionalRecordT[HtlcRfqIDType, ID]
+
+	// NoopAdd is a flag that indicates whether this HTLC should be marked
+	// as a noop_add for LND. A noop_add HTLC behaves identically to a
+	// normal HTLC except for the settlement step, where the satoshi amount
+	// is returned back to the sender, but the commitment blob is still
+	// updated to reflect the asset balance changes.
+	NoopAdd bool
 }
 
 // NewHtlc creates a new Htlc record with the given funded assets.
@@ -135,9 +143,19 @@ func (h *Htlc) Records() []tlv.Record {
 		records = append(records, r.Record())
 	})
 
+	if h.NoopAdd {
+		r := tlv.NewPrimitiveRecord[lnwallet.NoopAddHtlcType](true)
+		records = append(records, r.Record())
+	}
+
 	return records
 }
 
+// SetNoopAdd flags the HTLC as a noop_add.
+func (h *Htlc) SetNoopAdd(noopActive bool) {
+	h.NoopAdd = noopActive
+}
+
 // Encode serializes the Htlc to the given io.Writer.
 func (h *Htlc) Encode(w io.Writer) error {
 	tlvRecords := h.Records()

tapchannel/aux_traffic_shaper.go

@@ -431,7 +431,14 @@ func (s *AuxTrafficShaper) ProduceHtlcExtraData(totalAmount lnwire.MilliSatoshi,
 	if htlc.Amounts.Val.Sum() > 0 {
 		log.Tracef("Already have asset amount (sum %d) in HTLC, not "+
 			"producing extra data", htlc.Amounts.Val.Sum())
-		return totalAmount, htlcCustomRecords, nil
+
+		htlc.SetNoopAdd(rfqmsg.UseNoOpHTLCs)
+		updatedRecords, err := htlc.ToCustomRecords()
+		if err != nil {
+			return 0, nil, err
+		}
+
+		return totalAmount, updatedRecords, nil
 	}
 
 	if htlc.RfqID.ValOpt().IsNone() {
@@ -496,6 +503,12 @@ func (s *AuxTrafficShaper) ProduceHtlcExtraData(totalAmount lnwire.MilliSatoshi,
 	// amount that should be sent on-chain, which is a value in satoshi that
 	// is just above the dust limit.
 	htlcAmountMSat := rfqmath.DefaultOnChainHtlcMSat
+
+	// Now we set the flag that marks this HTLC as a noop_add, which means
+	// that the above dust will eventually return to us. This means that
+	// only the assets will be sent and not any btc balance.
+	htlc.SetNoopAdd(rfqmsg.UseNoOpHTLCs)
+
 	updatedRecords, err := htlc.ToCustomRecords()
 	if err != nil {
 		return 0, nil, fmt.Errorf("error encoding HTLC blob: %w", err)

tapchannel/commitment.go

@@ -98,12 +98,12 @@ func ComputeView(ourBalance, theirBalance uint64,
 	remoteHtlcIndex := make(map[uint64]lnwallet.AuxHtlcDescriptor)
 
 	for _, entry := range original.Updates.Local {
-		if entry.EntryType == lnwallet.Add {
+		if entry.IsAdd() {
 			localHtlcIndex[entry.HtlcIndex] = entry
 		}
 	}
 	for _, entry := range original.Updates.Remote {
-		if entry.EntryType == lnwallet.Add {
+		if entry.IsAdd() {
 			remoteHtlcIndex[entry.HtlcIndex] = entry
 		}
 	}
@@ -115,6 +115,9 @@ func ComputeView(ourBalance, theirBalance uint64,
 		case lnwallet.Add:
 			continue
 
+		case lnwallet.NoOpAdd:
+			continue
+
 		// Fee updates don't concern us at the asset level.
 		case lnwallet.FeeUpdate:
 			continue
@@ -162,6 +165,9 @@ func ComputeView(ourBalance, theirBalance uint64,
 		case lnwallet.Add:
 			continue
 
+		case lnwallet.NoOpAdd:
+			continue
+
 		// Fee updates don't concern us at the asset level.
 		case lnwallet.FeeUpdate:
 			continue
@@ -207,7 +213,7 @@ func ComputeView(ourBalance, theirBalance uint64,
 	// settled HTLCs, and debiting the chain state balance due to any newly
 	// added HTLCs.
 	for _, entry := range original.Updates.Local {
-		isAdd := entry.EntryType == lnwallet.Add
+		isAdd := entry.IsAdd()
 
 		// Skip any entries that aren't adds or adds that were already
 		// settled or failed by a child HTLC entry we processed above.
@@ -249,7 +255,7 @@ func ComputeView(ourBalance, theirBalance uint64,
 		newView.OurUpdates = append(newView.OurUpdates, decodedEntry)
 	}
 	for _, entry := range original.Updates.Remote {
-		isAdd := entry.EntryType == lnwallet.Add
+		isAdd := entry.IsAdd()
 
 		// Skip any entries that aren't adds or adds that were already
 		// settled or failed by a child HTLC entry we processed above.