diff --git a/lnwallet/channel.go b/lnwallet/channel.go
index fb1e3ac4b..02f5f9ccf 100644
--- a/lnwallet/channel.go
+++ b/lnwallet/channel.go
@@ -833,6 +833,20 @@ type LightningChannel struct {
 // is created.
 type ChannelOpt func(*channelOpts)
 
+// AuxHtlcValidator is an interface for validating whether an HTLC can be added
+// to a custom channel. It is called during HTLC validation with the current
+// channel state and HTLC details. This allows external components (like the
+// traffic shaper) to perform final validation checks against the most
+// up-to-date channel state before the HTLC is committed.
+type AuxHtlcValidator interface {
+	// ValidateHtlc checks whether the given HTLC can be added to the
+	// channel given the current link bandwidth, custom records, and HTLC
+	// view.
+	ValidateHtlc(amount, linkBandwidth lnwire.MilliSatoshi,
+		customRecords lnwire.CustomRecords,
+		view AuxHtlcView) error
+}
+
 // channelOpts is the set of options used to create a new channel.
 type channelOpts struct {
 	localNonce  *musig2.Nonces
@@ -842,6 +856,10 @@ type channelOpts struct {
 	auxSigner   fn.Option[AuxSigner]
 	auxResolver fn.Option[AuxContractResolver]
 
+	// auxHtlcValidator is an optional validator that performs custom
+	// validation on HTLCs before they are added to the channel state.
+	auxHtlcValidator fn.Option[AuxHtlcValidator]
+
 	skipNonceInit bool
 }
 
@@ -894,6 +912,15 @@ func WithAuxResolver(resolver AuxContractResolver) ChannelOpt {
 	}
 }
 
+// WithAuxHtlcValidator is used to specify a custom HTLC validator for the
+// channel. This validator will be called during HTLC addition to perform
+// final validation checks against the most up-to-date channel state.
+func WithAuxHtlcValidator(validator AuxHtlcValidator) ChannelOpt {
+	return func(o *channelOpts) {
+		o.auxHtlcValidator = fn.Some(validator)
+	}
+}
+
 // defaultChannelOpts returns the set of default options for a new channel.
 func defaultChannelOpts() *channelOpts {
 	return &channelOpts{}
@@ -2738,9 +2765,21 @@ func (lc *LightningChannel) FetchLatestAuxHTLCView() AuxHtlcView {
 	lc.RLock()
 	defer lc.RUnlock()
 
-	return newAuxHtlcView(lc.fetchHTLCView(
-		lc.updateLogs.Remote.logIndex, lc.updateLogs.Local.logIndex,
-	))
+	nextHeight := lc.commitChains.Local.tip().height + 1
+
+	// We use the remote ACKed index from the last signed local commitment
+	// (tail) rather than the remote's latest log index. This ensures we
+	// only include remote HTLCs that have been locked into a signed
+	// commitment, giving the aux validator a stable, consistent view that
+	// matches the actual commitment state used for balance calculations.
+	remoteACKedIndex := lc.commitChains.Local.tail().messageIndices.Remote
+	view := lc.fetchHTLCView(
+		remoteACKedIndex, lc.updateLogs.Local.logIndex,
+	)
+
+	view.NextHeight = nextHeight
+
+	return newAuxHtlcView(view)
 }
 
 // fetchHTLCView returns all the candidate HTLC updates which should be
@@ -6065,6 +6104,52 @@ func (lc *LightningChannel) addHTLC(htlc *lnwire.UpdateAddHTLC,
 		return 0, err
 	}
 
+	// If an auxiliary HTLC validator is configured, call it now to perform
+	// custom validation checks against the current channel state. This is
+	// the final validation point before the HTLC is added to the update
+	// log, ensuring that the validator sees the most up-to-date state
+	// including all previously validated HTLCs in this batch.
+	//
+	// NOTE: This is called after the standard commitment sanity checks to
+	// ensure we only perform (potentially) expensive custom validation on
+	// HTLCs that have already passed the basic Lightning protocol
+	// constraints.
+	err := fn.MapOptionZ(
+		lc.opts.auxHtlcValidator,
+		func(validator AuxHtlcValidator) error {
+			// Fetch the current HTLC view which includes all
+			// pending HTLCs that haven't been committed yet. This
+			// provides the validator with the most accurate state.
+			commitChain := lc.commitChains.Local
+			remoteIndex := commitChain.tail().messageIndices.Remote
+			view := lc.fetchHTLCView(
+				remoteIndex, lc.updateLogs.Local.logIndex,
+			)
+
+			nextHeight := lc.commitChains.Local.tip().height + 1
+			view.NextHeight = nextHeight
+
+			lc.log.Debugf("Setting view nextheight=%v", nextHeight)
+
+			auxView := newAuxHtlcView(view)
+
+			// Get the current available balance for the link
+			// bandwidth check. This is needed for the balance
+			// validation in the traffic shaper. We use NoBuffer
+			// since the buffer check was already performed earlier,
+			// and assets don't pay on-chain fees.
+			linkBandwidth, _ := lc.availableBalance(NoBuffer)
+
+			return validator.ValidateHtlc(
+				pd.Amount, linkBandwidth, pd.CustomRecords,
+				auxView,
+			)
+		},
+	)
+	if err != nil {
+		return 0, fmt.Errorf("aux HTLC validation failed: %w", err)
+	}
+
 	lc.updateLogs.Local.appendHtlc(pd)
 
 	return pd.HtlcIndex, nil
@@ -6216,6 +6301,7 @@ func (lc *LightningChannel) htlcAddDescriptor(htlc *lnwire.UpdateAddHTLC,
 // remote commitments.
 func (lc *LightningChannel) validateAddHtlc(pd *paymentDescriptor,
 	buffer BufferType) error {
+
 	// Make sure adding this HTLC won't violate any of the constraints we
 	// must keep on the commitment transactions.
 	remoteACKedIndex := lc.commitChains.Local.tail().messageIndices.Remote