diff --git a/app/app.go b/app/app.go
index 12fea597f..a082e93f4 100644
--- a/app/app.go
+++ b/app/app.go
@@ -35,6 +35,9 @@ type App struct {
 	// Current block header
 	header abci.Header
 
+	// Unmarshal []byte into types.Tx
+	txParser TxParser
+
 	// Handler for CheckTx and DeliverTx.
 	handler types.Handler
 
@@ -59,6 +62,18 @@ func (app *App) SetCommitMultiStore(ms types.CommitMultiStore) {
 	app.ms = ms
 }
 
+/*
+SetBeginBlocker
+SetEndBlocker
+SetInitStater
+*/
+
+type TxParser func(txBytes []byte) (types.Tx, error)
+
+func (app *App) SetTxParser(txParser TxParser) {
+	app.txParser = txParser
+}
+
 func (app *App) SetHandler(handler types.Handler) {
 	app.handler = handler
 }
@@ -167,7 +182,15 @@ func (app *App) CheckTx(txBytes []byte) (res abci.ResponseCheckTx) {
 	// Initialize arguments to Handler.
 	var isCheckTx = true
 	var ctx = types.NewContext(app.header, isCheckTx, txBytes)
-	var tx types.Tx = nil // nil until a decorator parses one.
+	var tx types.Tx
+
+	var err error
+	tx, err = app.txParser(txBytes)
+	if err != nil {
+		return abci.ResponseCheckTx{
+			Code: 1, //  TODO
+		}
+	}
 
 	// Run the handler.
 	var result = app.handler(ctx, app.ms, tx)
@@ -192,7 +215,15 @@ func (app *App) DeliverTx(txBytes []byte) (res abci.ResponseDeliverTx) {
 	// Initialize arguments to Handler.
 	var isCheckTx = false
 	var ctx = types.NewContext(app.header, isCheckTx, txBytes)
-	var tx types.Tx = nil // nil until a decorator parses one.
+	var tx types.Tx
+
+	var err error
+	tx, err = app.txParser(txBytes)
+	if err != nil {
+		return abci.ResponseDeliverTx{
+			Code: 1, //  TODO
+		}
+	}
 
 	// Run the handler.
 	var result = app.handler(ctx, app.ms, tx)
diff --git a/app/example/basecoin/account.go b/app/example/basecoin/account.go
new file mode 100644
index 000000000..0668c86d4
--- /dev/null
+++ b/app/example/basecoin/account.go
@@ -0,0 +1,71 @@
+package main
+
+import (
+	"github.com/cosmos/cosmos-sdk/types"
+	crypto "github.com/tendermint/go-crypto"
+)
+
+// AppAccount - coin account structure
+type AppAccount struct {
+	Address_ types.Address `json:"address"`
+	Coins    types.Coins   `json:"coins"`
+	PubKey_  crypto.PubKey `json:"public_key"` // can't conflict with PubKey()
+	Sequence int64         `json:"sequence"`
+}
+
+// Implements auth.Account
+func (a *AppAccount) Get(key interface{}) (value interface{}, err error) {
+	switch key.(type) {
+	case string:
+		//
+	default:
+		panic("HURAH!")
+	}
+	return nil, nil
+}
+
+// Implements auth.Account
+func (a *AppAccount) Set(key interface{}, value interface{}) error {
+	switch key.(type) {
+	case string:
+		//
+	default:
+		panic("HURAH!")
+	}
+	return nil
+}
+
+// Implements auth.Account
+func (a *AppAccount) Address() types.Address {
+	return a.PubKey_.Address()
+}
+
+// Implements auth.Account
+func (a *AppAccount) PubKey() crypto.PubKey {
+	return a.PubKey_
+}
+
+func (a *AppAccount) SetPubKey(pubKey crypto.PubKey) error {
+	a.PubKey_ = pubKey
+	return nil
+}
+
+// Implements coinstore.Coinser
+func (a *AppAccount) GetCoins() types.Coins {
+	return a.Coins
+}
+
+// Implements coinstore.Coinser
+func (a *AppAccount) SetCoins(coins types.Coins) error {
+	a.Coins = coins
+	return nil
+}
+
+func (a *AppAccount) GetSequence() int64 {
+	return a.Sequence
+}
+
+func (a *AppAccount) SetSequence(seq int64) error {
+	a.Sequence = seq
+	return nil
+}
diff --git a/app/example/basecoin/account_store.go b/app/example/basecoin/account_store.go
new file mode 100644
index 000000000..53078ff6b
--- /dev/null
+++ b/app/example/basecoin/account_store.go
@@ -0,0 +1,55 @@
+package main
+
+import (
+	"encoding/json"
+	"path"
+
+	"github.com/cosmos/cosmos-sdk/types"
+)
+
+type AppAccountStore struct {
+	kvStore types.KVStore
+}
+
+func newAccountStore(kvStore types.KVStore) types.AccountStore {
+	return AppAccountStore{kvStore}
+}
+
+func (accStore AppAccountStore) NewAccountWithAddress(addr types.Address) types.Account {
+	return &AppAccount{
+		Address_: addr,
+	}
+}
+
+func (accStore AppAccountStore) GetAccount(addr types.Address) types.Account {
+	v := accStore.kvStore.Get(keyAccount(addr))
+
+	if len(v) == 0 {
+		return nil
+	}
+
+	acc := new(AppAccount)
+	if err := json.Unmarshal(v, acc); err != nil {
+		panic(err)
+	}
+
+	return acc
+}
+
+func (accStore AppAccountStore) SetAccount(acc types.Account) {
+	b, err := json.Marshal(acc)
+	if err != nil {
+		panic(err)
+	}
+
+	appAcc, ok := acc.(*AppAccount)
+	if !ok {
+		panic("acc is not *AppAccount") // XXX
+	}
+
+	accStore.kvStore.Set(keyAccount(appAcc.Address_), b)
+}
+
+func keyAccount(addr types.Address) []byte {
+	return []byte(path.Join("account", string(addr)))
+}
diff --git a/app/example/basecoin/main.go b/app/example/basecoin/main.go
new file mode 100644
index 000000000..96e1bd43c
--- /dev/null
+++ b/app/example/basecoin/main.go
@@ -0,0 +1,83 @@
+package main
+
+import (
+	"encoding/json"
+	"fmt"
+	"os"
+
+	"github.com/tendermint/abci/server"
+	cmn "github.com/tendermint/tmlibs/common"
+	dbm "github.com/tendermint/tmlibs/db"
+
+	"github.com/cosmos/cosmos-sdk/app"
+	"github.com/cosmos/cosmos-sdk/store"
+	"github.com/cosmos/cosmos-sdk/types"
+	"github.com/cosmos/cosmos-sdk/x/auth"
+	"github.com/cosmos/cosmos-sdk/x/sendtx"
+)
+
+func main() {
+
+	app := app.NewApp("basecoin")
+
+	db, err := dbm.NewGoLevelDB("basecoin", "basecoin-data")
+	if err != nil {
+		fmt.Println(err)
+		os.Exit(1)
+	}
+
+	// create CommitStoreLoader
+	cacheSize := 10000
+	numHistory := int64(100)
+	loader := store.NewIAVLStoreLoader(db, cacheSize, numHistory)
+
+	// Create MultiStore
+	multiStore := store.NewCommitMultiStore(db)
+	multiStore.SetSubstoreLoader("main", loader)
+
+	// Create Handler
+	handler := types.ChainDecorators(
+		// recover.Decorator(),
+		// logger.Decorator(),
+		auth.DecoratorFn(newAccountStore),
+	).WithHandler(
+		sendtx.TransferHandlerFn(newAccountStore),
+	)
+
+	// TODO: load genesis
+	// TODO: InitChain with validators
+	// accounts := newAccountStore(multiStore.GetKVStore("main"))
+	// TODO: set the genesis accounts
+
+	// Set everything on the app and load latest
+	app.SetCommitMultiStore(multiStore)
+	app.SetTxParser(txParser)
+	app.SetHandler(handler)
+	if err := app.LoadLatestVersion(); err != nil {
+		fmt.Println(err)
+		os.Exit(1)
+	}
+
+	// Start the ABCI server
+	srv, err := server.NewServer("0.0.0.0:46658", "socket", app)
+	if err != nil {
+		fmt.Println(err)
+		os.Exit(1)
+	}
+	srv.Start()
+
+	// Wait forever
+	cmn.TrapSignal(func() {
+		// Cleanup
+		srv.Stop()
+	})
+	return
+}
+
+// create ctx in begin block to be used as background for txs ...
+
+func txParser(txBytes []byte) (types.Tx, error) {
+	var tx sendtx.SendTx
+	err := json.Unmarshal(txBytes, &tx)
+	return tx, err
+}
diff --git a/app/example/dummy/main.go b/app/example/dummy/main.go
new file mode 100644
index 000000000..3ccb49ccb
--- /dev/null
+++ b/app/example/dummy/main.go
@@ -0,0 +1,136 @@
+package main
+
+import (
+	"bytes"
+	"fmt"
+	"os"
+
+	"github.com/tendermint/abci/server"
+	cmn "github.com/tendermint/tmlibs/common"
+	dbm "github.com/tendermint/tmlibs/db"
+
+	"github.com/cosmos/cosmos-sdk/app"
+	"github.com/cosmos/cosmos-sdk/store"
+	"github.com/cosmos/cosmos-sdk/types"
+)
+
+func main() {
+
+	app := app.NewApp("dummy")
+
+	db, err := dbm.NewGoLevelDB("dummy", "dummy-data")
+	if err != nil {
+		fmt.Println(err)
+		os.Exit(1)
+	}
+
+	// create CommitStoreLoader
+	cacheSize := 10000
+	numHistory := int64(100)
+	loader := store.NewIAVLStoreLoader(db, cacheSize, numHistory)
+
+	// Create MultiStore
+	multiStore := store.NewMultiStore(db)
+	multiStore.SetSubstoreLoader("main", loader)
+
+	// Create Handler
+	handler := types.Decorate(unmarshalDecorator, dummyHandler)
+
+	// Set everything on the app and load latest
+	app.SetCommitMultiStore(multiStore)
+	app.SetHandler(handler)
+	if err := app.LoadLatestVersion(); err != nil {
+		fmt.Println(err)
+		os.Exit(1)
+	}
+
+	// Start the ABCI server
+	srv, err := server.NewServer("0.0.0.0:46658", "socket", app)
+	if err != nil {
+		fmt.Println(err)
+		os.Exit(1)
+	}
+	srv.Start()
+
+	// Wait forever
+	cmn.TrapSignal(func() {
+		// Cleanup
+		srv.Stop()
+	})
+	return
+}
+
+type dummyTx struct {
+	key   []byte
+	value []byte
+
+	bytes []byte
+}
+
+func (tx dummyTx) Get(key interface{}) (value interface{}) {
+	switch k := key.(type) {
+	case string:
+		switch k {
+		case "key":
+			return tx.key
+		case "value":
+			return tx.value
+		}
+	}
+	return nil
+}
+
+func (tx dummyTx) SignBytes() []byte {
+	return tx.bytes
+}
+
+// Should the app be calling this? Or only handlers?
+func (tx dummyTx) ValidateBasic() error {
+	return nil
+}
+
+func (tx dummyTx) Signers() [][]byte {
+	return nil
+}
+
+func (tx dummyTx) TxBytes() []byte {
+	return tx.bytes
+}
+
+func (tx dummyTx) Signatures() []types.StdSignature {
+	return nil
+}
+
+func unmarshalDecorator(ctx types.Context, ms types.MultiStore, tx types.Tx, next types.Handler) types.Result {
+	txBytes := ctx.TxBytes()
+
+	split := bytes.Split(txBytes, []byte("="))
+	if len(split) == 1 {
+		k := split[0]
+		tx = dummyTx{k, k, txBytes}
+	} else if len(split) == 2 {
+		k, v := split[0], split[1]
+		tx = dummyTx{k, v, txBytes}
+	} else {
+		return types.Result{
+			Code: 1,
+			Log:  "too many =",
+		}
+	}
+
+	return next(ctx, ms, tx)
+}
+
+func dummyHandler(ctx types.Context, ms types.MultiStore, tx types.Tx) types.Result {
+	// tx is already unmarshalled
+	key := tx.Get("key").([]byte)
+	value := tx.Get("value").([]byte)
+
+	main := ms.GetKVStore("main")
+	main.Set(key, value)
+
+	return types.Result{
+		Code: 0,
+		Log:  fmt.Sprintf("set %s=%s", key, value),
+	}
+}
diff --git a/errors/abci.go b/errors/abci.go
index 6c5cebf11..4341eaef0 100644
--- a/errors/abci.go
+++ b/errors/abci.go
@@ -4,10 +4,6 @@ import (
 	abci "github.com/tendermint/abci/types"
 )
 
-type causer interface {
-	Cause() error
-}
-
 func getABCIError(err error) (ABCIError, bool) {
 	if err, ok := err.(ABCIError); ok {
 		return err, true
@@ -23,7 +19,7 @@ func getABCIError(err error) (ABCIError, bool) {
 
 func ResponseDeliverTxFromErr(err error) *abci.ResponseDeliverTx {
 	var code = CodeInternalError
-	var log = codeToDefaultLog(code)
+	var log = CodeToDefaultLog(code)
 
 	abciErr, ok := getABCIError(err)
 	if ok {
@@ -41,7 +37,7 @@ func ResponseDeliverTxFromErr(err error) *abci.ResponseDeliverTx {
 
 func ResponseCheckTxFromErr(err error) *abci.ResponseCheckTx {
 	var code = CodeInternalError
-	var log = codeToDefaultLog(code)
+	var log = CodeToDefaultLog(code)
 
 	abciErr, ok := getABCIError(err)
 	if ok {
@@ -53,7 +49,7 @@ func ResponseCheckTxFromErr(err error) *abci.ResponseCheckTx {
 		Code: code,
 		Data: nil,
 		Log:  log,
-		Gas:  0, // TODO
-		Fee:  0, // TODO
+		//		Gas:  0, // TODO
+		//		Fee:  0, // TODO
 	}
 }
diff --git a/errors/errors.go b/errors/errors.go
index f2d6f5e20..3bee90113 100644
--- a/errors/errors.go
+++ b/errors/errors.go
@@ -2,8 +2,6 @@ package errors
 
 import (
 	"fmt"
-
-	"github.com/pkg/errors"
 )
 
 const (
@@ -174,11 +172,11 @@ func ABCIErrorCause(err error) ABCIError {
 		}
 		errCause := cause.Cause()
 		if errCause == nil || errCause == err {
-			return err
+			return nil
 		}
 		err = errCause
 	}
-	return err
+	return nil
 }
 
 // Identitical to pkg/errors.Cause, except handles .Cause()
diff --git a/store/rootmultistore.go b/store/rootmultistore.go
index 7508d3c05..495df1839 100644
--- a/store/rootmultistore.go
+++ b/store/rootmultistore.go
@@ -28,7 +28,7 @@ type rootMultiStore struct {
 
 var _ CommitMultiStore = (*rootMultiStore)(nil)
 
-func NewMultiStore(db dbm.DB) *rootMultiStore {
+func NewCommitMultiStore(db dbm.DB) *rootMultiStore {
 	return &rootMultiStore{
 		db:           db,
 		nextVersion:  0,
diff --git a/types/account.go b/types/account.go
new file mode 100644
index 000000000..ebd17f82d
--- /dev/null
+++ b/types/account.go
@@ -0,0 +1,35 @@
+package types
+
+import (
+	"encoding/hex"
+
+	crypto "github.com/tendermint/go-crypto"
+)
+
+type Address []byte // TODO: cmn.HexBytes
+
+func (a Address) String() string {
+	return hex.EncodeToString(a)
+}
+
+type Account interface {
+	Address() Address
+
+	PubKey() crypto.PubKey
+	SetPubKey(crypto.PubKey) error
+
+	GetCoins() Coins
+	SetCoins(Coins) error
+
+	GetSequence() int64
+	SetSequence(int64) error
+
+	Get(key interface{}) (value interface{}, err error)
+	Set(key interface{}, value interface{}) error
+}
+
+type AccountStore interface {
+	NewAccountWithAddress(addr Address) Account
+	GetAccount(addr Address) Account
+	SetAccount(acc Account)
+}
diff --git a/types/coin.go b/types/coin.go
index 30e96b295..fae79647d 100644
--- a/types/coin.go
+++ b/types/coin.go
@@ -136,7 +136,7 @@ func (coins Coins) IsGTE(coinsB Coins) bool {
 	if len(diff) == 0 {
 		return true
 	}
-	return diff.IsNonnegative()
+	return diff.IsNotNegative()
 }
 
 // IsZero returns true if there are no coins
@@ -171,9 +171,9 @@ func (coins Coins) IsPositive() bool {
 	return true
 }
 
-// IsNonnegative returns true if there is no currency with a negative value
+// IsNotNegative returns true if there is no currency with a negative value
 // (even no coins is true here)
-func (coins Coins) IsNonnegative() bool {
+func (coins Coins) IsNotNegative() bool {
 	if len(coins) == 0 {
 		return true
 	}
diff --git a/types/signature.go b/types/signature.go
index 02c059e58..e22d0c78c 100644
--- a/types/signature.go
+++ b/types/signature.go
@@ -3,6 +3,7 @@ package types
 import crypto "github.com/tendermint/go-crypto"
 
 type StdSignature struct {
+	crypto.PubKey // optional
 	crypto.Signature
 	Sequence int64
 }
diff --git a/types/tx_msg.go b/types/tx_msg.go
index c704cc41f..2d432f845 100644
--- a/types/tx_msg.go
+++ b/types/tx_msg.go
@@ -15,7 +15,7 @@ type Msg interface {
 	// Signers returns the addrs of signers that must sign.
 	// CONTRACT: All signatures must be present to be valid.
 	// CONTRACT: Returns addrs in some deterministic order.
-	Signers() [][]byte
+	Signers() []Address
 }
 
 type Tx interface {
diff --git a/x/auth/context.go b/x/auth/context.go
index dd585f205..07e86b7d6 100644
--- a/x/auth/context.go
+++ b/x/auth/context.go
@@ -24,10 +24,10 @@ const (
 	contextKeyAccount contextKey = iota
 )
 
-func SetAccount(ctx types.Context, account Account) types.Context {
-	return ctx.WithValueSDK(contextKeyAccount, account)
+func SetAccount(ctx types.Context, account types.Account) types.Context {
+	return ctx.WithValueUnsafe(contextKeyAccount, account)
 }
 
-func GetAccount(ctx types.Context) Account {
-	return ctx.Value(contextKeyAccount).(Account)
+func GetAccount(ctx types.Context) types.Account {
+	return ctx.Value(contextKeyAccount).(types.Account)
 }
diff --git a/x/auth/decorator.go b/x/auth/decorator.go
new file mode 100644
index 000000000..38311563f
--- /dev/null
+++ b/x/auth/decorator.go
@@ -0,0 +1,78 @@
+package auth
+
+import (
+	"github.com/cosmos/cosmos-sdk/types"
+	crypto "github.com/tendermint/go-crypto"
+)
+
+func DecoratorFn(newAccountStore func(types.KVStore) types.AccountStore) types.Decorator {
+	return func(ctx types.Context, ms types.MultiStore, tx types.Tx, next types.Handler) types.Result {
+
+		accountStore := newAccountStore(ms.GetKVStore("main"))
+
+		// NOTE: we actually dont need Signers() since we have pubkeys in Signatures()
+		signers := tx.Signers()
+		signatures := tx.Signatures()
+
+		// assert len
+		if len(signatures) == 0 {
+			return types.Result{
+				Code: 1, // TODO
+			}
+		}
+		if len(signatures) != len(signers) {
+			return types.Result{
+				Code: 1, // TODO
+			}
+		}
+
+		// check each nonce and sig
+		for i, sig := range signatures {
+
+			// get account
+			_acc := accountStore.GetAccount(signers[i])
+
+			// assert it has the right methods
+			acc, ok := _acc.(Auther)
+			if !ok {
+				return types.Result{
+					Code: 1, // TODO
+				}
+			}
+
+			// if no pubkey, set pubkey
+			if acc.GetPubKey().Empty() {
+				err := acc.SetPubKey(sig.PubKey)
+				if err != nil {
+					return types.Result{
+						Code: 1, // TODO
+					}
+				}
+			}
+
+			// check sequence number
+			seq := acc.GetSequence()
+			if seq != sig.Sequence {
+				return types.Result{
+					Code: 1, // TODO
+				}
+			}
+
+			// check sig
+			if !sig.PubKey.VerifyBytes(tx.SignBytes(), sig.Signature) {
+				return types.Result{
+					Code: 1, // TODO
+				}
+			}
+		}
+		return next(ctx, ms, tx)
+	}
+}
+
+type Auther interface {
+	GetPubKey() crypto.PubKey
+	SetPubKey(crypto.PubKey) error
+
+	GetSequence() int64
+	SetSequence() (int64, error)
+}
diff --git a/x/auth/types.go b/x/auth/types.go
index 4f914bdbe..5f62fa5d3 100644
--- a/x/auth/types.go
+++ b/x/auth/types.go
@@ -1,15 +1,9 @@
 package auth
 
-import crypto "github.com/tendermint/go-crypto"
+import (
+	crypto "github.com/tendermint/go-crypto"
+)
 
-type Account interface {
-	Get(key interface{}) (value interface{})
-
-	Address() []byte
-	PubKey() crypto.PubKey
-}
-
-type AccountStore interface {
-	GetAccount(addr []byte) Account
-	SetAccount(acc Account)
+type SetPubKeyer interface {
+	SetPubKey(crypto.PubKey)
 }
diff --git a/x/coinstore/genesis.go b/x/coinstore/_attic/genesis.go
similarity index 100%
rename from x/coinstore/genesis.go
rename to x/coinstore/_attic/genesis.go
diff --git a/x/coinstore/utils.go b/x/coinstore/_attic/utils.go
similarity index 100%
rename from x/coinstore/utils.go
rename to x/coinstore/_attic/utils.go
diff --git a/x/coinstore/decorator.go b/x/coinstore/decorator.go
deleted file mode 100644
index 2ef0df008..000000000
--- a/x/coinstore/decorator.go
+++ /dev/null
@@ -1,13 +0,0 @@
-package coin
-
-import (
-	sdk "github.com/cosmos/cosmos-sdk"
-)
-
-func Decorator(ctx sdk.Context, store sdk.MultiStore, tx sdk.Tx, next sdk.Handler) sdk.Result {
-	if msg, ok := tx.(CoinsMsg); ok {
-		handleCoinsMsg(ctx, store, msg)
-	} else {
-		next(ctx, store, tx)
-	}
-}
diff --git a/x/coinstore/errors.go b/x/coinstore/errors.go
index f5419d9c9..a8fce42ac 100644
--- a/x/coinstore/errors.go
+++ b/x/coinstore/errors.go
@@ -2,18 +2,18 @@
 package coin
 
 import (
-	"fmt"
-
 	"github.com/cosmos/cosmos-sdk/errors"
 )
 
 const (
 	// Coin errors reserve 100 ~ 199.
-	CodeInvalidInput   uint32 = 101
-	CodeInvalidOutput  uint32 = 102
-	CodeInvalidAddress uint32 = 103
-	CodeUnknownAddress uint32 = 103
-	CodeUnknownRequest uint32 = errors.CodeUnknownRequest
+	CodeInvalidInput      uint32 = 101
+	CodeInvalidOutput     uint32 = 102
+	CodeInvalidAddress    uint32 = 103
+	CodeUnknownAddress    uint32 = 104
+	CodeInsufficientCoins uint32 = 105
+	CodeInvalidCoins      uint32 = 106
+	CodeUnknownRequest    uint32 = errors.CodeUnknownRequest
 )
 
 // NOTE: Don't stringer this, we'll put better messages in later.
@@ -27,6 +27,10 @@ func codeToDefaultLog(code uint32) string {
 		return "Invalid address"
 	case CodeUnknownAddress:
 		return "Unknown address"
+	case CodeInsufficientCoins:
+		return "Insufficient coins"
+	case CodeInvalidCoins:
+		return "Invalid coins"
 	case CodeUnknownRequest:
 		return "Unknown request"
 	default:
@@ -53,6 +57,14 @@ func ErrUnknownAddress(log string) error {
 	return newError(CodeUnknownAddress, log)
 }
 
+func ErrInsufficientCoins(log string) error {
+	return newError(CodeInsufficientCoins, log)
+}
+
+func ErrInvalidCoins(log string) error {
+	return newError(CodeInvalidCoins, log)
+}
+
 func ErrUnknownRequest(log string) error {
 	return newError(CodeUnknownRequest, log)
 }
@@ -60,11 +72,11 @@ func ErrUnknownRequest(log string) error {
 //----------------------------------------
 // Misc
 
-func logOrDefault(log string, code uint32) string {
+func logOrDefaultLog(log string, code uint32) string {
 	if log != "" {
 		return log
 	} else {
-		return codeToDefaultLog
+		return codeToDefaultLog(code)
 	}
 }
 
diff --git a/x/coinstore/store.go b/x/coinstore/store.go
new file mode 100644
index 000000000..7ee4467c3
--- /dev/null
+++ b/x/coinstore/store.go
@@ -0,0 +1,117 @@
+package coin
+
+import (
+	"fmt"
+
+	"github.com/cosmos/cosmos-sdk/types"
+)
+
+type Coins = types.Coins
+
+type Coinser interface {
+	GetCoins() Coins
+	SetCoins(Coins)
+}
+
+// CoinStore manages transfers between accounts
+type CoinStore struct {
+	types.AccountStore
+}
+
+// get the account as a Coinser. if the account doesn't exist, return nil.
+// if it's not a Coinser, return error.
+func (cs CoinStore) getCoinserAccount(addr types.Address) (types.Coinser, error) {
+	_acc := cs.GetAccount(addr)
+	if _acc == nil {
+		return nil, nil
+	}
+
+	acc, ok := _acc.(Coinser)
+	if !ok {
+		return nil, fmt.Errorf("Account %s is not a Coinser", addr)
+	}
+	return acc, nil
+}
+
+func (cs CoinStore) SubtractCoins(addr types.Address, amt Coins) (Coins, error) {
+	acc, err := cs.getCoinserAccount(addr)
+	if err != nil {
+		return amt, err
+	} else if acc == nil {
+		return amt, fmt.Errorf("Sending account (%s) does not exist", addr)
+	}
+
+	coins := acc.GetCoins()
+	newCoins := coins.Minus(amt)
+	if !newCoins.IsNotNegative() {
+		return amt, ErrInsufficientCoins(fmt.Sprintf("%s < %s", coins, amt))
+	}
+
+	acc.SetCoins(newCoins)
+	cs.SetAccount(acc.(types.Account))
+	return newCoins, nil
+}
+
+func (cs CoinStore) AddCoins(addr types.Address, amt Coins) (Coins, error) {
+	acc, err := cs.getCoinserAccount(addr)
+	if err != nil {
+		return amt, err
+	} else if acc == nil {
+		acc = cs.AccountStore.NewAccountWithAddress(addr).(Coinser)
+	}
+
+	coins := acc.GetCoins()
+	newCoins := coins.Plus(amt)
+
+	acc.SetCoins(newCoins)
+	cs.SetAccount(acc.(types.Account))
+	return newCoins, nil
+}
+
+/*
+// TransferCoins transfers coins from fromAddr to toAddr.
+// It returns an error if the from account doesn't exist,
+// if the accounts doin't implement Coinser,
+// or if the from account does not have enough coins.
+func (cs CoinStore) TransferCoins(fromAddr, toAddr types.Address, amt Coins) error {
+	var fromAcc, toAcc types.Account
+
+	// Get the accounts
+	_fromAcc := cs.GetAccount(fromAddr)
+	if _fromAcc == nil {
+		return ErrUnknownAccount(fromAddr)
+	}
+
+	_toAcc := cs.GetAccount(to)
+	if _toAcc == nil {
+		toAcc = cs.AccountStore.NewAccountWithAddress(to)
+	}
+
+	// Ensure they are Coinser
+	fromAcc, ok := _fromAcc.(Coinser)
+	if !ok {
+		return ErrAccountNotCoinser(from)
+	}
+
+	toAcc, ok = _toAcc.(Coinser)
+	if !ok {
+		return ErrAccountNotCoinser(from)
+	}
+
+	// Coin math
+	fromCoins := fromAcc.GetCoins()
+	newFromCoins := fromCoins.Minus(amt)
+	if newFromCoins.Negative() {
+		return ErrInsufficientCoins(fromCoins, amt)
+	}
+	toCoins := toAcc.GetCoins()
+	newToCoins := toCoins.Plus(amt)
+
+	// Set everything!
+	fromAcc.SetCoins(newFromCoins)
+	toAcc.SetCoins(newToCoins)
+	cs.SetAccount(fromAcc)
+	cs.SetAccount(toAcc)
+
+	return nil
+}*/
diff --git a/x/coinstore/tx.go b/x/coinstore/tx.go
deleted file mode 100644
index ab1289374..000000000
--- a/x/coinstore/tx.go
+++ /dev/null
@@ -1,168 +0,0 @@
-package coin
-
-// TODO rename this to msg.go
-
-import (
-	"fmt"
-	"github.com/cosmos/cosmos-sdk/types"
-	cmn "github.com/tendermint/tmlibs/common"
-)
-
-type CoinMsg interface {
-	AssertIsCoinMsg()
-	Type() string // "send", "credit"
-}
-
-//-----------------------------------------------------------------------------
-
-// Input is a source of coins in a transaction.
-type Input struct {
-	Address cmn.Bytes
-	Coins   types.Coins
-}
-
-func (in Input) ValidateBasic() error {
-	if !auth.IsValidAddress(in.Address) {
-		return ErrInvalidAddress()
-	}
-	if !in.Coins.IsValid() {
-		return ErrInvalidInput()
-	}
-	if !in.Coins.IsPositive() {
-		return ErrInvalidInput()
-	}
-	return nil
-}
-
-func (txIn TxInput) String() string {
-	return fmt.Sprintf("TxInput{%v,%v}", txIn.Address, txIn.Coins)
-}
-
-// NewTxInput - create a transaction input, used with SendTx
-func NewTxInput(addr Actor, coins types.Coins) TxInput {
-	input := TxInput{
-		Address: addr,
-		Coins:   coins,
-	}
-	return input
-}
-
-//-----------------------------------------------------------------------------
-
-// TxOutput - expected coin movement output, used with SendTx
-type TxOutput struct {
-	Address Actor       `json:"address"`
-	Coins   types.Coins `json:"coins"`
-}
-
-// ValidateBasic - validate transaction output
-func (txOut TxOutput) ValidateBasic() error {
-	if txOut.Address.App == "" {
-		return ErrInvalidAddress()
-	}
-	// TODO: knowledge of app-specific codings?
-	if len(txOut.Address.Address) == 0 {
-		return ErrInvalidAddress()
-	}
-	if !txOut.Coins.IsValid() {
-		return ErrInvalidCoins()
-	}
-	if !txOut.Coins.IsPositive() {
-		return ErrInvalidCoins()
-	}
-	return nil
-}
-
-func (txOut TxOutput) String() string {
-	return fmt.Sprintf("TxOutput{%X,%v}", txOut.Address, txOut.Coins)
-}
-
-// NewTxOutput - create a transaction output, used with SendTx
-func NewTxOutput(addr Actor, coins types.Coins) TxOutput {
-	output := TxOutput{
-		Address: addr,
-		Coins:   coins,
-	}
-	return output
-}
-
-//-----------------------------------------------------------------------------
-
-// SendTx - high level transaction of the coin module
-// Satisfies: TxInner
-type SendTx struct {
-	Inputs  []TxInput  `json:"inputs"`
-	Outputs []TxOutput `json:"outputs"`
-}
-
-// var _ types.Tx = NewSendTx(nil, nil)
-
-// NewSendTx - construct arbitrary multi-in, multi-out sendtx
-func NewSendTx(in []TxInput, out []TxOutput) SendTx { // types.Tx {
-	return SendTx{Inputs: in, Outputs: out}
-}
-
-// NewSendOneTx is a helper for the standard (?) case where there is exactly
-// one sender and one recipient
-func NewSendOneTx(sender, recipient Actor, amount types.Coins) SendTx {
-	in := []TxInput{{Address: sender, Coins: amount}}
-	out := []TxOutput{{Address: recipient, Coins: amount}}
-	return SendTx{Inputs: in, Outputs: out}
-}
-
-// ValidateBasic - validate the send transaction
-func (tx SendTx) ValidateBasic() error {
-	// this just makes sure all the inputs and outputs are properly formatted,
-	// not that they actually have the money inside
-	if len(tx.Inputs) == 0 {
-		return ErrNoInputs()
-	}
-	if len(tx.Outputs) == 0 {
-		return ErrNoOutputs()
-	}
-	// make sure all inputs and outputs are individually valid
-	var totalIn, totalOut types.Coins
-	for _, in := range tx.Inputs {
-		if err := in.ValidateBasic(); err != nil {
-			return err
-		}
-		totalIn = totalIn.Plus(in.Coins)
-	}
-	for _, out := range tx.Outputs {
-		if err := out.ValidateBasic(); err != nil {
-			return err
-		}
-		totalOut = totalOut.Plus(out.Coins)
-	}
-	// make sure inputs and outputs match
-	if !totalIn.IsEqual(totalOut) {
-		return ErrInvalidCoins()
-	}
-	return nil
-}
-
-func (tx SendTx) String() string {
-	return fmt.Sprintf("SendTx{%v->%v}", tx.Inputs, tx.Outputs)
-}
-
-//-----------------------------------------------------------------------------
-
-// CreditTx - this allows a special issuer to give an account credit
-// Satisfies: TxInner
-type CreditTx struct {
-	Debitor Actor `json:"debitor"`
-	// Credit is the amount to change the credit...
-	// This may be negative to remove some over-issued credit,
-	// but can never bring the credit or the balance to negative
-	Credit types.Coins `json:"credit"`
-}
-
-// NewCreditTx - modify the credit granted to a given account
-func NewCreditTx(debitor Actor, credit types.Coins) CreditTx {
-	return CreditTx{Debitor: debitor, Credit: credit}
-}
-
-// ValidateBasic - used to satisfy TxInner
-func (tx CreditTx) ValidateBasic() error {
-	return nil
-}
diff --git a/x/coinstore/tx_test.go b/x/coinstore/tx_test.go
deleted file mode 100644
index bff2f98da..000000000
--- a/x/coinstore/tx_test.go
+++ /dev/null
@@ -1,190 +0,0 @@
-package coin
-
-import (
-	"testing"
-
-	"github.com/stretchr/testify/assert"
-	"github.com/stretchr/testify/require"
-
-	"github.com/tendermint/go-wire/data"
-
-	sdk "github.com/cosmos/cosmos-sdk"
-)
-
-// these are some constructs for the test cases
-var actors = []struct {
-	actor sdk.Actor
-	valid bool
-}{
-	{sdk.Actor{}, false},
-	{sdk.Actor{App: "fooz"}, false},
-	{sdk.Actor{Address: []byte{1, 2, 3, 4}}, false},
-	{sdk.Actor{App: "fooz", Address: []byte{1, 2, 3, 4}}, true},
-	{sdk.Actor{ChainID: "dings", App: "fooz", Address: []byte{1, 2, 3, 4}}, true},
-	{sdk.Actor{ChainID: "dat", App: "fooz"}, false},
-}
-
-var (
-	zeroCoin = Coin{"zeros", 0}
-	plusCoin = Coin{"plus", 23}
-	negCoin  = Coin{"neg", -42}
-)
-
-var coins = []struct {
-	coins Coins
-	valid bool
-}{
-	{Coins{}, false},
-	{Coins{zeroCoin}, false},
-	{Coins{plusCoin}, true},
-	{Coins{negCoin}, false},
-	{Coins{plusCoin, plusCoin}, false},
-	{Coins{plusCoin, zeroCoin}, false},
-	{Coins{negCoin, plusCoin}, false},
-}
-
-func TestTxValidateInput(t *testing.T) {
-	assert := assert.New(t)
-
-	for i, act := range actors {
-		for j, coin := range coins {
-			input := NewTxInput(act.actor, coin.coins)
-			err := input.ValidateBasic()
-			if act.valid && coin.valid {
-				assert.Nil(err, "%d,%d: %+v", i, j, err)
-			} else {
-				assert.NotNil(err, "%d,%d", i, j)
-			}
-		}
-	}
-}
-
-func TestTxValidateOutput(t *testing.T) {
-	assert := assert.New(t)
-
-	for i, act := range actors {
-		for j, coin := range coins {
-			input := NewTxOutput(act.actor, coin.coins)
-			err := input.ValidateBasic()
-			if act.valid && coin.valid {
-				assert.Nil(err, "%d,%d: %+v", i, j, err)
-			} else {
-				assert.NotNil(err, "%d,%d", i, j)
-			}
-		}
-	}
-}
-
-func TestTxValidateTx(t *testing.T) {
-	assert := assert.New(t)
-
-	addr1 := sdk.Actor{App: "coin", Address: []byte{1, 2}}
-	addr2 := sdk.Actor{App: "coin", Address: []byte{3, 4}, ChainID: "over-there"}
-	addr3 := sdk.Actor{App: "role", Address: []byte{7, 8}}
-	noAddr := sdk.Actor{}
-
-	noCoins := Coins{}
-	someCoins := Coins{{"atom", 123}}
-	moreCoins := Coins{{"atom", 124}}
-	otherCoins := Coins{{"btc", 15}}
-	bothCoins := someCoins.Plus(otherCoins)
-	minusCoins := Coins{{"eth", -34}}
-
-	// cases: all valid (one), all valid (multi)
-	// no input, no outputs, invalid inputs, invalid outputs
-	// totals don't match
-	cases := []struct {
-		valid bool
-		tx    sdk.Tx
-	}{
-		// 0-2. valid cases
-		{true, NewSendTx(
-			[]TxInput{NewTxInput(addr1, someCoins)},
-			[]TxOutput{NewTxOutput(addr2, someCoins)},
-		)},
-		{true, NewSendTx(
-			[]TxInput{NewTxInput(addr1, someCoins), NewTxInput(addr2, otherCoins)},
-			[]TxOutput{NewTxOutput(addr3, bothCoins)},
-		)},
-		{true, NewSendTx(
-			[]TxInput{NewTxInput(addr1, bothCoins)},
-			[]TxOutput{NewTxOutput(addr2, someCoins), NewTxOutput(addr3, otherCoins)},
-		)},
-
-		// 3-4. missing cases
-		{false, NewSendTx(
-			nil,
-			[]TxOutput{NewTxOutput(addr2, someCoins)},
-		)},
-		{false, NewSendTx(
-			[]TxInput{NewTxInput(addr1, someCoins)},
-			nil,
-		)},
-
-		// 5-7. invalid inputs
-		{false, NewSendTx(
-			[]TxInput{NewTxInput(noAddr, someCoins)},
-			[]TxOutput{NewTxOutput(addr2, someCoins)},
-		)},
-		{false, NewSendTx(
-			[]TxInput{NewTxInput(addr1, noCoins)},
-			[]TxOutput{NewTxOutput(addr2, noCoins)},
-		)},
-		{false, NewSendTx(
-			[]TxInput{NewTxInput(addr1, minusCoins)},
-			[]TxOutput{NewTxOutput(addr2, minusCoins)},
-		)},
-
-		// 8-10. totals don't match
-		{false, NewSendTx(
-			[]TxInput{NewTxInput(addr1, someCoins)},
-			[]TxOutput{NewTxOutput(addr2, moreCoins)},
-		)},
-		{false, NewSendTx(
-			[]TxInput{NewTxInput(addr1, someCoins), NewTxInput(addr2, minusCoins)},
-			[]TxOutput{NewTxOutput(addr3, someCoins)},
-		)},
-		{false, NewSendTx(
-			[]TxInput{NewTxInput(addr1, someCoins), NewTxInput(addr2, moreCoins)},
-			[]TxOutput{NewTxOutput(addr3, bothCoins)},
-		)},
-	}
-
-	for i, tc := range cases {
-		err := tc.tx.ValidateBasic()
-		if tc.valid {
-			assert.Nil(err, "%d: %+v", i, err)
-		} else {
-			assert.NotNil(err, "%d", i)
-		}
-	}
-}
-
-func TestTxSerializeTx(t *testing.T) {
-	assert := assert.New(t)
-	require := require.New(t)
-
-	addr1 := sdk.Actor{App: "coin", Address: []byte{1, 2}}
-	addr2 := sdk.Actor{App: "coin", Address: []byte{3, 4}}
-	someCoins := Coins{{"atom", 123}}
-
-	send := NewSendTx(
-		[]TxInput{NewTxInput(addr1, someCoins)},
-		[]TxOutput{NewTxOutput(addr2, someCoins)},
-	)
-
-	js, err := data.ToJSON(send)
-	require.Nil(err)
-	var tx sdk.Tx
-	err = data.FromJSON(js, &tx)
-	require.Nil(err)
-	assert.Equal(send, tx)
-
-	bin, err := data.ToWire(send)
-	require.Nil(err)
-	var tx2 sdk.Tx
-	err = data.FromWire(bin, &tx2)
-	require.Nil(err)
-	assert.Equal(send, tx2)
-
-}
diff --git a/x/sendtx/errors.go b/x/sendtx/errors.go
new file mode 100644
index 000000000..ffcf426e8
--- /dev/null
+++ b/x/sendtx/errors.go
@@ -0,0 +1,17 @@
+package sendtx
+
+import "fmt"
+
+// TODO! Deal coherently with this and coinstore/errors.go
+
+func ErrNoInputs() error {
+	return fmt.Errorf("No inputs")
+}
+
+func ErrNoOutputs() error {
+	return fmt.Errorf("No outputs")
+}
+
+func ErrInvalidSequence(seq int64) error {
+	return fmt.Errorf("Bad sequence %d", seq)
+}
diff --git a/x/sendtx/handler.go b/x/sendtx/handler.go
new file mode 100644
index 000000000..fcbb66a00
--- /dev/null
+++ b/x/sendtx/handler.go
@@ -0,0 +1,41 @@
+package sendtx
+
+import (
+	"github.com/cosmos/cosmos-sdk/types"
+	coinstore "github.com/cosmos/cosmos-sdk/x/coinstore"
+)
+
+func TransferHandlerFn(newAccStore func(types.KVStore) types.AccountStore) types.Handler {
+	return func(ctx types.Context, ms types.MultiStore, tx types.Tx) types.Result {
+
+		accStore := newAccStore(ms.GetKVStore("main"))
+		cs := coinstore.CoinStore{accStore}
+
+		sendTx, ok := tx.(SendTx)
+		if !ok {
+			panic("tx is not SendTx") // ?
+		}
+
+		// NOTE: totalIn == totalOut should already have been checked
+
+		for _, in := range sendTx.Inputs {
+			_, err := cs.SubtractCoins(in.Address, in.Coins)
+			if err != nil {
+				return types.Result{
+					Code: 1, // TODO
+				}
+			}
+		}
+
+		for _, out := range sendTx.Outputs {
+			_, err := cs.AddCoins(out.Address, out.Coins)
+			if err != nil {
+				return types.Result{
+					Code: 1, // TODO
+				}
+			}
+		}
+
+		return types.Result{} // TODO
+	}
+}
diff --git a/x/sendtx/tx.go b/x/sendtx/tx.go
new file mode 100644
index 000000000..839eaa3be
--- /dev/null
+++ b/x/sendtx/tx.go
@@ -0,0 +1,212 @@
+package sendtx
+
+import (
+	"encoding/json"
+	"fmt"
+
+	"github.com/cosmos/cosmos-sdk/types"
+	coinstore "github.com/cosmos/cosmos-sdk/x/coinstore"
+	crypto "github.com/tendermint/go-crypto"
+)
+
+type (
+	Address = types.Address
+	Coins   = types.Coins
+)
+
+//-----------------------------------------------------------------------------
+
+// TxInput
+type TxInput struct {
+	Address  Address `json:"address"`
+	Coins    Coins   `json:"coins"`
+	Sequence int64   `json:"sequence"`
+
+	signature crypto.Signature
+}
+
+// ValidateBasic - validate transaction input
+func (txIn TxInput) ValidateBasic() error {
+	if len(txIn.Address) == 0 {
+		return coinstore.ErrInvalidAddress(txIn.Address.String())
+	}
+	if txIn.Sequence < 0 {
+		return ErrInvalidSequence(txIn.Sequence)
+	}
+	if !txIn.Coins.IsValid() {
+		return coinstore.ErrInvalidCoins(txIn.Coins.String())
+	}
+	if !txIn.Coins.IsPositive() {
+		return coinstore.ErrInvalidCoins(txIn.Coins.String())
+	}
+	return nil
+}
+
+func (txIn TxInput) String() string {
+	return fmt.Sprintf("TxInput{%v,%v}", txIn.Address, txIn.Coins)
+}
+
+// NewTxInput - create a transaction input, used with SendTx
+func NewTxInput(addr Address, coins Coins) TxInput {
+	input := TxInput{
+		Address: addr,
+		Coins:   coins,
+	}
+	return input
+}
+
+//-----------------------------------------------------------------------------
+
+// TxOutput - expected coin movement output, used with SendTx
+type TxOutput struct {
+	Address Address `json:"address"`
+	Coins   Coins   `json:"coins"`
+}
+
+// ValidateBasic - validate transaction output
+func (txOut TxOutput) ValidateBasic() error {
+	if len(txOut.Address) == 0 {
+		return coinstore.ErrInvalidAddress(txOut.Address.String())
+	}
+	if !txOut.Coins.IsValid() {
+		return coinstore.ErrInvalidCoins(txOut.Coins.String())
+	}
+	if !txOut.Coins.IsPositive() {
+		return coinstore.ErrInvalidCoins(txOut.Coins.String())
+	}
+	return nil
+}
+
+func (txOut TxOutput) String() string {
+	return fmt.Sprintf("TxOutput{%X,%v}", txOut.Address, txOut.Coins)
+}
+
+// NewTxOutput - create a transaction output, used with SendTx
+func NewTxOutput(addr Address, coins Coins) TxOutput {
+	output := TxOutput{
+		Address: addr,
+		Coins:   coins,
+	}
+	return output
+}
+
+//-----------------------------------------------------------------------------
+
+// SendTx - high level transaction of the coin module
+// Satisfies: TxInner
+type SendTx struct {
+	Inputs  []TxInput  `json:"inputs"`
+	Outputs []TxOutput `json:"outputs"`
+}
+
+var _ types.Tx = (*SendTx)(nil)
+
+// NewSendTx - construct arbitrary multi-in, multi-out sendtx
+func NewSendTx(in []TxInput, out []TxOutput) types.Tx {
+	return SendTx{Inputs: in, Outputs: out}
+}
+
+// NewSendOneTx is a helper for the standard (?) case where there is exactly
+// one sender and one recipient
+func NewSendOneTx(sender, recipient types.Address, amount types.Coins) types.Tx {
+	in := []TxInput{{Address: sender, Coins: amount}}
+	out := []TxOutput{{Address: recipient, Coins: amount}}
+	return SendTx{Inputs: in, Outputs: out}
+}
+
+// ValidateBasic - validate the send transaction
+func (tx SendTx) ValidateBasic() error {
+	// this just makes sure all the inputs and outputs are properly formatted,
+	// not that they actually have the money inside
+	if len(tx.Inputs) == 0 {
+		return ErrNoInputs()
+	}
+	if len(tx.Outputs) == 0 {
+		return ErrNoOutputs()
+	}
+	// make sure all inputs and outputs are individually valid
+	var totalIn, totalOut Coins
+	for _, in := range tx.Inputs {
+		if err := in.ValidateBasic(); err != nil {
+			return err
+		}
+		totalIn = totalIn.Plus(in.Coins)
+	}
+	for _, out := range tx.Outputs {
+		if err := out.ValidateBasic(); err != nil {
+			return err
+		}
+		totalOut = totalOut.Plus(out.Coins)
+	}
+	// make sure inputs and outputs match
+	if !totalIn.IsEqual(totalOut) {
+		return coinstore.ErrInvalidCoins(totalIn.String()) // TODO
+	}
+	return nil
+}
+
+func (tx SendTx) String() string {
+	return fmt.Sprintf("SendTx{%v->%v}", tx.Inputs, tx.Outputs)
+}
+
+// TODO
+//------------------------
+func (tx SendTx) Get(key interface{}) (value interface{}) {
+	switch k := key.(type) {
+	case string:
+		switch k {
+		case "key":
+		case "value":
+		}
+	}
+	return nil
+}
+
+func (tx SendTx) SignBytes() []byte {
+	b, err := json.Marshal(tx) // XXX: ensure some canonical form
+	if err != nil {
+		panic(err)
+	}
+	return b
+}
+
+func (tx SendTx) Signers() []types.Address {
+	addrs := make([]types.Address, len(tx.Inputs))
+	for i, in := range tx.Inputs {
+		addrs[i] = in.Address
+	}
+	return addrs
+}
+
+func (tx SendTx) TxBytes() []byte {
+	b, err := json.Marshal(struct {
+		Tx        types.Tx           `json:"tx"`
+		Signature []crypto.Signature `json:"signature"`
+	}{
+		Tx:        tx,
+		Signature: tx.signatures(),
+	})
+	if err != nil {
+		panic(err)
+	}
+	return b
+}
+
+func (tx SendTx) Signatures() []types.StdSignature {
+	stdSigs := make([]types.StdSignature, len(tx.Inputs))
+	for i, in := range tx.Inputs {
+		stdSigs[i] = types.StdSignature{
+			Signature: in.signature,
+			Sequence:  in.Sequence,
+		}
+	}
+	return stdSigs
+}
+
+func (tx SendTx) signatures() []crypto.Signature {
+	sigs := make([]crypto.Signature, len(tx.Inputs))
+	for i, in := range tx.Inputs {
+		sigs[i] = in.signature
+	}
+	return sigs
+}