Merge pull request #75 from halseth/batcher-impl

SwapPublicationDeadline for LoopOut contracts

cmd/loop/loopin.go

@@ -68,7 +68,7 @@ func loopIn(ctx *cli.Context) error {
 	}
 
 	limits := getInLimits(amt, quote)
-	err = displayLimits(swap.TypeIn, amt, limits, external)
+	err = displayLimits(swap.TypeIn, amt, limits, external, "")
 	if err != nil {
 		return err
 	}

cmd/loop/loopout.go

@@ -3,6 +3,7 @@ package main
 import (
 	"context"
 	"fmt"
+	"time"
 
 	"github.com/lightninglabs/loop"
 	"github.com/lightninglabs/loop/looprpc"
@@ -44,6 +45,16 @@ var loopOutCommand = cli.Command{
 				"should be swept within",
 			Value: uint64(loop.DefaultSweepConfTarget),
 		},
+		cli.BoolFlag{
+			Name: "fast",
+			Usage: "Indicate you want to swap immediately, " +
+				"paying potentially a higher fee. If not " +
+				"set the swap server might choose to wait up " +
+				"to 30 minutes before publishing the swap " +
+				"HTLC on-chain, to save on chain fees. Not " +
+				"setting this flag might result in a lower " +
+				"swap fee.",
+		},
 	},
 	Action: loopOut,
 }
@@ -92,9 +103,19 @@ func loopOut(ctx *cli.Context) error {
 		return err
 	}
 
-	limits := getLimits(amt, quote)
+	// Show a warning if a slow swap was requested.
+	fast := ctx.Bool("fast")
+	warning := ""
+	if fast {
+		warning = "Fast swap requested."
+	} else {
+		warning = fmt.Sprintf("Regular swap speed requested, it "+
+			"might take up to %v for the swap to be executed.",
+			defaultSwapWaitTime)
+	}
 
-	err = displayLimits(swap.TypeOut, amt, limits, false)
+	limits := getLimits(amt, quote)
+	err = displayLimits(swap.TypeOut, amt, limits, false, warning)
 	if err != nil {
 		return err
 	}
@@ -104,16 +125,24 @@ func loopOut(ctx *cli.Context) error {
 		unchargeChannel = ctx.Uint64("channel")
 	}
 
+	// Set our maximum swap wait time. If a fast swap is requested we set
+	// it to now, otherwise to 30 minutes in the future.
+	swapDeadline := time.Now()
+	if !fast {
+		swapDeadline = time.Now().Add(defaultSwapWaitTime)
+	}
+
 	resp, err := client.LoopOut(context.Background(), &looprpc.LoopOutRequest{
-		Amt:                 int64(amt),
-		Dest:                destAddr,
-		MaxMinerFee:         int64(limits.maxMinerFee),
-		MaxPrepayAmt:        int64(*limits.maxPrepayAmt),
-		MaxSwapFee:          int64(limits.maxSwapFee),
-		MaxPrepayRoutingFee: int64(*limits.maxPrepayRoutingFee),
-		MaxSwapRoutingFee:   int64(*limits.maxSwapRoutingFee),
-		LoopOutChannel:      unchargeChannel,
-		SweepConfTarget:     sweepConfTarget,
+		Amt:                     int64(amt),
+		Dest:                    destAddr,
+		MaxMinerFee:             int64(limits.maxMinerFee),
+		MaxPrepayAmt:            int64(*limits.maxPrepayAmt),
+		MaxSwapFee:              int64(limits.maxSwapFee),
+		MaxPrepayRoutingFee:     int64(*limits.maxPrepayRoutingFee),
+		MaxSwapRoutingFee:       int64(*limits.maxSwapRoutingFee),
+		LoopOutChannel:          unchargeChannel,
+		SweepConfTarget:         sweepConfTarget,
+		SwapPublicationDeadline: uint64(swapDeadline.Unix()),
 	})
 	if err != nil {
 		return err

cmd/loop/main.go

@@ -26,6 +26,8 @@ var (
 	maxRoutingFeeBase = btcutil.Amount(10)
 
 	maxRoutingFeeRate = int64(20000)
+
+	defaultSwapWaitTime = 30 * time.Minute
 )
 
 func printRespJSON(resp proto.Message) {
@@ -117,7 +119,7 @@ func getLimits(amt btcutil.Amount, quote *looprpc.QuoteResponse) *limits {
 }
 
 func displayLimits(swapType swap.Type, amt btcutil.Amount, l *limits,
-	externalHtlc bool) error {
+	externalHtlc bool, warning string) error {
 
 	totalSuccessMax := l.maxMinerFee + l.maxSwapFee
 	if l.maxSwapRoutingFee != nil {
@@ -138,6 +140,10 @@ func displayLimits(swapType swap.Type, amt btcutil.Amount, l *limits,
 		amt, swapType, totalSuccessMax,
 	)
 
+	if warning != "" {
+		fmt.Println(warning)
+	}
+
 	fmt.Printf("CONTINUE SWAP? (y/n), expand fee detail (x): ")
 
 	var answer string

cmd/loopd/swapclient_server.go

@@ -5,6 +5,7 @@ import (
 	"errors"
 	"fmt"
 	"sort"
+	"time"
 
 	"github.com/lightningnetwork/lnd/queue"
 
@@ -76,6 +77,9 @@ func (s *swapClientServer) LoopOut(ctx context.Context,
 		MaxSwapRoutingFee:   btcutil.Amount(in.MaxSwapRoutingFee),
 		MaxSwapFee:          btcutil.Amount(in.MaxSwapFee),
 		SweepConfTarget:     sweepConfTarget,
+		SwapPublicationDeadline: time.Unix(
+			int64(in.SwapPublicationDeadline), 0,
+		),
 	}
 	if in.LoopOutChannel != 0 {
 		req.LoopOutChannel = &in.LoopOutChannel

interface.go

@@ -64,8 +64,12 @@ type OutRequest struct {
 	SweepConfTarget int32
 
 	// LoopOutChannel optionally specifies the short channel id of the
-	// channel to uncharge.
+	// channel to loop out.
 	LoopOutChannel *uint64
+
+	// SwapPublicationDeadline can be set by the client to allow the server
+	// delaying publication of the swap HTLC to save on chain fees.
+	SwapPublicationDeadline time.Time
 }
 
 // Out contains the full details of a loop out request. This includes things
@@ -149,7 +153,7 @@ type LoopInRequest struct {
 	// MaxSwapFee is the maximum we are willing to pay the server for the
 	// swap. This value is not disclosed in the swap initiation call, but if
 	// the server asks for a higher fee, we abort the swap. Typically this
-	// value is taken from the response of the UnchargeQuote call. It
+	// value is taken from the response of the LoopInQuote call. It
 	// includes the prepay amount.
 	MaxSwapFee btcutil.Amount
 
@@ -157,7 +161,7 @@ type LoopInRequest struct {
 	// spent. If we publish the on-chain htlc and the fee estimate turns out
 	// higher than this value, we cancel the swap.
 	//
-	// MaxMinerFee is typically taken from the response of the UnchargeQuote
+	// MaxMinerFee is typically taken from the response of the LoopInQuote
 	// call.
 	MaxMinerFee btcutil.Amount
 
@@ -166,7 +170,7 @@ type LoopInRequest struct {
 	HtlcConfTarget int32
 
 	// LoopInChannel optionally specifies the short channel id of the
-	// channel to charge.
+	// channel to loop in.
 	LoopInChannel *uint64
 
 	// ExternalHtlc specifies whether the htlc is published by an external
@@ -174,7 +178,7 @@ type LoopInRequest struct {
 	ExternalHtlc bool
 }
 
-// LoopInTerms are the server terms on which it executes charge swaps.
+// LoopInTerms are the server terms on which it executes loop in swaps.
 type LoopInTerms struct {
 	// MinSwapAmount is the minimum amount that the server requires for a
 	// swap.

loopdb/loopout.go

@@ -45,6 +45,12 @@ type LoopOutContract struct {
 	// MaxPrepayRoutingFee is the maximum off-chain fee in msat that may be
 	// paid for the prepayment to the server.
 	MaxPrepayRoutingFee btcutil.Amount
+
+	// SwapPublicationDeadline is a timestamp that the server commits to
+	// have the on-chain swap published by. It is set by the client to
+	// allow the server to delay the publication in exchange for possibly
+	// lower fees.
+	SwapPublicationDeadline time.Time
 }
 
 // LoopOut is a combination of the contract and the updates.
@@ -158,6 +164,13 @@ func deserializeLoopOutContract(value []byte, chainParams *chaincfg.Params) (
 		contract.UnchargeChannel = &unchargeChannel
 	}
 
+	var deadlineNano int64
+	err = binary.Read(r, byteOrder, &deadlineNano)
+	if err != nil {
+		return nil, err
+	}
+	contract.SwapPublicationDeadline = time.Unix(0, deadlineNano)
+
 	return &contract, nil
 }
 
@@ -243,5 +256,10 @@ func serializeLoopOutContract(swap *LoopOutContract) (
 		return nil, err
 	}
 
+	err = binary.Write(&b, byteOrder, swap.SwapPublicationDeadline.UnixNano())
+	if err != nil {
+		return nil, err
+	}
+
 	return b.Bytes(), nil
 }

loopdb/meta.go

@@ -4,6 +4,7 @@ import (
 	"errors"
 	"fmt"
 
+	"github.com/btcsuite/btcd/chaincfg"
 	"github.com/coreos/bbolt"
 )
 
@@ -24,14 +25,17 @@ var (
 // migration is a function which takes a prior outdated version of the database
 // instances and mutates the key/bucket structure to arrive at a more
 // up-to-date version of the database.
-type migration func(tx *bbolt.Tx) error
+type migration func(tx *bbolt.Tx, chainParams *chaincfg.Params) error
 
 var (
 	// dbVersions is storing all versions of database. If current version
 	// of database don't match with latest version this list will be used
 	// for retrieving all migration function that are need to apply to the
 	// current db.
-	migrations = []migration{migrateCosts}
+	migrations = []migration{
+		migrateCosts,
+		migrateSwapPublicationDeadline,
+	}
 
 	latestDBVersion = uint32(len(migrations))
 )
@@ -76,7 +80,7 @@ func setDBVersion(tx *bbolt.Tx, version uint32) error {
 // syncVersions function is used for safe db version synchronization. It
 // applies migration functions to the current database and recovers the
 // previous state of db if at least one error/panic appeared during migration.
-func syncVersions(db *bbolt.DB) error {
+func syncVersions(db *bbolt.DB, chainParams *chaincfg.Params) error {
 	currentVersion, err := getDBVersion(db)
 	if err != nil {
 		return err
@@ -112,7 +116,7 @@ func syncVersions(db *bbolt.DB) error {
 			log.Infof("Applying migration #%v", v+1)
 
 			migration := migrations[v]
-			if err := migration(tx); err != nil {
+			if err := migration(tx, chainParams); err != nil {
 				log.Infof("Unable to apply migration #%v",
 					v+1)
 				return err

loopdb/migration_01_costs.go

@@ -4,12 +4,13 @@ import (
 	"errors"
 	"fmt"
 
+	"github.com/btcsuite/btcd/chaincfg"
 	"github.com/coreos/bbolt"
 )
 
 // noMigrationAvailable is the fall back migration in case there is no migration
 // implemented.
-func migrateCosts(tx *bbolt.Tx) error {
+func migrateCosts(tx *bbolt.Tx, _ *chaincfg.Params) error {
 	if err := migrateCostsForBucket(tx, loopInBucketKey); err != nil {
 		return err
 	}

loopdb/migration_02_swap_publication_deadline.go

@@ -0,0 +1,58 @@
+package loopdb
+
+import (
+	"bytes"
+	"errors"
+	"fmt"
+
+	"github.com/btcsuite/btcd/chaincfg"
+	"github.com/coreos/bbolt"
+)
+
+// migrateSwapPublicationDeadline migrates the database to v02, by adding the
+// SwapPublicationDeadline field to loop out contracts.
+func migrateSwapPublicationDeadline(tx *bbolt.Tx, chainParams *chaincfg.Params) error {
+	rootBucket := tx.Bucket(loopOutBucketKey)
+	if rootBucket == nil {
+		return errors.New("bucket does not exist")
+	}
+
+	return rootBucket.ForEach(func(swapHash, v []byte) error {
+		// Only go into things that we know are sub-bucket
+		// keys.
+		if v != nil {
+			return nil
+		}
+
+		// From the root bucket, we'll grab the next swap
+		// bucket for this swap from its swaphash.
+		swapBucket := rootBucket.Bucket(swapHash)
+		if swapBucket == nil {
+			return fmt.Errorf("swap bucket %x not found",
+				swapHash)
+		}
+
+		// With the main swap bucket obtained, we'll grab the
+		// raw swap contract bytes.
+		contractBytes := swapBucket.Get(contractKey)
+		if contractBytes == nil {
+			return errors.New("contract not found")
+		}
+
+		// Write the current contract serialization into a buffer.
+		b := &bytes.Buffer{}
+		if _, err := b.Write(contractBytes); err != nil {
+			return err
+		}
+
+		// We migrate to the new format by copying the first 8 bytes
+		// (the creation time) to the end (the swap deadline)
+		var swapDeadline [8]byte
+		copy(swapDeadline[:], contractBytes[:8])
+		if _, err := b.Write(swapDeadline[:]); err != nil {
+			return err
+		}
+
+		return swapBucket.Put(contractKey, b.Bytes())
+	})
+}

loopdb/store.go

@@ -135,7 +135,7 @@ func NewBoltSwapStore(dbPath string, chainParams *chaincfg.Params) (
 
 	// Finally, before we start, we'll sync the DB versions to pick up any
 	// possible DB migrations.
-	err = syncVersions(bdb)
+	err = syncVersions(bdb, chainParams)
 	if err != nil {
 		return nil, err
 	}

loopdb/store_test.go

@@ -82,12 +82,13 @@ func TestLoopOutStore(t *testing.T) {
 			// doesn't interfere with DeepEqual.
 			InitiationTime: time.Unix(0, initiationTime.UnixNano()),
 		},
-		MaxPrepayRoutingFee: 40,
-		PrepayInvoice:       "prepayinvoice",
-		DestAddr:            destAddr,
-		SwapInvoice:         "swapinvoice",
-		MaxSwapRoutingFee:   30,
-		SweepConfTarget:     2,
+		MaxPrepayRoutingFee:     40,
+		PrepayInvoice:           "prepayinvoice",
+		DestAddr:                destAddr,
+		SwapInvoice:             "swapinvoice",
+		MaxSwapRoutingFee:       30,
+		SweepConfTarget:         2,
+		SwapPublicationDeadline: time.Unix(0, initiationTime.UnixNano()),
 	}
 
 	// checkSwap is a test helper function that'll assert the state of a

loopout.go

@@ -79,29 +79,36 @@ func newLoopOutSwap(globalCtx context.Context, cfg *swapConfig,
 	// the server revocation key and the swap and prepay invoices.
 	log.Infof("Initiating swap request at height %v", currentHeight)
 
-	swapResp, err := cfg.server.NewLoopOutSwap(globalCtx, swapHash,
-		request.Amount, receiverKey,
+	// The swap deadline will be given to the server for it to use as the
+	// latest swap publication time.
+	swapResp, err := cfg.server.NewLoopOutSwap(
+		globalCtx, swapHash, request.Amount, receiverKey,
+		request.SwapPublicationDeadline,
 	)
 	if err != nil {
 		return nil, fmt.Errorf("cannot initiate swap: %v", err)
 	}
 
-	err = validateLoopOutContract(cfg.lnd, currentHeight, request, swapHash, swapResp)
+	err = validateLoopOutContract(
+		cfg.lnd, currentHeight, request, swapHash, swapResp,
+	)
 	if err != nil {
 		return nil, err
 	}
 
-	// Instantiate a struct that contains all required data to start the swap.
+	// Instantiate a struct that contains all required data to start the
+	// swap.
 	initiationTime := time.Now()
 
 	contract := loopdb.LoopOutContract{
-		SwapInvoice:         swapResp.swapInvoice,
-		DestAddr:            request.DestAddr,
-		MaxSwapRoutingFee:   request.MaxSwapRoutingFee,
-		SweepConfTarget:     request.SweepConfTarget,
-		UnchargeChannel:     request.LoopOutChannel,
-		PrepayInvoice:       swapResp.prepayInvoice,
-		MaxPrepayRoutingFee: request.MaxPrepayRoutingFee,
+		SwapInvoice:             swapResp.swapInvoice,
+		DestAddr:                request.DestAddr,
+		MaxSwapRoutingFee:       request.MaxSwapRoutingFee,
+		SweepConfTarget:         request.SweepConfTarget,
+		UnchargeChannel:         request.LoopOutChannel,
+		PrepayInvoice:           swapResp.prepayInvoice,
+		MaxPrepayRoutingFee:     request.MaxPrepayRoutingFee,
+		SwapPublicationDeadline: request.SwapPublicationDeadline,
 		SwapContract: loopdb.SwapContract{
 			InitiationHeight: currentHeight,
 			InitiationTime:   initiationTime,

looprpc/client.pb.go

@@ -158,10 +158,17 @@ type LoopOutRequest struct {
 	//*
 	//The number of blocks from the on-chain HTLC's confirmation height that it
 	//should be swept within.
-	SweepConfTarget      int32    `protobuf:"varint,9,opt,name=sweep_conf_target,json=sweepConfTarget,proto3" json:"sweep_conf_target,omitempty"`
-	XXX_NoUnkeyedLiteral struct{} `json:"-"`
-	XXX_unrecognized     []byte   `json:"-"`
-	XXX_sizecache        int32    `json:"-"`
+	SweepConfTarget int32 `protobuf:"varint,9,opt,name=sweep_conf_target,json=sweepConfTarget,proto3" json:"sweep_conf_target,omitempty"`
+	//*
+	//The latest time (in unix seconds) we allow the server to wait before
+	//publishing the HTLC on chain. Setting this to a larger value will give the
+	//server the opportunity to batch multiple swaps together, and wait for
+	//low-fee periods before publishing the HTLC, potentially resulting in a
+	//lower total swap fee.
+	SwapPublicationDeadline uint64   `protobuf:"varint,10,opt,name=swap_publication_deadline,json=swapPublicationDeadline,proto3" json:"swap_publication_deadline,omitempty"`
+	XXX_NoUnkeyedLiteral    struct{} `json:"-"`
+	XXX_unrecognized        []byte   `json:"-"`
+	XXX_sizecache           int32    `json:"-"`
 }
 
 func (m *LoopOutRequest) Reset()         { *m = LoopOutRequest{} }
@@ -252,6 +259,13 @@ func (m *LoopOutRequest) GetSweepConfTarget() int32 {
 	return 0
 }
 
+func (m *LoopOutRequest) GetSwapPublicationDeadline() uint64 {
+	if m != nil {
+		return m.SwapPublicationDeadline
+	}
+	return 0
+}
+
 type LoopInRequest struct {
 	//*
 	//Requested swap amount in sat. This does not include the swap and miner
@@ -804,74 +818,76 @@ func init() {
 func init() { proto.RegisterFile("client.proto", fileDescriptor_014de31d7ac8c57c) }
 
 var fileDescriptor_014de31d7ac8c57c = []byte{
-	// 1061 bytes of a gzipped FileDescriptorProto
-	0x1f, 0x8b, 0x08, 0x00, 0x00, 0x00, 0x00, 0x00, 0x02, 0xff, 0x9c, 0x56, 0x4f, 0x73, 0xda, 0x46,
-	0x1c, 0x8d, 0x40, 0x18, 0xf1, 0xb3, 0x90, 0xc5, 0x3a, 0x71, 0x08, 0x6d, 0x26, 0x94, 0x36, 0x29,
-	0xe3, 0x83, 0x69, 0x9d, 0x53, 0x7b, 0xa3, 0x98, 0xc4, 0x78, 0x6c, 0xe3, 0x0a, 0x9c, 0x99, 0xf6,
-	0xa2, 0x6e, 0x61, 0xb1, 0x35, 0x83, 0x76, 0x15, 0x69, 0xf1, 0x9f, 0xe9, 0xe4, 0xd2, 0xaf, 0xd0,
-	0x4f, 0xd2, 0x99, 0x7e, 0x93, 0xde, 0x7b, 0xea, 0xf4, 0x73, 0x74, 0xf6, 0xb7, 0x42, 0x16, 0x26,
-	0xbe, 0xe4, 0x66, 0x9e, 0xde, 0xbe, 0xdf, 0x1f, 0xbd, 0xb7, 0x32, 0xd8, 0x93, 0x79, 0xc0, 0xb8,
-	0xdc, 0x8b, 0x62, 0x21, 0x05, 0x29, 0xcf, 0x85, 0x88, 0xe2, 0x68, 0xd2, 0xf8, 0xfc, 0x42, 0x88,
-	0x8b, 0x39, 0xeb, 0xd0, 0x28, 0xe8, 0x50, 0xce, 0x85, 0xa4, 0x32, 0x10, 0x3c, 0xd1, 0xb4, 0xd6,
-	0x3f, 0x05, 0x70, 0x8e, 0x85, 0x88, 0x86, 0x0b, 0xe9, 0xb1, 0xf7, 0x0b, 0x96, 0x48, 0xe2, 0x42,
-	0x91, 0x86, 0xb2, 0x6e, 0x34, 0x8d, 0x76, 0xd1, 0x53, 0x7f, 0x12, 0x02, 0xe6, 0x94, 0x25, 0xb2,
-	0x5e, 0x68, 0x1a, 0xed, 0x8a, 0x87, 0x7f, 0x93, 0x0e, 0x3c, 0x0e, 0xe9, 0x8d, 0x9f, 0x5c, 0xd3,
-	0xc8, 0x8f, 0xc5, 0x42, 0x06, 0xfc, 0xc2, 0x9f, 0x31, 0x56, 0x2f, 0xe2, 0xb1, 0x5a, 0x48, 0x6f,
-	0x46, 0xd7, 0x34, 0xf2, 0xf4, 0x93, 0x37, 0x8c, 0x91, 0xd7, 0xb0, 0xa3, 0x0e, 0x44, 0x31, 0x8b,
-	0xe8, 0xed, 0xca, 0x11, 0x13, 0x8f, 0x6c, 0x87, 0xf4, 0xe6, 0x0c, 0x1f, 0xe6, 0x0e, 0x35, 0xc1,
-	0xce, 0xaa, 0x28, 0x6a, 0x09, 0xa9, 0x90, 0xaa, 0x2b, 0xc6, 0x57, 0xe0, 0xe4, 0x64, 0x55, 0xe3,
-	0x1b, 0xc8, 0xb1, 0x33, 0xb9, 0x6e, 0x28, 0x49, 0x0b, 0xaa, 0x8a, 0x15, 0x06, 0x9c, 0xc5, 0x28,
-	0x54, 0x46, 0xd2, 0x66, 0x48, 0x6f, 0x4e, 0x14, 0xa6, 0x94, 0xda, 0xe0, 0xaa, 0x9d, 0xf9, 0x62,
-	0x21, 0xfd, 0xc9, 0x25, 0xe5, 0x9c, 0xcd, 0xeb, 0x56, 0xd3, 0x68, 0x9b, 0x9e, 0x33, 0xd7, 0x1b,
-	0xea, 0x69, 0x94, 0xec, 0x42, 0x2d, 0xb9, 0x66, 0x2c, 0xf2, 0x27, 0x82, 0xcf, 0x7c, 0x49, 0xe3,
-	0x0b, 0x26, 0xeb, 0x95, 0xa6, 0xd1, 0x2e, 0x79, 0x5b, 0xf8, 0xa0, 0x27, 0xf8, 0x6c, 0x8c, 0x70,
-	0xeb, 0x2f, 0x03, 0xaa, 0x6a, 0xc1, 0x03, 0xfe, 0xf0, 0x7e, 0xef, 0x4f, 0x59, 0x58, 0x9b, 0x72,
-	0xad, 0xff, 0xe2, 0x7a, 0xff, 0xaf, 0x60, 0x0b, 0xfb, 0x0f, 0x78, 0xd6, 0xbe, 0x89, 0xed, 0x57,
-	0xe7, 0x58, 0x7f, 0xd9, 0xfd, 0x97, 0x50, 0x65, 0x37, 0x92, 0xc5, 0x9c, 0xce, 0xfd, 0x4b, 0x39,
-	0x9f, 0xe0, 0x52, 0x2d, 0xcf, 0x5e, 0x82, 0x87, 0x72, 0x3e, 0x69, 0x75, 0xc1, 0xc6, 0xf7, 0xc7,
-	0x92, 0x48, 0xf0, 0x84, 0x11, 0x07, 0x0a, 0xc1, 0x14, 0x7b, 0xae, 0x78, 0x85, 0x60, 0x4a, 0xbe,
-	0x00, 0x5b, 0x9d, 0xf5, 0xe9, 0x74, 0x1a, 0xb3, 0x24, 0x49, 0xad, 0xb1, 0xa9, 0xb0, 0xae, 0x86,
-	0x5a, 0x2e, 0x38, 0x27, 0x82, 0x07, 0x52, 0xc4, 0xe9, 0xe4, 0xca, 0x6c, 0xa0, 0x54, 0x47, 0x92,
-	0xca, 0x45, 0xf2, 0x91, 0x45, 0xe8, 0x2a, 0x85, 0xac, 0xca, 0x4b, 0x30, 0xe5, 0x6d, 0xa4, 0xa7,
-	0x75, 0xf6, 0x6b, 0x7b, 0xa9, 0xa7, 0xf7, 0x94, 0xc8, 0xf8, 0x36, 0x62, 0x1e, 0x3e, 0x26, 0x6d,
-	0x28, 0x25, 0x92, 0x4a, 0xed, 0x24, 0x67, 0x9f, 0xac, 0xf0, 0x54, 0x31, 0xe6, 0x69, 0x02, 0xf9,
-	0x1a, 0xb6, 0x02, 0x1e, 0xc8, 0x00, 0x33, 0xe0, 0xcb, 0x20, 0x5c, 0x5a, 0xca, 0xb9, 0x83, 0xc7,
-	0x41, 0xa8, 0xcd, 0x40, 0x13, 0xe9, 0x2f, 0xa2, 0x29, 0x95, 0x4c, 0x33, 0xb5, 0xb1, 0x1c, 0x85,
-	0x9f, 0x23, 0x8c, 0xcc, 0xfb, 0x9b, 0x28, 0xaf, 0x6d, 0x82, 0xbc, 0x80, 0xcd, 0x89, 0x48, 0xa4,
-	0x9f, 0xb0, 0xf8, 0x8a, 0xc5, 0x68, 0xaa, 0xa2, 0x07, 0x0a, 0x1a, 0x21, 0xa2, 0x34, 0x90, 0x20,
-	0xf8, 0xe4, 0x92, 0x06, 0x1c, 0xbd, 0x54, 0xf4, 0xf0, 0xd0, 0x50, 0x43, 0xea, 0xad, 0x69, 0xca,
-	0x6c, 0xa6, 0x39, 0xa0, 0x6d, 0x8e, 0x9c, 0x14, 0x6b, 0x39, 0x60, 0x8f, 0x59, 0x1c, 0x26, 0xcb,
-	0x85, 0x7f, 0x80, 0x6a, 0xfa, 0x3b, 0x7d, 0x8d, 0xaf, 0x60, 0x2b, 0x0c, 0xb8, 0x76, 0x1a, 0x0d,
-	0xc5, 0x82, 0xcb, 0x74, 0xfe, 0x6a, 0x18, 0x70, 0xb5, 0xad, 0x2e, 0x82, 0xc8, 0x5b, 0x3a, 0x32,
-	0xe5, 0x6d, 0xa4, 0x3c, 0x6d, 0x4a, 0xcd, 0x3b, 0x32, 0x2d, 0xc3, 0x2d, 0x1c, 0x99, 0x56, 0xc1,
-	0x2d, 0x1e, 0x99, 0x56, 0xd1, 0x35, 0x8f, 0x4c, 0xcb, 0x74, 0x4b, 0x47, 0xa6, 0x55, 0x76, 0xad,
-	0xd6, 0x0c, 0xec, 0x1f, 0x17, 0x42, 0xb2, 0x87, 0x9d, 0x8f, 0x9b, 0xb9, 0xcb, 0x50, 0x01, 0x33,
-	0x04, 0x93, 0x2c, 0x3e, 0xeb, 0x66, 0x2d, 0x7e, 0xc4, 0xac, 0x7f, 0x1a, 0x50, 0x4d, 0x0b, 0xa5,
-	0x73, 0x3e, 0x03, 0x2b, 0x4b, 0x93, 0x2e, 0x57, 0x4e, 0xd2, 0x28, 0x3d, 0x07, 0xc8, 0x5d, 0x16,
-	0x3a, 0x6a, 0x95, 0x28, 0xbb, 0x29, 0x3e, 0x83, 0xca, 0xfd, 0x94, 0x59, 0xe1, 0x32, 0x62, 0x18,
-	0x7c, 0x1a, 0xf9, 0x11, 0xbd, 0x0d, 0x19, 0x97, 0x3e, 0xde, 0x8a, 0xca, 0x74, 0xb6, 0x0a, 0x3e,
-	0x8d, 0xce, 0x34, 0x7e, 0xa0, 0x86, 0x7d, 0x0e, 0x30, 0x99, 0xcb, 0x2b, 0x7f, 0xca, 0xe6, 0x92,
-	0xe2, 0x96, 0x4b, 0x5e, 0x45, 0x21, 0x07, 0x0a, 0xd8, 0x7d, 0x09, 0xd6, 0xd2, 0xc5, 0xc4, 0x06,
-	0xeb, 0x78, 0x38, 0x3c, 0xf3, 0x87, 0xe7, 0x63, 0xf7, 0x11, 0xd9, 0x84, 0x32, 0xfe, 0x1a, 0x9c,
-	0xba, 0xc6, 0x6e, 0x02, 0x95, 0xcc, 0xc4, 0xa4, 0x0a, 0x95, 0xc1, 0xe9, 0x60, 0x3c, 0xe8, 0x8e,
-	0xfb, 0x07, 0xee, 0x23, 0xf2, 0x04, 0x6a, 0x67, 0x5e, 0x7f, 0x70, 0xd2, 0x7d, 0xdb, 0xf7, 0xbd,
-	0xfe, 0xbb, 0x7e, 0xf7, 0xb8, 0x7f, 0xe0, 0x1a, 0x84, 0x80, 0x73, 0x38, 0x3e, 0xee, 0xf9, 0x67,
-	0xe7, 0x3f, 0x1c, 0x0f, 0x46, 0x87, 0xfd, 0x03, 0xb7, 0xa0, 0x34, 0x47, 0xe7, 0xbd, 0x5e, 0x7f,
-	0x34, 0x72, 0x8b, 0x04, 0x60, 0xe3, 0x4d, 0x77, 0xa0, 0xc8, 0x26, 0xd9, 0x86, 0xad, 0xc1, 0xe9,
-	0xbb, 0xe1, 0xa0, 0xd7, 0xf7, 0x47, 0xfd, 0xf1, 0x58, 0x81, 0xa5, 0xfd, 0xff, 0x4c, 0x9d, 0xd3,
-	0x1e, 0x7e, 0x50, 0x88, 0x07, 0xe5, 0xf4, 0x13, 0x41, 0x9e, 0x66, 0xd1, 0x5a, 0xfd, 0x68, 0x34,
-	0x9e, 0xac, 0x64, 0x6e, 0xf9, 0x1e, 0x5a, 0x4f, 0x7f, 0xff, 0xfb, 0xdf, 0x3f, 0x0a, 0xb5, 0x96,
-	0xdd, 0xb9, 0xfa, 0xb6, 0xa3, 0x18, 0x1d, 0xb1, 0x90, 0xdf, 0x1b, 0xbb, 0x64, 0x08, 0x1b, 0xfa,
-	0x56, 0x24, 0x3b, 0x2b, 0x92, 0xd9, 0x35, 0xf9, 0x90, 0xe2, 0x0e, 0x2a, 0xba, 0xad, 0xcd, 0x4c,
-	0x31, 0xe0, 0x4a, 0xf0, 0x3b, 0x28, 0xa7, 0xb7, 0x4d, 0xae, 0xc9, 0xd5, 0xfb, 0xa7, 0xb1, 0xbd,
-	0x76, 0x31, 0x2c, 0x92, 0x6f, 0x0c, 0xf2, 0x13, 0xd8, 0xe9, 0x34, 0x18, 0x16, 0x72, 0x57, 0x39,
-	0x1f, 0xa6, 0xc6, 0xce, 0x7d, 0x38, 0xed, 0xa8, 0x81, 0x1d, 0x3d, 0x26, 0x24, 0x3f, 0x63, 0x47,
-	0xa2, 0x94, 0x9f, 0x49, 0xa3, 0x3f, 0x73, 0xd2, 0xf9, 0x60, 0xe4, 0xa4, 0x57, 0x6c, 0xdc, 0x6a,
-	0xa2, 0x74, 0x83, 0xd4, 0x57, 0xa4, 0xdf, 0x2b, 0x4e, 0xe7, 0x37, 0x1a, 0xca, 0x0f, 0xe4, 0x67,
-	0x70, 0xde, 0x32, 0xa9, 0x37, 0xf7, 0x49, 0xdd, 0x3f, 0xc3, 0x12, 0xdb, 0xa4, 0x96, 0xdb, 0x67,
-	0xda, 0xfc, 0x2f, 0x39, 0xed, 0x4f, 0x6a, 0xff, 0x05, 0x6a, 0x3f, 0x23, 0x4f, 0xf3, 0xda, 0xb9,
-	0xee, 0x7f, 0xdd, 0xc0, 0x7f, 0x42, 0x5e, 0xff, 0x1f, 0x00, 0x00, 0xff, 0xff, 0x26, 0x06, 0x26,
-	0x30, 0xbb, 0x08, 0x00, 0x00,
+	// 1096 bytes of a gzipped FileDescriptorProto
+	0x1f, 0x8b, 0x08, 0x00, 0x00, 0x00, 0x00, 0x00, 0x02, 0xff, 0x9c, 0x56, 0x4f, 0x73, 0xda, 0xc6,
+	0x1b, 0x8e, 0x40, 0x18, 0xf1, 0x5a, 0xc8, 0x62, 0x9d, 0xd8, 0x98, 0xdf, 0x2f, 0x13, 0xaa, 0x36,
+	0x29, 0xe3, 0x43, 0x68, 0x93, 0x53, 0x73, 0xa3, 0x40, 0x12, 0x3c, 0xb6, 0xa1, 0x02, 0x67, 0xa6,
+	0xbd, 0xa8, 0x1b, 0x58, 0x6c, 0xcd, 0x48, 0x2b, 0x45, 0x5a, 0xfc, 0x67, 0x3a, 0xb9, 0xf4, 0x2b,
+	0xf4, 0xd6, 0x6f, 0xd1, 0x99, 0x7e, 0x93, 0xde, 0x7b, 0xea, 0xf4, 0x73, 0x74, 0xf6, 0x5d, 0x81,
+	0x85, 0x89, 0x2f, 0xb9, 0x99, 0x67, 0x9f, 0x7d, 0xde, 0x3f, 0xfb, 0xbc, 0xaf, 0x0c, 0xe6, 0x34,
+	0xf0, 0x19, 0x17, 0xcf, 0xe3, 0x24, 0x12, 0x11, 0x29, 0x07, 0x51, 0x14, 0x27, 0xf1, 0xb4, 0xf1,
+	0xff, 0xf3, 0x28, 0x3a, 0x0f, 0x58, 0x9b, 0xc6, 0x7e, 0x9b, 0x72, 0x1e, 0x09, 0x2a, 0xfc, 0x88,
+	0xa7, 0x8a, 0xe6, 0xfc, 0x5e, 0x04, 0xeb, 0x38, 0x8a, 0xe2, 0xe1, 0x42, 0xb8, 0xec, 0xc3, 0x82,
+	0xa5, 0x82, 0xd8, 0x50, 0xa4, 0xa1, 0xa8, 0x6b, 0x4d, 0xad, 0x55, 0x74, 0xe5, 0x9f, 0x84, 0x80,
+	0x3e, 0x63, 0xa9, 0xa8, 0x17, 0x9a, 0x5a, 0xab, 0xe2, 0xe2, 0xdf, 0xa4, 0x0d, 0x0f, 0x43, 0x7a,
+	0xed, 0xa5, 0x57, 0x34, 0xf6, 0x92, 0x68, 0x21, 0x7c, 0x7e, 0xee, 0xcd, 0x19, 0xab, 0x17, 0xf1,
+	0x5a, 0x2d, 0xa4, 0xd7, 0xe3, 0x2b, 0x1a, 0xbb, 0xea, 0xe4, 0x35, 0x63, 0xe4, 0x25, 0xec, 0xc9,
+	0x0b, 0x71, 0xc2, 0x62, 0x7a, 0xb3, 0x76, 0x45, 0xc7, 0x2b, 0xbb, 0x21, 0xbd, 0x1e, 0xe1, 0x61,
+	0xee, 0x52, 0x13, 0xcc, 0x55, 0x14, 0x49, 0x2d, 0x21, 0x15, 0x32, 0x75, 0xc9, 0xf8, 0x0a, 0xac,
+	0x9c, 0xac, 0x4c, 0x7c, 0x0b, 0x39, 0xe6, 0x4a, 0xae, 0x13, 0x0a, 0xe2, 0x40, 0x55, 0xb2, 0x42,
+	0x9f, 0xb3, 0x04, 0x85, 0xca, 0x48, 0xda, 0x0e, 0xe9, 0xf5, 0x89, 0xc4, 0xa4, 0x52, 0x0b, 0x6c,
+	0xd9, 0x33, 0x2f, 0x5a, 0x08, 0x6f, 0x7a, 0x41, 0x39, 0x67, 0x41, 0xdd, 0x68, 0x6a, 0x2d, 0xdd,
+	0xb5, 0x02, 0xd5, 0xa1, 0xae, 0x42, 0xc9, 0x21, 0xd4, 0xd2, 0x2b, 0xc6, 0x62, 0x6f, 0x1a, 0xf1,
+	0xb9, 0x27, 0x68, 0x72, 0xce, 0x44, 0xbd, 0xd2, 0xd4, 0x5a, 0x25, 0x77, 0x07, 0x0f, 0xba, 0x11,
+	0x9f, 0x4f, 0x10, 0x26, 0xaf, 0xe0, 0x00, 0xb3, 0x8f, 0x17, 0xef, 0x03, 0x7f, 0x8a, 0xbd, 0xf7,
+	0x66, 0x8c, 0xce, 0x02, 0x9f, 0xb3, 0x3a, 0xa0, 0xfc, 0xbe, 0x24, 0x8c, 0x6e, 0xcf, 0x7b, 0xd9,
+	0xb1, 0xf3, 0xa7, 0x06, 0x55, 0xf9, 0x38, 0x03, 0x7e, 0xff, 0xdb, 0xdc, 0xed, 0x50, 0x61, 0xa3,
+	0x43, 0x1b, 0xb5, 0x17, 0x37, 0x6b, 0x7f, 0x06, 0x3b, 0x58, 0xbb, 0xcf, 0x57, 0xa5, 0xeb, 0x98,
+	0x5b, 0x35, 0xc0, 0xf8, 0xcb, 0xca, 0xbf, 0x84, 0x2a, 0xbb, 0x16, 0x2c, 0xe1, 0x34, 0xf0, 0x2e,
+	0x44, 0x30, 0xc5, 0x07, 0x31, 0x5c, 0x73, 0x09, 0xbe, 0x15, 0xc1, 0xd4, 0xe9, 0x80, 0x89, 0x6f,
+	0xcf, 0xd2, 0x38, 0xe2, 0x29, 0x23, 0x16, 0x14, 0xfc, 0x19, 0xe6, 0x5c, 0x71, 0x0b, 0xfe, 0x8c,
+	0x7c, 0x01, 0xa6, 0xbc, 0xeb, 0xd1, 0xd9, 0x2c, 0x61, 0x69, 0x9a, 0xd9, 0x6a, 0x5b, 0x62, 0x1d,
+	0x05, 0x39, 0x36, 0x58, 0x27, 0x11, 0xf7, 0x45, 0x94, 0x64, 0x95, 0x3b, 0x7f, 0x17, 0x00, 0xa4,
+	0xea, 0x58, 0x50, 0xb1, 0x48, 0x3f, 0xd1, 0x08, 0x15, 0xa5, 0xb0, 0x8a, 0xf2, 0x14, 0x74, 0x71,
+	0x13, 0xab, 0x6a, 0xad, 0x17, 0xb5, 0xe7, 0xd9, 0x3c, 0x3c, 0x97, 0x22, 0x93, 0x9b, 0x98, 0xb9,
+	0x78, 0x4c, 0x5a, 0x50, 0x4a, 0x05, 0x15, 0xca, 0x85, 0xd6, 0x0b, 0xb2, 0xc6, 0x93, 0xc1, 0x98,
+	0xab, 0x08, 0xe4, 0x6b, 0xd8, 0xf1, 0xb9, 0x2f, 0x7c, 0xf5, 0x86, 0xc2, 0x0f, 0x97, 0x76, 0xb4,
+	0x6e, 0xe1, 0x89, 0x1f, 0x2a, 0x23, 0xd1, 0x54, 0x78, 0x8b, 0x78, 0x46, 0x05, 0x53, 0x4c, 0x65,
+	0x4a, 0x4b, 0xe2, 0x67, 0x08, 0x23, 0xf3, 0x6e, 0x27, 0xca, 0x1b, 0x9d, 0x20, 0x4f, 0x60, 0x7b,
+	0x1a, 0xa5, 0xc2, 0x4b, 0x59, 0x72, 0xc9, 0x12, 0x34, 0x64, 0xd1, 0x05, 0x09, 0x8d, 0x11, 0x91,
+	0x1a, 0x48, 0x88, 0xf8, 0xf4, 0x82, 0xfa, 0x1c, 0x7d, 0x58, 0x74, 0xf1, 0xd2, 0x50, 0x41, 0xf2,
+	0xd5, 0x14, 0x65, 0x3e, 0x57, 0x1c, 0x50, 0x23, 0x82, 0x9c, 0x0c, 0x73, 0x2c, 0x30, 0x27, 0x2c,
+	0x09, 0xd3, 0x65, 0xc3, 0x3f, 0x42, 0x35, 0xfb, 0x9d, 0x3d, 0xe3, 0x33, 0xd8, 0x09, 0x7d, 0xae,
+	0x9c, 0x46, 0xc3, 0x68, 0xc1, 0x45, 0x56, 0x7f, 0x35, 0xf4, 0xb9, 0xec, 0x56, 0x07, 0x41, 0xe4,
+	0x2d, 0x1d, 0x99, 0xf1, 0xb6, 0x32, 0x9e, 0x32, 0xa5, 0xe2, 0x1d, 0xe9, 0x86, 0x66, 0x17, 0x8e,
+	0x74, 0xa3, 0x60, 0x17, 0x8f, 0x74, 0xa3, 0x68, 0xeb, 0x47, 0xba, 0xa1, 0xdb, 0xa5, 0x23, 0xdd,
+	0x28, 0xdb, 0x86, 0x33, 0x07, 0xf3, 0x87, 0x45, 0x24, 0xd8, 0xfd, 0xce, 0xc7, 0xce, 0xdc, 0xce,
+	0x5f, 0x01, 0xe7, 0x0f, 0xa6, 0xb7, 0xa3, 0xb7, 0x61, 0xd6, 0xe2, 0x27, 0xcc, 0xfa, 0x87, 0x06,
+	0xd5, 0x2c, 0x50, 0x56, 0xe7, 0x01, 0x18, 0xab, 0x69, 0x52, 0xe1, 0xca, 0x69, 0x36, 0x4a, 0x8f,
+	0x01, 0x72, 0x8b, 0x46, 0x8d, 0x5a, 0x25, 0x5e, 0x6d, 0x99, 0xff, 0x41, 0xe5, 0xee, 0x94, 0x19,
+	0xe1, 0x72, 0xc4, 0x70, 0x69, 0xc8, 0x45, 0x40, 0x6f, 0x42, 0xc6, 0x85, 0x87, 0x1b, 0x55, 0x9a,
+	0xce, 0x94, 0x4b, 0x83, 0xc6, 0x23, 0x85, 0xf7, 0x64, 0xb1, 0x8f, 0x01, 0xa6, 0x81, 0xb8, 0xf4,
+	0x66, 0x2c, 0x10, 0x14, 0xbb, 0x5c, 0x72, 0x2b, 0x12, 0xe9, 0x49, 0xe0, 0xf0, 0x29, 0x18, 0x4b,
+	0x17, 0x13, 0x13, 0x8c, 0xe3, 0xe1, 0x70, 0xe4, 0x0d, 0xcf, 0x26, 0xf6, 0x03, 0xb2, 0x0d, 0x65,
+	0xfc, 0x35, 0x38, 0xb5, 0xb5, 0xc3, 0x14, 0x2a, 0x2b, 0x13, 0x93, 0x2a, 0x54, 0x06, 0xa7, 0x83,
+	0xc9, 0xa0, 0x33, 0xe9, 0xf7, 0xec, 0x07, 0xe4, 0x11, 0xd4, 0x46, 0x6e, 0x7f, 0x70, 0xd2, 0x79,
+	0xd3, 0xf7, 0xdc, 0xfe, 0xbb, 0x7e, 0xe7, 0xb8, 0xdf, 0xb3, 0x35, 0x42, 0xc0, 0x7a, 0x3b, 0x39,
+	0xee, 0x7a, 0xa3, 0xb3, 0xef, 0x8f, 0x07, 0xe3, 0xb7, 0xfd, 0x9e, 0x5d, 0x90, 0x9a, 0xe3, 0xb3,
+	0x6e, 0xb7, 0x3f, 0x1e, 0xdb, 0x45, 0x02, 0xb0, 0xf5, 0xba, 0x33, 0x90, 0x64, 0x9d, 0xec, 0xc2,
+	0xce, 0xe0, 0xf4, 0xdd, 0x70, 0xd0, 0xed, 0x7b, 0xe3, 0xfe, 0x64, 0x22, 0xc1, 0xd2, 0x8b, 0x7f,
+	0x75, 0x35, 0xa7, 0x5d, 0xfc, 0x18, 0x11, 0x17, 0xca, 0xd9, 0xe7, 0x85, 0xec, 0xaf, 0x46, 0x6b,
+	0xfd, 0x83, 0xd3, 0x78, 0xb4, 0x36, 0x73, 0xcb, 0x77, 0x70, 0xf6, 0x7f, 0xfd, 0xeb, 0x9f, 0xdf,
+	0x0a, 0x35, 0xc7, 0x6c, 0x5f, 0x7e, 0xdb, 0x96, 0x8c, 0x76, 0xb4, 0x10, 0xaf, 0xb4, 0x43, 0x32,
+	0x84, 0x2d, 0xb5, 0x15, 0xc9, 0xde, 0x9a, 0xe4, 0x6a, 0x4d, 0xde, 0xa7, 0xb8, 0x87, 0x8a, 0xb6,
+	0xb3, 0xbd, 0x52, 0xf4, 0xb9, 0x14, 0xfc, 0x0e, 0xca, 0xd9, 0xb6, 0xc9, 0x25, 0xb9, 0xbe, 0x7f,
+	0x1a, 0xbb, 0x1b, 0x8b, 0x61, 0x91, 0x7e, 0xa3, 0x91, 0x1f, 0xc1, 0xcc, 0xaa, 0xc1, 0x61, 0x21,
+	0xb7, 0x91, 0xf3, 0xc3, 0xd4, 0xd8, 0xbb, 0x0b, 0x67, 0x19, 0x35, 0x30, 0xa3, 0x87, 0x84, 0xe4,
+	0x6b, 0x6c, 0x0b, 0x94, 0xf2, 0x56, 0xd2, 0xe8, 0xcf, 0x9c, 0x74, 0x7e, 0x30, 0x72, 0xd2, 0x6b,
+	0x36, 0x76, 0x9a, 0x28, 0xdd, 0x20, 0xf5, 0x35, 0xe9, 0x0f, 0x92, 0xd3, 0xfe, 0x85, 0x86, 0xe2,
+	0x23, 0xf9, 0x09, 0xac, 0x37, 0x4c, 0xa8, 0xce, 0x7d, 0x56, 0xf6, 0x07, 0x18, 0x62, 0x97, 0xd4,
+	0x72, 0xfd, 0xcc, 0x92, 0xff, 0x39, 0xa7, 0xfd, 0x59, 0xe9, 0x3f, 0x41, 0xed, 0x03, 0xb2, 0x9f,
+	0xd7, 0xce, 0x65, 0xff, 0x7e, 0x0b, 0xff, 0x81, 0x79, 0xf9, 0x5f, 0x00, 0x00, 0x00, 0xff, 0xff,
+	0xc2, 0x6b, 0xe2, 0x2f, 0xf7, 0x08, 0x00, 0x00,
 }
 
 // Reference imports to suppress errors if they are not otherwise used.

looprpc/client.proto

@@ -146,6 +146,15 @@ message LoopOutRequest {
     should be swept within.
     */
     int32 sweep_conf_target = 9;
+
+    /**
+    The latest time (in unix seconds) we allow the server to wait before
+    publishing the HTLC on chain. Setting this to a larger value will give the
+    server the opportunity to batch multiple swaps together, and wait for
+    low-fee periods before publishing the HTLC, potentially resulting in a
+    lower total swap fee.
+    */
+    uint64 swap_publication_deadline = 10;
 }
 
 message LoopInRequest {

looprpc/client.swagger.json

@@ -265,6 +265,11 @@
           "type": "integer",
           "format": "int32",
           "description": "*\nThe number of blocks from the on-chain HTLC's confirmation height that it\nshould be swept within."
+        },
+        "swap_publication_deadline": {
+          "type": "string",
+          "format": "uint64",
+          "description": "*\nThe latest time (in unix seconds) we allow the server to wait before\npublishing the HTLC on chain. Setting this to a larger value will give the\nserver the opportunity to batch multiple swaps together, and wait for\nlow-fee periods before publishing the HTLC, potentially resulting in a\nlower total swap fee."
         }
       }
     },

looprpc/server.pb.go

@@ -24,12 +24,14 @@ var _ = math.Inf
 const _ = proto.ProtoPackageIsVersion3 // please upgrade the proto package
 
 type ServerLoopOutRequest struct {
-	ReceiverKey          []byte   `protobuf:"bytes,1,opt,name=receiver_key,json=receiverKey,proto3" json:"receiver_key,omitempty"`
-	SwapHash             []byte   `protobuf:"bytes,2,opt,name=swap_hash,json=swapHash,proto3" json:"swap_hash,omitempty"`
-	Amt                  uint64   `protobuf:"varint,3,opt,name=amt,proto3" json:"amt,omitempty"`
-	XXX_NoUnkeyedLiteral struct{} `json:"-"`
-	XXX_unrecognized     []byte   `json:"-"`
-	XXX_sizecache        int32    `json:"-"`
+	ReceiverKey []byte `protobuf:"bytes,1,opt,name=receiver_key,json=receiverKey,proto3" json:"receiver_key,omitempty"`
+	SwapHash    []byte `protobuf:"bytes,2,opt,name=swap_hash,json=swapHash,proto3" json:"swap_hash,omitempty"`
+	Amt         uint64 `protobuf:"varint,3,opt,name=amt,proto3" json:"amt,omitempty"`
+	/// The unix time in seconds we want the on-chain swap to be published by.
+	SwapPublicationDeadline int64    `protobuf:"varint,4,opt,name=swap_publication_deadline,json=swapPublicationDeadline,proto3" json:"swap_publication_deadline,omitempty"`
+	XXX_NoUnkeyedLiteral    struct{} `json:"-"`
+	XXX_unrecognized        []byte   `json:"-"`
+	XXX_sizecache           int32    `json:"-"`
 }
 
 func (m *ServerLoopOutRequest) Reset()         { *m = ServerLoopOutRequest{} }
@@ -78,6 +80,13 @@ func (m *ServerLoopOutRequest) GetAmt() uint64 {
 	return 0
 }
 
+func (m *ServerLoopOutRequest) GetSwapPublicationDeadline() int64 {
+	if m != nil {
+		return m.SwapPublicationDeadline
+	}
+	return 0
+}
+
 type ServerLoopOutResponse struct {
 	SwapInvoice          string   `protobuf:"bytes,1,opt,name=swap_invoice,json=swapInvoice,proto3" json:"swap_invoice,omitempty"`
 	PrepayInvoice        string   `protobuf:"bytes,2,opt,name=prepay_invoice,json=prepayInvoice,proto3" json:"prepay_invoice,omitempty"`
@@ -671,48 +680,50 @@ func init() {
 func init() { proto.RegisterFile("server.proto", fileDescriptor_ad098daeda4239f7) }
 
 var fileDescriptor_ad098daeda4239f7 = []byte{
-	// 641 bytes of a gzipped FileDescriptorProto
-	0x1f, 0x8b, 0x08, 0x00, 0x00, 0x00, 0x00, 0x00, 0x02, 0xff, 0xac, 0x55, 0x6b, 0x4e, 0xdb, 0x4c,
-	0x14, 0x95, 0xed, 0x10, 0xbe, 0x5c, 0x12, 0xf8, 0x98, 0x3e, 0x64, 0x02, 0xa9, 0xc0, 0x52, 0x11,
-	0x42, 0x2d, 0x48, 0xed, 0x0a, 0xa8, 0x10, 0x2a, 0x2a, 0x2a, 0xc5, 0xf0, 0xdf, 0x9a, 0x26, 0xb7,
-	0xc4, 0x6a, 0xec, 0x99, 0xda, 0x93, 0x40, 0x36, 0xd0, 0x35, 0xb4, 0x0b, 0xeb, 0x42, 0xba, 0x83,
-	0x6a, 0x1e, 0x26, 0x7e, 0x42, 0x91, 0xfa, 0x8f, 0x39, 0xf7, 0x70, 0xef, 0xb9, 0x67, 0xce, 0x38,
-	0xd0, 0x4d, 0x31, 0x99, 0x61, 0x72, 0xc0, 0x13, 0x26, 0x18, 0x59, 0x9e, 0x30, 0xc6, 0x13, 0x3e,
-	0xec, 0x6f, 0x5d, 0x33, 0x76, 0x3d, 0xc1, 0x43, 0xca, 0xc3, 0x43, 0x1a, 0xc7, 0x4c, 0x50, 0x11,
-	0xb2, 0x38, 0xd5, 0x34, 0x6f, 0x0c, 0x4f, 0x2f, 0xd5, 0xbf, 0x9d, 0x31, 0xc6, 0xcf, 0xa7, 0xc2,
-	0xc7, 0x6f, 0x53, 0x4c, 0x05, 0xd9, 0x81, 0x6e, 0x82, 0x43, 0x0c, 0x67, 0x98, 0x04, 0x5f, 0x71,
-	0xee, 0x5a, 0xdb, 0xd6, 0x5e, 0xd7, 0x5f, 0xc9, 0xb0, 0x0f, 0x38, 0x27, 0x9b, 0xd0, 0x49, 0x6f,
-	0x28, 0x0f, 0xc6, 0x34, 0x1d, 0xbb, 0xb6, 0xaa, 0xff, 0x27, 0x81, 0xf7, 0x34, 0x1d, 0x93, 0xff,
-	0xc1, 0xa1, 0x91, 0x70, 0x9d, 0x6d, 0x6b, 0xaf, 0xe5, 0xcb, 0x3f, 0xbd, 0x1f, 0x16, 0x3c, 0x2b,
-	0x8d, 0x4a, 0x39, 0x8b, 0x53, 0x94, 0xb3, 0x54, 0xa3, 0x30, 0x9e, 0xb1, 0x70, 0x88, 0x6a, 0x56,
-	0xc7, 0x5f, 0x91, 0xd8, 0xa9, 0x86, 0xc8, 0x4b, 0x58, 0xe5, 0x09, 0x72, 0x3a, 0xbf, 0x23, 0xd9,
-	0x8a, 0xd4, 0xd3, 0x68, 0x46, 0x1b, 0x00, 0xa4, 0x18, 0x8f, 0x8c, 0x66, 0x47, 0x69, 0xea, 0x68,
-	0x44, 0x2a, 0x7e, 0x0e, 0x6d, 0xbc, 0xe5, 0x61, 0x32, 0x77, 0x5b, 0xdb, 0xd6, 0xde, 0x92, 0x6f,
-	0x4e, 0xde, 0x6b, 0xd8, 0x28, 0x28, 0xbb, 0x98, 0x32, 0x81, 0x99, 0x13, 0x66, 0x13, 0x6b, 0xb1,
-	0xc9, 0x4f, 0x1b, 0x48, 0x95, 0x4f, 0xf6, 0x61, 0x5d, 0xad, 0xc1, 0xe9, 0x3c, 0xc2, 0x58, 0x04,
-	0x23, 0x4c, 0x85, 0xd9, 0x65, 0x4d, 0x16, 0x3e, 0x69, 0xfc, 0x58, 0x36, 0xdd, 0x00, 0x65, 0x55,
-	0xf0, 0x05, 0xf5, 0x26, 0x8e, 0xbf, 0x2c, 0xcf, 0x27, 0x88, 0x64, 0x17, 0x7a, 0x59, 0x29, 0x48,
-	0xa8, 0x40, 0xb5, 0x86, 0xf3, 0xce, 0x76, 0x2d, 0x6d, 0xc9, 0x09, 0xa2, 0x4f, 0x85, 0xda, 0xd5,
-	0x58, 0x22, 0xe5, 0xb5, 0x94, 0xbc, 0x8e, 0x46, 0x8e, 0x22, 0x41, 0xf6, 0x61, 0x2d, 0x0a, 0xe3,
-	0x40, 0xb5, 0xa2, 0x11, 0x9b, 0xc6, 0xc2, 0x5d, 0x92, 0x1c, 0xd5, 0xa8, 0x17, 0x85, 0xf1, 0xe5,
-	0x0d, 0xe5, 0x47, 0xaa, 0xa0, 0xb8, 0xf4, 0xb6, 0xc0, 0x6d, 0xe7, 0xb8, 0xf4, 0x36, 0xc7, 0x1d,
-	0x00, 0x0c, 0x27, 0x62, 0x16, 0x8c, 0x70, 0x22, 0xa8, 0xbb, 0xac, 0x7c, 0xec, 0x48, 0xe4, 0x58,
-	0x02, 0xde, 0x66, 0xc9, 0xca, 0x2b, 0x4c, 0xa2, 0xd4, 0x58, 0xe9, 0x8d, 0x4a, 0xbe, 0xa9, 0x22,
-	0xd9, 0xad, 0x2a, 0xd5, 0x66, 0x97, 0x54, 0xee, 0x56, 0x55, 0xda, 0x86, 0x97, 0x57, 0xe8, 0x7d,
-	0xb7, 0xe0, 0xc9, 0x62, 0xcc, 0x69, 0x9c, 0x5d, 0x64, 0x31, 0x1c, 0x56, 0x39, 0x1c, 0x8f, 0x8b,
-	0x73, 0x25, 0xb4, 0xad, 0x4a, 0x68, 0xbd, 0x8b, 0xfc, 0xdb, 0x92, 0x3a, 0x16, 0x79, 0x7f, 0xe8,
-	0x6d, 0x2d, 0x92, 0x6a, 0x17, 0x92, 0xfa, 0x0a, 0xdc, 0x7c, 0xcb, 0x07, 0x82, 0xfa, 0xcb, 0xca,
-	0xdf, 0xc6, 0x1d, 0xdd, 0xc8, 0xc8, 0x67, 0xd0, 0x7a, 0x20, 0x83, 0x76, 0x7d, 0x06, 0x6b, 0x42,
-	0xd6, 0x7a, 0x44, 0xc8, 0x96, 0xfe, 0x2e, 0x64, 0xed, 0x72, 0xc8, 0xfa, 0x45, 0x17, 0x0a, 0x19,
-	0x1b, 0xc2, 0x7a, 0xa5, 0xf6, 0xaf, 0x23, 0xf6, 0xe6, 0xb7, 0x03, 0x20, 0x8f, 0x7a, 0x12, 0x39,
-	0x87, 0x6e, 0x21, 0xd1, 0xde, 0x81, 0xf9, 0xf8, 0x1e, 0x34, 0xbe, 0x85, 0xfe, 0xe6, 0x3d, 0x1c,
-	0x72, 0x0e, 0xab, 0x1f, 0xf1, 0xc6, 0x40, 0x72, 0x10, 0x19, 0xd4, 0xd3, 0xb3, 0x6e, 0x2f, 0x9a,
-	0xca, 0xe6, 0xae, 0x17, 0x0a, 0xf5, 0xb7, 0xaa, 0x41, 0x61, 0x3e, 0x4f, 0x4d, 0x0a, 0x75, 0x83,
-	0x33, 0x58, 0xc9, 0x1b, 0xbc, 0x53, 0xc3, 0x2d, 0x5e, 0x4c, 0xbf, 0xdf, 0x4c, 0x21, 0x67, 0xd0,
-	0x33, 0xfb, 0x9e, 0xaa, 0xeb, 0x20, 0x5b, 0xb5, 0xe4, 0xac, 0xd5, 0xa0, 0xa1, 0x6a, 0x96, 0xbd,
-	0xca, 0xb4, 0x69, 0xa9, 0xf5, 0xda, 0x0a, 0xab, 0x7a, 0xf7, 0x51, 0x74, 0xd7, 0xcf, 0x6d, 0xf5,
-	0x83, 0xf9, 0xf6, 0x4f, 0x00, 0x00, 0x00, 0xff, 0xff, 0xf1, 0xf9, 0x2f, 0x6f, 0x67, 0x07, 0x00,
-	0x00,
+	// 674 bytes of a gzipped FileDescriptorProto
+	0x1f, 0x8b, 0x08, 0x00, 0x00, 0x00, 0x00, 0x00, 0x02, 0xff, 0xac, 0x55, 0xdd, 0x4e, 0xdb, 0x4c,
+	0x10, 0x95, 0xed, 0x10, 0xbe, 0x0c, 0x09, 0x7c, 0x6c, 0xff, 0x4c, 0x20, 0x15, 0x58, 0x2a, 0x42,
+	0xa8, 0x05, 0xa9, 0xbd, 0xeb, 0x1d, 0x15, 0x42, 0x45, 0x45, 0xa5, 0x18, 0xee, 0xad, 0x25, 0x99,
+	0x82, 0xd5, 0x78, 0x77, 0x6b, 0x6f, 0x02, 0x79, 0x81, 0x3e, 0x43, 0x7b, 0xdf, 0x57, 0xea, 0x83,
+	0xf4, 0x0d, 0xaa, 0xfd, 0x31, 0xb1, 0x9d, 0x84, 0x14, 0xa9, 0x77, 0xec, 0x99, 0xc3, 0xec, 0x99,
+	0x33, 0x67, 0x1d, 0x68, 0x66, 0x98, 0x0e, 0x31, 0xdd, 0x13, 0x29, 0x97, 0x9c, 0x2c, 0xf6, 0x39,
+	0x17, 0xa9, 0xe8, 0xb6, 0x37, 0xae, 0x38, 0xbf, 0xea, 0xe3, 0x3e, 0x15, 0xf1, 0x3e, 0x65, 0x8c,
+	0x4b, 0x2a, 0x63, 0xce, 0x32, 0x43, 0x0b, 0x7e, 0x3a, 0xf0, 0xf8, 0x5c, 0xff, 0xdf, 0x09, 0xe7,
+	0xe2, 0x74, 0x20, 0x43, 0xfc, 0x3a, 0xc0, 0x4c, 0x92, 0x2d, 0x68, 0xa6, 0xd8, 0xc5, 0x78, 0x88,
+	0x69, 0xf4, 0x05, 0x47, 0xbe, 0xb3, 0xe9, 0xec, 0x34, 0xc3, 0xa5, 0x1c, 0xfb, 0x80, 0x23, 0xb2,
+	0x0e, 0x8d, 0xec, 0x86, 0x8a, 0xe8, 0x9a, 0x66, 0xd7, 0xbe, 0xab, 0xeb, 0xff, 0x29, 0xe0, 0x3d,
+	0xcd, 0xae, 0xc9, 0xff, 0xe0, 0xd1, 0x44, 0xfa, 0xde, 0xa6, 0xb3, 0x53, 0x0b, 0xd5, 0x9f, 0xe4,
+	0x2d, 0xac, 0x69, 0xba, 0x18, 0x5c, 0xf6, 0xe3, 0xae, 0x56, 0x11, 0xf5, 0x90, 0xf6, 0xfa, 0x31,
+	0x43, 0xbf, 0xb6, 0xe9, 0xec, 0x78, 0xe1, 0x33, 0x45, 0xf8, 0x34, 0xae, 0x1f, 0xda, 0x72, 0xf0,
+	0xdd, 0x81, 0x27, 0x15, 0x99, 0x99, 0xe0, 0x2c, 0x43, 0xa5, 0x53, 0x77, 0x8d, 0xd9, 0x90, 0xc7,
+	0x5d, 0xd4, 0x3a, 0x1b, 0xe1, 0x92, 0xc2, 0x8e, 0x0d, 0x44, 0x5e, 0xc0, 0xb2, 0x48, 0x51, 0xd0,
+	0xd1, 0x1d, 0xc9, 0xd5, 0xa4, 0x96, 0x41, 0x73, 0x5a, 0x07, 0x20, 0x43, 0xd6, 0xb3, 0xf3, 0x7a,
+	0x7a, 0x9e, 0x86, 0x41, 0xd4, 0xb4, 0x4f, 0xa1, 0x8e, 0xb7, 0x22, 0x4e, 0x47, 0x5a, 0xeb, 0x42,
+	0x68, 0x4f, 0xc1, 0x2b, 0x58, 0x2b, 0x29, 0x3b, 0x1b, 0x70, 0x89, 0xb9, 0x8b, 0xd6, 0x05, 0xe7,
+	0xce, 0x85, 0xe0, 0x87, 0x0b, 0x64, 0x92, 0x4f, 0x76, 0x61, 0xd5, 0x98, 0x43, 0x47, 0x09, 0x32,
+	0x19, 0xf5, 0x30, 0x93, 0x76, 0x96, 0x15, 0x6d, 0x8a, 0xc1, 0x0f, 0x55, 0xd3, 0x35, 0xd0, 0x36,
+	0x47, 0x9f, 0xd1, 0x4c, 0xe2, 0x85, 0x8b, 0xea, 0x7c, 0x84, 0x48, 0xb6, 0xa1, 0x95, 0x97, 0xa2,
+	0x94, 0x4a, 0xd4, 0x63, 0x78, 0xef, 0x5c, 0xdf, 0x31, 0x96, 0x1c, 0x21, 0x86, 0x54, 0xea, 0x59,
+	0xad, 0x25, 0x4a, 0x5e, 0x4d, 0xcb, 0x6b, 0x18, 0xe4, 0x20, 0x91, 0x64, 0x17, 0x56, 0x92, 0x98,
+	0x45, 0xba, 0x15, 0x4d, 0xf8, 0x80, 0x49, 0x7f, 0x41, 0x71, 0x74, 0xa3, 0x56, 0x12, 0xb3, 0xf3,
+	0x1b, 0x2a, 0x0e, 0x74, 0x41, 0x73, 0xe9, 0x6d, 0x89, 0x5b, 0x2f, 0x70, 0xe9, 0x6d, 0x81, 0xdb,
+	0x01, 0xe8, 0xf6, 0xe5, 0x30, 0xea, 0x61, 0x5f, 0x52, 0x7f, 0x51, 0xfb, 0xd8, 0x50, 0xc8, 0xa1,
+	0x02, 0x82, 0xf5, 0x8a, 0x95, 0x17, 0x98, 0x26, 0x99, 0xb5, 0x32, 0xe8, 0x55, 0x7c, 0xd3, 0x45,
+	0xb2, 0x3d, 0xa9, 0xd4, 0x98, 0x5d, 0x51, 0xb9, 0x3d, 0xa9, 0xd2, 0xb5, 0xbc, 0xa2, 0xc2, 0xe0,
+	0x9b, 0x03, 0x8f, 0xc6, 0xd7, 0x1c, 0xb3, 0x7c, 0x91, 0xe5, 0x70, 0x38, 0xd5, 0x70, 0x3c, 0xf0,
+	0x29, 0x54, 0x43, 0x5b, 0x9b, 0x08, 0x6d, 0x70, 0x56, 0x7c, 0x97, 0x4a, 0xc7, 0x38, 0xef, 0xf3,
+	0xde, 0xe5, 0x38, 0xa9, 0x6e, 0x29, 0xa9, 0x2f, 0xc1, 0x2f, 0xb6, 0x9c, 0x13, 0xd4, 0x5f, 0x4e,
+	0x71, 0x1b, 0x77, 0x74, 0x2b, 0xa3, 0x98, 0x41, 0x67, 0x4e, 0x06, 0xdd, 0xe9, 0x19, 0x9c, 0x12,
+	0xb2, 0xda, 0x03, 0x42, 0xb6, 0xf0, 0x77, 0x21, 0xab, 0x57, 0x43, 0xd6, 0x2e, 0xbb, 0x50, 0xca,
+	0x58, 0x17, 0x56, 0x27, 0x6a, 0xff, 0x3a, 0x62, 0xaf, 0x7f, 0x7b, 0x00, 0xea, 0x68, 0x6e, 0x22,
+	0xa7, 0xd0, 0x2c, 0x25, 0x3a, 0xd8, 0xb3, 0x5f, 0xee, 0xbd, 0x99, 0x6f, 0xa1, 0xbd, 0x7e, 0x0f,
+	0x87, 0x9c, 0xc2, 0xf2, 0x47, 0xbc, 0xb1, 0x90, 0xba, 0x88, 0x74, 0xa6, 0xd3, 0xf3, 0x6e, 0xcf,
+	0x67, 0x95, 0xed, 0xae, 0xc7, 0x0a, 0xcd, 0xb7, 0x6a, 0x86, 0xc2, 0x62, 0x9e, 0x66, 0x29, 0x34,
+	0x0d, 0x4e, 0x60, 0xa9, 0x68, 0xf0, 0xd6, 0x14, 0x6e, 0x79, 0x31, 0xed, 0xf6, 0x6c, 0x0a, 0x39,
+	0x81, 0x96, 0x9d, 0xf7, 0x58, 0xaf, 0x83, 0x6c, 0x4c, 0x25, 0xe7, 0xad, 0x3a, 0x33, 0xaa, 0x76,
+	0xd8, 0x8b, 0x5c, 0x9b, 0x91, 0x3a, 0x5d, 0x5b, 0x69, 0xd4, 0xe0, 0x3e, 0x8a, 0xe9, 0x7a, 0x59,
+	0xd7, 0xbf, 0xb6, 0x6f, 0xfe, 0x04, 0x00, 0x00, 0xff, 0xff, 0x91, 0x34, 0x08, 0x26, 0xa4, 0x07,
+	0x00, 0x00,
 }
 
 // Reference imports to suppress errors if they are not otherwise used.

looprpc/server.proto

@@ -24,6 +24,9 @@ message ServerLoopOutRequest {
     bytes swap_hash = 2;
 
     uint64 amt = 3;
+
+    /// The unix time in seconds we want the on-chain swap to be published by.
+    int64 swap_publication_deadline = 4;
 }
 
 message ServerLoopOutResponse {

server_mock_test.go

@@ -53,7 +53,7 @@ func newServerMock() *serverMock {
 
 func (s *serverMock) NewLoopOutSwap(ctx context.Context,
 	swapHash lntypes.Hash, amount btcutil.Amount,
-	receiverKey [33]byte) (
+	receiverKey [33]byte, _ time.Time) (
 	*newLoopOutResponse, error) {
 
 	_, senderKey := test.CreateKey(100)

swap_server_client.go

@@ -6,6 +6,7 @@ import (
 	"encoding/hex"
 	"errors"
 	"fmt"
+	"time"
 
 	"github.com/lightninglabs/loop/looprpc"
 	"github.com/lightningnetwork/lnd/lntypes"
@@ -31,7 +32,8 @@ type swapServerClient interface {
 
 	NewLoopOutSwap(ctx context.Context,
 		swapHash lntypes.Hash, amount btcutil.Amount,
-		receiverKey [33]byte) (
+		receiverKey [33]byte,
+		swapPublicationDeadline time.Time) (
 		*newLoopOutResponse, error)
 
 	NewLoopInSwap(ctx context.Context,
@@ -153,15 +155,17 @@ func (s *grpcSwapServerClient) GetLoopInQuote(ctx context.Context,
 
 func (s *grpcSwapServerClient) NewLoopOutSwap(ctx context.Context,
 	swapHash lntypes.Hash, amount btcutil.Amount,
-	receiverKey [33]byte) (*newLoopOutResponse, error) {
+	receiverKey [33]byte, swapPublicationDeadline time.Time) (
+	*newLoopOutResponse, error) {
 
 	rpcCtx, rpcCancel := context.WithTimeout(ctx, serverRPCTimeout)
 	defer rpcCancel()
 	swapResp, err := s.server.NewLoopOutSwap(rpcCtx,
 		&looprpc.ServerLoopOutRequest{
-			SwapHash:    swapHash[:],
-			Amt:         uint64(amount),
-			ReceiverKey: receiverKey[:],
+			SwapHash:                swapHash[:],
+			Amt:                     uint64(amount),
+			ReceiverKey:             receiverKey[:],
+			SwapPublicationDeadline: swapPublicationDeadline.Unix(),
 		},
 	)
 	if err != nil {