diff --git a/types/account.go b/types/account.go
new file mode 100644
index 0000000000..28f8d7b08f
--- /dev/null
+++ b/types/account.go
@@ -0,0 +1,21 @@
+package main
+
+import "fmt"
+
+func main() {
+	fmt.Println("vim-go")
+}
+
+type Account interface {
+	Get(key interface{}) (value interface{})
+	Address() []byte
+	PubKey() crypto.PubKey
+
+	// Serialize the Account to bytes.
+	Bytes() []byte
+}
+
+type AccountStore interface {
+	GetAccount(addr []byte) Account
+	SetAccount(acc Account)
+}
diff --git a/types/coins.go b/types/coins.go
new file mode 100644
index 0000000000..e34f7d1bdb
--- /dev/null
+++ b/types/coins.go
@@ -0,0 +1,197 @@
+package types
+
+import (
+	"fmt"
+	"regexp"
+	"strconv"
+	"strings"
+)
+
+type Coin struct {
+	Denom  string `json:"denom"`
+	Amount int64  `json:"amount"`
+}
+
+func (coin Coin) String() string {
+	return fmt.Sprintf("%v%v", coin.Amount, coin.Denom)
+}
+
+//regex codes for extracting coins from string
+var reDenom = regexp.MustCompile("([^\\d\\W]+)")
+var reAmt = regexp.MustCompile("(\\d+)")
+
+func ParseCoin(str string) (Coin, error) {
+
+	var coin Coin
+
+	if len(str) > 0 {
+		amt, err := strconv.Atoi(reAmt.FindString(str))
+		if err != nil {
+			return coin, err
+		}
+		denom := reDenom.FindString(str)
+		coin = Coin{denom, int64(amt)}
+	}
+
+	return coin, nil
+}
+
+//----------------------------------------
+
+type Coins []Coin
+
+func (coins Coins) String() string {
+	if len(coins) == 0 {
+		return ""
+	}
+
+	out := ""
+	for _, coin := range coins {
+		out += fmt.Sprintf("%v,", coin.String())
+	}
+	return out[:len(out)-1]
+}
+
+func ParseCoins(str string) (Coins, error) {
+
+	split := strings.Split(str, ",")
+	var coins []Coin
+
+	for _, el := range split {
+		if len(el) > 0 {
+			coin, err := ParseCoin(el)
+			if err != nil {
+				return coins, err
+			}
+			coins = append(coins, coin)
+		}
+	}
+
+	return coins, nil
+}
+
+// Must be sorted, and not have 0 amounts
+func (coins Coins) IsValid() bool {
+	switch len(coins) {
+	case 0:
+		return true
+	case 1:
+		return coins[0].Amount != 0
+	default:
+		lowDenom := coins[0].Denom
+		for _, coin := range coins[1:] {
+			if coin.Denom <= lowDenom {
+				return false
+			}
+			if coin.Amount == 0 {
+				return false
+			}
+			// we compare each coin against the last denom
+			lowDenom = coin.Denom
+		}
+		return true
+	}
+}
+
+// TODO: handle empty coins!
+// Currently appends an empty coin ...
+func (coinsA Coins) Plus(coinsB Coins) Coins {
+	sum := []Coin{}
+	indexA, indexB := 0, 0
+	lenA, lenB := len(coinsA), len(coinsB)
+	for {
+		if indexA == lenA {
+			if indexB == lenB {
+				return sum
+			} else {
+				return append(sum, coinsB[indexB:]...)
+			}
+		} else if indexB == lenB {
+			return append(sum, coinsA[indexA:]...)
+		}
+		coinA, coinB := coinsA[indexA], coinsB[indexB]
+		switch strings.Compare(coinA.Denom, coinB.Denom) {
+		case -1:
+			sum = append(sum, coinA)
+			indexA += 1
+		case 0:
+			if coinA.Amount+coinB.Amount == 0 {
+				// ignore 0 sum coin type
+			} else {
+				sum = append(sum, Coin{
+					Denom:  coinA.Denom,
+					Amount: coinA.Amount + coinB.Amount,
+				})
+			}
+			indexA += 1
+			indexB += 1
+		case 1:
+			sum = append(sum, coinB)
+			indexB += 1
+		}
+	}
+	return sum
+}
+
+func (coins Coins) Negative() Coins {
+	res := make([]Coin, 0, len(coins))
+	for _, coin := range coins {
+		res = append(res, Coin{
+			Denom:  coin.Denom,
+			Amount: -coin.Amount,
+		})
+	}
+	return res
+}
+
+func (coinsA Coins) Minus(coinsB Coins) Coins {
+	return coinsA.Plus(coinsB.Negative())
+}
+
+func (coinsA Coins) IsGTE(coinsB Coins) bool {
+	diff := coinsA.Minus(coinsB)
+	if len(diff) == 0 {
+		return true
+	}
+	return diff.IsNonnegative()
+}
+
+func (coins Coins) IsZero() bool {
+	return len(coins) == 0
+}
+
+func (coinsA Coins) IsEqual(coinsB Coins) bool {
+	if len(coinsA) != len(coinsB) {
+		return false
+	}
+	for i := 0; i < len(coinsA); i++ {
+		if coinsA[i] != coinsB[i] {
+			return false
+		}
+	}
+	return true
+}
+
+func (coins Coins) IsPositive() bool {
+	if len(coins) == 0 {
+		return false
+	}
+	for _, coinAmount := range coins {
+		if coinAmount.Amount <= 0 {
+			return false
+		}
+	}
+	return true
+}
+
+func (coins Coins) IsNonnegative() bool {
+	if len(coins) == 0 {
+		return true
+	}
+	for _, coinAmount := range coins {
+		if coinAmount.Amount < 0 {
+			return false
+		}
+	}
+	return true
+}
diff --git a/types/coins_test.go b/types/coins_test.go
new file mode 100644
index 0000000000..8cbc708a49
--- /dev/null
+++ b/types/coins_test.go
@@ -0,0 +1,85 @@
+package types
+
+import (
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/require"
+)
+
+func TestCoins(t *testing.T) {
+	assert := assert.New(t)
+
+	//Define the coins to be used in tests
+	good := Coins{
+		Coin{"GAS", 1},
+		Coin{"MINERAL", 1},
+		Coin{"TREE", 1},
+	}
+	neg := good.Negative()
+	sum := good.Plus(neg)
+	empty := Coins{
+		Coin{"GOLD", 0},
+	}
+	badSort1 := Coins{
+		Coin{"TREE", 1},
+		Coin{"GAS", 1},
+		Coin{"MINERAL", 1},
+	}
+	badSort2 := Coins{ // both are after the first one, but the second and third are in the wrong order
+		Coin{"GAS", 1},
+		Coin{"TREE", 1},
+		Coin{"MINERAL", 1},
+	}
+	badAmt := Coins{
+		Coin{"GAS", 1},
+		Coin{"TREE", 0},
+		Coin{"MINERAL", 1},
+	}
+	dup := Coins{
+		Coin{"GAS", 1},
+		Coin{"GAS", 1},
+		Coin{"MINERAL", 1},
+	}
+
+	assert.True(good.IsValid(), "Coins are valid")
+	assert.True(good.IsPositive(), "Expected coins to be positive: %v", good)
+	assert.True(good.IsGTE(empty), "Expected %v to be >= %v", good, empty)
+	assert.False(neg.IsPositive(), "Expected neg coins to not be positive: %v", neg)
+	assert.Zero(len(sum), "Expected 0 coins")
+	assert.False(badSort1.IsValid(), "Coins are not sorted")
+	assert.False(badSort2.IsValid(), "Coins are not sorted")
+	assert.False(badAmt.IsValid(), "Coins cannot include 0 amounts")
+	assert.False(dup.IsValid(), "Duplicate coin")
+
+}
+
+//Test the parse coin and parse coins functionality
+func TestParse(t *testing.T) {
+	assert, require := assert.New(t), require.New(t)
+
+	makeCoin := func(str string) Coin {
+		coin, err := ParseCoin(str)
+		require.Nil(err)
+		return coin
+	}
+
+	makeCoins := func(str string) Coins {
+		coin, err := ParseCoins(str)
+		require.Nil(err)
+		return coin
+	}
+
+	//testing ParseCoin Function
+	assert.Equal(Coin{}, makeCoin(""), "ParseCoin makes bad empty coin")
+	assert.Equal(Coin{"fooCoin", 1}, makeCoin("1fooCoin"), "ParseCoin makes bad coins")
+	assert.Equal(Coin{"barCoin", 10}, makeCoin("10 barCoin"), "ParseCoin makes bad coins")
+
+	//testing ParseCoins Function
+	assert.True(Coins{{"fooCoin", 1}}.IsEqual(makeCoins("1fooCoin")),
+		"ParseCoins doesn't parse a single coin")
+	assert.True(Coins{{"barCoin", 99}, {"fooCoin", 1}}.IsEqual(makeCoins("99barCoin,1fooCoin")),
+		"ParseCoins doesn't properly parse two coins")
+	assert.True(Coins{{"barCoin", 99}, {"fooCoin", 1}}.IsEqual(makeCoins("99 barCoin, 1 fooCoin")),
+		"ParseCoins doesn't properly parse two coins which use spaces")
+}
diff --git a/types/msg.go b/types/msg.go
new file mode 100644
index 0000000000..e7738bd73d
--- /dev/null
+++ b/types/msg.go
@@ -0,0 +1,27 @@
+package types
+
+import "github.com/tendermint/tmlibs/crypto"
+
+// The parsed tx bytes is called a Msg.
+type Msg interface {
+	Get(key interface{}) (value interface{})
+	Origin() (tx []byte)
+
+	// Signers() returns the crypto.PubKey of signers
+	// responsible for signing the Msg.
+	// CONTRACT: All signatures must be present to be valid.
+	// CONTRACT: Returns pubkeys in some deterministic order
+	// CONTRACT: Get(MsgKeySigners) compatible.
+	Signers() []crypto.PubKey
+
+	// Signatures() returns the crypto.Signature of sigenrs
+	// who signed the Msg.
+	// CONTRACT: Length returned is same as length of
+	// pubkeys returned from MsgKeySigners, and the order
+	// matches.
+	// CONTRACT: If the signature is missing (ie the Msg is
+	// invalid), then the corresponding signature is
+	// .Empty().
+	// CONTRACT: Get(MsgKeySignatures) compatible.
+	Signatures() []crypto.Signature
+}
diff --git a/x/auth/signature.go b/x/auth/decorator.go
similarity index 100%
rename from x/auth/signature.go
rename to x/auth/decorator.go