Add optional memo to TAP addresses

address/address.go

@@ -119,6 +119,9 @@ type Tap struct {
 	// ProofCourierAddr is the address of the proof courier that will be
 	// used to distribute related proofs for this address.
 	ProofCourierAddr url.URL
+
+	// Memo is an optional memo that can be attached to the address.
+	Memo string
 }
 
 // newAddrOptions are a set of options that can modified how a new address is
@@ -154,7 +157,7 @@ func New(version Version, genesis asset.Genesis, groupKey *btcec.PublicKey,
 	groupWitness wire.TxWitness, scriptKey btcec.PublicKey,
 	internalKey btcec.PublicKey, amt uint64,
 	tapscriptSibling *commitment.TapscriptPreimage,
-	net *ChainParams, proofCourierAddr url.URL,
+	net *ChainParams, proofCourierAddr url.URL, memo string,
 	opts ...NewAddrOpt) (*Tap, error) {
 
 	options := defaultNewAddrOptions()
@@ -214,6 +217,7 @@ func New(version Version, genesis asset.Genesis, groupKey *btcec.PublicKey,
 		Amount:           amt,
 		assetGen:         genesis,
 		ProofCourierAddr: proofCourierAddr,
+		Memo:             memo,
 	}
 	return &payload, nil
 }
@@ -323,7 +327,7 @@ func (a *Tap) TaprootOutputKey() (*btcec.PublicKey, error) {
 // EncodeRecords determines the non-nil records to include when encoding an
 // address at runtime.
 func (a *Tap) EncodeRecords() []tlv.Record {
-	records := make([]tlv.Record, 0, 9)
+	records := make([]tlv.Record, 0, 10)
 	records = append(records, newAddressVersionRecord(&a.Version))
 	records = append(records, newAddressAssetVersionRecord(&a.AssetVersion))
 	records = append(records, newAddressAssetID(&a.AssetID))
@@ -345,6 +349,10 @@ func (a *Tap) EncodeRecords() []tlv.Record {
 		records, newProofCourierAddrRecord(&a.ProofCourierAddr),
 	)
 
+	if a.Memo != "" {
+		records = append(records, newMemoRecord(&a.Memo))
+	}
+
 	return records
 }
 
@@ -361,6 +369,7 @@ func (a *Tap) DecodeRecords() []tlv.Record {
 		newAddressTapscriptSiblingRecord(&a.TapscriptSibling),
 		newAddressAmountRecord(&a.Amount),
 		newProofCourierAddrRecord(&a.ProofCourierAddr),
+		newMemoRecord(&a.Memo),
 	}
 }
 

address/address_test.go

@@ -23,8 +23,8 @@ var (
 		"a0afeb165f0ec36880b68e0baabd9ad9c62fd1a69aa998bc30e9a346202e" +
 			"078f",
 	)
-	pubKey, _ = schnorr.ParsePubKey(pubKeyBytes)
-
+	pubKey, _               = schnorr.ParsePubKey(pubKeyBytes)
+	addrMemo                = "memo"
 	generatedTestVectorName = "address_tlv_encoding_generated.json"
 
 	allTestVectorFiles = []string{
@@ -79,7 +79,7 @@ func randAddress(t *testing.T, net *ChainParams, v Version, groupPubKey,
 
 	return New(
 		v, genesis, groupKey, groupWitness, scriptKey, internalKey,
-		amount, tapscriptSibling, net, proofCourierAddr,
+		amount, tapscriptSibling, net, proofCourierAddr, addrMemo,
 		addrOpts...,
 	)
 }
@@ -112,6 +112,7 @@ func assertAddressEqual(t *testing.T, a, b *Tap) {
 	require.Equal(t, a.ScriptKey, b.ScriptKey)
 	require.Equal(t, a.InternalKey, b.InternalKey)
 	require.Equal(t, a.Amount, b.Amount)
+	require.Equal(t, a.Memo, b.Memo)
 }
 
 // TestNewAddress tests edge cases around creating a new address.

address/book.go

@@ -250,7 +250,7 @@ func (b *Book) queryAssetInfo(ctx context.Context,
 
 // NewAddress creates a new Taproot Asset address based on the input parameters.
 func (b *Book) NewAddress(ctx context.Context, assetID asset.ID, amount uint64,
-	tapscriptSibling *commitment.TapscriptPreimage,
+	tapscriptSibling *commitment.TapscriptPreimage, memo string,
 	proofCourierAddr url.URL, addrOpts ...NewAddrOpt,
 ) (*AddrWithKeyInfo, error) {
 
@@ -278,7 +278,7 @@ func (b *Book) NewAddress(ctx context.Context, assetID asset.ID, amount uint64,
 
 	return b.NewAddressWithKeys(
 		ctx, assetID, amount, scriptKey, internalKeyDesc,
-		tapscriptSibling, proofCourierAddr, addrOpts...,
+		tapscriptSibling, proofCourierAddr, memo, addrOpts...,
 	)
 }
 
@@ -288,7 +288,7 @@ func (b *Book) NewAddressWithKeys(ctx context.Context, assetID asset.ID,
 	amount uint64, scriptKey asset.ScriptKey,
 	internalKeyDesc keychain.KeyDescriptor,
 	tapscriptSibling *commitment.TapscriptPreimage,
-	proofCourierAddr url.URL,
+	proofCourierAddr url.URL, memo string,
 	addrOpts ...NewAddrOpt) (*AddrWithKeyInfo, error) {
 
 	// Before we proceed, we'll make sure that the asset group is known to
@@ -312,7 +312,7 @@ func (b *Book) NewAddressWithKeys(ctx context.Context, assetID asset.ID,
 	baseAddr, err := New(
 		V0, *assetGroup.Genesis, groupKey, groupWitness,
 		*scriptKey.PubKey, *internalKeyDesc.PubKey, amount,
-		tapscriptSibling, &b.cfg.Chain, proofCourierAddr,
+		tapscriptSibling, &b.cfg.Chain, proofCourierAddr, memo,
 		addrOpts...,
 	)
 	if err != nil {

address/encoding.go

@@ -91,3 +91,24 @@ func VersionDecoder(r io.Reader, val any, buf *[8]byte, l uint64) error {
 	}
 	return tlv.NewTypeForDecodingErr(val, "Version", l, 1)
 }
+
+func memoEncoder(w io.Writer, val any, buf *[8]byte) error {
+	if t, ok := val.(*string); ok {
+		memoBytes := []byte(*t)
+		return tlv.EVarBytes(w, &memoBytes, buf)
+	}
+	return tlv.NewTypeForEncodingErr(val, "*string")
+}
+
+func memoDecoder(r io.Reader, val any, buf *[8]byte, l uint64) error {
+	if t, ok := val.(*string); ok {
+		var memoBytes []byte
+		err := tlv.DVarBytes(r, &memoBytes, buf, l)
+		if err != nil {
+			return err
+		}
+		*t = string(memoBytes)
+		return nil
+	}
+	return tlv.NewTypeForDecodingErr(val, "*string", l, l)
+}

address/mock.go

@@ -73,10 +73,12 @@ func RandAddr(t testing.TB, params *ChainParams,
 		assetVersion = asset.V1
 	}
 
+	randMemo := test.RandHash().String()
+
 	tapAddr, err := New(
 		V0, genesis, groupPubKey, groupWitness, *scriptKey.PubKey,
 		*internalKey.PubKey(), amount, tapscriptSibling, params,
-		proofCourierAddr, WithAssetVersion(assetVersion),
+		proofCourierAddr, randMemo, WithAssetVersion(assetVersion),
 	)
 	require.NoError(t, err)
 

address/records.go

@@ -40,6 +40,9 @@ const (
 
 	// addrProofCourierType is the TLV type of the proof courier address.
 	addrProofCourierAddrType addressTLVType = 12
+
+	// addrMemoType is the TLV type of the memo.
+	addrMemoType addressTLVType = 13
 )
 
 func newAddressVersionRecord(version *Version) tlv.Record {
@@ -118,3 +121,16 @@ func newProofCourierAddrRecord(addr *url.URL) tlv.Record {
 		urlEncoder, urlDecoder,
 	)
 }
+
+func newMemoRecord(memo *string) tlv.Record {
+	var memoBytes []byte
+	if memo != nil {
+		memoBytes = []byte(*memo)
+	}
+	recordSize := tlv.SizeVarBytes(&memoBytes)
+
+	return tlv.MakeDynamicRecord(
+		addrMemoType, memo, recordSize,
+		memoEncoder, memoDecoder,
+	)
+}

cmd/tapcli/addrs.go

@@ -31,6 +31,7 @@ const (
 	amtName              = "amt"
 	assetVersionName     = "asset_version"
 	proofCourierAddrName = "proof_courier_addr"
+	memoName             = "memo"
 )
 
 var newAddrCommand = cli.Command{
@@ -59,6 +60,10 @@ var newAddrCommand = cli.Command{
 				"default proof courier should be " +
 				"overwritten; format: protocol://host:port",
 		},
+		cli.StringFlag{
+			Name:  memoName,
+			Usage: "(optional) a memo to attach to the address",
+		},
 	},
 	Action: newAddr,
 }
@@ -90,6 +95,7 @@ func newAddr(ctx *cli.Context) error {
 		Amt:              ctx.Uint64(amtName),
 		AssetVersion:     assetVersion,
 		ProofCourierAddr: ctx.String(proofCourierAddrName),
+		Memo:             ctx.String(memoName),
 	})
 	if err != nil {
 		return fmt.Errorf("unable to make addr: %w", err)

itest/addrs_test.go

@@ -360,8 +360,10 @@ func testAddressAssetSyncer(t *harnessTest) {
 		AssetId:      firstAsset.AssetGenesis.AssetId,
 		Amt:          firstAsset.Amount,
 		AssetVersion: firstAsset.Version,
+		Memo:         "first_address",
 	})
 	require.NoError(t.t, err)
+	require.Equal(t.t, "first_address", firstAddr.Memo)
 	AssertAddr(t.t, firstAsset, firstAddr)
 
 	secondAsset := secondRpcAssets[1]

rpcserver.go

@@ -1106,8 +1106,8 @@ func (r *rpcServer) NewAddr(ctx context.Context,
 		// Now that we have all the params, we'll try to add a new
 		// address to the addr book.
 		addr, err = r.cfg.AddrBook.NewAddress(
-			ctx, assetID, req.Amt, tapscriptSibling, *courierAddr,
-			address.WithAssetVersion(assetVersion),
+			ctx, assetID, req.Amt, tapscriptSibling, req.Memo,
+			*courierAddr, address.WithAssetVersion(assetVersion),
 		)
 		if err != nil {
 			return nil, fmt.Errorf("unable to make new addr: %w",
@@ -1147,7 +1147,7 @@ func (r *rpcServer) NewAddr(ctx context.Context,
 		// address to the addr book.
 		addr, err = r.cfg.AddrBook.NewAddressWithKeys(
 			ctx, assetID, req.Amt, *scriptKey, internalKey,
-			tapscriptSibling, *courierAddr,
+			tapscriptSibling, *courierAddr, req.Memo,
 			address.WithAssetVersion(assetVersion),
 		)
 		if err != nil {
@@ -1896,6 +1896,7 @@ func marshalAddr(addr *address.Tap,
 		TaprootOutputKey: taprootOutputKey,
 		AssetType:        taprpc.AssetType(addr.AssetType()),
 		ProofCourierAddr: addr.ProofCourierAddr.String(),
+		Memo:             addr.Memo,
 	}
 
 	if addr.GroupKey != nil {

tapdb/addrs.go

@@ -282,6 +282,7 @@ func (t *TapAddressBook) InsertAddrs(ctx context.Context,
 				AssetType:        int16(assetGen.AssetType),
 				CreationTime:     addr.CreationTime.UTC(),
 				ProofCourierAddr: proofCourierAddrBytes,
+				Memo:             addr.Memo,
 			})
 			if err != nil {
 				return fmt.Errorf("unable to insert addr: %w",
@@ -438,6 +439,7 @@ func (t *TapAddressBook) QueryAddrs(ctx context.Context,
 				groupKey, groupWitness,
 				*scriptKey, *internalKey, uint64(addr.Amount),
 				tapscriptSibling, t.params, *proofCourierAddr,
+				addr.Memo,
 				address.WithAssetVersion(
 					asset.Version(addr.AssetVersion),
 				),
@@ -587,7 +589,7 @@ func fetchAddr(ctx context.Context, db AddrBook, params *address.ChainParams,
 	tapAddr, err := address.New(
 		address.Version(dbAddr.Version), genesis, groupKey,
 		groupWitness, *scriptKey, *internalKey, uint64(dbAddr.Amount),
-		tapscriptSibling, params, *proofCourierAddr,
+		tapscriptSibling, params, *proofCourierAddr, dbAddr.Memo,
 		address.WithAssetVersion(asset.Version(dbAddr.AssetVersion)),
 	)
 	if err != nil {

tapdb/sqlc/migrations/000015_addr_memo.down.sql

@@ -0,0 +1,2 @@
+-- Alter the addrs table to add a memo field.
+ALTER TABLE addrs DROP COLUMN memo;

tapdb/sqlc/migrations/000015_addr_memo.up.sql

@@ -0,0 +1,2 @@
+-- Alter the addrs table to add a memo field.
+ALTER TABLE addrs ADD COLUMN memo TEXT NOT NULL DEFAULT '';

tapdb/sqlc/queries/addrs.sql

@@ -2,14 +2,14 @@
 INSERT INTO addrs (
     version, asset_version, genesis_asset_id, group_key, script_key_id,
     taproot_key_id, tapscript_sibling, taproot_output_key, amount, asset_type,
-    creation_time, proof_courier_addr
-) VALUES ($1, $2, $3, $4, $5, $6, $7, $8, $9, $10, $11, $12) RETURNING id;
+    creation_time, proof_courier_addr, memo
+) VALUES ($1, $2, $3, $4, $5, $6, $7, $8, $9, $10, $11, $12, $13) RETURNING id;
 
 -- name: FetchAddrs :many
 SELECT 
     version, asset_version, genesis_asset_id, group_key, tapscript_sibling,
     taproot_output_key, amount, asset_type, creation_time, managed_from,
-    proof_courier_addr,
+    proof_courier_addr, memo,
     script_keys.tweaked_script_key,
     script_keys.tweak AS script_key_tweak,
     raw_script_keys.raw_key AS raw_script_key,
@@ -36,7 +36,7 @@ LIMIT @num_limit OFFSET @num_offset;
 SELECT
     version, asset_version, genesis_asset_id, group_key, tapscript_sibling,
     taproot_output_key, amount, asset_type, creation_time, managed_from,
-    proof_courier_addr,
+    proof_courier_addr, memo,
     script_keys.tweaked_script_key,
     script_keys.tweak AS script_key_tweak,
     raw_script_keys.raw_key as raw_script_key,